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Sample records for brushed dc motor

  1. Brushed permanent magnet DC MLC motor operation in an external magnetic field

    International Nuclear Information System (INIS)

    Purpose: Linac-MR systems for real-time image-guided radiotherapy will utilize the multileaf collimators (MLCs) to perform conformal radiotherapy and tumor tracking. The MLCs would be exposed to the external fringe magnetic fields of the linac-MR hybrid systems. Therefore, an experimental investigation of the effect of an external magnetic field on the brushed permanent magnet DC motors used in some MLC systems was performed. Methods: The changes in motor speed and current were measured for varying external magnetic field strengths up to 2000 G generated by an EEV electromagnet. These changes in motor characteristics were measured for three orientations of the motor in the external magnetic field, mimicking changes in motor orientations due to installation and/or collimator rotations. In addition, the functionality of the associated magnetic motor encoder was tested. The tested motors are used with the Varian 120 leaf Millennium MLC (Maxon Motor half leaf and full leaf motors) and the Varian 52 leaf MKII MLC (MicroMo Electronics leaf motor) including a carriage motor (MicroMo Electronics). Results: In most cases, the magnetic encoder of the motors failed prior to any damage to the gearbox or the permanent magnet motor itself. This sets an upper limit of the external magnetic field strength on the motor function. The measured limits of the external magnetic fields were found to vary by the motor type. The leaf motor used with a Varian 52 leaf MKII MLC system tolerated up to 450±10 G. The carriage motor tolerated up to 2000±10 G field. The motors used with the Varian 120 leaf Millennium MLC system were found to tolerate a maximum of 600±10 G. Conclusions: The current Varian MLC system motors can be used for real-time image-guided radiotherapy coupled to a linac-MR system, provided the fringe magnetic fields at their locations are below the determined tolerance levels. With the fringe magnetic fields of linac-MR systems expected to be larger than the tolerance

  2. Intelligent Sensor Based Bayesian Neural Network for Combined Parameters and States Estimation of a Brushed DC Motor

    Directory of Open Access Journals (Sweden)

    Hacene MELLAH

    2016-07-01

    Full Text Available The objective of this paper is to develop an Artificial Neural Network (ANN model to estimate simultaneously, parameters and state of a brushed DC machine. The proposed ANN estimator is novel in the sense that his estimates simultaneously temperature, speed and rotor resistance based only on the measurement of the voltage and current inputs. Many types of ANN estimators have been designed by a lot of researchers during the last two decades. Each type is designed for a specific application. The thermal behavior of the motor is very slow, which leads to large amounts of data sets. The standard ANN use often Multi-Layer Perceptron (MLP with Levenberg-Marquardt Backpropagation (LMBP, among the limits of LMBP in the case of large number of data, so the use of MLP based on LMBP is no longer valid in our case. As solution, we propose the use of Cascade-Forward Neural Network (CFNN based Bayesian Regulation backpropagation (BRBP. To test our estimator robustness a random white-Gaussian noise has been added to the sets. The proposed estimator is in our viewpoint accurate and robust.

  3. Research on Hybrid Drive Technology of Brush DC Motor and Brushless DC Motor Based on CPLD%基于CPLD的有刷和无刷直流电动机混合驱动技术研究

    Institute of Scientific and Technical Information of China (English)

    王穆移; 马瑞卿; 孙银川; 徐蕾

    2009-01-01

    Researched the hybrid drive technology which based on the three - phase bridge inverter for the brushless DC motor (BLDCM) and the H-bridge inverter for the brush DC motor by making full use the resources of complex programmable logic devices (CPLD). It gave the overall design, different chopper ways and forward/reverse switch methods. Simulation results show that the hybrid driver has a character of high integration, and it can eliminate the competition adventure of the combination logics, and owns sev-eral functions, such as the fault protection, the choice of control ways, the embargo of logic, and so on.%充分利用可编程逻辑器件(CPLD)资源,研究了基于三相桥逆变器的无刷直流电动机(BLDCM)和基于H桥逆变器的有刷直流电动机的混合驱动技术,给出了总体设计、不同斩波方式及正、反转切换方法.仿真结果证明,混合驱动器集成度高,可消除组合逻辑竞争冒险,具有故障保护、控制方式选择和逻辑封锁等多种功能.

  4. Motor Brush Testing for Mars and Vacuum

    Science.gov (United States)

    Noon, Don E.

    1999-01-01

    Brush motors have been qualified and flown successfully on Mars missions, but upcoming missions require longer life and higher power. A test program was therefore undertaken to identify the best brush material for operation in the Mars atmosphere. Six different brush materials were used in 18 identical motors and operated under various load conditions for a period of four weeks in low-pressure CO2. All motors performed acceptably, with accumulated motor revolutions between 98 and 144 million revolutions, depending on load. A proprietary silver-graphite material from Superior Carbon (SG54-27) appears to be the best choice for long life, but even the stock copper-graphite brushes performed reliably with acceptable wear. The motors from the CO2 test were then cleaned and run in vacuum for 2 weeks. The difference in results was dramatic, with 5 motors failing catastrophically and wear rates increasing by orders of magnitude for the SG54-27 material. Three brush materials survived the test with no failures: SG54-27 with a proprietary Ball Aerospace impregnation, a silver-graphite-molybdenum disulfide material from Superior Carbon (SG59), and a copper sulfide-graphite material also from Superior Carbon (BG91).

  5. Improved Rotor Speed Brushless DC Motor Using Fuzzy Controller

    Directory of Open Access Journals (Sweden)

    Jafar Mostafapour

    2015-04-01

    Full Text Available A brushless DC (BLDC Motors have advantages over brushed, Direct current (DC Motors and , Induction motor (IM. They have better speed verses torque characteristics, high dynamic response, high efficiency, long operating life, noiseless operation, higher speed ranges, and rugged construction. Also, torque delivered to motor size is higher, making it useful in application where space and weight are critical factors. With these advantages BLDC motors find wide spread application in automotive appliance, aerospace medical, and instrumentation and automation industries This paper can be seen as fuzzy controllers compared to PI control BLDC motor rotor speed has improved significantly and beter result can be achieve.

  6. Design and Test of the Controller for EPS System with Brush-less DC Motor%无刷直流电机助力式EPS控制器设计与试验

    Institute of Scientific and Technical Information of China (English)

    江浩斌; 唐斌; 耿国庆

    2011-01-01

    基于无刷直流电机(BLDCM)模型和汽车电动助力转向(EPS)动力学模型,构建了BLDCM控制仿真模型和EPS性能仿真模型;设计了以ARM7 LPC2131为控制器内核和以MC33034P120为驱动模块的EPS控制器硬件;分析了EPS的助力、回正和阻尼控制对控制器硬件的要求,给出了EPS控制软件的主程序和A/D、速度信号采集与中断服务子程序流程;最后将BLDCM助力式EPS及其控制系统装车进行原地转向试验和蛇形试验,试验结果表明,所设计的EPS控制器与整车匹配良好,性能稳定.%Based on the model for brush-less DC motor (BLDCM) and the dynamic model for electric power steering (EPS) system, the simulation models for BLDCM control and EPS performance are set up. The EPS controller hardware with ARM7LPC2131 as its core and MC33034P120 as drive module is designed, and the requirements of power assistance, aligning and damping controls on controller hardware are analyzed. The flow charts of main program and its subroutine for A/D and speed signals acquisition and interrupt service are given. Finally the BLDCM assisted EPS and its control system are installed on a newly-launched car for spot turn and slalom tests. The results of tests show that the EPS controller designed well matches the vehicle with stable performance.

  7. PWM ZCS DC Motor Drive and DC Power Supply

    OpenAIRE

    Bardia Montazeri

    2011-01-01

    Following the extension and increase in capacity of power electronic elements, many convertors with special applications have been designed. Convertors such as rectifiers, AC and DC power supplies, AC and DC drivers and so on. At present, optimization of these convertors, decreasing loss and bringing down the electromagnetic interference are desired. In this paper, a DC to DC convertor for controlling the speed  of DC motor is designed and  one prototype is presented in which switching losses...

  8. SIMULATION AND IMPLEMENTATION OF CURRENT CONTROL OF BRUSHLESS DC MOTOR BASED ON A COMMON DC SIGNAL

    Directory of Open Access Journals (Sweden)

    J.Karthikeyan

    2010-06-01

    Full Text Available The objective of this project is to build a simple current controlled modulation technique for brushless dc motors. In electric traction and most other applications, a wide range of speed and torque control of the electric motor is required. The dc machine fulfills these requirements, but the dc machine requires constant maintenance. But the brushless permanent magnet motors do not have brushes and so they require less maintenance only. Brushless dc motors are widely used in applications which require wide range of speed and torque control because of its low inertia, fast response, high reliability and maintenance free. This current controlled technique is based on the generation of quasi- square wave currents using only one controller for the three phases. The current control strategy uses a triangular carrier for the power transistors which is simpler and more accuratethan any other options. The advantages of this technique are: a The stator currents are completely characterized by their maximum amplitude , b The three phases are controlled with the same dc component , and then the phase currents are kept at exactly the same magnitude I max, c The dc link current measurement is not required .d phase currents are kept balanced and phase over currents are eliminated.

  9. A 30 mm Wide DC-Driven Brush-Shaped Cold Air Plasma Without Airflow Supplement

    International Nuclear Information System (INIS)

    This paper reports a cold atmospheric pressure DC-driven air plasma brush. Three stainless steel needles are symmetrically mounted on a slot shaped PVC slab to act as the electrodes. The brush driven by a direct current (DC) power supply can generate an air plasma glow up to 30 mm wide with no inert gas addition and no air flow supplement. The plasma glow appears uniform no matter what kinds of material are processed. The measured current and the simulated current all show that each pulsed discharge including two peaks always occurs for different gaps between electrodes. Emission spectra measurement result shows that the obtained rotational temperatures are 300 K and the vibrational temperatures are 2250 K. Some reactive species are presented in the plasma glow, which suggest that the proposed plasma brush is beneficial to practical applications. (low temperature plasma)

  10. PWM ZCS DC Motor Drive and DC Power Supply

    Directory of Open Access Journals (Sweden)

    Bardia Montazeri

    2011-01-01

    Full Text Available Following the extension and increase in capacity of power electronic elements, many convertors with special applications have been designed. Convertors such as rectifiers, AC and DC power supplies, AC and DC drivers and so on. At present, optimization of these convertors, decreasing loss and bringing down the electromagnetic interference are desired. In this paper, a DC to DC convertor for controlling the speed  of DC motor is designed and  one prototype is presented in which switching losses is close to zero and it has a very low electromagnetic interference. In this convertor, the switches  turn on and turn off approximately with zero current. The speed of motor is controlled by PWM.  This plan includes advantages of  PWM and resonant convertors.The disadvantages, such as ;  high switching losses and changing switching  frequency  for controlling output were removed. As switching frequency has a direct relation with switching losses, when losses decreased, it is possible to increase the frequency, then volume and weight of passive filter elements can be decreased. Besides, by decreasing the losses ,  the need of  heatsink , which is  the heavy and voluminous elements of convertors, can be removed.

  11. Series BK contactless DC motors

    Energy Technology Data Exchange (ETDEWEB)

    Buss, V.A.; Vevyurko, I.A.; Ivanov, G.V.; Kuzmin, V.N.; Mikhaylov, E.M.; Stoma, A.S.

    1985-05-01

    Implementation of principles described in a previous work has allowed development and introduction to series production of a motor series including 36 standard types and sizes. The series is designed to operate at a nominal voltage of 27 V and includes two main versions: the BK-1 for fans and BK-2 for pumps. The BK-2 motor differs from the BK-1 in that it has a thin sealed sleeve of high impedance nonmagnetic metal separating the rotor and stator cavities, allowing the rotor of the BK-2 to operate in the fluids or other media being pumped. Characteristics of the motors are presented. The BK-1316 has an operating life of about 50,000 hours at nominal speed of 6000 rpm. The experience of series production of the BK motors has shown the need for further improvement of the design and technology in order to decrease the number of metal cutting, winding and assembly operations required. The use of plastic structures is suggested to this end.

  12. The analysis and design of brushless D.C. motors

    Science.gov (United States)

    Benarous, Maamar

    In modern computer systems electrical drives are used to rotate hard discs. These motors require special torque- speed characteristics. The speed of the hard disc must be constant in order for the unit to function correctly. One type of drive, which is used for hard discs is the brushless-DC-motor. This machine has permanent magnet excitation and a polyphase armature winding. It therefore takes the form of a synchronous machine, and in order to be brushless the armature winding is stationary and the excitation rotates. To run at adjustable speed a variable frequency supply is required. In the brushless D.C form the inverter output is phase locked to the rotor position, it is therefore electro-magnetically similar to the D.C machine where fixed brushes determine the frequency and phase of the current in the armature winding. In order to perform the phase lock action signals measuring the rotor position are needed. In one form of machine Hall effect probes detect the position of the rotor poles, in a second given that the rotor is in motion the induced back emf is used. Experimentally it is convenient to replace these magnet systems with a photo- transistor and rotating shutter system and this was the approach used in this thesis. The objective of this research is to investigate different aspects of this motor. The generation, measurement, and placement of signals is described and illustrated, and the design and construction of an inverter supply circuit is described. Both 2D and 3D finite element analysis is used in order to find the machine parameters as well as cogging torque analysis, using the concept of permanent magnet magnetisation characteristics. It is shown that the cogging can be reduced for certain types of magnetisation. The finite element analysis is taken further by connecting the drive circuit needed to run the machine into the finite element mesh, the machine parameters are defined using this method. The close agreement between the simulation and

  13. Electronically commutated dc motors for electric vehicles

    Science.gov (United States)

    Maslowski, E. A.

    1981-01-01

    A motor development program to explore the feasibility of electronically commutated dc motors (also known as brushless) for electric cars is described. Two different design concepts and a number of design variations based on these concepts are discussed. One design concept is based on a permanent magnet, medium speed, machine rated at 7000 to 9000 rpm, and powered via a transistor inverter power conditioner. The other concept is based on a permanent magnet, high speed, machine rated at 22,000 to 26,000 rpm, and powered via a thyristor inverter power conditioner. Test results are presented for a medium speed motor and a high speed motor each of which have been fabricated using samarium cobalt permanent magnet material.

  14. Intelligent Controller for Networked DC Motor Control

    OpenAIRE

    B. Sharmila; N. Devarajan

    2010-01-01

    This paper focuses on the feasibility of Neural Network controller for Networked Control Systems. The Intelligent Controllers has been developed for controlling the speed of the Networked DC Motor by exploiting the features of Neural Networks and Fuzzy Logic Controllers. The major challenges in Networked Control Systems are the network induced delays and data packet losses in the closed loop. These challenges degrade the performance and destabilize the systems. The aim of the proposed Neural ...

  15. On the Application of Brushless DC Motor in Power Tools%浅谈无刷直流电机在电动工具中的应用

    Institute of Scientific and Technical Information of China (English)

    孙超英

    2014-01-01

    Make a general introduction to brushless DC motor application of power tools manufacturers, compare the technical difference between brushless DC motor and brush DC motor in powers tools from the structures and principles, combining with the significant advantages and disadvantages of brushless DC motor brushless compared with brush DC motor, to give advice of selection of brushless DC motor or brush DC motor in power tools motor from the cost of manufacturing and quality control.%介绍电动工具制造企业应用无刷直流电机的大致情况,从结构和原理上对比电动工具用无刷直流电机与有刷直流电机的技术性差异,结合无刷直流电机相比有刷直流电机的显著优缺点,从企业制造成本、质量控制角度提出了电动工具用电机选用无刷直流或有刷直流的建议方向。

  16. 双余度永磁无刷直流电机设计与实验研究%An Effective Design of and Experimental Research on Dual-Redundancy BrushLess DC Motor (BLDCM)

    Institute of Scientific and Technical Information of China (English)

    付朝阳; 刘景林; 金英汉

    2012-01-01

    In order to improve the reliability of the system, the redundancy technology is introduced into the design of permanent magnet BLDCM. Sections 1 through 3 of the full paper explain our design, computer simulation and experimental research; we believe that our design is effective. The core of section 1 consists of; (1) two kinds of stator structure are designed, including one slot and two slots; ( 2 ) the mathematical model of the motor is set up; the winding inductance is analyzed and calculated, and the relationship between the winding inductance and mutual inductance is deduced. The core of section 2 is that, according to the mathematical model, the parameters of the motor are designed and the rotational speed and torque are simulated. The core of section 3 consists of; (1) the motor is tested on the MAGTROL testing system; ( 2 ) the mechanical characteristic curves of both kinds of stator structure under different working modes are compared. The simulation results are given in Figs. 3 through 6 and the experimental results are given in Figs. 7 through 12. Both the simulation and the experiment results show that; (1) the motor of each kind can achieve good dynamic characteristics and the torque is increased by 100% with two sets of windings; ( 2) two sets of winding did not affect motor performance, but it did indeed greatly improve the system reliability.%为了提高系统可靠性,将余度技术引入到永磁无刷直流电机设计中.设计了2种定子绕组方式,包括同槽嵌放和隔槽嵌放结构.建立了2种结构下的数学模型,对绕组电感进行了分析计算,推导了绕组自感和互感之间的关系.根据数学模型,设计了双余度永磁无刷直流电机的具体结构参数,对转速和转矩进行了仿真.利用magtrol测试系统对双余度永磁无刷直流电机进行了实验,对比分析了2种结构不同工作模式下的机械特性曲线.实验结果表明:2种结构的双余度无刷直流电机在运行过程

  17. Speed Control of DC Motor using AC/AC/DC Converter Based on Intelligent Techniques

    Directory of Open Access Journals (Sweden)

    Rakan Kh Antar

    2013-05-01

    Full Text Available    This paper describes the application of ac/ac/dc and ac/dc converters to control the speed of a separately excited DC motor. Artificial neural network and PI controller are trained to select the desired values of firing angles for triggering thyristors of the ac/ac/dc and ac/dc bridge converters in order to control the speed of the dc motor at a desired value with constant and different load torques in order to obtain the best speed response. Simulation results show that the rising time for ac/dc and ac/ac/dc converters at 250rpm are reduced about 79% and 89% respectively, while delay time it reduced about 69% and 64% respectively. Therefore, speed response of the dc motor is more efficient for closed loop system compared with open loop also the response of ac/ac/dc converter is better than ac/dc converter.

  18. Advanced DC Motor Drive for Haptic Devices

    Directory of Open Access Journals (Sweden)

    Miroslav Božić

    2012-06-01

    Full Text Available Haptics covers many different forms of mechanical interaction with human senses by engaging, touch, vibrations and forces/torques, established for the purpose of augmenting the feedback structure during human-machine interaction. A haptic device has mechanical part, moved by actuators from one and human hand or fingers from the other, actuators, drives, sensing elements, as well as algorithms designed to control the interaction between human and machine in positioning and motion control tasks. With such a system, motors can be controlled in a way to simulate various environments, defined by their material and dynamics, for example pushing soft ball uphill. Haptic devices are becoming more popular in medical applications after introduction of modern medical robots with many different extensions for minimally invasive surgery or diagnostics based on palpation. This paper discusses one DC motor driver custom designed for the purpose of designing a haptic device for medical applications.

  19. Rotor position sensor switches currents in brushless dc motors

    Science.gov (United States)

    1965-01-01

    Reluctance switch incorporated in an induction motor is used for sensing rotor position and switching armature circuits in a brushless dc motor. This device drives the solar array system of an unmanned space satellite.

  20. Voice-Based Control of a DC Servo Motor

    Directory of Open Access Journals (Sweden)

    Musaab Hassan

    2012-01-01

    Full Text Available Problem statement: Motors play a very important role in our life and among which is the DC servo motors. The techniques of controlling these DC motors are plenty, among which is sound. In this study, a voce-based technique was implemented to control the speed and the direction of rotation for a DC motor. Approach: A Microcontroller-based electronic control circuit was designed and implemented to achieve this goal. Results: The speed of the motor was controlled, in both directions, using pulse width modulation and a microcontroller was used to generate the right signal to be applied to the motor. Conclusion: The loudness of human voice was successfully divided into different levels where each level drives the motor at different speed."

  1. Simulation of Brushless DC Motor using Direct Torque Control

    Directory of Open Access Journals (Sweden)

    Mrs.G. Kusuma

    2014-04-01

    Full Text Available This paper deals with modelling of three phases brushless dc motor with MATLAB/SIMULINK software BLDC motor have advantages according to brushless dc motor and induction motor’s. They have improve speed torque charactistics, high efficiency high transient response and small size. It approaches for reducing the torque ripples of BLDC motor using DTC, by using control technique’s ,but present work mainly concentrate on advanced method. The whole drive system is simulated based on the system devices, BLDC motor source inverter, space vector modulation.

  2. Comparison and Survey of a Double Armature DC Motor with a Regular DC Motor in Terms of Speed and Efficiency

    Directory of Open Access Journals (Sweden)

    Dr. Mehrdad Jafarboland

    2014-11-01

    Full Text Available Due to special working conditions and also the need for extend range of speed because of high maneuver power in different conditions, there uses DC motors in submarines. Double armature motor due to the ability to produce torque in extend range of speed as well as high confidentiality in comparison with regular DC motors has noticed considerably and has used as actuator system in submarines structures. In this paper, first we will survey a regular DC motor behavior in terms of working speed range and efficiency in different powers. Then, some properties of a double armature motor will be comparison with a same regular DC motor case from the aspect of working speed range and efficiency factors

  3. PID controller simulator software for DC motor of gamma scanning

    International Nuclear Information System (INIS)

    Mostly PID controller (Proportional-Integral-Derivative) has been used in industry. For certain applications, it can be used as a Proportional (P) model only, or as a Proportional-Integral (PI) model. The aim of this paper is to design a PID controller simulator software for DC motor which is used in gamma scanning system. A DC motor is described as a plant of SISO (Single Input Single Output) which is used for pulling down the load (detector + casing) and gamma radiation source (Co-60 + container) by using sling cable. A DC motor consist of an armature and a rotor, the equivalent circuit of DC motor is shown in a transfer function equation between output parameter (angular speed DC motor) and input parameter (voltage of DC motor). Methods used for the process of PID controller design is to arrange the PID controller parameter (Kc, Ti, Td) so that there are more PID controller transfer function model which are able to control angular speed of DC motor in stable condition, as design criteria requirement is needed. Design criteria requirement for control system are the settling time < 3 second, overshoot < 5%, rise time = 0.25 second, steady state gain = 1 and peak time < 3 second with step response reference 1 rad/second. The result of simulation gives several models of PID controller in function transfer equation which is similar with design criteria requirement in a equation of function transfer of order 2 for numerator and order 1 for denominator. (author)

  4. Design optimization of brushed permanent magnet D C motor by genetic algorithm

    International Nuclear Information System (INIS)

    Because of field winding replacement with permanent magnet in brushed permanent magnet D C (PMDC) motors, field losses are eliminated and the structure of the motor is more simple. Efficiency of these motors is therefore increased and the manufacturing process is simplified. Hence, these motors are commonly used in low power applications and their design and optimization is an important consideration. Genetic algorithms are proposed for design optimization of PMD motors because of their independence to objective function structure and its derivative. In this paper genetic algorithms are evaluated for PMDC motor design optimization. an introduction is first presented about PMDC motors, general design procedure and elements of their optimization. Genetic algorithms are then briefly described. Finally results of optimization by genetic algorithms are compared with the one obtained using a conventional method

  5. Virtual test system for permanent-magnet DC motor

    Institute of Scientific and Technical Information of China (English)

    崔淑梅; 王悦; 柴凤; 吴红星; 刘宝廷; 程树康

    2003-01-01

    In order to obtain the primary parameters and operating characteristics of a DC motor without directlymeasuring its torque and rational speed, it is proposed to use a PC and a data acquisition card to acquire boththe dynamic and static data of armature current to establish the performance of a DC permanent-magnet motor.The accuracy and validity of this virtual test system proposed were verified by comparing the measurements madewith the system proposed with the measurements made with conventional torque meters. It is concluded from theresults of comparison that from the mathematic model established for the DC permant-magnet motors, both majorparameters and operating characteristics can be directly established for the DC motors without measuring theirtorques and rotational speed, a perfect on-line measurement and test system has been established for the DCpermanent-magnet motors using the theory of virtual test system. The system proposed features shorter test time,higher efficiency and lower cost.

  6. A Hybrid Model of a Brushless DC Motor

    DEFF Research Database (Denmark)

    Bendtsen, Jan Dimon; Hansen, Hans Brink; Kallesøe, Carsten Skovmose

    2007-01-01

    This paper presents a novel approach to modeling of a Brush-Less Direct Current Motor (BLDCM) driven by an inverter using hybrid systems theory. Hybrid systems combine continuous and discrete (event-based) dynamics, which is exactly the case in an inverter-driven BLDCM. The model presented in this...... work consists of a general automaton with discrete states, combined with a set of continuous dynamic equations describing the electro-mechanical behavior of the motor. One of the significant benefits of this strategy is that the model describes the motor under all possible operating conditions. The...

  7. Mathematical modeling of electromechanical processes in a brushless DC motor

    Directory of Open Access Journals (Sweden)

    V.I. Tkachuk

    2014-03-01

    Full Text Available On the basis of initial assumptions, a mathematical model that describes electromechanical processes in a brushless DC electric motor with a salient-pole stator and permanent-magnet excitation is created.

  8. Universal Brushless-DC Motor Controller for Space Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The goal of this SBIR is to adapt an initial prototype ultra-miniature high-performance brushless-DC-motor controller, code named 'Puck', for use by NASA across a...

  9. Summary on Sensorless permanent magnet Brushless DC Motor Control Strategies

    Directory of Open Access Journals (Sweden)

    Li Hai Xia

    2016-01-01

    Full Text Available This paper aims at discussing the development process and application of permanent magnet brushless DC motor. By referring to the related literatures, this thesis gives an overview of several common non-position sensor detection technologies, analyzing their strengths and weaknesses as well as a number of new and improved methods in practical applications. Besides, The application situation of the electric door with sensorless permanent magnet brushless DC motor was illustrated.

  10. PERFORMANCE EVALUATION OF HYBRID FUZZY LOGIC CONTROLLER FOR BRUSHLESS DC MOTOR DRIVE

    Directory of Open Access Journals (Sweden)

    C. SUBBA RAMI REDDY

    2011-06-01

    Full Text Available This paper presents Hybrid fuzzy logic controller (HFLC for the well developed and sophisticated simulation model of Brush less DC (BLDC motor drive using MATLAB. The developed simulation model has been examined by the PID controller and HFLC. The performance of the controllers is evaluated more precisely from various simulation studies for variations in the load torque and speed of BLDC motor drive. A performance comparison of two controllers is also carried out by taking various performance measures such as settling time, steady state error, peak overshoot, the integral of the absolute value of the error (IAE and the integral of the time-weighted squared error (ITSE. The results confirm that the developed simulation model is very convenient for the precise evaluation of performance and the HFLC shows improved performance over the PID controller in terms of disturbance rejection or parameter variation.

  11. The Model of Brushless Dc Motor Drive

    Directory of Open Access Journals (Sweden)

    Aurelijus Pitrėnas

    2013-05-01

    Full Text Available The research considered the operation, control, mathematical and simulation models of BLDC motor. A simplified idealized simulation model was designed and tested using Matlab Simulink software package. The simulation model uses Hall effect sensor signals for determining the rotor position. Simulation was done for Maxon, EC-4 pole 22 BL A series motor. The obtained model testing results deviate from the data supplied by the motor manufacturer by as little as 0.2–10.6%; consequently, the implemented model is suitable for BLDC motor control study and research.Article in Lithuanian

  12. Swarming Speed Control for DC Permanent Magnet Motor Drive via Pulse Width Modulation Technique and DC/DC Converter

    Directory of Open Access Journals (Sweden)

    A.S. Oshaba

    2013-05-01

    Full Text Available This study presents an approach for the speed control of a permanent magnet DC motor drive via Pulse Width Modulation (PWM technique and a DC/DC converter. The Particle Swarm Optimization (PSO technique is used to minimize a time domain objective function and obtain the optimal controller parameters. The performance of the proposed technique has been evaluated using various types of disturbances including load torque variations. Simulation results illustrate clearly the robustness of the controller and validity of the design technique for controlling the speed of permanent magnet motors.

  13. James Webb Space Telescope Deployment Brushless DC Motor Characteristics Analysis

    Science.gov (United States)

    Tran, Ahn N.

    2016-01-01

    A DC motor's performance is usually characterized by a series of tests, which are conducted by pass/fail criteria. In most cases, these tests are adequate to address the performance characteristics under environmental and loading effects with some uncertainties and decent power/torque margins. However, if the motor performance requirement is very stringent, a better understanding of the motor characteristics is required. The purpose of this paper is to establish a standard way to extract the torque components of the brushless motor and gear box characteristics of a high gear ratio geared motor from the composite geared motor testing and motor parameter measurement. These torque components include motor magnetic detent torque, Coulomb torque, viscous torque, windage torque, and gear tooth sliding torque. The Aerospace Corp bearing torque model and MPB torque models are used to predict the Coulomb torque of the motor rotor bearings and to model the viscous components. Gear tooth sliding friction torque is derived from the dynamo geared motor test data. With these torque data, the geared motor mechanical efficiency can be estimated and provide the overall performance of the geared motor versus several motor operating parameters such as speed, temperature, applied current, and transmitted power.

  14. DC Motor Parameter Identification Using Speed Step Responses

    Directory of Open Access Journals (Sweden)

    Wei Wu

    2012-01-01

    Full Text Available Based on the DC motor speed response measurement under a step voltage input, important motor parameters such as the electrical time constant, the mechanical time constant, and the friction can be estimated. A power series expansion of the motor speed response is presented, whose coefficients are related to the motor parameters. These coefficients can be easily computed using existing curve fitting methods. Experimental results are presented to demonstrate the application of this approach. In these experiments, the approach was readily implemented and gave more accurate estimates than conventional methods.

  15. 简介永磁无刷直流电机的原理及特点%Brief in Principle and Feature of Permanent Magnetic Brushless DC Motor

    Institute of Scientific and Technical Information of China (English)

    刘志刚

    2014-01-01

    介绍无刷直流电机在电动工具中的运用概况,对无刷电机相比有刷电机的特点、结构和控制原理进行分析,展望对电动工具应用新型电机的未来趋势。%Introduce the brushless DC motor used in power tools, analyze the characteristics, structures and control principles of brushless motor compared with brush motor, looking forward to the future trend of the new motor for power tools applications.

  16. Steering Control of Wheeled Armored Vehicle with Brushless DC Motor

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Considering the steering characters of one type of wheeled armored vehicle, a brushless direct current (DC) motor is adapted as the actuator for steering control. After investigating the known algorithms, one kind of algorithm, which combines the fuzzy logic control with the self-adapting PID control and the startup and pre-brake control, is put forward. Then a test-bed is constructed, and an experiment is conducted. The result of experiment confirms the validity of this algorithm in steering control of wheeled armored vehicle with brushless DC motor.

  17. Advanced dc motor controller for battery-powered electric vehicles

    Science.gov (United States)

    Belsterling, C. A.

    1981-01-01

    A motor generation set is connected to run from the dc source and generate a voltage in the traction motor armature circuit that normally opposes the source voltage. The functional feasibility of the concept is demonstrated with tests on a Proof of Principle System. An analog computer simulation is developed, validated with the results of the tests, applied to predict the performance of a full scale Functional Model dc Controller. The results indicate high efficiencies over wide operating ranges and exceptional recovery of regenerated energy. The new machine integrates both motor and generator on a single two bearing shaft. The control strategy produces a controlled bidirectional plus or minus 48 volts dc output from the generator permitting full control of a 96 volt dc traction motor from a 48 volt battery, was designed to control a 20 hp traction motor. The controller weighs 63.5 kg (140 lb.) and has a peak efficiency of 90% in random driving modes and 96% during the SAE J 227a/D driving cycle.

  18. Digital Signal Controller Based Digital Control of Brushless DC Motor

    Directory of Open Access Journals (Sweden)

    Anjana Elizabeth Thomas

    2013-07-01

    Full Text Available This paper presents the digital control of a brushless dc (BLDC motor using TMS320F2812 DSP controller and an EPROM. The real-time control of electrical motors is an application area that is not usually the domain of Digital Signal Processors. The TMS320F2812 has got dedicated modules for digital motor control. Control algorithms used for the control has been in TMS320F2812 DSP controller. The output of the driver is 6 independent PWM pulses that have to be given to the corresponding gates of the six MOSFETs power switches used in the three-phase bridge driving circuit whose output is given to the stator of the Brushless DC Motor. The commutation technique used in this work is the trapezoidal commutation owing to its excellent speed and current control and it has been implemented using an EPROM

  19. Hybrid Adaptive Observer for a Brushless DC Motor

    DEFF Research Database (Denmark)

    Niemczyk, Piotr; Porchez, Thomas; Bendtsen, Jan Dimon;

    2008-01-01

    A novel hybrid adaptive observer for Brushless DC Motors (BLDCM) is presented. It uses two current measurements of BLDCM phases to estimate the angle and the speed of the rotor. The observer is designed on the basis of a hybrid model, which is also presented in this paper. The parameters of the o...

  20. Brushless DC motor Drive during Speed regulation with Current Controller

    Directory of Open Access Journals (Sweden)

    Bhikshalu Manchala

    2015-04-01

    Full Text Available Brushless DC Motor (BLDC is one of the best electrical drives that have increasing popularity, due to their high efficiency, reliability, good dynamic response and very low maintenance. Due to the increasing demand for compact & reliable motors and the evolution of low cost power semiconductor switches and permanent magnet (PM materials, brushless DC motors become popular in every application from home appliances to aerospace industry. The conventional techniques for controlling the stator phase current in a brushless DC drive are practically effective in low speed and cannot reduce the commutation torque ripple in high speed range. This paper presents the PI controller for speed control of BLDC motor. The output of the PI controllers is summed and is given as the input to the current controller. The BLDC motor is fed from the inverter where the rotor position and current controller is the input. The complete model of the proposed drive system is developed and simulated using MATLAB/Simulink software. The operation principle of using component is analysed and the simulation results are presented in this to verify the theoretical analysis.

  1. Brushless DC Motor Control System Design Based on DSP2812

    Directory of Open Access Journals (Sweden)

    Wei Min

    2016-01-01

    Full Text Available By comparison various control methods currently for permanent magnet brushless DC motor, on the basis of motor principle analysis, a current smallest and most real-time all-digital rare earth permanent magnet brushless DC motor control system is designed. The high-speed digital signal processor DSP2812 is applied as the main control unit. The fuzzy PID control algorithm is used to control rectifier regulator and speed, which the speed and current is double closed loop in the system. The principle of control system, control strategy and software is analyzed in this paper. The system has some features such as less overshoot, rapid response speed, good performance of anti-jamming, simple structure, high control precision, flexible in changing control policies and so on. Validity of the design is verified by prototype test.

  2. Estimation of Nonlinear DC-Motor Models Using a Sensitivity Approach

    DEFF Research Database (Denmark)

    Knudsen, Morten; Jensen, J.G.

    1995-01-01

    A nonlinear model structure for a permanent magnet DC-motor, appropriate for simulation and controller design, is developed.......A nonlinear model structure for a permanent magnet DC-motor, appropriate for simulation and controller design, is developed....

  3. Mathematical Modeling of the Three Phase Induction Motor Couple to DC Motor in Hybrid Electric Vehicle

    Directory of Open Access Journals (Sweden)

    Zulkarnain Lubis

    2009-01-01

    Full Text Available Problem statement: With emphasis on a cleaner environment and efficient operation, vehicles today rely more and more heavily on electrical power generation for success. Approach: Mathematical modeling the components of the HEV as the three phase induction motor couple to DC motor in hybrid electric vehicle was introduced. The controller of Induction Motor (IM was designed based on input-output feedback linearization technique. It allowed greater electrical generation capacity and the fuel economy and emissions benefits of hybrid electric automotive propulsion. Results: A typical series hybrid electric vehicle was modeled and investigated. Conclusion: Various tests, such as acceleration traversing ramp and fuel consumption and emission were performed on the proposed model of 3 phase induction motor coupler DC motor in electric hybrid vehicles drive.

  4. Development of Electronic Circulating Pump by Axial Air-gap Type Brush less Motor for Boiler

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sang Uk; Lee, Chang Eon; Kim, Young Seok; Yim, Chang Soon [Inha University (Korea, Republic of); Kim, Dong Chun [Pyung Taek Technical Junior College (Korea, Republic of); Suh, Sung Won [Bupyung Technical High School (Korea, Republic of)

    1997-04-30

    Canned type household circulating pump in the country almost depends on the act of imports, however it has disadvantage of low efficiency because an air gap of between rotor and stator is large and when the boiler is not used in a period of summer, a can and a rotor become adhered each other. Accordingly the pump is impossible to drive the initial state, and a lifetime of the pump gets shortening. To overcome these defects a electronic circulating pump by axial air-gap type brush less motor which is completely depart from the general idea for the conventional pump is developed. This paper is verified through experiments that the developed pump has good performance for reduction of size and noise, retrenchment of cost, and improvement of efficiency in comparison with the conventional pump. (author). refs., figs., tabs.

  5. Forward and Reverse Motoring of DC Hoist Motor on Container Crane (CC Operation

    Directory of Open Access Journals (Sweden)

    Rukmini

    2015-03-01

    Full Text Available Container cranes (CC become the highest electric energy consumption equipment in container terminal. Therefore it is important to study and analyze the hoist motor as the largest motor on container crane operation to look for opportunities in use energy efficiently. Lifting and lowering the container as the fixed operation of CC. Lifting the container as forward operating of hoist motor and lowering the container as reverse operating of hoist motor. The type of DC motor have used to modelling. Simulink (one of Matlab toolboxes was used to model the forward and reverse of DC hoist motor. When lifting the container (forward motoring, the current required depends on the applied load torque. But when lowering the containers (reverse motoring, the voltage generated by the engine polarity reverse is determined by the downward movement of containers (mass and height. Reverse the polarity, and let the motor functions as a generator, produces a current and then the potential energy was calculated. Conclusions were drawn at the end of the paper.

  6. Disc rotors with permanent magnets for brushless DC motor

    Science.gov (United States)

    Hawsey, Robert A.; Bailey, J. Milton

    1992-01-01

    A brushless dc permanent magnet motor drives an autonomous underwater vehe. In one embodiment, the motor comprises four substantially flat stators in stacked relationship, with pairs of the stators axially spaced, each of the stators comprising a tape-wound stator coil, and first and second substantially flat rotors disposed between the spaced pairs of stators. Each of the rotors includes an annular array of permanent magnets embedded therein. A first shaft is connected to the first rotor and a second, concentric shaft is connected to the second rotor, and a drive unit causes rotation of the two shafts in opposite directions. The second shaft comprises a hollow tube having a central bore in which the first shaft is disposed. Two different sets of bearings support the first and second shafts. In another embodiment, the motor comprises two ironless stators and pairs of rotors mounted on opposite sides of the stators and driven by counterrotating shafts.

  7. Electric motors for robotics; Moteurs electriques pour la robotique

    Energy Technology Data Exchange (ETDEWEB)

    Maye, P.

    2000-07-01

    This book presents the technology of DC motors, DC brush-less motors and step by step motors as used in robotics. It describes also the speed and positioning servo-systems with their electronic circuits, the overheating problems and the selection criteria for a given electric motor. (J.S.)

  8. Signal differentiation in position tracking control of dc motors

    International Nuclear Information System (INIS)

    An asymptotic differentiation approach with respect to time is used for on-line estimation of velocity and acceleration signals in controlled dc motors. The attractive feature of this differentiator of signals is that it does not require any system mathematical model, which allows its use in engineering systems that require the signal differentiation for its control, identification, fault detection, among other applications. Moreover, it is shown that the differentiation approach can be applied for output signals showing a chaotic behavior. In addition a differential flatness control scheme with additional integral compensation of the output error is proposed for tracking tasks of position reference trajectories for direct current electric motors using angular position measurements only

  9. Sensorless Operation of Brushless DC Motor Drive using Back EMF Technique

    Directory of Open Access Journals (Sweden)

    R. Saranya, S. Saravana kumar,R. Baskaran, A. Vinidha Roc, K. Sathiyasekar

    2014-04-01

    Full Text Available The Brushless Direct Current (BLDC motors are one of the motor types that is gaining rapid popularity. Its major appliances include refrigerators, washing machines, vacuum cleaners, freezers, etc. As the name implies, BLDC motors do not use brushes for commutation; instead, they are electronically commutated. This paper proposes a new optimized technique for the Sensorless operation of permanent magnet brushless direct current (BLDC motor, which is based on back Electro Motive Force (back EMF, Zero Crossing Detection (ZCD. This proposed commutation technique of BLDC motor significantly reduces sensing circuits and cost of motor drive.

  10. Sensorless Passivity Based Control of a DC Motor

    Directory of Open Access Journals (Sweden)

    M.Seethamathavi

    2015-02-01

    Full Text Available In last couple of decades, the control of motors has increased drastically. With this increase, current control techniques are developed. In sensor-less passivity control of a DC Motor the term passivity means the property of stability in an input and output. To maintain the stability at the input side the solar pv panel is connected with MPPT which extract maximum and stable voltage. For output we simultaneously regulate, both, the output voltage of the SEPIC-converter to a value larger than the solar panel output voltage, and the speed of motor, in any of the turning senses, so that it tracks a prespecified constant reference. For a sensor less current control of a PMDC motor, its small-signal model that contains a number of parasitic parameters the observed current may diverge due to the parasitic resistors and the forward conduction voltage of the diode. Moreover, the divergence of the observed current will cause steady state errors in the output voltage a self-correction differential current observer (SDCO is proposed to eliminate this steady-state error and gain high transient response speed. By carrying out a series of MATLAB simulation verifications, further investigation proves that the proposed algorithm has good robustness.

  11. Fault detection and diagnosis of permanent-magnetic DC motors based on current analysis and BP neural networks

    Institute of Scientific and Technical Information of China (English)

    LIU Man-lan; ZHU Chun-bo; WANG Tie-cheng

    2005-01-01

    In order to guarantee quality during mass serial production of motors, a convenient approach on how to detect and diagnose the faults of a permanent-magnetic DC motor based on armature current analysis and BP neural networks was presented in this paper. The fault feature vector was directly established by analyzing the armature current. Fault features were extracted from the current using various signal processing methods including Fourier analysis, wavelet analysis and statistical methods. Then an advanced BP neural network was used to finish decision-making and separate fault patterns. Finally, the accuracy of the method in this paper was verified by analyzing the mechanism of faults theoretically. The consistency between the experimental results and the theoretical analysis shows that four kinds of representative faults of low power permanent-magnetic DC motors can be diagnosed conveniently by this method. These four faults are brush fray, open circuit of components, open weld of components and short circuit between armature coils. This method needs fewer hardware instruments than the conventional method and whole procedures can be accomplished by several software packages developed in this paper.

  12. Dynamical and steady-state characteristics of DC motors powered by photovoltaic systems via DC-DC buck-boost switch mode converter

    Energy Technology Data Exchange (ETDEWEB)

    Widyan, M.S.

    2010-07-01

    Photovoltaic (PV) cells for powering direct current (DC) motors are designed to provide maximum output power at the rated conditions of the motors. This paper presented the dynamic and steady-state characteristics of DC shunt, series and permanent-magnet motors fed by PV cells via a DC-DC buck-boost (step up-step down) switch mode converter. It considered the nonlinearities of the output characteristics of the PV cells and that of the magnetization curve of the machines. In order to address the problem of voltage regulation of the PV cells and the variation in solar illumination, the duty cycle controls the output voltage of the DC-DC converter to maintain a fixed voltage across the terminals of the motors at any realistic loading conditions. In this study, the DC-DC buck-boost switch mode converter achieved a fixed voltage across the terminals of the motors and therefore good speed regulation under a wide range of loading conditions and solar intensities. The entire study was carried out using the Matrix Laboratory Program MATLAB{sup TM} software.

  13. Electric vehicle motors and controllers

    Science.gov (United States)

    Secunde, R. R.

    1981-01-01

    Improved and advanced components being developed include electronically commutated permanent magnet motors of both drum and disk configuration, an unconventional brush commutated motor, and ac induction motors and various controllers. Test results on developmental motors, controllers, and combinations thereof indicate that efficiencies of 90% and higher for individual components, and 80% to 90% for motor/controller combinations can be obtained at rated power. The simplicity of the developmental motors and the potential for ultimately low cost electronics indicate that one or more of these approaches to electric vehicle propulsion may eventually displace presently used controllers and brush commutated dc motors.

  14. Speed Control Analysis of Brushless DC Motor Based on Maximum Amplitude DC Current Feedback

    Directory of Open Access Journals (Sweden)

    Hassan M.A.A.

    2014-07-01

    Full Text Available This paper describes an approach to develop accurate and simple current controlled modulation technique for brushless DC (BLDC motor drive. The approach is applied to control phase current based on generation of quasi-square wave current by using only one current controller for the three phases. Unlike the vector control method which is complicated to be implemented, this simple current modulation technique presents advantages such as phase currents are kept in balance and the current is controlled through only one dc signal which represent maximum amplitude value of trapezoidal current (Imax. This technique is performed with Proportional Integral (PI control algorithm and triangular carrier comparison method to generate Pulse Width Modulation (PWM signal. In addition, the PI speed controller is incorporated with the current controller to perform desirable speed operation of non-overshoot response. The performance and functionality of the BLDC motor driver are verified via simulation by using MATLAB/SIMULINK. The simulation results show the developed control system performs desirable speed operation of non-overshoot and good current waveforms.

  15. Dual-mode operation of DC-excited memory motors under flux regulation

    OpenAIRE

    Yu, C.; Chau, KT

    2011-01-01

    The concept of memory is due to the fact that the magnetization level of permanent magnets (PMs) in the motor can be easily regulated by a temporary dc current pulse and then be memorized automatically. By incorporating this concept into the hybrid-field doubly salient PM (DSPM) motor, the resulting dc-excited memory motor can offer effective and efficient air-gap flux control. The purpose of this paper is to newly propose and implement dual-mode operation for the dc-excited memory motor. Nam...

  16. Performance Enhancement of PID Controllers by Modern Optimization Techniques for Speed Control of PMBL DC Motor

    Directory of Open Access Journals (Sweden)

    M. Antony Freeda Rani

    2015-08-01

    Full Text Available Permanent Magnet Brushless DC motor (PMBL DC is used in a large number of industrial and automotive applications because of their high efficiency, compactness and excellent reliability. However to design an efficient PMBL DC motor, it is necessary to provide an effective controller that has to reduce the overshoot, settling and rise time. In this study, an improved PID controller has been designed by optimizing the parameters of PID controller based on two advanced optimization techniques ANFIS and Cuckoo Search optimization for speed control of a PMBL DC motor. The proposed approach has superior features, including easy implementation, stable convergence characteristic and good computational efficiency. The PMBL DC motor is modeled in SIMULINK implementing the algorithms in MATLAB and the performance evaluation has been studied.

  17. Magnification of starting torques of dc motors by maximum power point trackers in photovoltaic systems

    Science.gov (United States)

    Appelbaum, J.; Singer, S.

    1989-01-01

    A calculation of the starting torque ratio of permanent magnet, series, and shunt-excited dc motors powered by solar cell arrays is presented for two cases, i.e., with and without a maximum-power-point tracker (MPPT). Defining motor torque magnification by the ratio of the motor torque with an MPPT to the motor torque without an MPPT, a magnification of 3 for the permanent magnet motor and a magnification of 7 for both the series and shunt motors are obtained. The study also shows that all motor types are less sensitive to solar insolation variation in systems including MPPTs as compared to systems without MPPTs.

  18. Dynamic modeling of brushless dc motors for aerospace actuation

    Science.gov (United States)

    Demerdash, N. A.; Nehl, T. W.

    1980-11-01

    A discrete time model for simulation of the dynamics of samarium cobalt-type permanent magnet brushless dc machines is presented. The simulation model includes modeling of the interaction between these machines and their attached power conditioners. These are transistorized conditioner units. This model is part of an overall discrete-time analysis of the dynamic performance of electromechanical actuators, which was conducted as part of prototype development of such actuators studied and built for NASA-Johnson Space Center as a prospective alternative to hydraulic actuators presently used in shuttle orbiter applications. The resulting numerical simulations of the various machine and power conditioner current and voltage waveforms gave excellent correlation to the actual waveforms collected from actual hardware experimental testing. These results, numerical and experimental, are presented here for machine motoring, regeneration and dynamic braking modes. Application of the resulting model to the determination of machine current and torque profiles during closed-loop actuator operation were also analyzed and the results are given here. These results are given in light of an overall view of the actuator system components. The applicability of this method of analysis to design optimization and trouble-shooting in such prototype development is also discussed in light of the results at hand.

  19. Online Performance Optimization of a DC Motor Driving a Variable Pitch Propeller

    OpenAIRE

    Cohen, Raphael; Miculescu, David; Reilley, Kevin; Pakmehr, Mehrdad; Feron, Eric

    2013-01-01

    A practical online optimization scheme is developed for performance optimization of an electrical aircraft propulsion system. The goal is to minimize the power extraction of the propulsion system for any given thrust value. The online optimizer computes the optimum pitch angle of a variable pitch propeller by minimizing the power of the system for a command thrust value. This algorithm is tested on a DC motor driving a variable pitch propeller; the experimental hardware setup of the DC motor ...

  20. Permanent magnet brushless DC motor drives and controls

    CERN Document Server

    Xia, Chang-liang

    2012-01-01

    An advanced introduction to the simulation and hardware implementation of BLDC motor drives A thorough reference on the simulation and hardware implementation of BLDC motor drives, this book covers recent advances in the control of BLDC motor drives, including intelligent control, sensorless control, torque ripple reduction and hardware implementation. With the guidance of the expert author team, readers will understand the principle, modelling, design and control of BLDC motor drives. The advanced control methods and new achievements of BLDC motor drives, of interest to more a

  1. Influence of PWM Modes on Commutation Torque Ripples in Sensorless Brushless DC Motor Control System

    Institute of Scientific and Technical Information of China (English)

    ZHANGXiang-jun; CHENBo-shi; 等

    2001-01-01

    This paper introduces four PWM modes used in the sensorless brushless DC motor control system,analyzes their different influences on the commutation torque ripple in detail,and selects the best PWM mode in four given types to reduce commutation torque ripple of Brushless OC( BLDC) motors,Simulation and experimental results show that the selection is correct and practical.

  2. Optimization of Consumed Power in Two Different DC Motors Coupled Based on Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Mehrdad Jafarboland

    2011-01-01

    Full Text Available A single DC motor can be substituted by two different couple DC motors in submarines. By this way, by varying the speed of submarine, the power of propellant and subsequently the mechanical power of these motors would vary. One important promlem in controlling the mechanical coupling of these motors is the power sharing between them. In the previous reports the mechanical power was shared between them in nonoptimized manner. In this paper an optimized cantroller is indroduced that optimize the efficiency of the system. The power sharing between these motors would vary according to their speed. The proposed controller is based on Genetic Algoritm and is able to share the mechanical power between the motors in an optimized manner at different speeds. The simutation results shows the well behavior of system and also the optimize power sharing.

  3. 永磁无刷直流电机在打草机设计中的应用研究%Study on Application of Permanent Magnet Brushless DC Motor in Grass Trimmer Design

    Institute of Scientific and Technical Information of China (English)

    杨闯; 王国辉

    2014-01-01

    结合永磁无刷直流电机设计和应用,以Φ300 mm、DC36 V打草机为例,从电池包空载放电时间、切割效率、单电池包工作时间、抗过载性及结构优化设计等五个方面分析永磁无刷直流电机与永磁有刷直流电机的区别,得出永磁无刷直流电机性能占优的结论。%Take the Φ300 mm DC36V grass trimmer for example, combined with the design and application of permanent magnet brushless DC motor, the author analyzes the difference between permanent magnet brushless DC motor and permanent magnet brush DC motor from five aspects such as battery pack discharge time, cutting efficiency, single battery pack working time, anti-overload resistance and structural optimization design, and comes to the conclusion that permanent magnet brushless DC motor superiors.

  4. The design and analysis of a novel brushless dc linear motor

    Science.gov (United States)

    Basak, A.; Filho, A. F. Flores

    1994-05-01

    A novel brushless dc linear motor was designed, with two armature cores and seven high energy product magnets. It was then built and tested. Both the design and the analysis were carried out assuming a linear magnetic circuit. The design procedure and the test results are presented and discussed in this paper. The new motor can also be used as a slotless linear stepping motor.

  5. DC Motor Load Analysis and Cooling Consideration to Optimise the Power Consumption- Case Study

    Directory of Open Access Journals (Sweden)

    Mr. K.G. Bante

    2013-06-01

    Full Text Available The need of energy conservation is the increased requirement of all industries as the cost of the energy increasing day by day. DC motors have been the workhorse of variable speed drives in the continuous steel rolling mills for many years. DC motors in the steel rolling mills are usually separately ventilated by providing air blower, heat exchanger and water. Cooling air is circulated inside the motor by air blower. Water circulates through the heat exchanger and cools the air. Energy consumption by the air blower plays a vital role in optimizing the energy consumption. This article indicates that the loading pattern of the DC motor should decide the control strategy for effective and efficient cooling arrangement.

  6. Extracting DC bus current information for optimal phase correction and current ripple in sensorless brushless DC motor drive

    Institute of Scientific and Technical Information of China (English)

    Zu-sheng HO; Chii-maw UANG; Ping-chieh WANG

    2014-01-01

    Brushless DC motor (BLDCM) sensorless driving technology is becoming increasingly established. However, op-timal phase correction still relies on complex calculations or algorithms. In finding the correct commutation point, the problem of phase lag is introduced. In this paper, we extract DC bus current information for auto-calibrating the phase shift to obtain the correct commutation point and optimize the control of BLDC sensorless driving. As we capture only DC bus current information, the original shunt resistor is used in the BLDCM driver and there is no need to add further current sensor components. Software processing using only simple arithmetic operations successfully accomplishes the phase correction. Experimental results show that the proposed method can operate accurately and stably at low or high speed, with light or heavy load, and is suitable for practical applications. This approach will not increase cost but will achieve the best performance/cost ratio and meet market expectations.

  7. Analysis of an AC-DC full-controlled converter supplying two DC-Series-Motor loads

    International Nuclear Information System (INIS)

    Phase-controlled converters are widely used because these converters are simple, less expensive, reliable, and do not require any communication circuit. Series motors are extensively used in many applications that require both high starting torque and essentially constant horse power. This paper is concerned with the detailed study of the performance characteristics of an AC-DC full-controlled converter supplying two DC-series-motor loads. The converter loads combination is simulated on a digital computer. Different modes of operation (continuous and discontinuous converter currents) are considered. The critical firing angle at which the mode of operation changes from one mode to another is deduced. The performance characteristics such input power factor, supply current distortion factor, supply current fundamental power factor, torque speed, and motor current ripple factor have been derived and studied for both constant firing angle and constant load factor have been derived and studied for both constant firing angle and constant load power of one motor. Waveforms for each load current and converter current are investigated for different modes of operation. (author)

  8. Brushless DC Motor and Resolver for Venusian Environment Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In response to the need for motors, actuators and sample acquisition system that can operate in the harsh Venusian environment for extended periods of time, on the...

  9. Brushless DC Motor and Resolver for Venusian Environment Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In response to the need for motors and actuators that can operate in the harsh venusian environment for extended periods of time, on the order of several hours to...

  10. Numerical and Experimental Investigation of Heat Flow in Permanent Magnet Brushless DC Hub Motor

    DEFF Research Database (Denmark)

    Fasil, Muhammed; Plesner, Daniel; Walther, Jens Honore;

    2014-01-01

    This paper investigates the heat dissipation in the hub motor of an electric two-wheeler using lumped parameter (LP), finite element (FE) and computational fluid dynamic (CFD) models. The motor uses external rotor permanent magnet brushless DC topology and nearly all of its losses are generated...... the internal and the external flow as well as the convective heat transfer of the hub motor. Finally, an optimization study of the hub motor has been carried out using the CFD model to improve heat transfer from the stator....

  11. High temperature brushless DC motor system and its operation mode control

    Institute of Scientific and Technical Information of China (English)

    邹继斌; 胡建辉; 徐永向

    2001-01-01

    The high temperature ( 175 ℃ ) operation of a motor spells out special requirements for control algorithms, materials and elements. The stability of motor characteristic is guaranteed by the digital control strategy. Constant velocity operation is achieved by phase-locked loop ( PLL), and constant power operation is achieved by a current-restricting circuit. A motor for constant speed and constant power operation has been built and the speed control system is tuned by MATLAB simulation. Experimental and simulation results for operation mode control of brushless DC motor are presented.

  12. Graphical User Interface Aided Online Fault Diagnosis of Electric Motor - DC motor case study

    Directory of Open Access Journals (Sweden)

    POSTALCIOGLU OZGEN, S.

    2009-10-01

    Full Text Available This paper contains graphical user interface (GUI aided online fault diagnosis for DC motor. The aim of the research is to prevent system faults. Online fault diagnosis has been studied. Design of fault diagnosis has two main levels: Level 1 comprises a traditional control loop; Level 2 contains knowledge based fault diagnosis. Fault diagnosis technique contains feature extraction module, feature cluster module and fault decision module. Wavelet analysis has been used for the feature extraction module. For the feature cluster module, fuzzy cluster has been applied. Faults effects are examined on the system using statistical analysis. In this study Fault Diagnosis technique obtains fault detection, identification and halting the system. In the meantime graphical user interface (GUI is opened when fault is detected. GUI shows the measurement value, fault time and fault type. This property gives some information about the system to the personnel. As seen from the simulation results, faults can be detected and identified as soon as fault appears. In summary, if the system has a fault diagnosis structure, system dangerous situations can be avoided.

  13. Neuro-Fuzzy DC Motor Speed Control Using Particle Swarm Optimization

    Directory of Open Access Journals (Sweden)

    Boumediene ALLAOUA

    2009-12-01

    Full Text Available This paper presents an application of Adaptive Neuro-Fuzzy Inference System (ANFIS control for DC motor speed optimized with swarm collective intelligence. First, the controller is designed according to Fuzzy rules such that the systems are fundamentally robust. Secondly, an adaptive Neuro-Fuzzy controller of the DC motor speed is then designed and simulated; the ANFIS has the advantage of expert knowledge of the Fuzzy inference system and the learning capability of neural networks. Finally, the ANFIS is optimized by Swarm Intelligence. Digital simulation results demonstrate that the deigned ANFIS-Swarm speed controller realize a good dynamic behavior of the DC motor, a perfect speed tracking with no overshoot, give better performance and high robustness than those obtained by the ANFIS alone.

  14. Research of Compound Control for DC Motor System Based on Global Sliding Mode Disturbance Observer

    Directory of Open Access Journals (Sweden)

    He Zhang

    2014-01-01

    Full Text Available Aiming at the problems of modeling errors, parameter variations, and load moment disturbances in DC motor control system, one global sliding mode disturbance observer (GSMDO is proposed based on the global sliding mode (GSM control theory. The output of GSMDO is used as the disturbance compensation in control system, which can improve the robust performance of DC motor control system. Based on the designed GSMDO in inner loop, one compound controller, composed of a feedback controller and a feedforward controller, is proposed in order to realize the position tracking of DC motor system. The gains of feedback controller are obtained by means of linear quadratic regulator (LQR optimal control theory. Simulation results present that the proposed control scheme possesses better tracking properties and stronger robustness against modeling errors, parameter variations, and friction moment disturbances. Moreover, its structure is simple; therefore it is easy to be implemented in engineering.

  15. Analysis of torque-current characteristic of brushless DC motor driven by three-phase H-bridge

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Presents the simulation and analysis of the steady state characteristic of a brushless DC motor studies the torque-current characteristic of the motor as well and discusses the design of a current-measure circuit for torque controlling.

  16. Sensorless Load Torque Estimation and Passivity Based Control of Buck Converter Fed DC Motor

    Directory of Open Access Journals (Sweden)

    S. Ganesh Kumar

    2015-01-01

    Full Text Available Passivity based control of DC motor in sensorless configuration is proposed in this paper. Exact tracking error dynamics passive output feedback control is used for stabilizing the speed of Buck converter fed DC motor under various load torques such as constant type, fan type, propeller type, and unknown load torques. Under load conditions, sensorless online algebraic approach is proposed, and it is compared with sensorless reduced order observer approach. The former produces better response in estimating the load torque. Sensitivity analysis is also performed to select the appropriate control variables. Simulation and experimental results fully confirm the superiority of the proposed approach suggested in this paper.

  17. Efficiency of particle swarm optimization applied on fuzzy logic DC motor speed control

    Directory of Open Access Journals (Sweden)

    Allaoua Boumediene

    2008-01-01

    Full Text Available This paper presents the application of Fuzzy Logic for DC motor speed control using Particle Swarm Optimization (PSO. Firstly, the controller designed according to Fuzzy Logic rules is such that the systems are fundamentally robust. Secondly, the Fuzzy Logic controller (FLC used earlier was optimized with PSO so as to obtain optimal adjustment of the membership functions only. Finally, the FLC is completely optimized by Swarm Intelligence Algorithms. Digital simulation results demonstrate that in comparison with the FLC the designed FLC-PSO speed controller obtains better dynamic behavior and superior performance of the DC motor, as well as perfect speed tracking with no overshoot.

  18. Incorporation of fractional-order dynamics into an existing PI/PID DC motor control loop.

    Science.gov (United States)

    Tepljakov, Aleksei; Gonzalez, Emmanuel A; Petlenkov, Eduard; Belikov, Juri; Monje, Concepción A; Petráš, Ivo

    2016-01-01

    The problem of changing the dynamics of an existing DC motor control system without the need of making internal changes is considered in the paper. In particular, this paper presents a method for incorporating fractional-order dynamics in an existing DC motor control system with internal PI or PID controller, through the addition of an external controller into the system and by tapping its original input and output signals. Experimental results based on the control of a real test plant from MATLAB/Simulink environment are presented, indicating the validity of the proposed approach.

  19. DC Motor Speed and Position Control System Connects Directly to Microcomputer Chips

    Directory of Open Access Journals (Sweden)

    Albert Zsolt Barabas

    2011-06-01

    Full Text Available The papers presents a high performance speed and position control system for separately-excited D.C. motor, which was designed and performed with a dedicated integrated circuits (L290, L291, L292, made by SGS-THOMSON Microelectronics Company. The L290, L291 and L292 together form a complete microprocessorcontrolled (microcomputer chips DC motor servo positioning system that is both fast and accurate with an adequate software . The papers presents a description of the system, detailed function descriptions of each device and application information.

  20. Comparative Study of Controller Design for Four Quadrant Operation of Three Phase BLDC Motor

    OpenAIRE

    Ms.K.Suganya*1

    2014-01-01

    Brushless DC motor drives are becoming more popular in industrial and traction applications. The control of BLDC motor in four quadrants is very vital. The three-phase permanent magnet brushless dc motor inherently needs an electronic commutation circuit to drive it, because it is not a self-commutating motor. It is contrary to the conventional brush motor which commutates itself. This paper presents a comparison study of three type of control such as PI, PID & fuzzy. The char...

  1. Simulation of Outer Rotor Permanent Magnet Brushless DC Motor Using Finite Element Method for Torque Improvement

    Directory of Open Access Journals (Sweden)

    Uma Devi Kumaravelu

    2012-01-01

    Full Text Available A method of simulation and modeling outer rotor permanent magnet brushless DC (ORPMBLDC motor under dynamic conditions using finite element method by FEMM 4.2 software package is presented. In the proposed simulation, the torque developed at various positions of the rotor, under a complete cycle of excitation of the stator, is analysed. A novel method of sinusoidal excitation is proposed to enhance the overall torque development of ORPMBLDC motor.

  2. Electric compressor with high-speed brushless DC motor; E-Kompressor mit buerstenlosem Gleichstrommotor

    Energy Technology Data Exchange (ETDEWEB)

    Biwersi, Stephan; Tavernier, Stephan; Equoy, Samuel [Moving Magnet Technologies (MMT), Besancon (France)

    2012-12-01

    Moving Magnet Technologies (MMT) from Besancon in France has developed a highly efficient brushless DC motor that is especially suitable for use in electrically supported compressors. It helps to further minimise so-called turbo lag in supercharged internal combustion engines. The following report presents technical details of the electric motor and practical results in combination with an electrically driven compressor. MMT was supported by Swissauto in designing the supercharging system.

  3. Controlling the Dc-link Midpoint Potential in a Six-phase Motor-drive

    DEFF Research Database (Denmark)

    Bendixen, Flemming Buus; Blaabjerg, Frede; Rasmussen, Peter Omand;

    2004-01-01

    inverter branch and filter inductances is needed for stabilizing the midpoint potential of the series connected dc-capacitor link. A new control strategy that pre-calculates the allowed voltage ripple and controls the motor voltage accordingly (using two standard three phase inverter modules) is suggested......Traditionally electrical motors have three phases, but multiphase motors have shown to improve motor performance and efficiency. This paper concentrates about the control algorithm for a six-phase induction motor with third harmonic current injection. The problem is that typically a seventh....... With this new control strategy the seventh branch and an inductance can be saved. It also opens the possibility to use two standard three-phase inverters to supply the six-phase motor. An experimental setup is build and the theory is verified in the test case. The proposed control strategy works satisfactory...

  4. Improved Analytical Model of a Permanent-Magnet Brushless DC Motor

    NARCIS (Netherlands)

    Kumar, P.; Bauer, P.

    2008-01-01

    In this paper, we develop a comprehensive model of a permanent-magnet brushless DC (BLDC) motor. An analytical model for determining instantaneous air-gap field density is developed. This instantaneous field distribution can be further used to determine the cogging torque, induced back electromotive

  5. Novel Motion Sensorless Control of Single Phase Brushless D.C. PM Motor Drive, with experiments

    DEFF Research Database (Denmark)

    Lepure, Liviu Ioan; Boldea, Ion; Andreescu, Gheorghe Daniel;

    2010-01-01

    A motion sensorless control for single phase permanent magnet brushless d.c. (PM-BLDC) motor drives, based on flux integration and prior knowledge of the PM flux/position characteristic is proposed here and an adequate correction algorithm is adopted, in order to increase the robustness to noise...

  6. Unbalanced Magnetic Force Calculation in Brushless DC Motors

    Directory of Open Access Journals (Sweden)

    Z. Valipoor

    2015-03-01

    Full Text Available In this paper, an analytical method to calculate the unbalance magnetic pull forces (UMP due to the eccentricity of the rotor with considering the slots impact, is presented. Unbalanced magnetic pull is important because it affects the wear on the bearings as well as noise and vibration. The results of the analytical method, using finite element analysis for a prototype motor, were valid. Some force harmonics have the potential to produce noise and vibration. In order to detect harmonics of unbalance magnet forces, Depending on the fault frequency, the stator currents and spectrum of the vibrations have been analyzed

  7. Magnetic Circuit & Torque Analysis Of Brushless DC Motor

    Directory of Open Access Journals (Sweden)

    Arif J. Abbas

    2013-05-01

    Full Text Available       This work is concerned with magnetic and torque analysis of BLDCM and with development of a method of designing BLDCM that have symmetric winding on the rotor .make significant contribution to the rotor inductance position difficult. It is also show that the prediction detent torque can be extremely sensitive to the permanent magnet by altering magnet arc width. Finally, simple lumped models that allow one to predict motor performance and characteristics as a function of main dimension, magnet residual flux density and phase current are developed. These models are used as a basis for an approach to designing BLDCM

  8. Characterization and enhancement of micro brushless DC motor response

    Science.gov (United States)

    Conroy, Joseph; Kehlenbeck, Andrew; Humbert, J. Sean; Nothwang, William

    2014-06-01

    Commercially available speed controllers, motors, and propellers typically comprise the powertrains of many micro aerial robotic systems, such as quadrotor vehicles. As on board state sensing and processing improves, actuation bandwidth is becoming a significant bottleneck that limits the performance of the entire closed loop system. The performance of the commercial products can be greatly enhanced through the implementation of classical control methods directly at the powertrain level. In this paper, reduced order open loop models for three representative commercially available powertrains were estimated and were compared with closed loop equivalents. Further performance improvement is realized by the addition of a static inverse to mitigate the steady state structured uncertainty of the system.

  9. Imitation of the characteristics of the wind turbine based on DC motor

    Institute of Scientific and Technical Information of China (English)

    LIU Qihui; HE Yikang; ZHAO Rende

    2007-01-01

    This paper analyzed the operating principles and power and torque characteristics of the wind turbine and the direct current motor(DC motor),and investigated the operating characteristics of the wind turbine compared to that of the DC motor.The torque imitation scheme,which has good performance and high feasibility,together with the whole wind turbine imitation system,was provided.The wind turbine imitation system includes not only a hardware platform composed of PC,data-collection board and thyristor-based velocity-regulator,but also monitor software of wind turbine imitation.The experimental results of different occasions verify the correctness and feasibility of the wind turbine imitation scheme proposed in this paper,which provided a valid idea for wind turbine imitation and investigation of wind power generation techniques in the laboratory.

  10. Identification of the parameters of a DC motor state space model

    Directory of Open Access Journals (Sweden)

    Momir Ranislav Stanković

    2013-06-01

    Full Text Available A method for the identification of the DC state space model parameters based on the minimization of the error function using the least squares method is described in this paper. The algorithm is practically applied in the laboratory environment on an industrial DC motor. The verification of the results was performed by comparing the characteristic signals of real and modeled systems. The results show that the quality of the identification is satisfactory.   Introduction The identification of system parameters is the first step in the analysis and synthesis of control systems. Identification Quality strongly impacts on the results of all other computations. In the theory of automatic control, many methods of identification are developed. Which method will be applied depends on the characteristics of the system. In this paper, we described an identification algorithm based on the least squares method. A practical test of this algorithm of estimation is done on a DC motor.   parameter estimation with the least squares method   A DC motor is a second-order system described with two differential equations: one which describes electrical and one which describes mechanical parts of the motor. The idea is to analyse the motor as two first-order systems. The main signals are responses of two first order sub-systems on appropriate inputs. Using a discrete state-space model of the motor and applying the least square method on the recorded signals, we get straightforward equations for the computation of all the necessary parameters: Rr,  Lr ,  Je ,  Fe ,  Kme and Kem (Eykhoff, Wilsoons, 1974.   Experimental results   The practical application was realized in the laboratory where a DC middle-power motor was used as a control object. It is coupled with a DC generator which serves as a load. Generation of the input signals and measure of the responses were performed with the acquisition system based on the appropriate acquisition card and the MATLAB

  11. Performance evaluation of directly photovoltaic powered DC PM (direct current permanent magnet) motor – propeller thrust system

    International Nuclear Information System (INIS)

    Photovoltaic (PV) powered directly coupled electro-mechanical system has wide applications (e.g. PV powered cooling fans in green houses, PV water pumping system, solar vehicles). The objective of this work is to analyse the operation of directly PV powered DC PM (direct current permanent magnet) motor – propeller system for selection of motor parameters. The performance of such system mainly depends on the incident solar radiation, operating cell temperature, DC motor and propeller load parameters. It is observed that the operating points of the PV DC PM motor – propeller system matches very closely with the maximum power points (MPPs) of the PV array, if the DC PM motor – propeller parameters have been properly selected. It is found that for a specific application of such type of system, matching of torque–speed operating points with respect to the maximum power points of PV array are very important. It is ascertained through results that the DC PM motor's armature resistance, magnetic field constant, starting current to overcome the starting torque and torque coefficient are the main parameters. In designing a PV powered DC PM motor for a specific application, selection of these parameters are important for maximum utilization of the PV array output. The results of this system are useful for designing of directly PV powered DC PM motor's for aerodynamic applications. - Highlights: • We analyse the performance of directly PV powered DC PM motor – propeller system. • We examine PV electro-mechanical system for selection of DC motor parameters. • Matching of torque–speed curve to maximum power points of PV array is important

  12. Study of direct back EMF detection for sensorless brushless DC motor

    Institute of Scientific and Technical Information of China (English)

    ZOU Ji-bin; JIANG Shan-lin; LIANG Wei-yan

    2010-01-01

    In this paper,a new rotor position detecting method for the sensorless control of brushless DC motor(BLDCM)is introduced.It obtains the phase back EMF signal from the motor terminal voltage by properly choosing the PWM and sensing strategy directly and needn' t the motor neutral point voltage information.The paper analyzes both the steady-state of PWM on the high side modulator mode which doesnt consider the parasitic capacitance Coes in the switches and the transient-state of PWM on the high side modulator mode which considers the parasitic capacitance Coes in the switches in detail.The experimental results verify that the proposed method is not sensitive to switching noise,no filtering is required,and good motor performance is achieved within a wide speed range.

  13. Speed and Displacement Control System of Bearingless Brushless DC Motor Based on Improved Bacterial Foraging Algorithm

    Directory of Open Access Journals (Sweden)

    Diao Xiaoyan

    2016-01-01

    Full Text Available To solve the deficiencies of long optimization time and poor precision existing in conventional bacterial foraging algorithm (BFA in the process of parameter optimization, an improved bacterial foraging algorithm (IBFA is proposed and applied to speed and displacement control system of bearingless brushless DC (Bearingless BLDC motors. To begin with the fundamental principle of BFA, the proposed method is introduced and the individual intelligence is efficiently used in the process of parameter optimization, and then the working principle of bearingless BLDC motors is expounded. Finally, modeling and simulation of the speed and displacement control system of bearingless BLDC motors based on the IBFA are carried out by taking the software of MATLAB/Simulink as a platform. Simulation results show that, speed overshoot, torque ripple and rotor position oscillation are dramatically reduced, thus the proposed method has good application prospects in the field of bearingless motors.

  14. A low-cost viscometer based on a permanent magnet dc motor

    International Nuclear Information System (INIS)

    This paper proposes a pragmatic approach to, and a feasibility study of, a very low cost instrument for on-line and in situ viscosity measurement for engineering applications. It is a simple rotational instrument based on the mixer technique. It utilizes a permanent magnet dc (PMDC) motor which drives a propeller immersed in the test fluid. The viscosity is derived from the motor current when the motor is connected to a fixed supply voltage. The theory which relates PMDC motor current to the resistance to the rotational movement of a body due to the viscosity of the liquid under the test is developed. It is believed that the system provides the basis for a new generation of inexpensive viscometers for process and storage environments. (paper)

  15. Effect of phase advance on the brushless dc motor torque speed respond

    Science.gov (United States)

    Mohd, M. S.; Karsiti, M. N.; Mohd, M. S.

    2015-12-01

    Brushless direct current (BLDC) motor is widely used in small and medium sized electric vehicles as it exhibit highest specific power and thermal efficiency as compared to the induction motor. Permanent magnets BLDC rotor create a constant magnetic flux, which limit the motor top speed. As the back electromotive force (EMF) voltage increases proportionally with motor rotational speed and it approaches the amplitude of the input voltage, the phase current amplitude will reach zero. By advancing the phase current, it is possible to extend the maximum speed of the BLDC motor beyond the rated top speed. This will allow smaller BLDC motor to be used in small electric vehicles (EV) and in larger applications will allow the use of BLDC motor without the use of multispeed transmission unit for high speed operation. However, increasing the speed of BLDC will affect the torque speed response. The torque output will decrease as speed increases. Adjusting the phase angle will affect the speed of the motor as each coil is energized earlier than the corresponding rise in the back emf of the coil. This paper discusses the phase advance strategy of Brushless DC motor by phase angle manipulation approaches using external hall sensors. Tests have been performed at different phase advance angles in advance and retard positions for different voltage levels applied. The objective is to create the external hall sensor system to commutate the BLDC motor, to establish the phase advance of the BLDC by varying the phase angle through external hall sensor manipulation, observe the respond of the motor while applying the phase advance by hall sensor adjustment.

  16. Adaptive Quasi-Sliding Mode Control for Permanent Magnet DC Motor

    Directory of Open Access Journals (Sweden)

    Fredy E. Hoyos

    2013-01-01

    Full Text Available The motor speed of a buck power converter and DC motor coupled system is controlled by means of a quasi-sliding scheme. The fixed point inducting control technique and the zero average dynamics strategy are used in the controller design. To estimate the load and friction torques an online estimator, computed by the least mean squares method, is used. The control scheme is tested in a rapid control prototyping system which is based on digital signal processing for a dSPACE platform. The closed loop system exhibits adequate performance, and experimental and simulation results match.

  17. POSITION CONTROL OF BRUSHLESS DC MOTOR BASED ON DIGITAL SIGNAL PROCESSING

    Directory of Open Access Journals (Sweden)

    Çetin GENÇER

    2006-01-01

    Full Text Available Brushless DC Motors (BLDC have been used widely high performance control systems which are depended on to development of power electronic and control technology. In these motors to fed commutated supply, the control of position without oscilation has been required. In this study, position control of BLDC with digital signal processing has been implemented by a proportional-derivative (PD controller because of its simple structure. It has been seen that the controller which is proposed from simulation and experimental studies, has a quick dynamic responce with nonoscillation.

  18. Novel Position and Speed Estimator for PM Single Phase Brushless D.C. Motor Drives

    DEFF Research Database (Denmark)

    Lepure, Liviu I.; Andreescu, Gheorghe-Daniel; Iles, Doris;

    2010-01-01

    the sensitivity to accuracy of flux linkage estimation. A speed and current close loop control is employed based on the Hall signal and the motor is controlled at different speeds in order to validate the proposed estimation algorithm with satisfying results. The position correction effect is analyzed......A novel position and speed estimator for single phase permanent magnet brushless d.c. (PMBLDC) motor drives, based on flux integration and prior knowledge of ΨPM (θ) is proposed here and an adequate correction algorithm is adopted in order to increase the robustness to noise and to reduce...... by examination of improvements in both position error and speed pulsations....

  19. Modelling of a Serial Wound DC Motor Supplied by a Semi-Controlled Rectifier

    Directory of Open Access Journals (Sweden)

    Pavel Zaskalicky

    2006-01-01

    Full Text Available A serial wound DC motor is one of most used electrical machines in a small electrical instruments and home equipments by reason, that its speed is easily controlled by a supply voltage. Suppose that the motor is supplied by a semicontrolled rectifier and operate in open circuit loop. After representing of the mathematical model, a simulation model based on the Matlab-Simulink is derived; this allows for the determination of the waveforms of the speed current and torque of the machine for different state operation. Induced voltage of the rotor is determined as a function of the magnetic core saturation and of the armature reaction.

  20. Genetic Design of an Interval Type-2 Fuzzy Controller for Velocity Regulation in a DC Motor

    Directory of Open Access Journals (Sweden)

    Yazmin Maldonado

    2012-11-01

    Full Text Available This paper proposes the design of a Type‐2 Fuzzy Logic Controller (T2‐FLC using Genetic Algorithms (GAs. The T2‐FLC was tested with different levels of uncertainty to regulate velocity in a Direct Current (DC motor. The T2‐FLC was synthesized in Very High Description Language (VHDL code for a Field‐programmable Gate Array (FPGA, using the Xilinx System Generator (XSG of Xilinx ISE and Matlab‐Simulink. Comparisons were made between the Type‐1 Fuzzy Logic Controller and the T2‐FLC in VHDL code and a Proportional Integral Differential (PID Controller so as to regulate the velocity of a DC motor and evaluate the difference in performance of the three types of controllers, using the t‐student test statistic.

  1. Comparison between Conventional and Fuzzy Logic PID Controllers for Controlling DC Motors

    Directory of Open Access Journals (Sweden)

    Essam Natsheh

    2010-09-01

    Full Text Available Fuzzy logic and proportional-integral-derivative (PID controllers are compared for use in direct current (DC motors positioning system. A simulation study of the PID position controller for the armature-controlled with fixed field and field controlled with fixed armature current DC motors is performed. Fuzzy rules and the inferencing mechanism of the fuzzy logic controller (FLC are evaluated by using conventional rule-lookup tables that encode the control knowledge in a rules form. The performance assessment of the studied position controllers is based on transient response and error integral criteria. The results obtained from the FLC are not only superior in the rise time, speed fluctuations, and percent overshoot but also much better in the controller output signal structure, which is much remarkable in terms of the hardware implementation.

  2. Control System of Sensorless Brushless DC Motor Based on TMS320F240

    Directory of Open Access Journals (Sweden)

    Li Zeng

    2011-11-01

    Full Text Available A brushless DC(BLDC motor with the characteristics of high speed and high power density has been more widely used in industrial area. The BLDC motor requires the position and speed sensors for control. However the position sensors are undesirable from standpoints of size, cost, maintenance and reliability. There are some different ways that can solve this problem, depending on the flux distribution. This paper describes a control system of sensorless BLDC motor. The back-EMF is adopted to detect the rotor position. The back-EMF is very small in the motor starting process, and it is difficult to obtain rotor position efficiently. A re-setting method of the rotor is proposed in the paper, and current closed loop is used for high-speed and safety in the motor starting process. A good speed and current double closed loops system is designed. The speed and current regulators are implemented by a digital signal processor(DSP. A simple algorithm is used to calculate motor speed indirectly by the software, which simplifies the system hardware structure. The hardware structure and software design of sensorless BLDC motor control system are described in details. The simulation and experimental results have shown the validity of the sensorless control system and the accuracy of the detective position signal obtained.

  3. Evaluation of linear DC motor actuators for control of large space structures

    OpenAIRE

    Ide, Eric Nelson

    1988-01-01

    This thesis examines the use of a linear DC motor as a proof mass actuator for the control of large space structures. A model for the actuator, including the current and force compensation used, is derived. Because of the force compensation, the actuator is unstable when placed on a structure. Relative position feedback is used for actuator stabilization. This method of compensation couples the actuator to the mast in a feedback configuration. Three compensator designs are prop...

  4. Fuzzy PID Controllers Using Matlab GUI Based for Real Time DC Motor Speed Control

    OpenAIRE

    Suhas Yadav*1

    2014-01-01

    In this paper, an integrated electronic system has been designed, constructed and tested. Controlling DC (Direct current) Motor drive is design and development of real time MATLAB –GUI based using fuzzy logic controller. First, a controller is designed according to fuzzy rules such that the systems are fundamentally robust. To obtain the globally optimal values, parameters of the fuzzy controller are improved by MATLAB-GUI based FLC and IFLC algorithms optimization model. Comp...

  5. 超低速直流电机电刷短路系数计算%Computation of brush short-circuit coefficients of DC machines for extremely low speed drives

    Institute of Scientific and Technical Information of China (English)

    张琪; 谢国栋; 黄苏融

    2006-01-01

    Short circuit due to the brushes over the commutator segments of DC machines causes reduction in the armature resistance and flux linkage, which is especially meaningful when the electric machine is running at zero or extremely low speed. In design computation of DC machines, usually the average values of the coefficients are used in consideration of the effects of the short circuit.However, the average values have complicated relationships with the parameters of electric machines, therefore, no usable mathematical model has been established yet for precise computation. In this paper, a relatively simple and generalized method for precise computation of the average values of the short-circuit coefficients is proposed. This method decouples some of the machine parameters and, therefore establishes a highly parameterized mathematical model and is convenient in formulation for computation. In addition, the computation data for one and two brush pairs, which are the most common cases, is provided.

  6. Control of a high-speed, brushless dc motor driven through a cycloconverter line

    Science.gov (United States)

    Cathey, J. J.; Reesor, D. B.; Weimer, J. A.

    Feasibility and concept of designing a high-speed, permanent magnet, brushless dc motor aircraft fuel pump drive using a cycloconverter link is examined. Analytical methods are developed to model the behavior of a three-phase permanent magnetic machine when operated as a self-synchronous motor supplied from a polyphase, variable voltage, variable frequency source through a midpoint cycloconverter link under circulating current free mode of control. A hybrid combination of sinusoidal and dc steady-state analysis methods is utilized to obtain a suitable equivalent circuit of the motor. Study of the motor model is made to establish the nature of the no load MMF angle as a function of current to give a minimum value while assuring proper thyristor commutation. Then, a closed loop control system with an outer loop on speed and an inner loop on current is postulated wherein a proportional plus integral controller is placed in the forward path to assure minimum speed error. A numerical study of performance is presented for speed runup and rundown conditions.

  7. A Modified High-Efficient Step-Up Sepic for DC Motor Drives

    Directory of Open Access Journals (Sweden)

    P. Dhanasekaran

    2013-12-01

    Full Text Available In this paper, Single-Ended Primary Inductor Converter (SEPIC fed DC motor is proposed. Soft-switching technique such as Zero-Voltage-Switching (ZVS and Zero-Current-Switching (ZCS operation plays a vital role in high voltage applications. Zero-Current-Switching (ZCS operation achieved due to resonance between the resonant inductor and the capacitor by using output diode and its reverse-recovery loss is subsequently reduced. Zero-Voltage-Switching (ZVS operation is achieved by using coupled inductor and auxiliary inductor. The model has been simulated through MATLAB/SIMULINK using Diode Bridge, SEPIC topology and closed loop DC motor load and it is modeled analytically. The proposed system is modeled with input side Diode Bridge Rectifier and SEPIC Topology with Proportional Integral (PI controller. The soft switching scheme for the proposed topology is developed with closed loop motor load. The motor voltage is achieved twice the rated voltage. The results are generated in MATLAB/SIMULINK and are shown.

  8. Electromagnetic Flux Analysis of Permanent Magnet Brushless DC Motor Using Magnet Software

    Directory of Open Access Journals (Sweden)

    G.R.Puttalakshmi

    2013-08-01

    Full Text Available Permanent Magnet Brushless DC (PMBLDC motors is emerging as a suitable motor for a number of drive applications in industrial and consumer products. Cogging torque is one of the important drawbacks of PMBLDC motor which results in shaft vibrations and noise. The focus of this work is to minimize the electromagnetic flux and cogging torque in PMBLDC by introducing structural design modifications. The performance of the machine is analyzed by varying the magnet pole shape, magnet pole width and by using magnetic material with different remenance value. For analyzing the performance of the machine, machine is modeled using Finite Element Analysis (FEA based software package Magnet. Cogging torque and average torque are taken as performance measures to determineoptimum pole shape and pole width.

  9. A New Energy Optimal Control Scheme for a Separately Excited DC Motor Based Incremental Motion Drive

    Institute of Scientific and Technical Information of China (English)

    Milan A.Sheta; Vivek Agarwal; Paluri S.V.Nataraj

    2009-01-01

    This paper considers minimization of resistive and frictional power dissipation in a separately excited DC motor based incremental motion drive (IMD). The drive is required to displace a given, fixed load through a definite angle in specified time, with minimum energy dissipation in the motor windings and minimum frictional losses. Accordingly, an energy optimal (EO) control strategy is proposed in which the motor is first accelerated to track a specific speed profile for a pre-determined optimal time period. Thereafter, both armature and field power supplies are disconnected, and the motor decelerates and comes to a halt at the desired displacement point in the desired total displacement time. The optimal time period for the initial acceleration phase is computed so that the motor stores just enough energy to decelerate to the final position at the specified displacement time. The parameters, such as the moment of inertia and coefficient of friction, which depend on the load and other external conditions, have been obtained using system identification method. Comparison with earlier control techniques is included. The results show that the proposed EO control strategy results in significant reduction of energy loases compared to the existing ones.

  10. Developing micro DC-brushless motor driver and position control for fiber positioners

    Science.gov (United States)

    Jenni, Laurent; Hörler, Philipp; Makarem, Laleh; Kneib, Jean-Paul; Gillet, Denis; Bleuler, Hannes; Bouri, Mohamed; Prada, Francisco; De Rivera, Guillermo; Sanchez, Justo

    2014-07-01

    In the large-scale, Dark Energy Spectroscopic Instrument (DESI), thousands of fiber positioners will be used. Those are robotic positioners, with two axis, and having the size of a pen. They are tightly packed on the focal plane of the telescope. Dedicated micro-robots have been developed and they use 4mm brushless DC motors. To simplify the implementation and reduce the space occupancy, each actuator will integrate its own electronic control board. This board will be used to communicate with the central trajectory generator, manage low level control tasks and motor current feeding. In this context, we present a solution for a highly compact electronic. This electronic is composed of two layers. The first is the power stage that can drive simultaneously two brushless motors. The second one consists of a fast microcontroller and deals with different control tasks: communication, acquisition of the hall sensor signals, commutation of the motors phases, and performing position and current regulation. A set of diagnostic functions are also implemented to detect failure in the motors or the sensors, and to sense abnormal load change that may be the result of two robots colliding.

  11. Optimization of PID Controller for Brushless DC Motor by using Bio-inspired Algorithms

    Directory of Open Access Journals (Sweden)

    Sanjay Kr. Singh

    2014-02-01

    Full Text Available This study presents the use and comparison of various bio-inspired algorithms for optimizing the response of a PID controller for a Brushless DC Motor in contrast to the conventional methods of tuning. For the optimization of the PID controllers Genetic Algorithm, Multi-objective Genetic Algorithm and Simulated Annealing have been used. PID controller tuning with soft-computing algorithms comprises of obtaining the best possible outcome for the three PID parameters for improving the steady state characteristics and performance indices like overshoot percentage, rise time and settling time. For the calculation and simulation of the results the Brushless DC Motor model, Maxon EC 45 flat ф 45 mm with Hall Sensors Motor has been used. The results obtained the optimization using Genetic Algorithms, Multi-objective Genetic Algorithm and Simulated Annealing is compared with the ones derived from the Ziegler-Nichols method and the MATLAB SISO Tool. And it is observed that comparatively better results are obtained by optimization using Simulated Annealing offering better steady state response.

  12. Efficiency consideration of DC link soft-switching inverters for motor drive applications

    Energy Technology Data Exchange (ETDEWEB)

    Lai, J.S.; Young, R.W.; McKeever, J.W.

    1994-12-31

    This paper critically evaluates efficiency of soft switching inverters including an actively clamped resonant dc link inverter and a clamped-mode resonant pole inverter. An analytical approach to evaluating efficiency of the clamped-mode soft switching inverter has been developed. The evaluation results are compared with that of the standard pulse-width-modulation (PWM) inverter. A 50-kW induction motor is used as the variable load, and the inverter efficiency is evaluated under different speed and torque conditions. The clamped-mode soft-switching inverter, although eliminating the switching loss, shows poor efficiency over the entire load range. Under low load conditions, the efficiency profile is even worse. The actively clamped resonant dc link inverter shows highest efficiency over the entire speed and torque range. However, its energy saving over the standard PWM inverter is marginal under full load or high speed conditions.

  13. 直流电动机新论%New Theory of DC Motor

    Institute of Scientific and Technical Information of China (English)

    王宗培; 陈敏祥

    2012-01-01

    The author found and put forward the new electromechanical concept of the DC rotating magnetic field in the New DCM research work. The DC rotating magnetic field is produced by the DC armature winding magnetic potential when commutation controller controls the conducting state and order of power switches in the electronic commutator. The change of the instantaneous current in the AC armature winding along the circumference produces an AC rotating magnetic field. Both DC and AC magnetic potential are produced by the armature winding circuit and are no relationship with the rotor mechanical relative motion. From the rotor? Perspective there is no difference between the armature winding magnetic potential produced by the DC winding current and the AC winding current. So the DC rotating magnetic field combined with different rotor structure can constitute the new concepts of the DC synchronous motor and the DC asynchronous motor, which are similar with the concepts of the AC synchronous motor and the AC asynchronous motor. This study will help to deepen our understanding and open mentality%作者在对新一代直流电动机( New DCM)的研究中发现并提出了直流旋转磁场这一电机学的新概念,是用换向控制器来控制电子换向器中功率开关管的导通状态及变化顺序,让通电直流电枢绕组磁势沿电枢表面圆周旋转而达到的.与交流旋转磁场一样,都是电枢绕组电路产生的磁势,它的旋转是由于电枢绕组线圈内电流瞬时值沿圆周分布变化引起的,与定转子机械相对运动没有关系.从转子的角度看电枢的旋转磁势是直流绕组电流还是交流绕组电流产生的并没有什么区别,所以对应不同的转子结构也能构成类似于交流同步电动机和交流异步电动机基本作用原理的电动机,又有所区别,出现了直流同步电动机和直流异步电动机的新概念和新名称.该文的研究有助于加深认识和开阔思路.

  14. Pengaturan Kecepatan Motor DC pada Mobil Listrik Menggunakan Bidirectional Buck-Boost Cascade Converter berbasis Fuzzy Logic Controller

    Directory of Open Access Journals (Sweden)

    Muhammad Taufiq Ramadhan

    2015-03-01

    Full Text Available Penggunaan mobil listrik secara umum terkendala pada beban, kecepatan aktual, serta efisiensi energi. Pemanfaatan Fuzzy Logic Controller untuk pengaturan kecepatan motor DC pada mobil listrik diperlukan untuk meraih kecepatan aktual yang lebih presisi  sehingga diperoleh efisiensi energi. Selain itu perlu juga  menggunakan Bidirectional Buck-Boost Cascade Converter untuk pengaturan motor DC secara bidirectional, yakni pengaturan saat motoring dan saat pengereman regeneratif (regenerative braking. Hal ini berdasar pada energi yang terbuang percuma, baik itu rugi elektris maupun rugi mekanis saat pengereman.

  15. Design of Fuzzy PID controller to control DC motor with zero overshoot

    Directory of Open Access Journals (Sweden)

    Meenakshi Chourasiya

    2014-10-01

    Full Text Available Most of the real time operation based physical system, digital PID is used in field such as servo-motor/dc motor/temperature control system, robotics, power electronics etc. need to interface with high speed constraints, higher density PLD’s such as FPGA used to integrate several logics on single IC. There are some limitations in it to overcome these limitations Fuzzy logic is introduced with PID and Fuzzy PID is formed. This paper explains experimental design of Fuzzy PID controller. We aimed to make controller power efficient, more compact, and zero overshoot. MATLAB is used to design PID controller to calculate and plot the time response of the control system and Simulink to generate a set of coefficients.

  16. Developing Micro DC-Brushless Motor Driver and Position Control for Fiber Positioners

    CERN Document Server

    Jenni, Laurent; Makarem, Laleh; Kneib, Jean-Paul; Gillet, Denis; Bleuler, Hannes; Bouri, Mohamed; Prada, Francisco; De Rivera, Guillermo; Sanchez, Justo

    2014-01-01

    In the large-scale, Dark Energy Spectroscopic Instrument (DESI), thousands of fiber positioners will be used. Those are robotic positioners, with two axis, and having the size of a pen. They are tightly packed on the focal plane of the telescope. Dedicated micro-robots have been developed and they use 4mm brushless DC motors. To simplify the implementation and reduce the space occupancy, each actuator will integrate its own electronic control board. This board will be used to communicate with the central trajectory generator, manage low level control tasks and motor current feeding. In this context, we present a solution for a highly compact electronic. This electronic is composed of two layers. The first is the power stage that can drive simultaneously two brushless motors. The second one consists of a fast microcontroller and deals with different control tasks: communication, acquisition of the hall sensor signals, commutation of the motors phases, and performing position and current regulation. A set of di...

  17. DC Brushless Motor Control Design and Preliminary Testing for Independent 4-Wheel Drive Rev-11 Robotic Platform

    Directory of Open Access Journals (Sweden)

    Roni Permana Saputra

    2012-03-01

    Full Text Available This paper discusses the design of control system for brushless DC motor using microcontroller ATMega 16 that will be applied to an independent 4-wheel drive Mobile Robot LIPI version 2 (REV-11. The control system consists of two parts which are brushless DC motor control module and supervisory control module that coordinates the desired command to the motor control module. To control the REV-11 platform, supervisory control transmit the reference data of speed and direction of motor to control the speed and direction of each actuator on the platform REV-11. From the test results it is concluded that the designed control system work properly to coordinate and control the speed and direction of motion of the actuator motor REV-11 platform. 

  18. METHODICAL TUNING OF PROPORTIONAL PLUS INTEGRAL CONTROLLERS FOR CASCADE CONTROL OF SEPARATELY EXCITED DC MOTORS

    Directory of Open Access Journals (Sweden)

    Ibrahim Al-Abbas

    2012-01-01

    Full Text Available The cascade control of DC motors by PI controllers was extensively used in industry. Approximation rules based on plotting the output of the system or on computer simulation were used to determine the parameters of these controllers. This study was done to develop mathematical expressions to calculate the parameters of these controllers. Output time functions of the system and there derivatives were used to obtain mathematical relationships relating directly the motor parameters and the controller parameters. These relationships were used in tuning process of the cascade system. The dynamic performances of the system were examined in single loop form and in closed loop form for a step change in control variable (the input voltage as well as for step change in disturbance (mechanical load. The performances of current closed loop system and the speed closed loop were acceptable. The steady state error was zero and the maximum overshoot was less than 20%. The developed relationships can be used in design and analysis of cascade DC drive systems and cascade AC drive systems.

  19. Comparative Study of Fuzzy Logic Based Speed Control of Multilevel Inverter fed Brushless DC Motor Drive

    Directory of Open Access Journals (Sweden)

    Pritha Agrawal

    2014-02-01

    Full Text Available This paper presents a comparative analysis of speed control of brushless DC motor (BLDC drive fed with conventional two-level, three and five level diode clamped multilevel inverter (DC-MLI. The performance of the drive system is successfully evaluated using Fuzzy Logic (FL based speed controller. The control structure of the proposed drive system is described. The speed and torque characteristic of conventional two-level inverter is compared with the three and five-level multilevel inverter (MLI for various operating conditions. The three and five level diode clamped multilevel inverters are simulated using IGBT’s and the mathematical model of BLDC motor has been developed in MATLAB/SIMULINK environment. The simulation results show that the Fuzzy based speed controller eliminate torque ripples and provides fast speed response. The developed Fuzzy Logic model has the ability to learn instantaneously and adapt its own controller parameters based on disturbances with minimum steady state error, overshoot and rise time of the output voltage.

  20. 无刷直流电动机双模式控制%Dual Mode Control for Brushless DC Motor

    Institute of Scientific and Technical Information of China (English)

    赵建勇; 许林荣; 徐交建

    2012-01-01

    在分析电机运行原理和应用要求的基础上,引用基于新型逆变器的无刷直流电动机双模式控制方法,设计出无刷直流电动机双模式控制器,基速以下采用双闭环控制方法,基速以上采用弱磁扩速控制方法.仿真和实验验证该方案可行,实现无刷直流电动机在宽速度范围内稳定工作.%Dual mode control method based on a new inverter for brushless DC motor was cited by analyzing the operation principle of brushless DC motor and application requirements. Dual mode controller for brushless DC motor was designed, which used dual closed loop control when motor was running below base speed and field-weakening control when motor was running above base speed. The simulation and experiment results show that brushless DC motor can operate in a wide speed range.

  1. Integrated solar pump design incorporating a brushless DC motor for use in a solar heating system

    Energy Technology Data Exchange (ETDEWEB)

    Swan, Lukas G.; Allen, Peter L. [Department of Mechanical Engineering, Dalhousie University, 1360 Barrington Street, Halifax, Nova Scotia B3J 1Z1 (Canada)

    2010-09-15

    Most solar thermal hot water heating systems utilize a pump for circulation of the working fluid. An elegant approach to powering the pump is via solar energy. A ''solar pump'' employs a photovoltaic module, electric motor, and pump to collect and convert solar energy to circulate the working fluid. This article presents an experimental investigation of a new integrated solar pump design that employs the stator of a brushless DC motor and a magnetically coupled pump that has no dynamic seal. This design significantly reduces total volume and mass, and eliminates redundant components. The integrated design meets a hydraulic load of 1.7 bar and 1.4 litres per minute, equal to 4.0 watts, at a rotational speed of 500 revolutions per minute. The brushless DC motor and positive displacement pump achieve efficiencies of 62% and 52%, respectively, resulting in an electric to hydraulic efficiency of 32%. Thus, a readily available photovoltaic module rated 15 watts output is suitable to power the system. A variety of design variations were tested to determine the impact of the armature winding, pump size, pulse width modulation frequency, seal can material, etcetera. The physical and magnetic design was found to dominate efficiency. The efficiency characteristics of a photovoltaic module are such that over-sizing is wasteful. The integrated design presents a robust, efficient package for use as a solar pump. Although focus has been placed on application to a solar thermal collector system, variations of the design are suitable for a wide variety of applications such as remote location water pumping. (author)

  2. 无刷直流电动机的DSP控制%DSP Control of Brushless DC Motor

    Institute of Scientific and Technical Information of China (English)

    王越; 甄长飞

    2012-01-01

    According to the characteristics of the brushless dc motor, and the demand in practical application, design solved the rapid control problem of brushless dc motor. Using the TMS320LF2407A of the TI company as control core, and PWM and PI, we designed control circuit and control procedures for brushless dc motor in order to achieve the actual effect.%为解决无刷直流电动机的快速控制问题,提出了无刷直流电动机的DSP控制方法。采用TI公司的TMS320LF2407A芯片为控制核心,结合PWM和PI调节设计无刷直流电动机的控制电路以及控制程序,以达到节能和使电动机快速启动的效果。

  3. High-order sliding mode control of a DC motor drive via a switched controlled multi-cellular converter

    Science.gov (United States)

    Djemaï, M.; Busawon, K.; Benmansour, K.; Marouf, A.

    2011-11-01

    In this article, we present a high-order sliding mode controller of a DC motor drive connected to a multi-cellular converter. More specifically, we design a second-order (super-twisting) control algorithm for the speed regulation of a DC motor. For this, a switching control for the multi-cellular converter is derived in order to supply the correct reference value for the speed regulation. A practical implementation of the controller is realised using a laboratory set-up. The performance and the validity of the controller are shown experimentally.

  4. Adaptive Neuro-Fuzzy Controller Experimental Design for DC Motor Connected to Unbalanced Load

    Directory of Open Access Journals (Sweden)

    Reza Nejati

    2007-09-01

    Full Text Available In two recent decades, fuzzy controllers have been used in controlling different systems successfully. In this article, a new method is given for controlling of permanent magnetic DC motor connected to unbalanced load. Imbalance of load leads to machine vibrations, fluctuation of power, making exhaustion in machine shaft, and equipment depreciation. In this article neuro-fuzzy controllers are used for controlling unbalanced load. Because of non-linear nature of load and machine, machine fluctuations are different in various speeds. For making controller adaptive with machine, using an artificial neural network, the input-output coefficients are be updated in any speed. Optimized coefficients obtained by using of direct search method, and with these coefficients, artificial neural network trained with Lauvenberg-Marcoardet method. Operational results obtained from developed system, shows the efficiency of given method.

  5. Dynamic Characteristic Analysis of Linear DC Motor by 3D EMCN Considering Input Voltage

    Energy Technology Data Exchange (ETDEWEB)

    Ha, Kyung Ho; Yeom, Sang Bu [Changwon National University, Changwon(Korea); Hong, JUNG Pyo; Hur Jin; Kang Do Hyunc [Hanyang University(Seoul Campus), Seoul(Korea)

    2002-02-01

    In order to design the Linear DC Motor (LDM) With improved characteristics, transient and steady state analysis are required. Furthermore, 3D analysis is also needed to analyze the precise characteristics like thrust, time harmonics. This paper deals with the transient and dynamic characteristic analysis if LDM by coupling of external circuit and motion equation using 3D Equivalent Magnetic Circuit Network Method (EMCN). For the three dimensional analysis of electric machine, EMCN is very effective method that ensures high accuracy similar to FEM and short computation time. Also, The modeling by EMCN easily allows the mover to move with respect to the Sartre at each time Also, and the spatial moving step is determined by the solution of the mechanical motion equation and the computed electromagnetic thrust. The results are compared with experimental ones to clarify the usefulness and verify the accuracy of the proposed method. (author). 11 refs., 20 figs., 2 tabs.

  6. POWER FACTOR CORRECTION IN PERMANENT MAGNET BRUSHLESS DC MOTOR DRIVE USING SINGLE-PHASE CUK CONVERTER

    Directory of Open Access Journals (Sweden)

    SANJEEV SINGH

    2010-12-01

    Full Text Available Permanent magnet brushless DC motor (PMBLDCM drives are being employed in many variable speed applications due to their high efficiency, silent operation, compact size, high reliability, ease of control, and low maintenance requirements. These drives have power quality problems and poor power factor at input AC mains as they are mostly fed through diode bridge rectifier based voltage source inverters. To overcome such problems a single-phase single-switch power factor correction AC-DC converter topology based on a Cuk converter is proposed to feed voltage source inverters based PMBLDCM. It focuses on the analysis, design and performance evaluation of the proposed PFC converter topology for a 1.5 kW, 1500 rpm, 400 V PMBLDCM drive used for an air-conditioning system. The proposed PFC converter topology is modelled and its performance is simulated in Matlab-Simulink environment and results show an improved power quality and good power factor in wide speed range of the drive.

  7. SPEED CONTROL OF BRUSHLESS DC MOTOR ON RESONANT POLE INVERTER USING FUZZY LOGIC CONTROLLER

    Directory of Open Access Journals (Sweden)

    S. Sivakotiah

    2011-10-01

    Full Text Available Brushless dc motor has been widely used in drive system and servo control because of its fast response ,high density ,high efficiency ,low inertia ,high reliability ,maintenance free. It is however driven by a hard switching frequency, high switching losses, high electromagnetic interference, high acoustic noise and low efficiency. The rectifier/inverter with a simple commutation circuit to provide zero voltage turn on for the switches and soft turn off for diodes. The converter is intended for high performance, medium power applications requiring bidirectional power flow .A new soft switching inverter has been developed to overcome over voltages and over current problems existing resonant link inverter .This inverter employs a single auxiliary switches. The introduces fuzzy logic based soft switching resonant pole inverter using transformer, which can generates dc link voltages notches during chopping which an minimized the drawback of soft switching, The operation principle and control scheme of the inverter are analyzed and performance of the fuzzy controller is compared with conventional PI controller .The simulation result show that the fuzzy controller is compared with the conventional PI controller.

  8. Optimal Control for Single-Phase Brushless DC Motor with Hall Sensor

    Directory of Open Access Journals (Sweden)

    Dawei Meng

    2013-02-01

    Full Text Available This study deals with the optimization control of a single-phase brushless DC motor (BLDCM with Hall sensor. A simple modeling method with feasible parameter identification is adopted to meet characteristics of single-phase BLDCM. With the linear Hall sensor feedback, the advantages of current-mode control scheme and soft-commutation scheme are proposed to achieve maximum efficiency over the entire speed range. This thesis also develops a low-cost and high efficiency control for single-phase BLDCM. The hardware test platform has been constructed on a single-chip Field Programmable Gate Array (FPGA of Cyclone II Family of Altera to verify the performance and feasibility of the proposed optimization control strategies. When using the control scheme with Hall sensor, experimental results show that there are at least a 10% improvement for average value of dc-link current, a 10% improvement for RMS value of phase current and a 40% improvement for peak value of phase current.

  9. Algorithm of brush short-circuit coefficients of DC machines for extremely low speed drives%极低速驱动用直流电机电刷短路系数的算法

    Institute of Scientific and Technical Information of China (English)

    张琪; 谢国栋; 黄苏融

    2008-01-01

    When a direct-current (DC) machine runs at extremely low speed or standstill, the reduction in the armature resistance and the armature flux linkage due to the short circuited coils by the brushes on the commutator should not be neglected. Taking this reduction effect into account, the average values of the reduction coefficients relate to the machine parameters in complicated forms. In this paper, an effective algorithm for the precise computation of the average values of these reduction coefficients is proposed. Furthermore, in the algorithm, the effect of the insulation thickness between the commutator segments and the multiplicity of the wave winding are considered for the first time. The proposed algorithm can also be accommodated into the computer-aided design (CAD) of a DC machine, which normally runs at extremely low speed or standstill.

  10. Rotor Pole Shape Optimization of Permanent Magnet Brushless DC Motors Using the Reduced Basis Technique

    Directory of Open Access Journals (Sweden)

    GHOLAMIAN, A. S.

    2009-06-01

    Full Text Available In this paper, a magnet shape optimization method for reduction of cogging torque and torque ripple in Permanent Magnet (PM brushless DC motors is presented by using the reduced basis technique coupled by finite element and design of experiments methods. The primary objective of the method is to reduce the enormous number of design variables required to define the magnet shape. The reduced basis technique is a weighted combination of several basis shapes. The aim of the method is to find the best combination using the weights for each shape as the design variables. A multi-level design process is developed to find suitable basis shapes or trial shapes at each level that can be used in the reduced basis technique. Each level is treated as a separated optimization problem until the required objective is achieved. The experimental design of Taguchi method is used to build the approximation model and to perform optimization. This method is demonstrated on the magnet shape optimization of a 6-poles/18-slots PM BLDC motor.

  11. PC based speed control of dc motor using fuzzy logic controller

    Energy Technology Data Exchange (ETDEWEB)

    Mandal, S.K.; Kanphade, R.D.; Lavekar, K.P.

    1998-07-01

    The dc motor is extensively used as constant speed drive in textile mills, paper mills, printing press, etc.. If the load and supply voltage are time varying, the speed will be changed. Since last few decades the conventional PID controllers are used to maintain the constant speed by controlling the duty ratio of Chopper. Generally, four quadrant chopper is used for regenerative braking and reverse motoring operation. Fuzzy Logic is newly introduced in control system. Fuzzy Control is based on Fuzzy Logic, a logical system which is too much closer in spirit to human thinking and natural language. The Fuzzy Logic Controller (FLC) provides a linguistic control strategy based on knowledge base of the system. Firstly, the machine is started very smoothly from zero to reference speed in the proposed scheme by increasing the duty ratio. Then change and rate of change of speed (dN, dN/dt), change and rate of change input voltage (dV, dV/dt) and load current are input to FLC. The new value of duty ratio is determined from the Fuzzy rule base and defuzzification method. The chopper will be 'ON' according to new duty ratio to maintain the constant speed. The dynamic and steady state performance of the proposed system is better than conventional control system. In this paper mathematical simulation and experimental implementation are carried out to investigate the drive performance.

  12. Electric motors for robotics; Moteurs electriques pour la robotique

    Energy Technology Data Exchange (ETDEWEB)

    Maye, P.

    2001-07-01

    Thanks to the recent progresses made in the domain of small motors and of their electronic control systems, the electrical actuators have become preponderant among the actuators used in robotics and automation. This book presents the knowledge necessary to deal with the domain of electric actuators. The three main types of motors encountered today are described with their characteristics: DC motors, brush-less DC motors and step-by-step motors. The mechanisms and their influence on the choice of a motor, the speed and position servo-controls and the overheating phenomena are detailed. An important part is devoted to the electronic circuits, responsible for a large part of the performances of actuators. Content: general considerations; principle and technology of DC motors; operation regimes; electronic power supplies; brush-less DC motors and their power supplies; step-by-step motors and their power supplies; servomechanisms; motors overheating; measurement of motors parameters; speed and position control; appendixes; dictionary, bibliography, index. (J.S.)

  13. Effect of short circuited DC link capacitor of an AC–DC–AC inverter on the performance of induction motor

    Directory of Open Access Journals (Sweden)

    Hadeed Ahmed Sher

    2016-07-01

    Full Text Available Induction motors are widely used in industrial power plants due to their robustness, reliability and high performance under variable operating conditions in the electrical power system. Modern industrial progress is dependent on these ruggedly constructed induction motors. Almost every sophisticated process of the industry is based on induction motors. Most of these motors are controlled by means of inverters that change the line frequency. The change in parameters of inverter makes it possible to control the motor according to the design requirements. The reliability of inverter based motor control is an important issue for industrial applications and therefore, it becomes very vital for design engineers to have comprehensive analysis of the inverter fed induction machine. This paper investigates one of the faults that may occur on the DC link of an inverter fed induction motor. The effect of the capacitor short circuit is presented in this paper. It also deals with the effects of short circuited capacitor on freewheeling diode. DC link capacitors are well designed and even the probability of capacitor failure is high, it is always a rare case if they puncture, however this analysis will add to the reliability of the induction machine under variable operating condition.

  14. Speed Control of Brushless Dc Motor Using Current Fed Quasi Z-source Inverter with Regeneration Capability

    Directory of Open Access Journals (Sweden)

    A. Santhi Mary Antony

    2015-06-01

    Full Text Available Current fed Quasi Z-Source Inverters (qZSI have the advantages of voltage buck-boost capability, improved reliability, reduced passive component ratings, continuous input current, a common dc rail between source and inverter and unique regeneration capability. This current-fed qZSIs are bidirectional with an additional diode, unlike the voltage-fed ZSI that needs a switch to achieve bidirectional power flow. Since current fed quasi Z Source Inverter has many advantages it can be employed for motor drive applications such as Brushless DC motor (BLDC drive. Therefore this study proposes the use of qZSI for BLDC motor. The simulation results for the same are presented in this study.

  15. SIMULATION ANALYSIS ON PROPORTIONAL INTEGRAL AND DERIVATIVE CONTROL OF CLOSED LOOP DC MOTOR DRIVE WITH BIPOLAR VOLTAGE SWITCHING

    Directory of Open Access Journals (Sweden)

    P. Karpagavalli

    2013-01-01

    Full Text Available This study presents the performance of a new four quadrant single phase DC drive closed loop system controlled by proportional integral and derivative controller with Pulse Width Modulation (PWM full bridge DC-DC converter using bipolar voltage switching. The proposed method is found to be more efficient in improving the step response characteristics such as reducing the settling time, rise time, steady state error and maximum overshoot in speed response of the closed loop DC motor drive and also reduced total harmonics distortion in the AC line current when compared to open loop system. The proposed topologies were simulated using MATLAB/Simulink software package and the results were obtained.

  16. Ureteral retrograde brush biopsy

    Science.gov (United States)

    Biopsy - brush - urinary tract; Retrograde ureteral brush biopsy cytology; Cytology - ureteral retrograde brush biopsy ... to be biopsied is rubbed with the brush. Biopsy forceps may be used instead to collect a ...

  17. Maximum torque per ampere control of sensorless induction motor drives with dc offset and parameter compensation

    International Nuclear Information System (INIS)

    Field orientation control of induction machine (IM) drives is a well-known strategy which has a fast dynamic response. In this paper, the direct rotor flux field orientation control of speed sensorless IM drive is presented. A two level space vector modulation inverter is employed to generate the command stator voltage. In proposed control scheme, a maximum torque per ampere strategy is achieved using a so-called fast flux search method. Based on this method, for a given load torque and rotor speed, the magnitude of rotor reference flux is adjusted step by step until the effective value of stator current becomes minimized finally. In addition, using the IM fifth order model in the stationary reference frame, a nonlinear rotor flux observer is developed which is also capable of motor resistances and rotor speed simultaneously estimation. Moreover, a useful method is introduced for dc offset compensation which is a major problem of ac drives especially at low speeds. The proposed control idea is experimentally implemented in real time using a CPLD board synchronized with a personal computer. Simulation and experimental results are finally presented to confirm the validity and effectiveness of the proposed method.

  18. On Stability of Open-Loop Operation without Rotor Information for Brushless DC Motors

    Directory of Open Access Journals (Sweden)

    Zhong Wu

    2014-01-01

    Full Text Available Open-loop operation mode is often used to control the Brushless DC Motors (BLDCMs without rotor position sensors when the back electromotive force (EMF is too weak due to the very low rotor velocity. The rotor position information is not necessary in this mode and the stator windings are supplied with voltages under a certain ratio of the amplitude to the frequency. However, the rotor synchronization will be destroyed once if the commutation instant is inappropriate. In order to improve the reliability of the open-loop operation mode, a dynamic equation is established to represent the synchronization error between the rotor and the stator. Thereafter, the stability of the open-loop control mode is analyzed by using Lyapunov indirect method. Theoretical analysis indicates that the open-loop control mode is asymptotically stable only when the commutation instant of the stator current lags behind the ideal one suitably. Finally, theoretical analysis is verified through the experimental results of a certain BLDCM.

  19. Feedback Control and Dynamic Behaviour of Z-Source Converter Fed Separately Excited DC Motor and Centrifugal Pump Set

    Directory of Open Access Journals (Sweden)

    Saswati Swapna Dash

    2014-07-01

    Full Text Available This paper presents an overall study of Feedback Control of Z-Source Converter Fed Separately excited DC motor with centrifugal Pump Set. Z-source converter can be used for both voltage buck and boost mode using LC impedance network. In this paper the dynamic modeling of Z-source with motor load and centrifugal pump set is carried out with new findings. The compensators for speed feedback loop are designed by taking average state space analysis and small signal model of the system. The feedback loop is designed by classical control methods. The experiment is done in MATLAB work environment and the result is verified by Simulation.

  20. Feedback Control and Dynamic Behaviour of Z-Source Converter Fed Separately Excited DC Motor and Centrifugal Pump Set

    OpenAIRE

    Saswati Swapna Dash; Byamakesh Nayak; Subrat Kumar

    2014-01-01

    This paper presents an overall study of Feedback Control of Z-Source Converter Fed Separately excited DC motor with centrifugal Pump Set. Z-source converter can be used for both voltage buck and boost mode using LC impedance network. In this paper the dynamic modeling of Z-source with motor load and centrifugal pump set is carried out with new findings. The compensators for speed feedback loop are designed by taking average state space analysis and small signal model of the system. The feedba...

  1. Analysis Of Innovative Applications of Single DC Motor in Series and Separately Excited Mode for Hybrid Electric Solar Car

    OpenAIRE

    Rahat Ullah Khan,; Mohd. Arif Khan,; Huma Arjumand

    2010-01-01

    In this paper an innovative technique is proposed to run a DC series motor and converting it into D C separately excited as and when required to do regenerative braking and controlling a loaded car. In this scheme we are proposing on alternate energy source for driving the car i.e. solar PV Cell based battery charging system. The implication, basic concept and limitations of this concept are discussed. Also the mode of operations including analysis and operating conditions is also discussed. ...

  2. Permanent magnet DC motor for welding machine%焊机用永磁直流电机

    Institute of Scientific and Technical Information of China (English)

    刘宝树

    2013-01-01

    永磁直流电动机以其体积小、效率高、结构简单、运行可靠、调节特性好(调节特性线性度好、调节范围宽且便于控制)等优点,广泛运用于焊接送丝领域.从永磁直流电动机的稳态运行特性、电机运行特性的温度敏感性、动态特性几个方面对电机的特性进行阐述,为送丝电机的造型提供参考.%Magnetic DC motor with its small size,high efficiency,simple structure,reliable operation,good regulation characteristics (regulation characteristics of good linearity, wide adjustable range and easy to control) and other advantages, is widely used in the field of welding wire feeding.From the permanent magnet DC motor steady state characteristic of motor operating characteristics,temperature sensitivity,dynamic characteristic of the motor characteristics are described.

  3. Diagnostics of DC and Induction Motors Based on the Analysis of Acoustic Signals

    Directory of Open Access Journals (Sweden)

    Glowacz A.

    2014-10-01

    Full Text Available In this paper, a non-invasive method of early fault diagnostics of electric motors was proposed. This method uses acoustic signals generated by electric motors. Essential features were extracted from acoustic signals of motors. A plan of study of acoustic signals of electric motors was proposed. Researches were carried out for faultless induction motor, induction motor with one faulty rotor bar, induction motor with two faulty rotor bars and flawless Direct Current, and Direct Current motor with shorted rotor coils. Researches were carried out for methods of signal processing: log area ratio coefficients, Multiple signal classification, Nearest Neighbor classifier and the Bayes classifier. A pattern creation process was carried out using 40 samples of sound. In the identification process 130 five-second test samples were used. The proposed approach will also reduce the costs of maintenance and the number of faulty motors in the industry.

  4. Simulation Research of Fault Model of Detecting Rotor Dynamic Eccentricity in Brushless DC Motor Based on Motor Current Signature Analysis

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The Brushless Direct Current (BLDC) motor is widely used in aerospace area, CNC machines and servo systems that require the high control accuracy Once the faults occur in the motor, it will cause great damage to the whole system. Mechanical faults are common in electric machines, and account for up to 50%-60% of the faults. Approximately, 80% of the mechanical faults lead to the eccentricity. So it is necessary to monitor the health condition of the motor to ensure the faults can be detected earlier and measures will be taken to imorove the reliability.

  5. An enhanced Z-source inverter topology-based permanent magnet brushless DC motor drive speed control

    Science.gov (United States)

    Geno Peter, P.; Rajaram, M.

    2015-08-01

    In this paper, an enhanced Z-source inverter (ZSI) is introduced for controlling the speed of permanent magnet brushless DC motor (PMBLDCM) drive. It is the extension of the conventional ZSI and the elements used in the circuit are the same as those of the conventional ZSI, except that the position of Inverter Bridge and diode would be exchanged from the classical circuit diagram. This exchanged circuit avoids the startup path of the inrush current and hence reduces the inrush current and improves the motor efficiency. Different modes of enhanced ZSI are studied with PMBLDCM. The voltage polarity of Z-source capacitors in the proposed circuit is the same as that of the input voltage polarity. Furthermore, to get the same voltage boost, the capacitor voltage stress is reduced to a significant extent. The speed control capability of the proposed brushless DC motor drive is compared with that of the conventional ZSI. The proposed ZSI is implemented in MATLAB/Simulink working platform and the output performance is evaluated. Also, the performance of voltage ratio is analysed both by simulation and mathematical models. All these analyses are known to express the innovative features of the proposed system.

  6. A 7-Level Single DC Source Cascaded H-Bridge Multilevel Inverter with a Modified DTC Scheme for Induction Motor-Based Electric Vehicle Propulsion

    OpenAIRE

    Farid Khoucha; Khoudir Marouani; Mohamed Benbouzid; Abdelaziz Kheloui; Abdeslam Mamoune

    2013-01-01

    International audience This paper presents a new hybrid cascaded H-bridge multilevel inverter motor drive DTC scheme for electric vehicles where each phase of the inverter can be implemented using a single DC source. Traditionally, each phase of the inverter requires n DC source for (2n + 1) output voltage levels. In this paper, a scheme is proposed that allows the use of a single DC source as the first DC source which would be available from batteries or fuel cells, with the remaining (n ...

  7. Analysis Of Innovative Applications of Single DC Motor in Series and Separately Excited Mode for Hybrid Electric Solar Car

    Directory of Open Access Journals (Sweden)

    Rahat Ullah Khan,

    2010-03-01

    Full Text Available In this paper an innovative technique is proposed to run a DC series motor and converting it into D C separately excited as and when required to do regenerative braking and controlling a loaded car. In this scheme we are proposing on alternate energy source for driving the car i.e. solar PV Cell based battery charging system. The implication, basic concept and limitations of this concept are discussed. Also the mode of operations including analysis and operating conditions is also discussed. The simulation results are provided to validate the concept.

  8. A DC motor rolling door controll er%直流电机卷帘门控制器

    Institute of Scientific and Technical Information of China (English)

    蔡小伟; 黄桂萍; 范宜标

    2016-01-01

    A STM8-based controller for DC motor rolling door is designed ,which is composed of relay control ,overcurrent detection ,battery charging ,radio reception ,power control and host control .The software of the controller is analyzed .%以STM8为主控的直流电机卷帘门控制器由继电器控制输出电路、过流检测电路、电池充电电路、无线接收电路、电源控制电路及主控电路组成,并对系统软件进行了分析。

  9. Diagnostics of separately excited DC motor based on analysis and recognition of signals using FFT and Bayes classifier

    Directory of Open Access Journals (Sweden)

    Glowacz Witold

    2015-03-01

    Full Text Available In this article results of diagnostic investigations of separately excited DC motor were presented. In diagnostics were applied a Fourier analysis method based on the fast Fourier transform (FFT and a recognition method using Bayes classifier. In training process a set of the most important frequencies has been determined for which differences of corresponding signals in two states are the largest. Three categories of signals have been recognized in identification process: faultless state, state of the rotor broken one coil and state of the rotor shorted three coils.

  10. A Five-Level Cascade Multilever Invertor Three-Phase Motor Drive Using a Single DC Source

    Energy Technology Data Exchange (ETDEWEB)

    Chiasson, J.N. (Univ. Tennessee-Knoxville)

    2006-09-15

    A method is presented showing that a 5-level cascade multilevel inverter for a three-phase permanent magnet synchronous motor drive can be implemented using only a single DC link to supply a standard 3-leg inverter along with three full H-bridges supplied by capacitors. It is shown that the capacitor voltages can be regulated while achieving an output voltage waveform that is 20% greater than that obtained using the standard 3-leg inverter alone. Finally conditions are given in terms of the power factor and modulation index that determine when the capacitor voltage can regulated.

  11. A Five-Level Cascade Multilevel Inverter Three-Phase Motor Drive Using a Single DC Source

    Energy Technology Data Exchange (ETDEWEB)

    Chiasson, J. N. [University of Tennessee, Knoxville (UTK)

    2006-10-01

    A method is presented showing that a 5-level cascade multilevel inverter for a three-phase permanent magnet sychronous motor drive can be implemented using only a single DC link to supply a standard 3-leg inverter along with three full H-bridges supplied by capacitors. It is shown that the capacitor voltages can be regulated while achieving an output voltage waveform that is 20% greater than that obained using the standard 3-leg inverter alone. Finally conditions are given in terms of the power factor and modulation index that determine when the capacitor voltage can regulated.

  12. Novel Sensorless Six-Step Communication Strategy for a Surface Permanent Magnet Synchronous Motor with DC Link Measurement

    DEFF Research Database (Denmark)

    Munteanu, A.; Agarlita, S. C.; Blaabjerg, Frede;

    2012-01-01

    The present paper introduces a novel six-step commutation strategy for sensorless control applied for a surface permanent magnet synchronous motor that implies only dc link measurement (battery current and battery voltage). The control strategy makes use of a modified I-f starting procedure...... and then switches seamlessly to sensorless speed control. Soft-switching for the six-step commutation pattern is considered. It will be shown that the current absorbed from the battery contains consistent information that can be used to determine the commutation points; the detection of the zero......-crossing of the back-emf are obtained from an observer that uses both current and battery voltage. The case study is represented by a surface permanent magnet synchronous motor prototype (6 /8 configuration), designed for the automotive air conditioning compressor drive....

  13. Analysis of armature reaction and winding inductances of permanent magnet brushless DC motor with deep slot concentrated coils

    Institute of Scientific and Technical Information of China (English)

    HUANG Ping-lin; HU Qian-sheng; YU Li; HUANG Yun-kai

    2006-01-01

    Based on the configuration of deep slot concentrated coils,an analytical model is developed for predicting the armature reaction field produced by the 3-phase stator windings of permanent magnet brushless DC motors with concentrated coils by using the image method and the analytical functions of the armature reaction and winding inductances are proposed accounting for the influence of statot slotting.This approach is different from the method of equivalent distributed current sheet and more suitable for electric machines,which have concentrated coils and deeper slots.Under different control mode,the different analytical functions are presented.This will be helpful when further analyzing the performance of the motor.The results agree with the experiment very well.

  14. Control of plasma layer in a fusion reactor correlated to DC motor control using PSO-ANFIS

    International Nuclear Information System (INIS)

    Plasma position and shape control is very crucial for the overall performance of the fusion reactor such as Tokamak. The quality of the discharge in the Saskatchewan TORus-Modified (STOR-M) tokamak is strongly related to the position of the plasma column within the discharge vessel. If the plasma column approaches too near the wall, then either minor or complete disruption occurs. Consequently it is necessary to be able to control dynamically the position of the plasma column throughout the entire discharge. Now a day's most fusion reactor employs the traditional PID controller for the confinement of plasma layer. Fuzzy logic is used for the control of Plasma layer. In this paper we have used the hybrid of PSO-ANFIS technique to control the speed of a DC motor. We have used two input parameters like speed, torque and output is firing angle. In our work first order Sugeno fuzzy model is taken with three rules and the parameters of Gaussian membership function is controlled by the PSO technique. PSO-ANFIS speed controller obtains better dynamic behavior and superior performance of the DC motor speed control. Similar approach can be correlated to the control of plasma layer. For the plasma control two inputs can be taken as plasma position ΔH and the plasma current and the single output, the control decision u(t). (author)

  15. Calculation Of The Brushless DC Motor Shaft Speed With Allowances For Incorrect Alignment Of Sensors

    Directory of Open Access Journals (Sweden)

    Kolano Krzysztof

    2015-09-01

    Full Text Available The paper treats of correcting calculation errors of the BLDC motor speed, based on the time elapsed between successive changes in the shaft position sensor signal. The developed method enables correction of errors of the deployment of sensors as well as rotating elements of the observation system of the motor shaft position. The correction algorithm performance was analysed with the aid of a model implemented in Matlab-Simulink environment. After confirming usefulness of the developed method through simulation, its usefulness was verified in real closed-loop feedback systems with a BLDC motor. The results of measurements carried out at the developed laboratory station are presented.

  16. Development of a Practical Low-Cost µC based Brushless DC Motor Controller using Proteus

    Directory of Open Access Journals (Sweden)

    Y. L. Karnavas

    2012-09-01

    Full Text Available Simulation, design and prototype construction of a low cost three phase permanent magnet (PM brushless DC (BLDC motor controller for low power applications is studied in this paper. The drive circuitry is based on the PIC16F877A microcontroller (µC, which –among others- performs pulse width modulation (PWM control for a 6-step, 120-degree trapezoidal PM BLDC motor drive. The specific processor is a widely used one and its characteristics are judged excellent in conjunction with its low cost. The prototype controller developed can perform rotation direction control, commutation sequence, speed control and reading Hall sensor signals. The controlling technique chosen is a “sensored type” one. The main reason for that, except control simplicity is the need for both low-speed and high-speed applications. The application of Proteus Virtual System Modelling (VSM software is also introduced in the paper. This software is used as a real-time simulation tool, in order to verify the performance of the BLDC motor drive, prior to its hardware implementation. Through virtual simulation of all the components used, the relevant results can be analyzed and monitored. Verification of the experimental results and validation of the simulated circuit has been done through the comparison of the results.

  17. Chaos control for the output-constrained system by using adaptive dynamic surface technology and application to the brushless DC motor

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Shaohua, E-mail: hua66com@163.com [The Jiangsu Key Laboratory of Advanced Manufacturing Technology, Huaiyin Institute of Technology, Huai’an 223003 (China); School of Automation, Chongqing University, Chongqing 400044 (China); Hou, Zhiwei; Chen, Zhong [The Jiangsu Key Laboratory of Advanced Manufacturing Technology, Huaiyin Institute of Technology, Huai’an 223003 (China)

    2015-12-15

    In this paper, chaos control is proposed for the output- constrained system with uncertain control gain and time delay and is applied to the brushless DC motor. Using the dynamic surface technology, the controller overcomes the repetitive differentiation of backstepping and boundedness hypothesis of pre-determined control gain by incorporating radial basis function neural network and adaptive technology. The tangent barrier Lyapunov function is employed for time-delay chaotic system to prevent constraint violation. It is proved that the proposed control approach can guarantee asymptotically stable in the sense of uniformly ultimate boundedness without constraint violation. Finally, the effectiveness of the proposed approach is demonstrated on the brushless DC motor example.

  18. Ring of Fire Accident Prevention and Handling of DC Motor%关于直流电机环火事故预防及处理

    Institute of Scientific and Technical Information of China (English)

    芶大斌

    2012-01-01

    某发电企业曾发生过发电机励磁机环火的事故,本文阐述了直流电机环火事故的预防和解决直流电机环火事故的措施.%A power generation companies have occurred in the generator exciter ring of fire accidents, This paper describes the measures of the ring of fire prevention of accidents of the DC motor and DC motor ring of fire accident.

  19. Chaos control for the output-constrained system by using adaptive dynamic surface technology and application to the brushless DC motor

    International Nuclear Information System (INIS)

    In this paper, chaos control is proposed for the output- constrained system with uncertain control gain and time delay and is applied to the brushless DC motor. Using the dynamic surface technology, the controller overcomes the repetitive differentiation of backstepping and boundedness hypothesis of pre-determined control gain by incorporating radial basis function neural network and adaptive technology. The tangent barrier Lyapunov function is employed for time-delay chaotic system to prevent constraint violation. It is proved that the proposed control approach can guarantee asymptotically stable in the sense of uniformly ultimate boundedness without constraint violation. Finally, the effectiveness of the proposed approach is demonstrated on the brushless DC motor example

  20. Mathematical field models of brushless DC motors with permanent magnets and their comparative analysis

    Directory of Open Access Journals (Sweden)

    A.V. Matyuschenko

    2015-03-01

    Full Text Available By means of JMAG-Designer 12 the author performed a comparative analysis of the calculation of the EMF, cogging torque and electromagnetic torque of brushless motor with permanent magnets in two-dimensional and three-dimensional formulation of the problem.

  1. Simulation to Implementation as Good Practices for Teaching Power Electronics to Undergraduate Students: Fuzzy Sliding Mode Control for DC Motors

    Directory of Open Access Journals (Sweden)

    Paul Cepeda

    2014-01-01

    Full Text Available How can students be given experience in the confused realities of engineering processes? How can undergraduate students be convinced that processes can be analyzed and improved? Computer simulations properly designed and applied could answer these challenges revolutionizing education in Power Electronics. In recent years, computer simulation has been commonly used in education to motivate students in their learning and help teachers to improve their teaching level. The present paper focuses on developing a speed controller for DC motors starting from theoretical aspects, passing through simulations, and finally reaching a control prototype. The control theory is based on a nonlinear technique known as Sliding Mode Control (SMC involving artificial intelligence for optimization such as Fuzzy Logic (FL, Adaptive Neurofuzzy Inference Systems (ANFIS, and Genetic Algorithms (GAs.

  2. Excited DC Motor Reverse Braking Exploration%他励直流电动机反接制动探析

    Institute of Scientific and Technical Information of China (English)

    王春; 赵宜静

    2013-01-01

    Separately excited DC motor braking teaching, students often have difficulty understanding potential energy load reverse connect brake and an armature of reverse braking of difference. The author from the armature circuit voltage balance equation, the mechanical characteristic curve of proceed analysis explain, make students more easily understand and master.%他励直流电动机的反接制动教学中,学生往往难以理解位能负载时的反接制动和电枢反接制动的区别.该文从电枢电路的电压平衡方程式、机械特性曲线着手进行分析讲解,使得学生较易理解和掌握.

  3. Low-cost sensorless control of four-switch, brushless DC motor drive with direct back-EMF detection

    Institute of Scientific and Technical Information of China (English)

    Abolfazl HALVAEI NIASAR; Abolfazl VAHEDI; Hassan MOGHBELLI

    2009-01-01

    We propose a position sensorless control scheme for a four-switch, three-phase brushless DC motor drive, based on the zero crossing point detection of phase back-EMF voltages using newly defined error functions (EFs). The commutation instants are 30° after detected zero crossing points of the EFs. Developed EFs have greater magnitude rather than phase or line voltages so that the sensorless control can work at a lower speed range. Moreover, EFs have smooth transitions around zero voltage level that reduces the commutation errors. EFs are derived from the filtered terminal voltages Vao and vbo of two low-pass filters, which are used to eliminate high frequency noises for calculation of the average terminal voltages. The feasibility of the proposed sensorless control is demonstrated by simulation and experimental results.

  4. 无轴承无刷直流电机的直接转矩控制%Direct torque control of bearingless brushless DC motor

    Institute of Scientific and Technical Information of China (English)

    许洁; 刘贤兴; 李兵伟

    2012-01-01

    无轴承无刷直流电机结合了无轴承电机和无刷直流电机的优点、具有良好的行特性和广泛的运用前景.研究了无轴承无刷直流电机的控制方法,并将直接转矩控制技术应用于无轴承无刷直流电机的转矩绕组.通过Matlab/Simulink仿真和实验结果表明,转矩绕组的直接转矩控制(DTC)能提高系统的响应速度,减少转矩脉动,提高系统的静动态性能且控制方法简单有效.%Bearingless brushless DC motor, combining advantages of brushless DC motor and bearingless motor, has favorable operating characteristics and wide range of applications. In this paper, the control method of bear ingless brushless DC motor is researched, and the bearingless brushless DC motor's torque winding is controlled by using the method of direct torque control ( DTC ). By Matlab/Simulink simulation and experiment of the con trol system, the results show that the application of DTC to torque winding control of bearingless brushless DC motor is correct and feasible. DTC improves the system's response speed, reduces torque ripple, and optimizes the control effect. The control method is relatively simple.

  5. Position and Speed Control of Brushless DC Motors Using Sensorless Techniques and Application Trends

    Directory of Open Access Journals (Sweden)

    Jaime Gómez-Gil

    2010-07-01

    Full Text Available This paper provides a technical review of position and speed sensorless methods for controlling Brushless Direct Current (BLDC motor drives, including the background analysis using sensors, limitations and advances. The performance and reliability of BLDC motor drivers have been improved because the conventional control and sensing techniques have been improved through sensorless technology. Then, in this paper sensorless advances are reviewed and recent developments in this area are introduced with their inherent advantages and drawbacks, including the analysis of practical implementation issues and applications. The study includes a deep overview of state-of-the-art back-EMF sensing methods, which includes Terminal Voltage Sensing, Third Harmonic Voltage Integration, Terminal Current Sensing, Back-EMF Integration and PWM strategies. Also, the most relevant techniques based on estimation and models are briefly analysed, such as Sliding-mode Observer, Extended Kalman Filter, Model Reference Adaptive System, Adaptive observers (Full-order and Pseudoreduced-order and Artificial Neural Networks.

  6. Brushing your infant's teeth

    Science.gov (United States)

    ... gov/ency/patientinstructions/000769.htm Brushing Your Child’s Teeth To use the sharing features on this page, ... how to brush their teeth on their own. Tooth and Gum Care for Young Children You should ...

  7. Friction between Polymer Brushes

    OpenAIRE

    Sokoloff, J. B.

    2006-01-01

    By solving the equilibrium equations for a polymer in a neutral polymer brush, the degree of interpenetration of two polymer brushes in contact and near contact is calculated. These results are used to calculate values of the force of static friction in agreement with recent friction measurements for polymer brush lubricated surfaces. It is shown that at sufficiently light loads polymer brush coated surfaces can slide, with the load supported entirely by osmotic pressure, at a sufficiently la...

  8. Sliding mode control of reaction flywheel-based brushless DC motor with buck converter

    Institute of Scientific and Technical Information of China (English)

    Liu Gang; Zhang Cong

    2013-01-01

    Reaction flywheel is a significant actuator for satellites' attitude control.To improve out-put torque and rotational speed accuracy for reaction flywheel,this paper reviews the modeling and control approaches of DC-DC converters and presents an application of the variable structure system theory with associated sliding regimes.Firstly,the topology of reaction flywheel is constructed.The small signal linearization process for a buck converter is illustrated.Then,based on the state averaging models and reaching qualification expressed by the Lee derivative,the general results of the sliding mode control (SMC) are analyzed.The analytical equivalent control laws for reaction flywheel are deduced detailedly by selecting various sliding surfaces at electromotion,energy consumption braking,reverse connection braking stages.Finally,numerical and experimental examples are presented for illustrative purposes.The results demonstrate that favorable agreement is established between the simulations and experiments.The proposed control strategy achieves preferable rotational speed regulation,strong rejection of modest disturbances,and high-precision output torque and rotational speed tracking abilities.

  9. Electromagnetic-Thermal Integrated Design Optimization for Hypersonic Vehicle Short-Time Duty PM Brushless DC Motor

    Directory of Open Access Journals (Sweden)

    Quanwu Li

    2016-01-01

    Full Text Available High reliability is required for the permanent magnet brushless DC motor (PM-BLDCM in an electrical pump of hypersonic vehicle. The PM-BLDCM is a short-time duty motor with high-power-density. Since thermal equilibrium is not reached for the PM-BLDCM, the temperature distribution is not uniform and there is a risk of local overheating. The winding is a main heat source and its insulation is thermally sensitive, so reducing the winding temperature rise is the key to the improvement of the reliability. In order to reduce the winding temperature rise, an electromagnetic-thermal integrated design optimization method is proposed. The method is based on electromagnetic analysis and thermal transient analysis. The requirements and constraints of electromagnetic and thermal design are considered in this method. The split ratio and the maximum flux density in stator lamination, which are highly relevant to the windings temperature rise, are optimized analytically. The analytical results are verified by finite element analysis (FEA and experiments. The maximum error between the analytical and the FEA results is 4%. The errors between the analytical and measured windings temperature rise are less than 8%. It can be proved that the method can obtain the optimal design accurately to reduce the winding temperature rise.

  10. Summary of Detecting Rotor Position Technique for Brushless DC Motor%无刷直流电机转子位置检测技术综述

    Institute of Scientific and Technical Information of China (English)

    吴红星; 叶宇骄; 倪天; 郭庆波

    2011-01-01

    无刷直流电机是一种先进的机电一体化装置,无刷直流电动机及控制技术由于其本身特点,使其成为驱动控制领域的研究焦点.该文根据无刷直流电机无位置传感器控制特点,分析了无刷直流电机工作原理,结合国内外基于无刷直流电机转子位置检查控制的相关文献,综述了无刷直流电机转子位置检测控制方法发展概况,并针对每种控制方法阐述了其优缺点.%The brushless DC Motor Drives is an advanced mechanical electronic devices. The technology of sensorless brushless DC motor control is becoming researching focus because of its special structure and low cost. The article presented analysis of characteristics and working principle of the brushless DC motor. It also discussed the development of detecting rotor position means for brushless DC motor based on the relevant literature home and abroad. At the same time it described the advantages and disadvantages of various methods according to each new detecting rotor position technique.

  11. Energy Conversion in Lifting Mass Vertically using a DC Electric Motor by Observing Required Time to Lift Object for a Certain Height

    CERN Document Server

    Viridi, Sparisoma; Permana, Sidik; Srigutomo, Wahyu; Susilawati, Anggie; Nuryadin, Bebeh Wahid; Nurhasan,

    2014-01-01

    In lifting mass vertically using a DC electric motor energy conversion from electric energy, through intermediate kinetic energy, to gravitation potential energy shows that time required {\\Delta}t to lift load mass m for height h is dependent quadratically to m. Several approaches to explain the experiment observation are discussed in this work, from ideal energy conversion to numerical solution from differential equation.

  12. Brushes and proteins

    NARCIS (Netherlands)

    Bosker, W.T.E.

    2011-01-01

      Brushes and Proteins   Wouter T. E. Bosker         Protein adsorption at solid surfaces can be prevented by applying a polymer brush at the surface. A polymer brush consists of polymer chains end-grafted to the surface at such a grafting density that th

  13. Study of Fuzzy Adaptive PID Control of Brushless DC Motor%无刷直流电机模糊自适应PID控制的研究

    Institute of Scientific and Technical Information of China (English)

    潘晓磊; 赵川; 吕海立

    2016-01-01

    为了提高无刷直流电机控制系统的动、静态性能,将模糊控制结合PID控制算法应用到无刷直流电机速度控制系统中。在分析了无刷直流电机速度控制系统的基础上,利用PSIM与MATLAB/Simulink共同建立了无刷直流电动机模糊自适应PID控制的仿真模型,充分发挥了PSIM和MATLAB/Simulink各自在仿真方面的优势,简化了建立仿真模型的过程。仿真结果表明,采用模糊PID集成控制算法能够使无刷直流电机速度控制系统具有更快的响应速度和更强的抗干扰能力,对无刷直流电机控制系统的设计具有一定的指导意义。%In order to improve the static and dynamic performance of brushless DC motor control system, fuzzy control combined with PID control algorithm is applied to the brushless DC motor speed control system, the integration of fuzzy PID control algorithm. On the analysis of the brushless dc motor speed control system, using the MATLAB/Simulink to establish brushless DC motor speed control system simulation model. Among them, the control system of brushless DC motor drive model and control algorithm were established in PSIM and MATLAB/Simulink environment, give full play to their advantages, the PSIM and MATLAB simplifies the process of establishing simulation model. The simulation results show that the integration of fuzzy PID control algorithm can make the brushless DC motor speed control system has better dynamic and static performance and strong anti-jamming capability, the design of brushless DC motor control system has a certain guiding significance.

  14. A 7-Level Single DC Source Cascaded H-Bridge Multilevel Inverter with a Modified DTC Scheme for Induction Motor-Based Electric Vehicle Propulsion

    Directory of Open Access Journals (Sweden)

    Farid Khoucha

    2013-01-01

    Full Text Available This paper presents a new hybrid cascaded H-bridge multilevel inverter motor drive DTC scheme for electric vehicles where each phase of the inverter can be implemented using a single DC source. Traditionally, each phase of the inverter requires DC source for output voltage levels. In this paper, a scheme is proposed that allows the use of a single DC source as the first DC source which would be available from batteries or fuel cells, with the remaining ( DC sources being capacitors. This scheme can simultaneously maintain the capacitors of DC voltage level and produce a nearly sinusoidal output voltage due to its high number of output levels. In this context, high performances and efficient torque and flux control are obtained, enabling a DTC solution for hybrid multilevel inverter powered induction motor drives intended for electric vehicle propulsion. Simulations and experiments show that the proposed multilevel inverter and control scheme are effective and very attractive for embedded systems such as automotive applications.

  15. Aspects Concerning the Torque Ripple Control of the Brushless DC Motor

    Directory of Open Access Journals (Sweden)

    BALUTA, G.

    2013-05-01

    Full Text Available This paper deals with two advanced numerical structures to control the electromagnetic torque ripple of Brushless Direct Current Motors (BLDCM, indirectly achieved by phase currents control and directly by the Direct Torque Control (DTC technique. In DTC there was implemented an observer to increase the rudimentary transducer resolution, containing three Hall Effect sensors. The experimental results describe the evolution of torque in both situations of control and are obtained by applying a control strategy for an electric drive system with BLDCM with trapezoidal Back-EMF in Two-Phase Mode.

  16. Combined Discrete Space Voltage Vector with Direct Torque Control for Bearingless Brushless DC Motor and Closed-Loop Suspended Force Control

    Directory of Open Access Journals (Sweden)

    Weiran Wang

    2013-06-01

    Full Text Available In order to improve the performance of bearingless brushless DC motor, a closed-loop suspended force controller combining the discrete space voltage vector modulation is applied and the direct torque control is presented in this paper. Firstly, we increase the number of the control vector to reduce the torque ripple. Then, the suspending equation is constructed which is spired by the direct torque control algorithm. As a result, the closed-loop suspended force controller is built. The simulated and experimental results evaluate the performance of the proposed method. The more advantage is that the proposed algorithm can achieve the fast torque response, reduce the torque ripple, and follow ideal stator flux track. Furthermore, the motor which implants the closed-loop suspended force controller cannot onlyobtain the dynamic response rapidly and displacement control accurately, but also has the characteristics of bearingless brushless DC motor (such as simple structure, high energy efficiency, small volume and low failure rate.

  17. Speed Control of a DC Motor for the Orientation of a Heliostat in a Solar Tower Power Plant using Artificial Intelligence Systems (FLC and NC

    Directory of Open Access Journals (Sweden)

    Abdelfettah Zeghoudi

    2015-06-01

    Full Text Available Recent research in the field of motor controls is becoming more interesting especially with the developments of new control methods. This study shows a comparative study between two artificial intelligence methods namely neural networks and fuzzy logic for the speed control of a DC motor for the orientation of a heliostat in a solar tower power plant. The speed controller of DC motor is performed using two Fuzzy Logic Configuration (FLC1 and FLC2 and neural controller in MATLAB environment. The simulation results are used to make sure the real possibility of using artificial intelligence systems to identify and control this type of installation. The performance of the Fuzzy Logic Controller and Neural control are compared using different errors metrics. The results show that Fuzzy logic method is more efficient compared with neural controller method.

  18. CSMP commutation model for design study of a brushless dc motor power conditioner for a cruise missile fin control actuator. Master's thesis

    Energy Technology Data Exchange (ETDEWEB)

    MacMillan, P.N.

    1985-06-01

    Recent improvements in rare earth magnets have made it possible to construct strong, lightweight, high-horsepower DC motors. This has occasioned a reassessment of electromechanical actuators as alternatives to comparable pneumatic and hydraulic systems for use as flight-control actuators for tactical missiles. A dynamic equivalent circuit model for the analysis of a small four pole brushless DC motor fed by a transistorized power conditioner utilizing high speed switching power transistors as final elements is presented. The influence of electronic commutation on instantaneous dynamic motor performance is particularly demonstrated and good correlation between computer simulation and typical experimentally obtained performance data is achieved. The model is implemented in CSMP language and features more accurate air gap flux representation over previous work. Hall-effect sensor rotor position feedback is simulated. Both constant and variable-air-gap flux is modeled and the variable flux model treats the flux as a fundamental and one harmonic.

  19. structure and performance analysis of DC brushless motor%直流无刷电动机的结构与性能分析

    Institute of Scientific and Technical Information of China (English)

    唐小元

    2013-01-01

      新世纪以来精密伺服装置向朝着高端不断发展,作为动力的直流无刷电动机作为高性能、高功率密度和长寿面的特种电机越来越引起了人们的重视。通过研究总结无刷电机结构与性能的各种联系与区别,有助于无刷电机的设计和使用。%In the new century, the precision power device has great development,the brushless DC motor as a special-ty motors of high performance and high power density and longevity have attracted people's attention. By studying relations and differences of the structure and properties of brushless motor .It is helpful for brushless motor design and use.

  20. 直流电机控制方法的Matlab仿真研究%Research on Matlab simulation for DC motor control method

    Institute of Scientific and Technical Information of China (English)

    徐莉

    2016-01-01

    The control method of brushless DC motor is studied deeply. According to the actual physical model of brushless DC motor,the corresponding mathematical model is established,in which the motor is controlled by double closed⁃loop scheme. On the basis of the real working characteristics of the motor,the conventional PID algorithm is replaced by the fuzzy adaptive PID algorithm to establish the speed control model,so the stability and anti⁃interference ability of the brushless DC motor speed control system can be improved. The simulation model of brushless DC motor was established by Matlab/Simulink toolbox. The re⁃search results show that the fuzzy adaptive PID algorithm can make the speed of the brushless DC motor stable,and the speed can recover to the setting speed quickly under load disturbance. The control system has perfect robustness.%针对无刷直流电机的控制方法进行了深入研究。根据无刷直流电机实际物理模型建立相应的数学模型,电机使用双闭环进行控制。根据电机的实际工作特点,使用模糊自适应PID算法替代常规PID算法建立速度控制模型,以提高无刷直流电机速度控制系统的稳定性和抗干扰能力。使用Matlab/Simulink工具箱建立无刷直流电机的仿真模型,研究结果表明,模糊自适应PID算法能够使无刷直流电机的速度更加平稳,在载荷扰动下快速恢复设定速度,使得控制系统具有更好的鲁棒性。

  1. Gate Driver Circuit of Power Electronic Switches with Reduced Number of Isolated DC/DC Converter for a Switched Reluctance Motor

    International Nuclear Information System (INIS)

    This paper presents a gate driver circuit for the switching devices used in the asymmetrical converter for a switched reluctance machine with reduced number of isolated dc/dc converters. Isolation required in the gate driver circuit of switching devices is indispensable. For the purpose of isolation different arrangements may be used such as pulse transformers. The dc/dc converter for isolation and powering the gate drive circuits is suitable, cheaper in cost and simple to implement. It is also significant that required number of isolation converters is much less than the switches used in converter. In addition, a simple logic circuit has been presented for producing the gate signals at correct phase sequence which is compared with the gated signals directly obtained from the encoder of an existing machine. (author)

  2. Chaos control for the output-constrained system by using adaptive dynamic surface technology and application to the brushless DC motor

    Directory of Open Access Journals (Sweden)

    Shaohua Luo

    2015-12-01

    Full Text Available In this paper, chaos control is proposed for the output- constrained system with uncertain control gain and time delay and is applied to the brushless DC motor. Using the dynamic surface technology, the controller overcomes the repetitive differentiation of backstepping and boundedness hypothesis of pre-determined control gain by incorporating radial basis function neural network and adaptive technology. The tangent barrier Lyapunov function is employed for time-delay chaotic system to prevent constraint violation. It is proved that the proposed control approach can guarantee asymptotically stable in the sense of uniformly ultimate boundedness without constraint violation. Finally, the effectiveness of the proposed approach is demonstrated on the brushless DC motor example.

  3. 无刷直流电机的智能控制研究%Research on the Intelligent Control of the Brushless DC Motor

    Institute of Scientific and Technical Information of China (English)

    文卫

    2011-01-01

    无刷直流电机具有交流电机结构简单,运行可靠,维护方便等优点,又具有直流电机那样良好的调速性能而无机械换向器等优势,得到广泛应用.针对大多数无刷直流电机位置伺服系统采用的是PID控制方式,此控制方式存在系统参数发生变化或带有非线性负载时,其稳态输出特性变差,难以获得满意的控制效果的情况,本文在分析无刷直流电机的模型后,提出一种能根据跟踪误差大小,利用模式切换开关自动切换到PID控制或滑模变结构控制的智能控制方法,从而实现无刷直流电机转子转速的快响应、低超调和高精度控制.%The brushless DC motor has some AC motor advantages in the simple structure, reliable operation and convenient maintenance, and also has the DC motor advantages that good performance of speed and no mechanical commutation, so it is widely used. For most of the brushless DC motor position servo system uses a PID control mode. With this control mode the steady - state output characteristics would become poor when system parameter changes or with nonlinear load, and it is difficult to obtain satisfactory control effect. After analyzed the model of brushless DC motor, this article presented an intelligent control method that can utilize mode switch automatically switch to PID control or sliding mode variable structure control according to the tracking error size, so as to realize the brushless DC motor rotor speed quick response, low overshoot and high precision control.

  4. Brushless DC Motor Self-Adaption Fuzzy PID Control System%无刷直流电机自适应模糊PID控制系统

    Institute of Scientific and Technical Information of China (English)

    王国玲; 李振宇; 范自道

    2013-01-01

      针对无刷直流电机传统PID控制存在精度低、抗干扰能力差及模糊控制稳态精度不高等问题,研究了一种自适应模糊PID控制方法。论文分析了直流无刷电机的工作原理,建立了直流无刷电机自适应模糊PID控制系统的计算机仿真数学模型,设计了系统速度环的模糊PID控制器,仿真结果表明,与传统PID控制相比,自适应模糊PID控制的BLDCM系统具有更高的稳定性和控制精度、更快的动态响应速度。%For the lower precision,bad anti-interference capability of traditional PID control and lower stable precision of fuzzy control for brushless DC motor,an adaptive fuzzy-PID control was deeply investigated in this paper. Working theory of brushless DC motor was analyzed,the simulated mathematical model of adaptive fuzzy-PID control for brushless DC motor was established,and the fuzzy-PID controller of speed regulator was designed. The results of simulation verified the better stability,the faster dynamic speed of adaptive fuzzy-PID control for brushless DC motor compared to traditional PID control.

  5. 无刷直流电机的模糊控制系统仿真%Simulation of Fuzzy Control for Brushless DC Motor

    Institute of Scientific and Technical Information of China (English)

    焦利利; 杨风

    2014-01-01

    This paper introduces the brushless DC motor of basic principle and mathematical model. Through the Simulink toolbox of the MATLAB model to build the fuzzy controller, the fuzzy control method of Brushless DC motor speed control., which achieves realization of Brushless DC motor fuzzy control system computer simulation. The results show that, the fuzzy controller has the advantages of simple structure, easy to implement, which can basically meet the system performance requirements.%本文介绍了无刷直流电机基本原理和数学模型。利用Matlab软件中Simulink工具箱搭建模糊控制器,采用模糊控制法对无刷直流电机进行调速。实现了无刷直流电机的模糊控制系统的计算机仿真。结果表明,该模糊控制器结构简单、易于实现,能够基本满足系统的性能要求。

  6. Four-quadrant speed control circuit of DC servo motor using integrated voltage control method; Den`atsu sekibunchi seigyo wo mochoiita chokuryu dendoki no shishogen sokudo seigyo

    Energy Technology Data Exchange (ETDEWEB)

    Okui, H. [Osaka polytechnic College, Osaka (Japan); Irie, H. [Osaka Electro-Communication Univ., Osaka (Japan)

    1996-08-20

    The Two-Quadrant chopper is constructed by using smoothing reactor in common of the step-down chopper and step-up chopper of the DC chopper. Furthermore, since the circuit connected in bridge type by using these two groups has both of positive and negative voltage from DC source and can supplies the current from positive and negative directions for load, it is called in general as the Four-Quadrant chopper. As the Four-Quadrant chopper may supply and regenerate power, it works as power amplifier with high efficiency. In this paper, the speed control circuit of DC servo motor using Four-Quadrant integrated voltage control circuit is described. The speed control circuit is composed of simple circuits of one adder integrator and four hysteresis comparators. The Four-Quadrant speed control circuit has a DC motor speed feedback loop and a voltage feedback loop which connects with AC, it plays the Four-Quadrant speed control without current inspection. The speed control characteristics with no steady state error over four quadrants may be obtained, changing of the quadrant is smooth and transition response is rapid. 9 refs., 11 figs.

  7. Study on Dual-redundancy Brushless DC Motor Control System%双余度无刷直流电机控制系统研究

    Institute of Scientific and Technical Information of China (English)

    李东

    2012-01-01

      在复杂工况条件下,由于维修不便,对无刷直流电机的可靠性要求较高。双余度无刷直流电机则能较好的解决此问题。本文设计了基于DSP的双余度无刷直流电动机驱动控制系统,详细介绍了系统DSP控制器的硬件电路设计,实现对电动机的位置、速度和电流的检测,给出了系统软件设计方案及控制策略,从而实现对整个系统的控制。结果表明,该控制系统,硬件电路结构简单,系统实时性好,响应快,具有良好的控制性能及动态特性。%  Under harsh operating condition, maintenance inconvenience, so the high reliability of brushless DC motor is required. Dual-redundancy brushless DC motor is a good solution to this problem. A control system of dual-redundancy brushless DC motor (BLDCM) based on digital signal processor is studied in this paper. The hardware design solutions of the DSP control er is detailed, then the position, speed and the current of the motor are detected, the software design solutions and the control method for the whole control system are presented. Experimental results show that the dual-redundancy motor system based on one piece of DSP has simple circuit, real-time and rapid response, and the system has good control performance and dynamic characteristic.

  8. Optimizing of Commutation Torque Ripple Strategy in Brushless DC Motor%BLDCM换相转矩脉动的优化策略

    Institute of Scientific and Technical Information of China (English)

    王晓锋; 林伟

    2014-01-01

    First of all, this article creates the mathematical model of blushless DC Motor.Secondly, analyze the reduction theory of commutation torque ripple. Finally, put forward a strategy to reduce the commutation torque ripple from the low-speed level and high-speed level.This method guarantee equal between current decline rate of shutdown phase and current rising rate of opening phase during commutation, thus keep the current of un-commutation stable.Build a real brushless DC motor control platform for experimental verification,the proposed strategy of brushless DC motor commutation torque ripple is suppressed effectively.%首先建立了无刷直流电机(Brushless direct current motor, BLDCM)的数学模型,然后分析了换相转矩脉动的抑制原理,最后提出了低速阶段和高速阶段抑制换相转矩脉动的策略。此方法保证在换相期间,关断相的电流下降率和开通相的电流上升率绝对值相等,继而保证在换相期间非换相相电流保持恒定。搭建了实际直流无刷电机控制平台并进行实验验证,所提出的策略有效地抑制了直流无刷电机换相转矩脉动。

  9. Speed Control Of Separately Excited Dc Motor Using A High Efficiency Flyback Converter With New Active Clamp Technique M.Subramanyam*, K.Eswaramma

    Directory of Open Access Journals (Sweden)

    M.Subramanyam

    2014-10-01

    Full Text Available This paper deals with Speed control of separately excited DC motor using flyback converter with a new non complementary active clamp control method to achieve soft switching and high efficiency for heavy motor load and light load conditions. This is quite attractive for low power application with universal ac inputs, such as external adaptors. With the proposed control technique, the energy in the leakage inductance can be fully recycled. The soft switching can be achieved for the main switch and the absorbed leakage energy is transferred to the output and input side. In the Proposed model the resistive and DC motor is connected to flyback converter and it is simulated with different nominal voltages and rated speed is controlled at different levels for the N-type active clamp flyback converter and P-type active clamp flyback converter respectively. N-type active clamp flyback converter is suitable for high speed variation applications and P-type active clamp flyback converter is suitable for low speed variation applications.

  10. Study of Angular Displacement Servo Control System Based on DC Motor%直流电机的角位移伺服控制系统研究

    Institute of Scientific and Technical Information of China (English)

    刘海成; 贺亮; 卞玉坤; 姚广俊

    2013-01-01

    DC motor angular displacement servo control system which takes STM32 microcontroller as the control core is introduced by the paper. The system takes photoelectric encoder as angular displacement sensor, has a motor drive circuit based on PWM and H-bridge, and through digital PID control strategy achieves the angular displacement control based on DC motor. The actual test shows that the system has the features of control precision, good stability and simple structure.%本文介绍一种以STM32微控制器作为控制核心的直流电机角位移伺服控制系统.系统以光电编码器为角位移传感器,还具有基于PWM和H桥的电机驱动电路,并通过数字PID控制策略,实现基于直流电机的角位移控制.实际测试表明,系统具有控制精确、稳定性好和结构简单等特点.

  11. 电动自行车用无刷直流电机控制系统设计%Brushless DC Motor of Electric Bicycle Control System Design

    Institute of Scientific and Technical Information of China (English)

    钟晓伟; 宋蛰存; 许刚

    2011-01-01

    根据以无刷直流电机为驱动电机的电动自行车工作原理,设计了一种以ATmega16单片机为控制核心的电动自行车用无刷直流电机控制系统,给出了系统详细的硬件电路和软件设计方法.在MATLAB/Simulink环境下仿真得出适当的速度环与电流环调节器参数值.与传统的专用模拟控制器相比,具有更大的灵活性、可靠性,容易实现附加功能和全数字化控制.%According to brushless DC motor-driven electric motor bike working principle, a brushless DC motor of electric bicycle control system based on ATmega16 microcontroller was designed, a detail of hardware circuit and software design methods were given. In MATLAB/Simulink simulation environment to draw the appropriate speed loop and current loop regulator parameters. Compared to the traditional specific analog controller, it had greater flexibility,reliability, also was easy to implement additional features and fully digital control.

  12. EMI performance comparison of two-level and three-level inverters in small dc-link capacitors based motor drives

    DEFF Research Database (Denmark)

    Maheshwari, Ram Krishan; Munk-Nielsen, Stig; Busquets-Monge, S.

    2012-01-01

    The size of passive components in an adjustable speed drive can be reduced by using small dc-link capacitors. The EMI filter in the drive also consists of passive components. The size of the filter can be reduced by using a three-level inverter, which can have low output voltage distortion. Howev....... Results show that the conducted emission from the three-level inverter is lower than that of the two-level inverter. Thus, a three-level inverter requires a smaller EMI filter in motor drives with small dc-link capacitors.......The size of passive components in an adjustable speed drive can be reduced by using small dc-link capacitors. The EMI filter in the drive also consists of passive components. The size of the filter can be reduced by using a three-level inverter, which can have low output voltage distortion. However......, the shaft voltage, and the conducted emission for the small dc-link capacitor based three-level inverter are compared with that of the two-level inverter operated with space vector PWM strategy. Experimental results for the common mode voltage, the shaft voltage, and the conducted emission are presented...

  13. Control algorithm for the inverter fed induction motor drive with DC current feedback loop based on principles of the vector control

    Energy Technology Data Exchange (ETDEWEB)

    Vuckovic, V.; Vukosavic, S. (Electrical Engineering Inst. Nikola Tesla, Viktora Igoa 3, Belgrade, 11000 (Yugoslavia))

    1992-01-01

    This paper brings out a control algorithm for VSI fed induction motor drives based on the converter DC link current feedback. It is shown that the speed and flux can be controlled over the wide speed and load range quite satisfactorily for simpler drives. The base commands of both the inverter voltage and frequency are proportional to the reference speed, but each of them is further modified by the signals derived from the DC current sensor. The algorithm is based on the equations well known from the vector control theory, and is aimed to obtain the constant rotor flux and proportionality between the electrical torque, the slip frequency and the active component of the stator current. In this way, the problems of slip compensation, Ri compensation and correction of U/f characteristics are solved in the same time. Analytical considerations and computer simulations of the proposed control structure are in close agreement with the experimental results measured on a prototype drive.

  14. Cross-Correlation of Motor Activity Signals from dc-Magnetoencephalography, Near-Infrared Spectroscopy, and Electromyography

    Directory of Open Access Journals (Sweden)

    Tilmann H. Sander

    2010-01-01

    Full Text Available Neuronal and vascular responses due to finger movements were synchronously measured using dc-magnetoencephalography (dcMEG and time-resolved near-infrared spectroscopy (trNIRS. The finger movements were monitored with electromyography (EMG. Cortical responses related to the finger movement sequence were extracted by independent component analysis from both the dcMEG and the trNIRS data. The temporal relations between EMG rate, dcMEG, and trNIRS responses were assessed pairwise using the cross-correlation function (CCF, which does not require epoch averaging. A positive lag on a scale of seconds was found for the maximum of the CCF between dcMEG and trNIRS. A zero lag is observed for the CCF between dcMEG and EMG. Additionally this CCF exhibits oscillations at the frequency of individual finger movements. These findings show that the dcMEG with a bandwidth up to 8 Hz records both slow and faster neuronal responses, whereas the vascular response is confirmed to change on a scale of seconds.

  15. Adjustment of Phase Change Opportunity in Brushless DC Motor%直流无刷电机换相时机的调整

    Institute of Scientific and Technical Information of China (English)

    刘佳峰; 谢杨华

    2006-01-01

    直流无刷电机BLDCM(Brushless DC Motor)采用电子换相代替机械换相,兼有交流电机和直流电机的优点.提出了在磁场畸变的情况下,应将直流无刷电机换相时机从几何中性线处调整到物理中型线处.仿真结果表明:此调整方案可使电机的电磁转矩提高约10%.

  16. 无位置传感器无刷直流电机的DSP控制%DSP Control of Brushless DC Motor Without Position Sensor

    Institute of Scientific and Technical Information of China (English)

    王宏伟; 梁晖

    2005-01-01

    设计了一种无位置传感器无刷直流电机(Brushless DC Motor,简称BLDCM)的变频调速系统.该系统基于PS21255智能功率模块(IPM)和TMS320LF2407A数字信号处理器(DSP),采用反电势法实现了WPS的BLDCM控制.整个系统集成度高,控制灵活,稳定性好.实验结果表明,该系统运行性能良好.

  17. DC Bus Control of Back-to-Back Connected Two-Level PWM Rectifier-Five-Level NPC Voltage Source Inverter to Torque Ripple Reduction in Induction Motor

    Directory of Open Access Journals (Sweden)

    Abdelkrim Thameur

    2015-01-01

    Full Text Available This paper proposes a regulation method of back-to-back connected two-level PWM rectifier-five-level Voltage Source Inverter (VSI in order to reduce the torque ripple in induction motor. First part is dedicated to the presentation of the feedback control of two-level PWM rectifier. In the second part, five-level Neutral Point Clamped (NPC voltage source inverter balancing DC bus algorithm is presented. A theoretical analysis with a complete simulation of the system is presented to prove the excellent performance of the proposed technique.

  18. Unbalanced Magnetic Pull Effect on Stiffness Models of Active Magnetic Bearing due to Rotor Eccentricity in Brushless DC Motor Using Finite Element Method

    Directory of Open Access Journals (Sweden)

    Bangcheng Han

    2013-01-01

    Full Text Available We firstly report on an investigation into the unbalanced magnetic pull (UMP effect on the static stiffness models of radial active magnetic bearing (RAMB in brushless DC motor (BDCM in no-loaded and loaded conditions using the finite element method (FEM. The influences of the UMP on the force-control current, force-position, current stiffness, and position stiffness of RAMB are clarified in BDCM with 100 kW rated power. We found the position stiffness to be more susceptible to UMP. The primary source of UMP is the permanent magnets of BDCM. In addition, the performance of RAMB is affected by the UMP ripples during motor commutation and also periodically affected by the angular position of rotor. The characteristic curves of RAMB force versus control current (or rotor position and angular position of rotor affected by the UMP are given. The method is useful in design and optimization of RAMB in magnetically suspended BDCMs.

  19. 永磁式直流力矩电动机稳速系统设计%Design of Speed Control System of Permanent Magnet DC Torque Motor

    Institute of Scientific and Technical Information of China (English)

    张晓青; 栗书贤

    2001-01-01

    In this paper,a new speed control system of permanent magnet DC torque motor is introduced.An IC chip TL494 is utilized to produce PWM pulses in order to control an IGBT device.Thus,the voltage supply of motor can be adjusted by the chopping circuit.Experimental results of the whole system are also provided.%介绍了一种新型的永磁式直流力矩电动机稳速控制系统,采用集成电路芯片TL494输出PWM脉冲来控制IGBT器件,从而实现了对电动机的斩波调压供电,性能稳定可靠。还提供了系统联调的试验结果。

  20. SIMULINK Modelling and Simulation for Permanent Magnet DC Motor%永磁直流电动机的Simulink建模仿真教学

    Institute of Scientific and Technical Information of China (English)

    曾进辉; 邓建国

    2015-01-01

    "Electrical machinery and system's computer simulation"is a professional electrical engineering and automation of an important subject, according to the basic structure of the motor establishment of mathematical model and simulation model is a basic skills training. In this paper, the selection of the most simple motor - permanent magnet DC motor for the study, according to his equivalent circuit establishment of the transient mathematical model,using dynamic library module simulation tool Simulink functional modules in MATLAB software,to build the simulation model. Permanent magnet DC motor is given five basic simulation model. Through the example simulation computation, has confirmed the modelling method accuracy and the validity.%"电机及其系统的计算机仿真"是电气工程及其自动化专业的一门重要课程,根据电机的基本结构建立数学模型并构建仿真模型是一种基本功训练. 本文选择最简单的电机-永磁直流电动机作为研究对象,根据他的等效电路建立瞬态数学模型,利用MATLAB软件中的动态仿真工具Simulink模块库中的功能模块,构建其仿真模型.给出了永磁直流电动机最基本的五种仿真模型.通过实例仿真计算,验证了建模方法的正确性和有效性.

  1. Brushless DC motor drives supplied by PV power system based on Z-source inverter and FL-IC MPPT controller

    Energy Technology Data Exchange (ETDEWEB)

    Mozaffari Niapour, S.A.KH., E-mail: s.a.kh.mozaffari.niapour@gmail.com [Faculty of Electrical and Computer Engineering, University of Tabriz, 51664 Tabriz (Iran, Islamic Republic of); Danyali, S.; Sharifian, M.B.B.; Feyzi, M.R. [Faculty of Electrical and Computer Engineering, University of Tabriz, 51664 Tabriz (Iran, Islamic Republic of)

    2011-08-15

    Highlights: {yields} Employing the BLDC motor in water pumping systems. {yields} Utilizing the ZSI as a single-stage power converter in the PV water pumping systems based on BLDC motor. {yields} Improvement of the conventional IC MPPT method with the fuzzy logic control scheme to save more energy from the PV array. {yields} Taking the advantages of the DTC drive of the BLDC motor. {yields} Optimizing the water pumping system speed response characteristic by PSO. - Abstract: This paper discusses operation performance of a water pumping system consist of a brushless dc (BLDC) motor coupled a centrifugal pump and accompanying a Z-source inverter (ZSI) fed by a photovoltaic (PV) array, to be improved. Despite conventional double-stage power converters, this paper proposes utilizing a single-stage ZSI to extract the maximum power of the PV array and supply the BLDC motor simultaneously. Utilizing the ZSI provides some inherent advantages such as high efficiency and low cost, which is very promising for PV systems due to its novel voltage buck/boost capability. In addition, in order to precisely perform the maximum power point tracking (MPPT) of the PV array the fuzzy logic-incremental conductance (FL-IC) MPPT scheme is proposed. The proposed FL-IC MPPT scheme provides enough modification to the conventional IC method to enjoy an appropriate variable step size MPPT control signal for the ZSI. Moreover, direct torque control (DTC) is found more effective in comparison with hysteresis current control with current shaping to drive the BLDC motor, because it benefits from faster torque response, reduced torque ripple, less sensitivity to parameters variations, and simple implementation. In the mean time, due to the frequently variations of the PV power generation; delivered mechanical power to the centrifugal pump is variable. Thus, the BLDC motor should be driven with variable reference speed. In order to improve the speed transient response of the BLDC motor and enhance

  2. Design of a PWM Speed - governing System for DC Motor Based on PLC%基于PLC的直流电机PWM调速系统设计

    Institute of Scientific and Technical Information of China (English)

    何新霞; 邢瑞军

    2011-01-01

    设计了基于SIMATIC S7-200 PLC直流电机PWM调速系统.主电路采用双极式可逆PWM变换器,选用集成驱动器M57962L,通过设计其驱动外围电路,实现了对IGBT的导通和关断控制.采用硬件延时电路,防止上、下桥臂直通事故的发生.利用PLC的高速计数功能实现了对电机转速的测量,设计开发了基于PLC的PI控制程序及PWM信号产生程序.从而实现了直流电机的PWM调速,并实现了转速的无静差调节.%The paper presents the design of PWM speed - governing system for DC motor based on S7 - 200 - PLC. The double - polar reversible PWM converter is used and integrated drive electronics M57962 is selected in main circuit. The conduction and switch control of IGBT is realized by designing the peripheral driving circuitry. The delayed circuit is adopted to prevent the shoot -through phenomenon between upper and lower bridge arm in a PWM. Programs for PLC PI control and for PWM signal generation are developed to implement PWM speed- governing for DC motor and floating control on speed.

  3. The Study of Permanent Magnet Brushless DC Motor%对永磁无刷直流电机的研究

    Institute of Scientific and Technical Information of China (English)

    杨杰城

    2016-01-01

    随着我国科技不断发展,永磁无刷直流电机已成为电力电子一体化高科技产品,凭借其结构简单、运行可靠、效率高,在航天、医学、家用民用产品制作中得到广泛应用。文章对永磁无刷直流电机设计、控制以及建模方法进行分析,展现其对生产起到的重要作用。%With the continuous development of science and technology in our country,permanent magnet brushless dc motor has become power and electricity integration high-tech products.With its simple structure,reliable operation,high efficiency,it has been widely used in the aerospace,medical,household production.In this paper,the design,control,and modeling methods of permanent magnet brushless dc motor are analyzed.

  4. An IFOC-DSVPWM Based DC-Link Voltage Compensation of Z-Source Inverter Fed Induction Motor Drive for EVs

    Directory of Open Access Journals (Sweden)

    Ananda Kumar Akkarapaka

    2015-01-01

    Full Text Available The drop in DC-link voltage of adjustable speed drives (ASD occurs mainly due to the increase in output power demands. This may lead to inefficient operation and eventually the tripping of the drive. This paper presents a Double Space Vector Pulse Width Modulation (DSVPWM technique for boosting and compensating the DC-link voltage of Z-source inverter (ZSI. The DSVPWM technique estimates the required shoot through period of the Z-source inverter to maintain the DC-link voltage constant at the desired level through capacitor voltage control. The DSVPWM can obtain maximum boost at any given modulation index in comparison to simple boost control (SBC method. It also utilizes the dead time more effectively. The speed control of the ZSI fed induction motor drive is done by employing indirect field-oriented (IFO control method. A 32-bit DSP (TMS320F28335 is used to implement the IFOC-DSVPWM method for ZSI. The power structure and the modulation technique are well suited for electric vehicle application.

  5. High Temperature All Silicon-Carbide (SiC) DC Motor Drives for Venus Exploration Vehicles Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This Small Business Innovation Research Phase I project seeks to prove the feasibility of creating high-temperature silicon-carbide (SiC) based motor drives for...

  6. A Study of Direct Identification Method of Brushless DC Motor Parameters%无刷直流电动机参数直接辨识法研究

    Institute of Scientific and Technical Information of China (English)

    袁国珍; 齐蓉; 白文伟

    2013-01-01

    Against the brushless DC motor already in mass production, a new and practical parameter identification method called direct identification method was proposed. Based on the basic characteristics of the motor's equivalent circuit , the motor's parameter identification strategy was studied, which provided control parameters for precise control of motor. In order to verify the effectiveness of this method, a parameter identification simulation of a finished motor was used. The result indicates that this identification method is simple to implement, has a low computation, has recognition accuracy that can meet the engineering requirements, and is easier to be implemented than traditional identification methods.%针对已经量产、产品化的无刷直流电动机,研究了一种新的实用的无刷直流电动机参数辨识方法——直接辨识法.基于电机等效电路的基本特性,研究电机参数辨识策略,为精确控制电机提供控制参数.为验证该辨识方法的有效性,对一个成品电机进行参数辨识仿真,结果表明该辨识方法的优点是实现简单、运算量小、辨识精度可以满足工程要求,并且较传统辨识方法更易实现.

  7. The DC Motor Control System Based on Wireless Remote Control Technology%无线电遥控式直流电机控制系统

    Institute of Scientific and Technical Information of China (English)

    余翔翔; 陈德传; 郑忠杰

    2013-01-01

    The motor actuating unit based on wireless remote control has a vast application prospect .There-fore, this paper proposes a wireless remote DC motor control system .Take the embedded microprocessor STM32F103 and the RF transceiver CC1101 as the core for the motor control system , and use the combination of the MOSFET and the relay for the motor control circuit;take the ultra-low-power MSP430 series micropro-cessor and the CC 1101 as the core for the wireless remote control of the motor system .This system has the characteristics of simple structure , perfect control and protection functions , and high universality .%无线电遥控式电机执行装置具有广阔的应用前景。该文提出一种无线电遥控式的直流电机控制系统,电机控制系统以嵌入式微处理器STM32F103与射频收发器CC1101为控制核心,并采用基于脉宽调制的MOSFET与继电器相结合的电机调速与正、反转控制电路;而无线遥控器以超低功耗的MSP430系列单片机与CC1101为核心,以实现对电机系统的无线遥控。该系统结构简单、控制与保护功能完善,通用性好。

  8. Research Status and Development Trends of Bearingless Brushless DC Motor%无轴承无刷直流电机研究现状及发展趋势

    Institute of Scientific and Technical Information of China (English)

    刘奕辰; 朱熀秋

    2014-01-01

    A bearingless brushless DC motor is a new type of high performance motor , which integrates the function of magnetic bearings into a brushless DC motor .It has the characteristic of no friction , no wear , high speed , long service life of the magnetic bearings , and also has the advantages of high efficiency , small volume, simple structure of the brushless DC motor , and it has a potential vast development and application prospects .In this paper , the motor structure of the bearingless brushless DC and the principle of suspension force generation were introduced .A comprehensive overview of the bearingless brushless DC motors was presented , with particular emphasis on the motor structure and the control strategy analysis .On the basis of the superiority and the existence problems of the bearingless brushless DC , the research development trend of the bearingless brushless DC motor was analyzed in this paper .The results provided the reference for the fur-ther study on the bearingless brushless DC motor.%无轴承无刷直流电机是一种高性能的新型电机,它将无刷直流电机和磁悬浮轴承功能集成一体,使其不仅具备磁轴承无摩擦、无磨损、高速度、寿命长等特点,还具有无刷直流电机的效率高、体积小、结构简单的优势,潜在发展和应用前景非常广阔。本文介绍无轴承无刷直流电机的结构特点、悬浮力产生的原理,从电机结构、控制策略方面分析了无轴承无刷直流电机的国内外发展现状,并根据无轴承无刷直流电机的优势及存在的问题,分析了未来无轴承无刷直流电机的研究发展趋势,为今后进一步开展无轴承无刷直流电机的研究提供参考。

  9. 三相直流电机伺服系统设计%Design of Three-phase DC Motor Servo System

    Institute of Scientific and Technical Information of China (English)

    陈志佳; 孙书鹰; 张炜栋

    2012-01-01

    In order to implement highly precise and real-time tracking for the objects, the DC motor servo system has been designed. The system is composed of the embedded microprocessor STM32F1O3 as the kernel, and the 3-phase DC hrushless motor equipped with Hall commutating sensor as servo motor. In addition, the fuzzy control scheme that is combination of incremental integral separation PID control and fuzzy control is adopted. The experimental test through emulated air-tracking shows that the system is able to reach higher dynamic tracking accuracy and faster response speed, and features stable and smooth performance. It does implement highly precise real-time tracking, and the design meets expected goal.%为实现对高精度实时目标的跟踪,设计了直流电机伺服系统.该伺服系统以STM32F103嵌入式微处理器为控制核心,以带有霍尔换向传感器的三相直流无刷电机作为伺服电机,并采用增量型积分分离式PID控制与模糊控制相结合的模糊PID控制策略.模拟对空跟踪试验测试表明,该系统具有较高的动态跟踪精度和较快的响应速度,平稳性好,实现了高精度实时跟踪,达到了设计的预期目的.

  10. Friction between Ring Polymer Brushes

    OpenAIRE

    2015-01-01

    Friction between ring-polymer brushes at melt densities sliding past each other are studied using extensive course-grained molecular dynamics simulations and scaling arguments, and the results are compared to the friction between linear-polymer brushes. We show that for a velocity range spanning over three decades, the frictional forces measured for ring-polymer brushes are half the corresponding friction in case of linear brushes. In the linear-force regime, the weak inter-digitation of two ...

  11. Preparation of carbon brushes with thermosetting resin binder

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Carbon brushes with a resin binder were prepared according to an industrial process and the effects of the molding pressure, grains size and cure temperature on the properties of brush samples were discussed. The results show that the bulk density,bending strength and Rockwell hardness increase, while resistivity decreases with increasing molding pressure. Cure temperature has much more influence on the properties of brushes than molding pressure and grains size. Isothermal differential scanning calorimetry(DSC) was used to estimate the degree of cure of resin binder and a novel method of using the true density to measure the degree of cure of resin binder was presented and discussed briefly. Based on optimal process parameters carbon brushes were manufactured, durability tests for brushes were carried out on an alternate current motor and scanning electron microscope(SEM)was adopted to observe the morphology of worn surface of brushes. The results show that a luster oxide film can be formed on the surface of brushes and their service life reaches 380 h.

  12. Handbook on linear motor application

    International Nuclear Information System (INIS)

    This book guides the application for Linear motor. It lists classification and speciality of Linear Motor, terms of linear-induction motor, principle of the Motor, types on one-side linear-induction motor, bilateral linear-induction motor, linear-DC Motor on basic of the motor, linear-DC Motor for moving-coil type, linear-DC motor for permanent-magnet moving type, linear-DC motor for electricity non-utility type, linear-pulse motor for variable motor, linear-pulse motor for permanent magneto type, linear-vibration actuator, linear-vibration actuator for moving-coil type, linear synchronous motor, linear electromagnetic motor, linear electromagnetic solenoid, technical organization and magnetic levitation and linear motor and sensor.

  13. Smart photonic carbon brush

    Science.gov (United States)

    Morozov, Oleg G.; Kuznetsov, Artem A.; Morozov, Gennady A.; Nureev, Ilnur I.; Sakhabutdinov, Airat Z.; Faskhutdinov, Lenar M.; Artemev, Vadim I.

    2016-03-01

    Aspects of the paper relate to a wear monitoring system for smart photonic carbon brush. There are many applications in which regular inspection is not feasible because of a number of factors including, for example, time, labor, cost and disruptions due to down time. Thus, there is a need for a system that can monitor the wear of a component while the component is in operation or without having to remove the component from its operational position. We propose a new smart photonic method for characterization of carbon brush wear. It is based on the usage of advantages of the multiplicative response of FBG and LPFG sensors and its double-frequency probing. Additional measuring parameters are the wear rate, the brush temperature, the engine rotation speed, the hangs control, and rotor speed. Sensor is embedded in brush. Firstly the change of sensor length is used to measure wear value and its central wavelength shift for temperature ones. The results of modeling and experiments are presented.

  14. Permanent magnet motors from ABB eliminate gearboxes%ABB永磁电机在船舶上的应用

    Institute of Scientific and Technical Information of China (English)

    钱丽春

    2004-01-01

    Permanent magnet motor is synchronous and eliminates brushes, rotor windings ABB's permanent magnet motor is an AC synchronous motor. With such a motor, there is no rotor slip, which provides better accuracy than induct asynchronous, motors.

  15. Design and Study of Dual-Redundancy Brushless DC Motor for Actuator Servo System%舵机用双余度无刷直流电动机设计研究

    Institute of Scientific and Technical Information of China (English)

    高金行; 戴志勇; 全兴源; 艾于琛

    2011-01-01

    以舵机用双余度无刷直流电动机为研究对象,通过数学建模,对无刷直流电动机进行性能仿真,重点介绍样机被测波形及性能数据列表,分析余度换向性能的关键技术,以实现性能调试最优.%A study of dual redundant brushless DC motor for actuator servo system was given. With the mathematical model of brushless DC motor, the simulation performance was shown. The waveforms of BLDC motor were introduced. The performance data of motor was listed. The key technology of commutation was analyzed. The performance was made perfectly.

  16. Brushless DC motor control system based on expert PID%基于专家PID的直流无刷电机控制系统*

    Institute of Scientific and Technical Information of China (English)

    张浩; 吴新开

    2015-01-01

    由于直流无刷电机存在时变性、非线性、不确定性、难以建模等特点,采用常规的PID很难达到理想的控制效果。通过专家PID控制理论并结合实践研究,提出一种高性能的速度控制方案。基于多旋翼飞行器常用的无刷电机转速控制这一实验平台,采用编码器测速实现无刷电机的闭环控制。无刷电机速度PID控制器的引入,开辟了多旋翼飞行器电机控制和姿态控制的新思路。%The brushless DC motor has the characteristics of time varing, nonliner, uncertainty and hardly modeling, so it is difficult to obtain ideal control effect by using conventional PID control. It is hoped to find a high-performance speed control scheme through the theory and practical research of expert PID. Based on the experiment platform of commonly used brushless motor speed control for multi rotor aircraft, the encoder is applied to measure the rotational speed and realize its closed-loop control. The introduction of brushless motor speed PID controller has opened up new ideas for motor control and attitude control of multi rotor aircraft.

  17. Brushless DC motor control system based on expert PID%基于专家PID的直流无刷电机控制系统*

    Institute of Scientific and Technical Information of China (English)

    张浩; 吴新开

    2015-01-01

    The brushless DC motor has the characteristics of time varing, nonliner, uncertainty and hardly modeling, so it is difficult to obtain ideal control effect by using conventional PID control. It is hoped to find a high-performance speed control scheme through the theory and practical research of expert PID. Based on the experiment platform of commonly used brushless motor speed control for multi rotor aircraft, the encoder is applied to measure the rotational speed and realize its closed-loop control. The introduction of brushless motor speed PID controller has opened up new ideas for motor control and attitude control of multi rotor aircraft.%由于直流无刷电机存在时变性、非线性、不确定性、难以建模等特点,采用常规的PID很难达到理想的控制效果。通过专家PID控制理论并结合实践研究,提出一种高性能的速度控制方案。基于多旋翼飞行器常用的无刷电机转速控制这一实验平台,采用编码器测速实现无刷电机的闭环控制。无刷电机速度PID控制器的引入,开辟了多旋翼飞行器电机控制和姿态控制的新思路。

  18. Interfacing the septa movement (DC motors) equipment to the PS control system and the MIL1553 bus

    CERN Document Server

    Dehavay, Claude

    1995-01-01

    Continuing the rejuvenation of the PS Control system , this application replaces the Single Transceiver Hybrid used to interface the Septa Movement Fquipment by a G64 system connected to the VME crate via the MIL1553 bus. This note explains the G64 hardware interface and details the standard message as defined in the Control Protocole for Power Converter, RF and Stepping Motor equipment.

  19. Carbon-brush collector maintenance on turbine-generators

    Energy Technology Data Exchange (ETDEWEB)

    Maughan, C.V. [Maughan Engineering Consultants, Schenectady, NY (United States)

    2005-07-01

    Carbon-brush collectors are small components in turbine generators that perform the function of transferring current from excitation power sources to the rotating fields of synchronous generators. Collectors operate at 100 to 700 volts DC in a noisy and windy atmosphere and are one of the most frequent causes of generator forced outages. As such, their condition must be monitored regularly through visual inspection. While the inspection and maintenance effort is relatively minor, it is often overlooked or done improperly. The key to reliable collector performance consists of making daily direct observations, recognizing the warning signals of impending failure, and taking timely corrective maintenance action. Dependable brush-to-collector current transfer relies on the following 3 conditions, which must be satisfied simultaneously: collector surface film; brush contact pressure; and continuous brush-to-ring contact. Causes of collector outages include planned outages to resurface the collector, or forced outages due to collector flashover. This paper presented suggestions on how to identify an impending failure, along with guidelines for corrective maintenance to avoid a turbine/generator forced outage. Information was provided on retrofit or fixed brush holders with removable brush holders. A checklist for daily inspection and weekly maintenance was presented along with measures to perform at each shutdown. 1 tab., 12 figs.

  20. 无刷直流电动机不导通相电流分析%Analysis of Floating Phase Current in Brushless DC Motor

    Institute of Scientific and Technical Information of China (English)

    王璞; 解恩; 翟猛

    2012-01-01

    分析了无刷直流电动机在三相六状态及不同的PWM方式下,绕组续流期间不导通相电流,并且指出各有不同.对常用的各种PWM方式通过原理分析及数学推导,得出不导通相电流存在的时段和幅值趋势.并通过实验测试,验证了分析结果.%The floating phase current during the free-wheeling and the difference of the brushless DC motor operating in three-phase-six-states and different PWM modes were analysed. The conclusion of existing time and amplitude trend were achieved by theory analysis and mathematical deduction of common PWM modes. The result was verified through the experiment test.

  1. Apparatus to measure chemical wear of carbon brushes

    Science.gov (United States)

    Kosky, P. G.; Peters, H. C.; Spiro, C. L.; Lamby, E. J.; McKee, D. W.

    1985-07-01

    It has been inferred for several years that the wear of a carbon brush at a sliding interface of a dc machine is influenced by chemical factors. Previously, the difficulties of isolating and measuring chemical factors in such circumstances have discouraged specific verification. An apparatus is described that hermetically seals a selected polarity brush and uses an artificial atmosphere of humidified oxygen and argon to simulate air. By monitoring the ratio of mass spectrometric peaks of CO+2 to 36Ar+, a consistent rise is observed in the amount of CO2 present. The amount of carbon thus gasified exceeded 25% of the total carbon lost.

  2. Interfacing the septa movement (DC motor) equipment to the PS control system and the MIL1553 bus

    CERN Document Server

    Dehavay, Claude

    1993-01-01

    Continuing the rejuvenation of the PS Control system , it is planned to replace the Single Transceiver Hybrid used to interface the Septa Movement Equipment by a G64 system connected to the VME crate via the MIL1553 bus. This note explains the G64 hardware interface and details the standard message as defined in the Control Protocole for Power Converter, RF and Stepping Motor equipment.

  3. Real Time Implementation of PID and Fuzzy PD Controllers for DC-Servo Motor Based on Lab View Environment

    Directory of Open Access Journals (Sweden)

    Safaa M. Z. Al-Ubaidi

    2012-06-01

    Full Text Available This paper presents an implementation of conventional PID (CPID controller using Ziegler-Nichols rules and fuzzy PD (FPD controller for position servo motor control based on Lab View (Laboratory Virtual Instrument Engineering Workbench Environment through Data Acquisition (DAQ Device PCI- 6521 of National Instrument's and Data Acquisition Accessory Board Model (CB-68LP.CPID controller is perhaps the most well-known and most widely used in industrial applications. However, it has been known that CPID controller generally don’t work well for non-linear systems, higher order and time-delayed linear system and particularly complex and vague system. To overcome these difficulties, this paper proposes to use the FPD controller for a servo motor system instead of CPID. The parameters of servo motor used are completely unknown. The FPD structure has two-input single-output and fairly similar characteristic to its conventional counterpart and provides good performance. Simple rules base are used for FPD (nine rules only. Performance evaluation was carried out via a comparison study for the proposed control scheme and other existing control scheme, such as CPID controller. The critical point for this experiment on position system is a steady state error and settling time.  The performance showing that the FPD has less settling time and zero steady state error over its CPID. The algorithms of FPD and CPID controllers are implemented using PID, Fuzzy Logic and simulation toolkits of the Lab View environment.

  4. 一种抑制无刷直流电机转矩脉动的新方法%A Method to Suppress Torque Ripple of Brushless DC Motor

    Institute of Scientific and Technical Information of China (English)

    谢少华; 瞿遂春

    2015-01-01

    对无刷直流电机转矩脉动产生的原因进行全面分析,提出增加前级直流变换器抑制转矩脉动的新方法,使用buck直流变换器,通过调整逆变器的母线电压来抑制转矩脉动,在MATLAB/Simulink环境下基于该方法搭建无刷直流电机仿真模型,并对系统进行仿真分析。仿真结果表明,该方法能够有效抑制无刷直流电机转矩脉动。%Analyzes comprehensively the torque ripple causes of brushless DC motor, and proposes a new method of adding the first stage DC converter to control torque ripple. By using buck DC converter and adjusting bus voltage of the inverter to suppress the torque ripple, on the basis establishes brushless DC motor model in MATLAB/Simulink and simulates the system. The result indicates that the method suppresses the torque ripple of brushless DC motor effectively.

  5. Adaptive GA-ADRC in Torque Ripple Reduction of Brushless DC Motor%自适应GA-ADRC在无刷直流电机转矩脉动抑制中的研究

    Institute of Scientific and Technical Information of China (English)

    刘慧博; 王静

    2012-01-01

    提出一种新型的无刷直流电机电磁转矩脉动抑制方法,该方法通过控制无刷直流电机导通相线电流跟踪给定电流来抑制电机的电磁转矩脉动.首先分析无刷直流电机数学模型,建立基于自适应遗传算法的无刷直流电机控制系统模型,由于自适应GA-ADRC控制器不需要无刷直流电机模型参数就可以实现干扰补偿,因此可以独立设计自适应GA-ADRC控制器.对文中所提出自适应GA-ADRC控制算法与经典PID控制算法的控制效果对比分析,控制效果明显优于传统PID控制效果.%The traditional PID control algorithm cannot satisfy the performance index of the brushless DC motor system because of the disadvantages of electromagnetic torque ripple, high complexity of detection method and control algorithm, and higher cost of current brushless DC motor. A novel electromagnet torque ripple suppression method of brushless DC motor was proposed in this paper. By virtue of controlling the conduction phase current of the brushless DC motor to track the given current, the motor electromagnet torque ripple was suppressed. The mathematical model of the motor was analyzed and a control system model of the brushless DC motor based on adaptive genetic algorithm was established. Since the adaptive GA-ADRC controller can realize disturbance compensation without model parameters of brushless DC motor, the GA-ADRC controller was independently designed. The comparative analysis shows that the proposed GA-ADRC control algorithm is obviously superior to that of the classical PID control algorithm.

  6. 永磁无刷直流电动机在微型空压机中的应用%Application of Permanent Magnet Brushless DC Motor in Miniature Air Compressor

    Institute of Scientific and Technical Information of China (English)

    凌永骧; 张华宗; 余仁田

    2013-01-01

    Compared with the traditional DC motor and induction motor,permanent magnet brushless DC(BLDC) motor has more superior performance,widely used in many fields,and has a tendency to gradually replace other motors.In this paper,the development and application of permanent magnet brushless DC motor in the miniature air compressor are analyzed.%永磁无刷直流电动机(简称BLDC)与传统的直流电机及感应电动机相比,永磁无刷直流电动机具有更多优越的性能,在许多领域得到了广泛应用,有逐步取代其它电动机的趋势.本文对永磁无刷直流电动机在微型空压机中的应用和发展情况进行分析.

  7. Water Soluble Responsive Polymer Brushes

    Directory of Open Access Journals (Sweden)

    Andrew J. Parnell

    2011-12-01

    Full Text Available Responsive polymer brushes possess many interesting properties that enable them to control a range of important interfacial behaviours, including adhesion, wettability, surface adsorption, friction, flow and motility. The ability to design a macromolecular response to a wide variety of external stimuli makes polymer brushes an exciting class of functional materials, and has been made possible by advances in modern controlled polymerization techniques. In this review we discuss the physics of polymer brush response along with a summary of the techniques used in their synthesis. We then review the various stimuli that can be used to switch brush conformation; temperature, solvent quality, pH and ionic strength as well as the relatively new area of electric field actuation We discuss examples of devices that utilise brush conformational change, before highlighting other potential applications of responsive brushes in real world devices.

  8. 一个新的适用于无刷直流电机驱动的单电流传感器技术%A Novel Current Sensor Technique for Brushless DC Motor Drives

    Institute of Scientific and Technical Information of China (English)

    谭徽; 江建中; 汪信尧; 王勇

    2000-01-01

    The torque output in a permanent magnet brushless DC motor (BLDCM) is usually controlled by regulating the motor phase currents. In this paper, three kinds of PWM strategies together with some critical review on traditional current measurements in a BLDCM drive system are discussed. A novel method for assessing the PWM information and measuring the motor phase currents by a dc link current sensor is proposed. An attractive feature of the proposed method is the simplicity with the current sample processing because there is no need to incorporate the conduction information of the power switches or diodes. Only the single sided PWM or the double sided complementary PWM is needed with the proposed technique.

  9. Bottle-Brush Brushes: Cylindrical Molecular Brushes of Poly(2-oxazoline) on Glassy Carbon

    KAUST Repository

    Zhang, Ning

    2009-07-28

    We report on the synthesis of brushes of bottle-brushes of poly(2-oxazoline)s on polished glassy carbon (GC) substrates. First, homogeneous and stable poly(2-isopropenyl-2-oxazoline) (PIPOx) brush layers with thicknesses up to 160 nm were created directly onto GC by the self-initiated photografting and photopolymerization (SIPGP) of 2-isopropenyl-2-oxazoline (IPOx). Kinetic studies reveal a linear increase in thickness with the polymerization time. In a second reaction, the pendant 2-oxazoline ring of the PIPOx brushes were used for the living cationic ring-opening polymerization (LCROP) with different substituted 2-oxazoline monomers to form the side chains. Also for the second surface-initiatedLCROPfrom the surface-bound macroinitiator brushes, the thickness increase with the polymerization time was found to be linear and reproducible. Characterization of the resulting bottle-brush brushes by FTIR spectroscopy,contact angle, and AFM indicates a high side chain grafting density and quantitative reactions. Finally, we have demonstrated the possibility of functionalizing the bottle-brush brushes side chain end groups with sterically demanding molecules. © 2009 American Chemical Society.

  10. 基于TB6556 FG的降低无刷直流电机噪声的设计%Design for Reducing Noise of Brushless DC Motor Based on TB6556 FG

    Institute of Scientific and Technical Information of China (English)

    陈治宇; 黄开胜; 陈风凯; 田燕飞; 何建源

    2014-01-01

    A minitype brushless DC motor of optimal magnet chamfering for 180o sinusoidal driving was designed to reduce vibration and noise of the motor. Firstly sinusoidal drive system was designed with TB6556FG and TP4124AK for suppressing mutation of commutation current;Finite element analysis software of ANSYS was employed to analyze brushless DC motor, and to calculate the optimal magnet chamfering for suppressing torque ripple. The motor was manufactured, and the vibration and noise of brushless DC motor were reduced effectively. This method could improve the characteristics of motors, and it was significant value to reduce vibration and noise of motors.%为降低小型无刷直流电机的振动和噪声,设计了一种180º正弦波驱动的具有最佳磁极削角的无刷直流电机。采用TB6556FG控制器和IPM模块TP4124AK构建正弦波驱动系统,来抑制换向电流的突变。结合ANSYS有限元分析软件对无刷直流电机进行分析,计算出最佳的磁极削角尺寸,来抑制转矩脉动,并进行了样机试验,电机的振动和噪声抑制效果明显。该方法可有效改善电机性能,对降低电机的振动和噪声具有一定的工程应用价值。

  11. Endobiliary brush biopsy

    DEFF Research Database (Denmark)

    Adamsen, Sven; Olsen, Marianne; Jendresen, Marianne Bille;

    2006-01-01

    OBJECTIVE: Obtaining cytological specimens by wire-guided endobiliary brushing at the time of endoscopic retrograde cholangiopancreatography (ERCP) is a convenient way to reach a diagnosis. Sensitivity for malignant disease is generally around 50% and specificity around 100%. The present study...... was designed to assess the reproducibility of the cytological examination. MATERIAL AND METHODS: Samples were obtained from 55 consecutive patients with biliary duct strictures that eventually turned out to be caused by malignant disease in 41 patients (73%). The cytology specimens were evaluated twice...

  12. PWM调制下无刷直流电机的转矩脉动抑制%Torque Ripple Reduction of Brushless DC Motors by PWM Modes

    Institute of Scientific and Technical Information of China (English)

    孟光伟; 李槐树; 熊浩

    2011-01-01

    分析无刷直流电机在PWM调制下稳态时的换相过程,通过在换相期间的PWM调制来实现高、低速条件下的换相转矩脉动补偿控制,确定了保持换相期间非换相相电流幅值不变的换相时间.分析PWM调制方式对三相六状态二二导通无刷直流电机控制系统的影响,提出了在PWM-ON-PWM调制方式下的换相转矩脉动补偿控制,不但能够完全消除非换相期间由于关断相出现电流而引起的电磁转矩脉动,而且能够完全补偿由于换相而引起的转矩脉动,实现电机在低速和高速时的无转矩脉动控制.%The steady commutation process of brushless DC motor by PWM modes was analyzed, and realized phase conversion torque ripple compensation control under both low speed and high speed operation by PWM control in commutation period,and confirmed commutation time to hold amplitude of current in commutation period. The effect by PWM modes on a three-phase six-state 120°conduction brushless DC motor was analyzed,and proposed torque ripple compensation control in PWM_ON_PWM mode, which can not only entirely eliminate torque ripple resulted from the current emerging in the turn-off phase during non-commutation period but also compensate torque ripple caused by the commutation current during commutation period. The torque ripple can be effectively reduced under both low speed and high speed operation using torque ripple compensation control in PWM ON PWM mode.

  13. Speed control of DC motor based on exact linearization%精确线性化电动机转速控制

    Institute of Scientific and Technical Information of China (English)

    史晓阳; 鲁芳; 刘艳萍

    2012-01-01

    基于精确线性化方法.设计了两种他励直流电动机转速非线性控制器,并对其性能进行了比较。从他励直流电动机的数学模型出发,运用微分几何理论,讨论给出了他励直流电动机可进行状态反馈线性化的条件。在此基础上,通过选择不同输出函数,设计了状态反馈控制器和输出反馈控制器,并研究了这两种控制器的动态响应特性、抗干扰能力和稳定运行区域。结果表明,对于他励直流电动机数学模型而言,输出反馈线性化控{l;6器相对于状态反馈线性化控制器.具有控制器结构简单、运行稳定、动态性能好、抗干扰能力强等优点。%Based on the feedback linearization method, two different speed nonlinear controllers of are designed by choosing different output functions, and its performance are studied. Based on the mathematical model of separately excited DC motor and differential geometry theory, state feedback linearization conditions are given. State feedback controller and output feedback controller are designed, and the dynamic response characteristics, the anti-interference ability and stable operation areas are discussed of the two controllers. The results show that, for separately excited DC motor mathematical model, compared to the state feedback hnearization controller, the output feedback linearization controller has a more simple structure, better stable operation and dynamic performance, stronger anti-interference capability, et al.

  14. 无刷直流电动机转子退磁故障的检测方法%Detection of rotor demagnetization fault on brushless DC motor

    Institute of Scientific and Technical Information of China (English)

    赵向阳; 葛文韬

    2012-01-01

    In order to study the demagnetization fault on brushless DC motor, the electro - motive - force (EMF) is resolved and the demagnetization fault is implemented based on the finite element method (FEA) with Ansoft/Maxwell. The system of brushless DC motor (BLDC) was simulated with Ansoft/ Simplorer software according to the mathematical model. In steady state, the fast Fourier transform (FFT) analysis was used on the stator current. The simulated model of detecting demagnetization based on the stator current signature analysis stator current signature analysis method was investigated and implemented ; the frequency used to indentify demagnetization fault, and the amplitude of frequency to estimate the demagnetization severity. In addition, the estimation of torque constant was used to detect the demagnetization fault. The results indicate that the stator current signature analysis can be used to detect the demagnetization fault when the speed pulsation is low and the estimation of torque constant method can be used to detect the demagnetization fault when the speed pulsation is high.%为了研究无刷直流电动机的转子退故障,基于Ansoft/Maxwell软件平台,设置转子退磁故障,建立求解电机反电动势的有限元模型;基于Ansoft/Simplorer软件平台,建立无刷直流电动机系统的仿真模型.在电机稳态运行下,对定子电流进行傅里叶分析,研究并建立基于定子电流监测转子退磁故障的仿真模型:退磁故障与特征频率的关系、退磁故障程度与特征频率幅值的关系.进一步,采用基于转矩常数估计的方法对无刷直流电机的转子退磁故障进行监测.仿真结果表明,在转速波动较小时采用定子电流分析法的效果更好,在转速波动较大时,采用转矩常数估计法可以在线监测无刷直流电动机转子的退磁故障.

  15. Study of Dual-redundancy Brushless DC Motor in Electric Aircraft Braking System%飞机刹车用双余度无刷直流电动机的研究

    Institute of Scientific and Technical Information of China (English)

    高金行; 全兴源; 戴志勇; 曹杨

    2012-01-01

    A study of dual redundant brushless DC motor in electric aircraft braking system was given. Based on Ansoft, the motor magnetic circuit was analyzed. The structure parameters were optimized. With the mathematical model of brushless DC motor, the simulation performance was shown. The key technologies of Commutation were analyzed. As shown of experiment, the design is reasonable and correct. Key words; dual redundant brushless DC motor; finite element analysis; performance simulation ; key developing technologies%以全电飞机刹车用双余度无刷直流电动机为研究对象,借助Ansoft软件对电机磁路进行分析计算,优化结构参数,并对其进行性能仿真.重点论述了确保无刷余度电机性能最优的调试关键技术.经过样机性能测试与设计相符,满足使用要求.

  16. 用IGA优化的直流电机的仿人智能控制%Human-simulated intelligent control of DC motor based on Improved Genetic Algorithm.

    Institute of Scientific and Technical Information of China (English)

    李楠; 陈韶飞; 薛方正; 许威

    2011-01-01

    The paper discusses the characteristic of the robot motion control algorithm, which has important influence to the road-holding of robot. After analyzing the mathematical model and control system, the human-simulated intelligent control (HSIC) is applied to the robot DC-motor motion control system. Improved Genetic Algorithm(IGA) is used to optimize the parameters for HSIC.Compared with PID controller, the HSIC controller has more effective control on motor, improves the performance of robot.%讨论了当前足球机器人运动控制系统的控制算法对足球机器人运动性能的影响.在分析了足球机器人运动控制系统组成和电机数学模型的基础上,对足球机器人运动控制器采用多模态控制的仿人智能控制(Human-Simulated Intelligent Control,HSIC)算法,利用改进的遗传算法(Improved Genetic Algorithm,IGA)对仿人智能控制器参数进行优化.通过与目前普遍采用的常规PID控制器作对比实验,表明采用IGA参数整定后的HSIC控制器对电机具有更好的控制品质,并改善了足球机器人的运动性能.

  17. Control System of Two-Phase Brushless DC Gyro Motor Based on DSP%基于DSP的两相无刷直流陀螺电机稳速系统

    Institute of Scientific and Technical Information of China (English)

    吴梅锡; 付鲁华; 林玉池

    2013-01-01

    The research of the influence of gyro motor speed stability on the north-finding result is studied in order to improve the gyro north-finding precision. The paper introduces a two-phase brushless DC gyro motor control system based on TMS320LF2407A. First,it expounds the two-phase brushless DC motor's working principle. Then through the design of the hardware and software system, the close-loop control of two-phase brushless DC gyro motor is realized. The experimental results show that,the system can drive the brushless DC gyro motor well starting,braking and smooth running. The precision of the steady speed is less than 10~6 and the characteristics of the system satisfy the gyroscope demand.%为了进一步提高陀螺仪的寻北精度,分析研究了陀螺电机转速大小和转速精度对寻北结果的影响.在此基础上设计了一种基于TMS320LF2407A的两相无刷直流陀螺电机控制系统,阐述了两相无刷直流电机的工作原理,给出了电机的简化结构及数学模型,并通过对硬件系统和软件算法的设计实现了两相无刷直流陀螺电机的闭环控制.实验结果表明:系统可以很好地完成电机的启动、制动和平稳运行,转速精度优于10-6,满足陀螺仪的工作要求.

  18. 一种减小无刷直流电机转矩脉动的广角波控制方法%A wide-angle wave control method of reducing torque ripple for brushless DC motor

    Institute of Scientific and Technical Information of China (English)

    吴春华; 陈国呈; 孙承波

    2007-01-01

    In order to deal with torque pulsation problem caused by traditional control method for brushless DC(BLDC)motor and to achieve high precision and good stability,a novel control strategy is proposed.Compared with the traditional control scheme,by using phase voltage as a control objective and making waveform of phase current approximately quasi-sinusoidal,torque ripple of BLDC motor is reduced from the original 14% to 3.4%,while toque is increased by 3.8%.Furthermore,by detecting zero-crossings of back electromotive force(BEMF)with non-conducting phases,sensorless control is realized.The new control strategy is simple.It carl minimize torque ripple,increase torque,and realize sensorless control for BLDC motor.Simulation and experiments show good performance of BLDC motor by using the new control method.

  19. 无刷直流电机转子位置检测方法综述%Summary on Rotor Position Detection Method for Brushless DC Motors

    Institute of Scientific and Technical Information of China (English)

    赵一衡; 顾伟康; 陈亚彬; 曹翔

    2014-01-01

    由于受到传统开关器件的限制,大电流开关电源存在功率小、效率低等问题,因此在对PWM软开关技术进行分析后,利用AT89 C52单片机的中断方式输出频率和占空比可调的PWM脉冲,控制大功率开关管GT40 T101的通断,从而实现以模拟继电器的方式控制电路的通断。通过搭建电路验证了PWM软开关在控制大功率电源方面的优越性,对于实际的电气工程应用具有一定的参考价值。%The brushless DC motor (BLDCM) is an advanced mechanical electronic device.Rotor position detection method is an important part of the BLDCM.Traditional method with position sensor is not suitable the need for the current applications because of its own shortcomings, so the position detection method has been the research hotspot recently.The basic principle and research situation of sensorless detection methods are introduced , and their advantages and disadvantages are compared .It provides a certain theoretical basis for researching on sensorless and has certain value.

  20. Design of PLC Program of DC Motor Speed Regulation Based on PID Algorithm%基于PID算法的直流电机调速的PLC程序设计

    Institute of Scientific and Technical Information of China (English)

    王海涛; 吴钦木; 韦书龙; 刘江宁

    2012-01-01

    Both ends of armature voltage of DC motor are used as feedback terminal. The Siemens $7-200 PLC is used as controller. The PID loop control instruction is used to make calculation. The PWM wave is output and the DC motor speed regulation is implemented.%以直流电机电枢两端电压作为反馈,采用西门子S7-200PLC作为控制器,利用其PID回路控制指令进行计算,然后输出PWM波,达到对直流电机转速进行调节的目的。

  1. 基于单片机的无刷直流电动机控制系统设计%Design of Brushless DC Motor Control System Based on MCU

    Institute of Scientific and Technical Information of China (English)

    闵次凡

    2012-01-01

    介绍了无刷直流电动机(BLDCM)的基本结构和工作原理.重点阐述了利用8751单片机控制无刷直流电动机的换相、调速、限制启动电流、正反转的原理和实现方法以及程序设计.%This paper introduces the basic structure and working principle of brushless DC motor (BLDCM). This paper expounds the principle and method to control the phase transformation, speed regulation, starting current limit, reverse rotation of brushless DC motor by single chip microcomputer 8751 , and the program design.

  2. 两相无槽无刷直流电机的无位置传感器控制%Sensorless control of two-phase slotless brushless DC motor

    Institute of Scientific and Technical Information of China (English)

    钟德刚; 方浩

    2011-01-01

    In order to eliminate the shortcomings of brushless DC motor control based on hall sensors and realize the sensorless control of two-phase slotless brushless DC motor,the structure of stator and rotor ,the winding connections of two-phase slotless brushless DC motor and the zero-crossing of back EMF detection method were analyzed. The hardware system and software system designs of two-phase slotless brushless DC motor were presented. The test results indicate the feasibility and stability of control system. A simple control circuit, low cost,less torque ripples and high stability are the advantages of the design presented.%为消除无刷直流电机基于霍尔位置传感器控制存在的缺点,实现两相无槽无刷直流电机的无位置传感器控制,首先在分析了两相无槽无刷直流电机的定、转子结构、绕组连接方式以及反电势过零点检测法的工作原理基础上,论述了两相无槽无刷直流电机无位置传感器控制的硬件系统和软件系统的设计方案,并对两相无刷直流电机进行了试验.试验结果证明了系统的可行性、稳定性.结果表明,该控制方案具有线路简单、成本低、转矩脉动小、系统运行稳定等优点.

  3. 关于直流电动机的电枢绕组及电枢电路(二)电枢主电路%About the Armature Winding and Armature Circuit of DC Motor (Ⅱ)Armature Main Circuit

    Institute of Scientific and Technical Information of China (English)

    王宗培; 陈敏祥

    2012-01-01

    电动机的电枢主电路包括:电枢绕组电路和电源二部分,属运动控制类的各种交流电动机,具有多相交流电枢绕组电路和逆变器供电的电源.与传统直流电动机原理一样的New DCM,具有直流的电枢绕组电路,通过电子换向器与直流电源相连.逆变器和电子换向器都是功率开关管的桥式电路,硬件电路上不易区分,容易混淆.本文用实例说明电子换向器不是逆变器,换向器构筑直流电枢绕组电路的独特功能,使得它与交流电枢绕组电路完全不同,电枢绕组电感对电动机运行性能的影响也随之不同.%The motor armature main circuit including: the armature winding circuit and power supply, all kinds of motion-control AC motors have the multiphase ac armature winding circuit and inverter power supply. The New DCM , with same principles of the traditional DC machines, has the DC armature winding circuit connected to DC power through electronic commutator. Inverter and electronic commutator is not easy to distinguish from hardware circuit structure, easy to confuse. This paper demonstrates the electronic commutator not inverter, the unique functions of the electronic commutator is to make the armature winding circuit as DC circuit, therefore , the armature winding circuits between New DCM and AC motor are completely different, the influences of the armature winding inductance to motor performance are different , too.

  4. Forces between asymmetric polymer brushes

    OpenAIRE

    Shim, D.F.K.; Cates, M. E.

    1990-01-01

    We study the equilibrium compression of asymmetric polymer brushes grafted on flat plates, under athermal and theta solvent conditions, using a lattice self-consistent field (SCF) approach. We find that the separation d between two plates coated asymmetrically with brushes of type 1 and 2, as a function of the force F, obeys the "bisection rule", d(F) = (d1(F) + d 2(F)) /2 where d1(F)and d 2(F) are the corresponding separations for the symmetric brushes of type 1 and 2 respectively.The bisect...

  5. Numerical Simulation of a Leakage Magnetic Flux of Permanent Magnet DC Motors for Underwater Vehicles%水下航行器用永磁直流电机漏磁场数值分析

    Institute of Scientific and Technical Information of China (English)

    李尉; 宋保维; 胡欲立

    2011-01-01

    Based on the Magnet software, a leakage magnetic flux of a permanent magnet DC motor for the propulsion of a certain underwater vehicle is numerically simulated by a finite element method, and the numerical relation between the leakage magnetic strength and the distance of the DC motor is obtained. Furthermore,a good method is presented to analyze a disadvantageous influence of the leakage magnetic flux of a permanent magnet DC motor for the propulsion of underwater vehicles to their nearby electronic instruments and equipments.%基于Magnet软件,对某型水下航行器推进用永磁直流电机漏磁场进行了有限元数值仿真,得到了电机漏磁场强度与电机距离之间的数值关系,也为分析水下航行器推进电机漏磁场对其附近电子仪器设备带来的不利影响,提出了一个良好的方法.

  6. The Research on Simulation Model of DTC with Brushless DC motor%无刷直流电机直接转矩控制系统仿真研究

    Institute of Scientific and Technical Information of China (English)

    宫殿强

    2012-01-01

    In this paper, the basic structure of the brushless DC motor starting, contacting the Direct Torque Control, it deduced improved brushless DC motor direct torque control system. The improved brushless DC motor direct torque control system's software model based full analysis of direct torque control principles and components, was presented by means of Matlab / Simulink software. The simulation results showed that the improved direct torque control had favourable dynamics and statics.%从无刷直流电机的基本结构出发,联系直接转矩控制理论,提出了改进型无刷直流电机直接转矩控制系统,在对系统的基本原理和组成部分进行充分分析的基础上,利用Matlab/Simulink建立了无刷直流电机直接转矩控制系统的软件模型.仿真结果表明改进型直接转矩控制系统具有良好的动静态性能.

  7. 基于DSP的无刷直流电动机控制系统的研究与设计%Research and Design of Brushless DC Motor Control System Based on DSP

    Institute of Scientific and Technical Information of China (English)

    王宪磊; 王淑红

    2012-01-01

      介绍了无刷直流电动机的基本结构、工作原理和运行特性,简述了基于DSP的无刷直流电动机的控制策略,对无刷直流电动机双闭环控制系统的硬、软件设计作了详细论述。文章所述无刷直流电动机控制系统的设计方案,可以获得良好的速度控制性能。%  The basic structure, working principle and operation characteristics of brushless DC motor were introduced. The control strategy of brushless DC motor based on DSP was expounded, and the hardware and software design of the double closed loop control system was expounded in detail. The brushless DC motor control system described in this paper show good performance in speed control.

  8. 直流无刷高速电机驱动电路设计及改进%Design and Improvement of the High - speed Brushless DC Motor Drive Circuit

    Institute of Scientific and Technical Information of China (English)

    石屾; 董春

    2011-01-01

    采用无传感器无刷直流低速电机专用调速控制芯片ML4425,设计制作了航模用直流无刷高速电机的控制器.针对目前航模用直流无刷电机速度高的特点,对用于直流无刷低速电机的传统ML4425控制系统中的相关环节进行了改进,尤其是电机的启动、驱动和保护部分.简化了航模用直流无刷高速电机的控制系统,减少了成本.%In this paper,a dedicated control chip is used to design a drive circuit of a low speed sensorless DC brushless motor.This paper has done some change of the traditional control system of ML4425,in order to adapt to the high speed of the DC brushless motor used in aircraft model, especially in parts of start, drive and protect.Simplified the control system of the DC brushless motor,so it can reduce the cost.

  9. A novel miniaturized zinc oxide/hydroxylated multiwalled carbon nanotubes as a stir-brush microextractor device for carbamate pesticides analysis.

    Science.gov (United States)

    Makkliang, Fonthip; Kanatharana, Proespichaya; Thavarungkul, Panote; Thammakhet, Chongdee

    2016-04-21

    A novel miniaturized "stir-brush microextractor" was prepared using a zinc oxide/hydroxylated multiwalled carbon nanotubes (ZnO/MWCNTs-OH) coated stainless steel brush connected to a small dc motor. The synthesized zinc oxide on each strand of stainless steel had a flower-like nanostructure when observed by a scanning electron microscope (SEM). This structure produced a large surface area before it was coated with the hydroxylated multiwalled carbon nanotubes sorbent. Under optimal conditions, the developed device provided a good linearity for the extraction of carbofuran and carbaryl, in the range of 25-500 ng mL(-1) and 50-500 ng mL(-1), respectively, with low limits of detection of 17.5 ± 2.0 ng mL(-1) and 13.0 ± 1.8 ng mL(-1). It also provided a good stir-brush-to-stir-brush reproducibility (% relative standard deviation < 5.6%, n = 6). The device was applied for the extraction and preconcentration of carbamate pesticides in fruit and vegetable samples prior to analysis with a gas chromatograph coupled with a flame ionization detector (GC-FID). Carbofuran was found at 9.24 ± 0.93 ng g(-1) and carbaryl was detected at 7.05 ± 0.61 ng g(-1) with good recoveries in the range of 73.7 ± 10.0% to 108.4 ± 2.6% for carbofuran and 75.7 ± 10.0% to 111.7 ± 5.7% for carbaryl. PMID:27026597

  10. 电动汽车用无刷直流电机控制器设计%Controller Design for DC Brushless Motor of Electric Vehicle

    Institute of Scientific and Technical Information of China (English)

    舒雄; 杜荣华; 柴健; 舒刚华; 李亚中

    2015-01-01

    针对四轮独立驱动电动汽车所用电机须调速性好、可靠性高的特点,从工程应用出发,设计一种以dsPIC及MC33035为核心的无刷直流电机控制器。阐述了控制方案及工作原理,给出了硬件电路组成和调速方法。把该控制器运用到自行研制的四轮独立驱动电动汽车上进行测试,其结果表明,该控制器不仅具有响应速度快、调速性能好和稳定性高的特点,且开发成本低,具有广泛的应用价值。%Based on dsPIC and MC33035, a kind of controller is designed for brushless dc motor with good speed regulating and high reliability, which is used in electric car with four-wheel independent drive. The control plan and operating principle are outlined, and the corresponding hardware circuit structure and speed regulation method are introduced. The controller was applied to test self-de-veloped electric car with four-wheel independent drive. The results indicate that the controller have characteristics of fast response, good speed control performance and high stability with low cost and extensive application.

  11. 基于DSP的小功率无刷直流电动机驱动器设计%Design of Low-power Brushless DC Motor Driver Based on DSP

    Institute of Scientific and Technical Information of China (English)

    侯玉宝; 欧阳宁; 王景芳

    2012-01-01

    There was an increasing demand for low power brushless DC motor in the appliance industry nowadays , in order to meet the requirements of higher performance about the motor control system, a low power brushless DC motor drive was designed out in this paper using TFs dedicated motor control chip TMS320F2812 digital signal processor. The hardware and software structure and control strategy of the drive were introduced in detail, and the experimental results show that the system has the characteristics of shorter response time, better steady performance and anti-interference ability.%现在家电行业对小功率无刷直流电动机的需求日见增多,为了满足用户对电机控制系统产品性能的更高要求.采用TI公司的数字信号处理器TMS320F2812专用电机控制芯片,设计了一种小功率无刷直流电动机的驱动器.详细介绍了该驱动器的硬件电路组成和软件结构及控制策略,通过实验结果表明该系统响应时间短,稳态性能好,抗干扰能力强等特点.

  12. 基于 Matlab 的直流电机控制系统硬件在环设计%HIL Design of DC Motor Control System Based on Matlab

    Institute of Scientific and Technical Information of China (English)

    朱虎; 林立; 刘正奇

    2015-01-01

    In order to save time for developer using C/C++language source code, as well as improve the effectiveness of DSP bipolar PWM DC motor control, studied automatic code generation based on Matlab/Simulink for TI C2000 DSP platform.The control model built in Matlab/Simulink converts to real-time con-trol code control DC motors through RTW ( Real_Time Workshop) conversion tools and realize the control of DC motor PWM bipolar control system on TMS320F2812 platform, the motor is running smoothly.Experi-mental results show that the Hardware-In-Loop ( HIL) simulation technology effectively shorten the product development cycle.%针对开发人员在利用C/C++语言编写源代码时浪费大量时间的问题,同时为提高DSP对直流电机PWM双极性控制的有效性,研究了基于Matlab/Simulink平台下TI C2000DSP代码自动生成的方法。在Matlab/Simulink环境下搭建控制模型,通过RTW( Real_Time Workshop)工具转换成实时控制代码控制直流电机。并利用此方法在TMS320F2812开发板上实现了对直流电机PWM双极性控制系统的控制,电机平稳运行。实验验证了硬件在环半实物仿真技术有效地缩短产品的开发周期。

  13. Brushless direct-current motor with stationary armature and field

    Science.gov (United States)

    Studer, P. A.

    1970-01-01

    Electronically commutated dc motor has an active fixed field winding, and active fixed armature winding, and passive rotor. By use of brushless dc motor switching technique, motor provides continuous controllable and reversible torque without use of sliding contacts.

  14. 四程脉宽调制模型对无传感器无电刷直流电机控制系统中换向力矩波动的影响%Influence of PWM Modes on Commutation Torque Ripples in Sensorless Brushless DC Motor Control System

    Institute of Scientific and Technical Information of China (English)

    张相军; 陈伯时

    2001-01-01

    This paper introduces four PWM modes used in the sensorless brushless DC motor control system, analyzes their different influences on the commutation torque ripple in detail, and selects the best PWM mode in four given types to reduce commutation torque ripple of Brushless OC(BLDC) motors. Simulation and experimental results show that the selection is correct and practical.

  15. 一种双向短行程永磁直线直流电机%A Bi-directional Short Stroke Permanent Magnet Linear DC Motor

    Institute of Scientific and Technical Information of China (English)

    杜志强; 沈文杰; 艾武; 金振荣

    2011-01-01

    阐述了一种双向短行程永磁动圈式直线直流电动机的结构及特点,直线电机采用双环形磁钢、直线轴承滚动副支撑结构形式,径向磁场中的动圈固接在轴上并被两个刚度相同的预压弹簧平衡,导向机构阻止动圈周向转动,带有分辨率为1 μm光栅尺,设计的行程范围为±5 mm.给出了样机的主要参数,并对样机进行了试验研究,结果表明直线电机输入电流与电磁力呈线性关系.在控制信号频率为30 Hz时,峰值电流为±2.56 A,峰值推力可达±30.9 N,最大速度可达±0.86 m/s,最大加速度可达±16.5 g.%The structure and features of a bi-directional short stroke linear DC motor with permanent magnets were presented. The magnetic field was produced by the two concentric ring permanent magnets embedded on the stator. The moving coil mounted on the shaft was a tubular coil situated within a radially oriented magnetic field and balanced by the two opposing forces generated by two springs along with the central axis and supported by the two linear bearings. The linear guide prevented the moving coil from rotating around on the central axis and carries with the linear optical encoder of 1 (xm resolution. The required controlled travel was limited in a ±5 mm displacement range. The prototype specifications were given. The experimental results show that between the electromagnetic force and the coil electric current exists a linear relation. When the frequency of control command is the 30Hz sine wave, the peak current, the peak force, the max velocity and the max acceleration are, respectively, ±2. 56A, ±30. 9N, ±0. 86m/s and ± 16. 5g.

  16. Starter Motor Protection

    OpenAIRE

    Gerhardsson, Daniel

    2010-01-01

    Starter motors are sensitive for overheating. By estimating the temperature and preventing cranking in time, there is an option to avoid the dangerous temperatures. The truck manufacturer Scania CV AB proposed a master thesis that should evaluate the need of an overheating protection for the starter motor. The aim is to evaluate any positive effects of implementing an algorithm that can estimate the brush temperature instead of using the available time constrain, which allows 35 seconds of cr...

  17. Wear property of high-resistivity carbon brushes made with and without MoS2 in variable humidity

    Institute of Scientific and Technical Information of China (English)

    HU Zhong-liang; CHEN Zhen-hua; XIA Jin-tong; DING Guo-yun

    2008-01-01

    Four kinds of high-resistivity carbon brushes with MoS2 contents of 0%, 2%, 4% and 6% (mass fraction) were prepared, respectively. Wear tests of brushes were conducted on an alternate current(AC) motor. Scanning electron microscopy(SEM) and energy dispersive X-ray analysis(EDS) were used to analyze the worn surface of brushes, and a thermocouple was used to measure the bulk temperature of the brush. The results show that wear rate of brush made without MoS2 in 10% relative humidity(RH) is two times larger than that in 50% RH, whereas the wear rates change little for the brushes made with MoS2. The wear of brushes has much to do with the surface film. In low humidity, the surface film can not be formed for the former brush while a sulfur layer can be formed for the latter brushes,which can reduce sparks, frictional heat and wear rate, and play a role like the water film in high humidity.

  18. 基于模糊预测控制的无刷直流电机控制研究%Study on Brushless DC Motor Control Based on Fuzzy Predictive Control

    Institute of Scientific and Technical Information of China (English)

    王玉娟; 张艳

    2015-01-01

    针对传统控制方法在对永磁无刷直流电机(Brushless DC Motor,BLDCM)进行控制时鲁棒性差、精度低、实时性不理想等缺点,提出了一种模糊与预测相结合的控制算法。将该算法应用于永磁无刷直流电机双闭环调速系统的转速闭环中,并利用 MATLAB 软件搭建无刷直流电机的控制系统进行仿真。实验结果表明该算法利用模糊控制与预测控制各自的优点,提高了无刷直流电机的性能,是可行和有效的。%When the Brushless DC Motor(BLDCM)is controlled by traditional methods,it is weak in robustness,accuracy and real-time .A fuzzy predictive control method is proposed in this paper.The control algorithm is applied in the double loop of speed servo system of BLDCM.The control system of Brushless DC motor is built and simulated by the MATLAB software.Ex-periments results show that the control algorithm combines the advantages of the fuzzy control and the predictive control and im-proves the performance of the BLDCM.This control method is proved to be feasible and effective.

  19. DC Servo Motor's Speed Regulation Method of Adjusting Frequency at Fixed Duty Cycle Based on PLC%基于PLC的直流伺服电机定占空比调频调速

    Institute of Scientific and Technical Information of China (English)

    王平; 高明华; 马坤; 公维帅; 荣伟

    2012-01-01

    Many programmable logic controllers (PLC) have integrated high-speed pulse output functions, which provide convenience for motion control. But high-speed pulse output of fixed duty cycle caused difficulties when PLC directly applied to the PWM speed regulation of DC servo motor. Took full use of PLC s highspeed pulse output selected the driver chip L298N, and proposed the method of adjusting the frequency to change speed at fixed duty cycle without extra external devices and applied to production line of IC card. Experimental result shows the DC servo motor speed and the pulse output frequency is linear relationship. The method can achieve the precise speed regulation of DC servo motor.%现在很多可编程控制器(PLC)中集成了高速脉冲输出功能,这为运动控制提供了方便,但是高速脉冲输出的占空比一般固定不变,这使PLC直接应用到直流伺服电机调速系统中出现了困难.选用L298N驱动芯片,充分利用PLC高速脉冲输出功能,在不增加外围器件情况下,提出定占空比调频调速的方法,并将其应用到IC卡生产线.实际应用结果表明直流伺服电机的转速与PLC脉冲输出频率成线性关系,定占空比调频能够在一定条件下实现电机的精确调速.

  20. 永磁直线直流电机控制系统设计与实验研究%Design and Experiment for Linear Permanent Magnet Brushless DC Motor

    Institute of Scientific and Technical Information of China (English)

    尹曾锋

    2012-01-01

    本文详细介绍了基于DSP TMS320LF2407的永磁直线直流无刷电动机硬件设计和PWM控制方法,给出了电机的控制程序流程,试验结果表明该方法简单可行。%This paper introduces a DSP-based PWM timing method for linear permanent magnet brushless DC motor in detail. The test results show that the method of control program is simple and feasible in practice.

  1. 一种内转子三槽无刷直流水泵电机的设计%Design on DC Brushless Pumping Motor with the Inner Rotor and Three-slot Stator Construction

    Institute of Scientific and Technical Information of China (English)

    马余洋

    2015-01-01

    A kind of high-efficiency DC brushless pumping motor together with its simple manufacturing pro-cess was introduced. The contents were included with the performance of 2-pole PM rotor, detailed stator construction and the manufacturing for the winding as well as relative control method.%介绍了一种效率高且制造工艺简单的无刷直流水泵电机。内容包括两极永磁体转子的性能、定子结构和绕组的制造及其控制方法。

  2. A discrete time model of a power conditioner fed permanent magnet brushless dc motor system for aerospace and electric vehicle applications for design purpose using finite elements for machine parameter determination

    Science.gov (United States)

    Nehl, T. W.

    1980-12-01

    A discrete state space model of a power conditioner fed permanent magnet brushless dc motor for aerospace and electric vehicle applications is developed. The parameters which describe that machine portion of this model are derived from a two dimensional nonlinear magnetic field analysis using the finite element method. The model predicts the instantaneous mechanical and electrical behavior of a prototype electromechanical actuator for possible use on board the shuttle orbiter. The model is also used to simulate the instantaneous performance of an advanced electric vehicle propulsion unit. The results of the computer simulations are compared with experimental test data and excellent agreement between the two is found in all cases.

  3. Electron spectroscopy analysis of contact surfaces in the wear of carbon brushes against copper commutators

    Science.gov (United States)

    Savage, D. E.; Lagally, M. G.; Schrader, M. E.

    Carbon brushes and copper commutator strips have been analyzed by a combination of techniques to investigate possible surface-related phenomena in the excessive wear of carbon brushes in motors and generators. X-ray photoelectron spectroscopy, scanning Auger microscopy, optical microscopy, scanning electron microscopy, and energy-dispersive X-ray analysis were used in this study. A thin SiO 2 film, of the order of 30 Å on the brushes, and of the order of several hundred Å on the commutators, was correlated with high wear and is believed to be the chief cause of the excessive wear. Possible models for the effect of SiO 2 on carbon brush wear are discussed.

  4. Determination of efficiencies, loss mechanisms, and performance degradation factors in chopper controlled dc vehical motors. Section 2: The time dependent finite element modeling of the electromagnetic field in electrical machines: Methods and applications. Ph.D. Thesis

    Science.gov (United States)

    Hamilton, H. B.; Strangas, E.

    1980-01-01

    The time dependent solution of the magnetic field is introduced as a method for accounting for the variation, in time, of the machine parameters in predicting and analyzing the performance of the electrical machines. The method of time dependent finite element was used in combination with an also time dependent construction of a grid for the air gap region. The Maxwell stress tensor was used to calculate the airgap torque from the magnetic vector potential distribution. Incremental inductances were defined and calculated as functions of time, depending on eddy currents and saturation. The currents in all the machine circuits were calculated in the time domain based on these inductances, which were continuously updated. The method was applied to a chopper controlled DC series motor used for electric vehicle drive, and to a salient pole sychronous motor with damper bars. Simulation results were compared to experimentally obtained ones.

  5. 关于直流力矩电机电枢灌封后胶层开裂问题的探析%Study on Crack of DC Torque Motor's Armature After Sealed with Epoxy Resin

    Institute of Scientific and Technical Information of China (English)

    罗润娟; 周钦沅; 董文生

    2012-01-01

    直流力矩电机电枢用环氧树脂灌封后胶层开裂的问题是直流力矩电机在生产制造过程中较为常见的一种问题.本文从灌封料配方及其它因素去分析,解决该类电机电枢灌封开裂.%In the producing of DC torque motor's armature,it's a usual problem about the glue layer cracking after sealed with epoxy resin. This problem was analyzed from sealing compounds to other factors in this paper,so as to solve the crack of this kind of motor's armature.

  6. About Armature Winding and Armature Circuit of DC Motor Circular Current Problem(Part 1)%关于直流电动机的电枢绕组及电枢电路(一)环流问题

    Institute of Scientific and Technical Information of China (English)

    王宗培; 陈敏祥

    2012-01-01

    The new DC motor (New DCM) shares the same armature winding with traditional DC motor (DCM) , all adopt seal connection (namely polygon connection) to combine K commutating units, the armature winding of New DCM is similar but are different with multi-phase AC motor's armature winding which employ typical polygon connection. New DCM is neither multi-phase AC motor nor multi-phase BLDCM. Multi-phase AC armature winding adopted typical polygon connection can have circular current in closed circuit. However, New DCM or DCM with seal connection armature winding will not and can not have circular current in closed circuit.%新直流电动机(New DCM)与传统有刷直流电动机(DCM)有相同的电枢绕组,都是分成K个换向单元成封闭形(多边形)接法,与多相交流电动机采取封闭形(多边形)接法的电枢绕组有类似之处但有区别,New DCM不是一台多相交流电动机,也不是一台多相无刷直流电动机.与典型多边形接法的多相交流电枢绕组闭合回路可能有环流的情况不同,New DCM或DCM为封闭形接法的电枢绕组,闭合回路内不存在环流,不可能产生环流.

  7. How to Choose Suitable Carbon Brushes of DC Motor Under low-load Running%低负荷运行中的直流电动机如何选用好电刷

    Institute of Scientific and Technical Information of China (English)

    姚竞红; 严国祥

    2002-01-01

    造纸行业中的直流传动系统,在设计时一般设计输出功率往往要比实际运行时的输出功率大许多,本文就如何选用好直流电动机在低负荷下运行的电刷,提高直流电动机的使用寿命做些研究和探讨.

  8. How to choose suitable carbon brushes of DC motor under low-load running%低负荷运行中的直流电动机如何选用好电刷

    Institute of Scientific and Technical Information of China (English)

    姚竞红; 严国祥

    2002-01-01

    造纸行业中的直流传动系统,在设计时一般设计输出功率往往要比实际运行时的输出功率大许多,本文就如何选用好直流电动机在低负荷下运行的电刷,提高直流电动机的使用寿命做些研究和探讨.

  9. Loop polymer brushes from polymer single crystals

    Science.gov (United States)

    Zhou, Tian; Li, Christopher

    2014-03-01

    Loop polymer brushes represent a category of polymer brushes with both chain ends being tethered to a surface or interface with sufficiently high density. Due to this morphological difference, loop brushes exhibit distinct properties compared with traditional polymer brushes with single chain end being tethered. In our study, α, ω-functionalized polycaprolactone (PCL) single crystals were prepared as templates for polymer brush synthesis. By carefully controlling crystallization condition and immobilization, looped polymer brushes were successfully prepared. Comprehensive studies on the morphology and physical properties of these polymer brushes were carried out using Atomic Force Microscopy and FTIR. Advantages of using this method include exclusive loop morphology, high grafting density, controlled tethering sites and tunable loop size.

  10. Analysis and troubleshooting of a car power leakage after the composition of DC600V motor cars%DC600V动车编组后单车漏电的分析及查找方法

    Institute of Scientific and Technical Information of China (English)

    赵明

    2001-01-01

    @@ 采用DC600V供电的动车组,由于其电气原理复杂,电气元件相对较多,布线受动车结构限制,全列编组后,DC110 V联接器和通信联接器全部连在一起.当有一台车DC110 V漏电,检测时却发现在故障车或其他车上漏电故障时有时无,即有时在故障车或其他车上可以检测出故障,有时检测不出来,给故障查找带来很大困难.若不及时解决漏电问题,将严重影响行车安全.下面对漏电原因作一具体分析,并提出解决方法.

  11. 水下航行器永磁直流电机瞬态磁场数值模拟%Numerical Simulation of a Transient Magnetic Flux of Permanent Magnet DC Motors for Underwater Vehicles

    Institute of Scientific and Technical Information of China (English)

    李尉; 宋保维; 胡欲立

    2012-01-01

    Underwater vehicles are widely used in ocean. Electrical power underwater vehicles, which have the advantage of simple structure, convenient maintenance, et al. are used more widely than thermal power underwater vehicles. By using the finite element analysis software Magnet, inner and outer magnetic fluxes of a permanent magnet DC motor for the propulsion of a certain electrical power underwater vehicle is numerically simulated with and without load. The acquired results can apply to analyzing interference of the leakage magnetic flux of a permanent magnet DC motor for the propulsion of underwater vehicles to their nearby electronic instruments and equipments.%水下航行器在海洋中已得到广泛应用,而电动力水下航行器较热动力水下航行器由于具有结构简单、维护方便等优点应用更广泛.应用有限元分析软件Magnet,对某型电动力水下航行器推进用永磁直流电机有无负载时内、外磁场进行了数值模拟,所获得的结果可用于分析电机漏磁场对其周围电子仪器设备的干扰.

  12. 高速无刷直流电动机寿命试验故障分析与试验方法改进%Fault Analysis and Method Improvement of High-Speed Brushless DC Motor Life Testing

    Institute of Scientific and Technical Information of China (English)

    秦虎; 王孝利; 程远; 罗新华

    2012-01-01

    Based on the theoretical analysis and experimental verification on shaft breakdowns of the high-speed brash-less DC motor,a new test method was proposed to improve the present ones. The method was applied to the testing process of high-speed brushless DC motor. The experimental results demonstrate that this method is correct and effective.%针对高转速无刷直流电动机寿命试验中出现的转轴卡死故障进行理论分析和试验验证,找出现行的试验方法的不足,结合高转速无刷直流电机的运动特性,提出了一种新的试验方法并将其应用于实际试验过程中,通过试验验证了方法的正确和有效.

  13. 基于磁编码器无刷直流电机转速及位置的检测*%Detection of Brushless DC Motor Speed and Location Based on Magnetic Encoder

    Institute of Scientific and Technical Information of China (English)

    郭丹; 王大明; 李寒

    2015-01-01

    论文采用了磁编码器作为无刷直流电机位置传感器,介绍了其工作原理和输出模式,以及相应的电机转子位置和转子速度测量的几种方法。最后给出了基于STM32F407ZG的无刷直流电机转子位置和转速测量单元的实现,实验表明,该方案具有良好的精确度及可靠性。%Regarding magnetic encoder as position sensor of the brushless DC motor ,the operating principle and output modes of magnetic decoder ,as well as the measuring methods of rotor position and rotor speed are introduced .Finally the uint of measuring rotor position and rotor speed of the brushless DC motor based on STM32F407ZG are achieved ,and the experiments show that the scheme has good accuracy and reliability .

  14. 大功率高速比直流电机设计简介%Brief of Design of the Large-size DC Motor with High Speed-regulation Ratio

    Institute of Scientific and Technical Information of China (English)

    陶宝英

    2014-01-01

    The single stack of different-slot armature winding with equalizing line and block brush was applied in the design of 2 000 kW motor with high speed-regulation ratio, to improve the commutation performance;the down-ward-pressure weftless tape was employed in the end wind-ing structure, to ift with the high-speed operation;the radial ventilation was furnished in the armature shaft and inclined air guide plate was welded between the shafts to enhance the cooling and ventilating effectiveness of the armature.%在2000 kW高速比直流电机电磁设计中,采用带均压线的单叠异槽式电枢绕组和分块电刷等,来提高电机的换向性能;绕组端部采用下压式无纬带结构,以满足电机的高速运行;电枢铁心采用径向通风,在转轴筋之间焊接倾斜导风板,以提高电枢通风冷却效果。

  15. A Novel Motor-Speed-Regulation Method

    Directory of Open Access Journals (Sweden)

    Huang Zhou

    2016-01-01

    Full Text Available The traditional doubly-fed motor has less reliability because it needs carbon brushes and sliding rings which are not highly reliable. The brushless doubly-fed machine costs a lot for its framework requires special designing and processing. To overcome the disadvantages of the two kinds of motors, this paper focuses on a novel method of motor speed regulation which is based on rotating feeding. The motor speed changing around its rated speed can be realized based on the method without any carbon brush or sliding ring on the prosaic electrical motors. On the basis of the full controlled thyristor rectifying bridge structure, the basic idea is introduced; the advantages and disadvantages of this method are analyzed. This kind of systems can replace the brushed or brushless double-fed systems. They are very suitable for driving fans or pumps, or power-generating systems with variable speed constant frequency such as wind power or water power generating systems.

  16. Design of control system of brushless DC motor based on DSP for small vessels%基于 DSP 的小型船舶直流无刷电机控制系统的设计

    Institute of Scientific and Technical Information of China (English)

    杨立宏

    2015-01-01

    随着永磁材料和控制技术的不断进步,直流无刷电机的功率越来越大,其优势包括效率比较高、使用时间长、噪声非常小、转速平稳、输出转矩大等,它在小型船舶的电力推进系统中扮演着越来越重要的角色。目前,直流无刷电机在船舶上的工作效果不理想,阻碍其在高性能电力推进船舶中大量的普及推广。直流无刷电机简称BLDCM,其关键问题是电机的控制策略、转矩稳定控制以及无位置传感器。本文根据 BLDCM 的速度环和电流环的响应特点,利用传统的 PID 算法和现代模糊控制算法,设计了相应的硬件系统和软件系统,然后建立了基于 DSP 的小型船舶直流无刷电机控制装置。实验结果显示,采用模糊 PID 算法对电机进行控制的效果更好,可以实现脉动更小的输出转矩和更大的转速,同时此系统能够在小型船舶的电力推进系统中稳定、持续地工作,能够满足实际应用的要求。%With the progress of magnetic materials and control technology, brushless DC motor power is growing, its advantages include high efficiency, long life, noise is very small, steady speed, output torque, etc. , it is small ship electric propulsion system increasingly important role in the actor. Currently, the brushless DC motor operating performance on a ship is not ideal, hinder its propulsion in a lot of the popularization of high-performance power. Brushless DC motors referred BLDCM, the key issue is the control strategy of the motor, the torque stability control, and no position sensor. In this paper, the characteristics of loop and current loop response based BLDCM speed, using traditional PID algorithms and modern fuzzy control algorithm, designed the corresponding hardware and software systems, and the establishment of a small ship DSP-based brushless DC motor control device. Experimental results show that the fuzzy PID algorithm to better motor control, can achieve a

  17. 基于Maxwell的单相无刷直流电动机分析与设计%Analysis and Design of Single-phase Brushless DC Motors Using Maxwell

    Institute of Scientific and Technical Information of China (English)

    陈文敏; 黄开胜; 何良远; 杨勇

    2013-01-01

    This paper designed a single phase brushless DC motor of 2000 r/min,6 poles,200 V,100 W,and presented the way to design the motor.The motor was manufactured and tested.The paper established a 2D finite element analysis model for the motor using Maxwell of Ansoft,and then simulated some static and dynamic performances of the motor.The paper provided test results together with its simulation results.The errors between the simulation results and the test results were less than 8%,which confirmed the accuracy of the 2D finite element model and the simulation with the model.%以一款2000 r/min、6极、200 V、100 W单相无刷直流电动机为例,给出了设计这种单相无刷直流电动机的思路,完成了电磁方案设计,并试制了样机,进行了有关性能测试.利用Ansoft/Maxwell建立了这款电动机的二维有限元仿真模型,对其静态和动态性能进行仿真.仿真结果与样机试验结果各项性能指标误差在8%以内,验证了仿真模型和仿真分析的准确性.

  18. High-Accuracy Constant-Speed Research of Great Angular Momentum Brushless DC Gyro Motor%大角动量无刷直流陀螺电动机的高精度稳速研究

    Institute of Scientific and Technical Information of China (English)

    段晓妮; 孙纯祥

    2012-01-01

    A high-accuracy constant-speed system of great angular momentum permanent magnet brushless DC gyro motor was introduced. Based on the analysis of the operational principle of the brushless DC gyro motor, a speed closed -loop control strategy was designed, and the model of the BLDCM and controller was proposed in Simulink. DSP and CPLD were used as the main components of the controller. Piecewise PI was used as the control algorithm on steady speed. The motor was controlled by the combination of hardware and software to achieve soft start, protection of over current and steady speed controlling. Through prototype testing, the result shows that such control strategy has short starting time, high starting reliability and high-accuracy steady speed.%介绍了一种大角动量永磁无刷直流陀螺电动机的高精度稳速控制系统.在研究无刷直流陀螺电动机运行原理的基础上,应用了一种简单实用的速度闭环控制策略,并在Simulink中建立电机本体及控制模型.陀螺电动机的主控制器由硬件电路和软件程序组成.DSP和CPLD作为控制器主体,以分段PI算法为稳速控制方法,两者配合实现了软起动、过流保护和稳速控制等功能.样机试验结果表明,该控制系统起动迅速、起动可靠性高及稳速精度高.

  19. Nanotribology of charged polymer brushes

    Science.gov (United States)

    Klein, Jacob

    Polymers at surfaces, whose modern understanding may be traced back to early work by Sam Edwards1, have become a paradigm for modification of surface properties, both as steric stabilizers and as remarkable boundary lubricants2. Charged polymer brushes are of particular interest, with both technological implications and especially biological relevance where most macromolecules are charged. In the context of biolubrication, relevant in areas from dry eye syndrome to osteoarthritis, charged polymer surface phases and their complexes with other macromolecules may play a central role. The hydration lubrication paradigm, where tenaciously-held yet fluid hydration shells surrounding ions or zwitterions serve as highly-efficient friction-reducing elements, has been invoked to understand the excellent lubrication provided both by ionized3 and by zwitterionic4 brushes. In this talk we describe recent advances in our understanding of the nanotribology of such charged brush systems. We consider interactions between charged end-grafted polymers, and how one may disentangle the steric from the electrostatic surface forces5. We examine the limits of lubrication by ionized brushes, both synthetic and of biological origins, and how highly-hydrated zwitterionic chains may provide extremely effective boundary lubrication6. Finally we describe how the lubrication of articular cartilage in the major joints, a tribosystem presenting some of the greatest challenges and opportunities, may be understood in terms of a supramolecular synergy between charged surface-attached polymers and zwitterionic groups7. Work supported by European Research Council (HydrationLube), Israel Science Foundation (ISF), Petroleum Research Fund of the American Chemical Society, ISF-NSF China Joint Program.

  20. 直流无刷电机再生制动系统试验台的设计与验证%Design and Verification of Brushless DC Motor Regenerative Braking System Test Bench

    Institute of Scientific and Technical Information of China (English)

    隋妮; 王广萍; 李仲兴; 张德望; 顾剑波

    2011-01-01

    基于再生制动理论,以电动汽车用轮毂电机为主体,搭建了直流无刷电机再生制动试验台.以回收能量最大化为目标,提出了相应的再生制动控制策略.结合电机的输出特性和工作原理,利用SIMULINK软件建立了再生制动系统模型.通过模型仿真和试验台试验结果的对比分析,验证了再生制动试验台设计方案的可行性和控制策略的合理性.%Basod on theory of regenerative braking, with electric vehicle hub motor as subject, a brushless DC motor regenerative braking test bench is built. To maximize energy recovery, regenerative braking control strategy is proposed in the paper. In accordance with output characteristic and working principle of motor,regenerative braking system is established with software SIMULINK.By modeling simulation and contrastive analysis of the test result, feasibility of design program of regenerative braking test bench and rationality of control strategy are validated.

  1. Design of 9kW Permanent Magnet Brushless DC Motor Using Combination of Magnetic Circuit and Electromagnetic Field Solution%场路结合的9kW永磁无刷直流电动机设计

    Institute of Scientific and Technical Information of China (English)

    白娅梅; 罗玲; 黄其

    2012-01-01

    The design of 9kW permanent magnet brushless DC motor using the combination of magnetic circuit and electromagnetic field solution was presented in the paper. Main electromagnetic parameters, the number and shape of stator slot, the structure of stator and rotor were determined by using the equivalent magnetic circuit while no-load electromagnetic field and speed-torque characteristic were analyzed by means of electromagnetic field analysis software MagNet. The test values of no-load speed and current of the prototype motor match well with the results of simulation analysis. The validity of this method was shown in the motor design.%采用场路结合法设计9kW永磁无刷直流电动机,用磁路法确定电机的主要电磁参数、定子槽数和槽形、转子的磁路结构,运用电磁场分析软件MagNet分析计算空载磁场和机械特性,样机的空载转速、电流与仿真分析结果相一致,验证了采用场路结合法设计电机的有效性.

  2. Aerosol generation by blower motors as a bias in assessing aerosol penetration into cabin filtration systems.

    Science.gov (United States)

    Heitbrink, William A; Collingwood, Scott

    2005-01-01

    In cabin filtration systems, blower motors pressurize a vehicle cabin with clean filtered air and recirculate air through an air-conditioning evaporator coil and a heater core. The exposure reduction offered by these cabins is evaluated by optical particle counters that measure size-dependent aerosol concentration inside and outside the cabin. The ratio of the inside-to-outside concentration is termed penetration. Blower motors use stationary carbon brushes to transmit an electrical current through a rotating armature that abrades the carbon brushes. This creates airborne dust that may affect experimental evaluations of aerosol penetration. To evaluate the magnitude of these dust emissions, blower motors were placed in a test chamber and operated at 12 and 13.5 volts DC. A vacuum cleaner drew 76 m3/hour (45 cfm) of air through HEPA filters, the test chamber, and through a 5 cm diameter pipe. An optical particle counter drew air through an isokinetic sampling probe and measured the size-dependent particle concentrations from 0.3 to 15 microm. The concentration of blower motor aerosol was between 2 x 10(5) and 1.8 x 10(6) particles/m3. Aerosol penetration into three stationary vehicles, two pesticide application vehicles and one tractor were measured at two conditions: low concentration (outside in the winter) and high concentration (inside repair shops and burning incense sticks used as a supplemental aerosol source). For particles smaller than 1 microm, the in-cabin concentrations can be explained by the blower motor emissions. For particles larger than 1 microm, other aerosol sources, such as resuspended dirt, are present. Aerosol generated by the operation of the blower motor and by other sources can bias the exposure reduction measured by optical particle counters. PMID:15764523

  3. Comparing the efficiency of Denture brush and Ordinary brush in complete Denture cleaning

    OpenAIRE

    Amir Fayaz; Mohaddeseh Shakerian; Ghassem Ansari

    2013-01-01

    Please cite this article as: Fayaz A, Shakerian M, Ansari GH. Comparing the Efficiency of Denture brush and Ordinary brush in complete Denture cleaning. Novel Biomed 2013;1(2):62-65.Background & objective: Denture cleansing is a key element in retaining mucosa free of any inflammation. However, many denture users usually ignore this important factor. This investigation was designed to compare the efficacy of a denture brush and an ordinary brush in cleansing process of complete dentures.M...

  4. Advanced DC/DC converters

    CERN Document Server

    Luo, Fang Lin

    2003-01-01

    INTRODUCTIONHistorical ReviewMultiple Quadrant ChoppersPump CircuitsDevelopment of DC/DC Conversion TechniqueCategorize Prototypes and DC/DC Converters Family TreeVOLTAGE-LIFT CONVERTERSIntroductionSeven Self-Lift ConvertersPositive Output Luo-ConvertersNegative Output Luo-ConvertersModified Positive Output Luo-Converters Double Output Luo-ConvertersPOSITIVE OUTPUT SUPER-LIFT LUO-CONVERTERS IntroductionMain SeriesAdditional SeriesEnhanced Series Re-Enhanced Series Multiple-Enhanced Series Summary of Positive Output

  5. Nanopatterned polymer brushes: conformation, fabrication and applications

    Science.gov (United States)

    Yu, Qian; Ista, Linnea K.; Gu, Renpeng; Zauscher, Stefan; López, Gabriel P.

    2015-12-01

    Surfaces with end-grafted, nanopatterned polymer brushes that exhibit well-defined feature dimensions and controlled chemical and physical properties provide versatile platforms not only for investigation of nanoscale phenomena at biointerfaces, but also for the development of advanced devices relevant to biotechnology and electronics applications. In this review, we first give a brief introduction of scaling behavior of nanopatterned polymer brushes and then summarize recent progress in fabrication and application of nanopatterned polymer brushes. Specifically, we highlight applications of nanopatterned stimuli-responsive polymer brushes in the areas of biomedicine and biotechnology.

  6. 飞轮储能系统用永磁无刷直流电机设计与分析%Design and Analysis of Permanent Magnet Brushless DC Motor for Flywheel Energy Storage System

    Institute of Scientific and Technical Information of China (English)

    李保军; 王志新; 吴定国

    2012-01-01

    采用Ansoft中基于磁路法的RMxprt模块对2 kW/100 Wh容量的飞轮储能试验系统中所用的高速永磁无刷直流电机进行了具体设计,并在Ansoft Maxwell 2D中运用有限元的方法分析了电机内电磁场的分布情况及电机的静态和动态特性,分析结果表明所采用的电机方案能够满足飞轮储能系统的要求,具有一定的可行性和实用性.与传统的设计方法相比,提高了效率和精度,具有很强的工程实用性.%The RMxprt module of Ansoft was adopted to design the permanent brushless DC motor for the 2 kW/ 100 Wh flywheel energy storage system, the magnetic field distribution of the motor was calculated through the method of finite element analysis method in Ansoft Maxwell 2D,the static and dynamic characteristic of the motor was also analyzed. The results showed that the design scheme which is feasible and practical of the motor can meet the demand of the flywheel energy storage system. Compared with the traditional design method, efficiency and accuracy has been greatly improved and it also has a strong engineering practicability.

  7. 屏蔽罩对永磁直流电机磁场的影响分析%Magnetic Field Analysis of Permanent Magnet DC Motor with Different Shields

    Institute of Scientific and Technical Information of China (English)

    李继明; 胡欲立

    2011-01-01

    This paper numerically simulated and analyzed the inside and outside magnetic fields of a permanent magnet DC motor with different shield thickness for a certain underwater vehicle in static and load conditions. The acquired results can guide the selection of the shield and it has a good engineering application value.%利用电磁场有限元分析软件MagNet,对某型水下航行器推进用永磁直流电动机分别在静态和负载条件下采用不同厚度屏蔽罩时的磁场进行了数值仿真,分析研究了屏蔽罩对电机内外磁场的影响,所得结果可以指导屏蔽罩的选用,具有较好的工程应用价值.

  8. Application of IMC-PID controller in a brushless DC motor speed control system%内模PID控制器在无刷直流电机调速系统中的应用

    Institute of Scientific and Technical Information of China (English)

    秦刚; 谭进; 吴丹怡; 杜超

    2012-01-01

    针对无刷直流电机中传统PID控制器参数调节复杂、对环境适应能力较弱等问题,在分析内模控制与经典PID控制的内部对应关系的基础上,综合其优点,设计采用了一种基于内部模型的PID控制器(简称IMC-PID)对无刷直流电机进行调速。在建立对象理论模型的基础上,通过对控制器在线仿真比较表明:针对本设计对象,基于内部模型的PID控制器不论在系统阶跃响应或是扰动跟踪等控制效果上都能到达经典PID控制的要求,同时还降低了参数设计的复杂性和随机性。%This paper focuses on the problem that complexity and inconvenience of the traditional PID controller parameters adjustment and the weakness of its ability to adapt to the environment in brushless DC motor, analyzes the internal corresponding relationship of the internal model control and the classic PID, combines their advantages, designs a PID controller based on internal model to control speed of the brnshless DC motor. Based on the creation of object theoretical models, the online simulation and compare of controller shows that: to this object, the PID controller based on internal model can reach the requirements of the classic PID control in system step response and disturbance tracking control, while reducing the complexity and randomness of the parameters design.

  9. Influence of Temperature Rise on Shunt DC Motor Performance%温升对并励直流电动机性能的影响

    Institute of Scientific and Technical Information of China (English)

    陈旭东; 冯攀

    2011-01-01

    Because the resistance of the field winding is much larger than that of the armature, the influence of temperature rise on the performance of shunt motor is marked. The modeling and simulation in Matlab were presented,and studied that influence on the motor physical parameters and performance by the temperature rise was studied. The results show that it is counteractive on motor performance between armature and field winding among temperature rise. In order to depress the influence,the armature stuffs whose temperature coefficient is large was selected.%并励直流电动机因励磁绕组电阻远大于电枢绕组电阻,温升对电机性能的影响较为显著.该文在Mat-lab软件平台下,对并励电动机进行了建模和仿真,着重研究温升导致的电机物理参数和工作性能的变化,结果显示励磁线圈和电枢线圈在温升过程中对电机性能的影响具有“反效果”,因此可以选用具有较大温度系数的电枢绕组材料来降低温升的影响.

  10. BSA adsorption on bimodal PEO brushes

    NARCIS (Netherlands)

    Bosker, WTE; Iakovlev, PA; Norde, W; Stuart, Martien A. Cohen

    2005-01-01

    BSA adsorption onto bimodal PEO brushes at a solid surface was measured using optical reflectometry. Bimodal brushes consist of long (N = 770) and short (N = 48) PEO chains and were prepared on PS surfaces, applying mixtures of PS29-PEO48 and PS37-PEO770 block copolymers and using the Langmuir-Blodg

  11. BSA adsorption on bimodal PEO brushes

    NARCIS (Netherlands)

    Bosker, W.T.E.; Iakovlev, P.A.; Norde, W.; Cohen Stuart, M.A.

    2005-01-01

    BSA adsorption onto bimodal PEO brushes at a solid surface was measured using optical reflectometry. Bimodal brushes consist of long (N=770) and short (N=48) PEO chains and were prepared on PS surfaces, applying mixtures of PS 29-PEO48 and PS37-PEO770 block copolymers and using the Langmuir-Blodgett

  12. Novel Resonant Pole Voltage Source Inverter for Brushless DC Motor%新型无刷直流电动机专用谐振极逆变器研究

    Institute of Scientific and Technical Information of China (English)

    贺虎成; 杜京义; 刘卫国

    2009-01-01

    无刷直流电动机通常采用硬开关逆变器驱动.硬开关逆变器的系统效率较低,散热器的体积和重量较大,限制了无刷直流电动机驱动系统功率密度和性能的进一步提升.针对硬开关逆变器问题,提出了一种无刷直流电动机驱动系统专用的谐振极软开关电压源逆变器.通过在传统硬开关逆变器三个输出端和直流母线之间添加辅助谐振单元,实现了逆变桥主开关器件的PWM软开关动作.谐振控制开关零电流开关条件开通,零电压开关条件关断.对提出的新型谐振极逆变器进行了数学分析和仿真研究;仿真结果验证了电路结构和理论分析的正确性与可行性.%The brushless DC motor (BLDCM) has high torque, compact size, and high efficiency.Therefore, BLDCM is widely used in computers, household and industrial products, and automobiles.It is usually driven by a hard-switching PWM inverter, which has low switching frequency, high switc-hing loss, high EMI and acoustic noise, etc. To improve performance in brushless DC motor system,proposed a novel resonant pole voltage-source-inverter (VSI) for BLDCM. Realized soft switching oper-ation of switch devices in inverter by adding auxiliary remnant unit from three output ends to DC link.Auxiliary resonant switch was turned on under zero current switching (ZCS) and turned off under zero voltage switching (ZVS). Mathematic analysis and simulation were performed for novel inverter, and the simulation results were consistent with the theoretical analysis.

  13. A Realtime Fault Diagnosis Scheme for DC Motor in an Electrically-controlled Steering System%电控转向系统直流电机实时故障诊断方法

    Institute of Scientific and Technical Information of China (English)

    王祥; 宗长富; 邢海涛; 吴仁军; 张太武; 何晨雨

    2013-01-01

    Electric motors, as the actuator of electric power steering (EPS) system and steer-by-wire (SBW) system, its reliable operation is of utmost importance for the driving safety of vehicle with electrically controlled steering. In this paper, by building a model for permanent magnet DC motor (PMDCM) and applying recursive least square method with forgetting factor, a fault diagnosis scheme for PMDCM is proposed. A real SBW vehicle test is conducted for validation with a result indicating that the scheme proposed can accurately diagnose the faults of PMDCM realtime, laying a foundation for the fault-tolerant control of electrically controlled steering system.%作为电动助力转向系统和线控转向系统执行元件的电动机,其可靠运行对电控转向汽车的行驶安全至关重要.本文中通过建立永磁直流电机模型和运用带有遗忘因子的递推最小二乘法,提出了一种电控转向系统直流电机故障诊断方法.线控转向实车试验验证的结果表明,该方法可准确、实时地诊断直流电机故障,为电控转向系统的容错控制奠定基础.

  14. Design of Brushless DC Motor Controller Tracking Complex Position Curve%实现复杂位置曲线跟踪的直流无刷电机控制器设计

    Institute of Scientific and Technical Information of China (English)

    许家林; 王鹤; 朴仁官

    2012-01-01

    In order to resolve the problem that exiting Brushless DC (BLDC) motor controllers are incapable of tracking a complex position curve due to their low-frequency command reception, a BLDC motor controller was designed with enhanced reception that was able to handle instructions updating at a rate of 1 kHz. In the aspect of hardware, the microcontroller ARM Cortex-M3 was used as the CPU and the chip A4936 was a-dopted as its 3-phase bridge pre-driver. In the aspect of software, a PID control algorithm with speed and acceleration feed-forward was applied. Tests were implemented using instructions which update at a rate of 1 kHz, the results acquired illustrated that the BLDC motor controller has high tracking precision and fast response speed.%针对现有的无刷直流电机控制器不能接收高频数字指令以实现复杂位置曲线跟踪的问题,设计了指令更新速率高达1 kHz的控制器.硬件上,采用ARM Cortex-M3微控制器作为处理器,使用芯片A4936作为3相桥的换相逻辑控制器.软件上,应用了带有速度、加速度前馈的PID控制算法.使用更新速率是1 kHz的指令进行测试,结果表明,有很高的跟踪精度和较快的响应速度.

  15. Effectiveness of denture cleanser associated with microwave disinfection and brushing of complete dentures: in vivo study.

    Science.gov (United States)

    Sesma, Newton; Rocha, Alessandra Lima; Laganá, Dalva Cruz; Costa, Bruno; Morimoto, Susana

    2013-01-01

    Complete dentures acts as a reservoir for microbial colonization, which may lead to systemic infections. Microwave irradiation has been used as an efficient method of denture disinfection. Even though current methods eliminate denture-base microorganisms, a recurrence rate of denture stomatitis (DS) is still observed among denture-wearing patients. It was hypothesized that microwave disinfection kills microorganisms but do not remove dead bacteria from the denture surface. To test this hypothesis, the biofilm found in the dentures of 10 patients with DS was evaluated. In addition, the effects of microwave irradiation plus brushing (MW+B) on the denture biofilm and the combination of denture cleanser with microwave irradiation and brushing (MW+DC+B) for the removal of denture-accumulating microorganisms were investigated. Microbiological data were analyzed statistically by nonparametric analysis (Friedman/Wilcoxon, α=0.05). MW+B and MW+DC+B were effective in reducing the rate of microorganisms (99.2% and 99.5% respectively), but without significant difference between them (p=0.553). However, it was observed that the complete removal of microorganisms from denture surface was only possible when all regimens were combined (MW+DC+B). Microwave irradiation in combination with soaking in denture cleanser and brushing effectively disinfected the dentures and removed denture biofilm.

  16. Interfacial Friction and Adhesion of Polymer Brushes

    KAUST Repository

    Landherr, Lucas J. T.

    2011-08-02

    A bead-probe lateral force microscopy (LFM) technique is used to characterize the interfacial friction and adhesion properties of polymer brushes. Our measurements attempt to relate the physical structure and chemical characteristics of the brush to their properties as thin-film, tethered lubricants. Brushes are synthesized at several chain lengths and surface coverages from polymer chains of polydimethylsiloxane (PDMS), polystyrene (PS), and a poly(propylene glycol)-poly(ethylene glycol) block copolymer (PPG/PEG). At high surface coverage, PDMS brushes manifest friction coefficients (COFs) that are among the lowest recorded for a dry lubricant film (μ ≈ 0.0024) and close to 1 order of magnitude lower than the COF of a bare silicon surface. Brushes synthesized from higher molar mass chains exhibit higher friction forces than those created using lower molar mass polymers. Increased grafting density of chains in the brush significantly reduces the COF by creating a uniform surface of stretched chains with a decreased surface viscosity. Brushes with lower surface tension and interfacial shear stresses manifest the lowest COF. In particular, PDMS chains exhibit COFs lower than PS by a factor of 3.7 and lower than PPG/PEG by a factor of 4.7. A scaling analysis conducted on the surface coverage (δ) in relation to the fraction (ε) of the friction force developing from adhesion predicts a universal relation ε ∼ δ4/3, which is supported by our experimental data. © 2011 American Chemical Society.

  17. 无刷直流电机与控制模块安规认证%Safety Certificate of Brushless DC Motor and its Control Module

    Institute of Scientific and Technical Information of China (English)

    Flex Wang

    2008-01-01

    @@ 1 串激式电机的应用与特性 串激式电机(Series Motorg)也称作电刷式电机(Conventional Motors),具备高扭力输出的特性,常常运用在毋需精确转速控制的电动工具中,例如手提式电钻、圆盘锯或是台式木工锯床、木工角度切割锯床等.在构造上使用机械式换相器(Commutator),将电源供应给电机转子绕组(Armature).

  18. PWM SiNYALİ İLE DC MOTOR HlZ KONTROLÜ VE SÜRÜCÜ DEVRESİNİN ESD ETKİLERİNDEN KORUNMASI

    Directory of Open Access Journals (Sweden)

    Fatih Kurt

    2002-09-01

    Full Text Available PWM sinyali, motor hızını kontrol etntek ıçın başvurulan verimli bir yöntemdir. PWM sinyalini yazılım ile üretmek çok kolayd ır. Temel olarak motorun dönme hız ı, darbeler şeklin de ENABLE girişine uygulanacak lojik voltajm darbe zaman aralığına bağhdır. Bu yazıda PWM sinyalinin; 8254 terminali ve yazılam ile üretilmesi, devrenin işleyişi ve aynı devre üzerin de elektronik bileşenler için hassas bir nok taya gelen Elektrostatik Deşarj (ESD etkisinden korunma olayına değinilmiştir

  19. Design of Fully-integrated and H-bridge for DC Motor Driver IC%全集成全桥直流马达驱动芯片的设计

    Institute of Scientific and Technical Information of China (English)

    郭振宗; 何进; 罗将; 王豪; 常胜; 黄启俊

    2016-01-01

    基于CSMC 0.5μm HV CMOS工艺,实现了一款具有优良动态性能和全面失效保护功能的全集成全桥直流马达驱动芯片.芯片提供了待机、正转、反转和制动四种基本驱动模式,以及脉冲宽度调制(PWM )调速和模拟电压调速两种调速模式;集成了全面的失效保护电路,包括欠压保护电路、过温保护电路和过流保护电路.流片封装后的样片测试结果表明,芯片各工作模式正常;在电源电压分别为5V,4V,3V时,驱动MOS管的导通电阻分别约为0.65Ω,0.8Ω,1Ω;在2.5~5.5V工作电压范围内,可以提供最大值为1A的驱动电流.%A fully integrated and H‐bridge DC motor driver with excellent dynamic performance and comprehensive fail‐safe function has been implemented in CSMC 0 .5‐μm HV CMOS technology .In addition to operation with four basic modes ,such as idle ,forward ,reverse and brake ,this IC also can drive motor with two kinds of speed regulated modes :pulse width modulator (PWM ) signal and analog voltage .The IC integrates comprehensive fail‐safe circuits ,including the under voltage protection circuit ,over‐temperature protection circuit and overcurrent protection circuit .The measured results of packaged IC sample show that all drive modes operated well .The power MOSFET’s on resistance are about 0 .65 Ω、0 .8 Ω and1 Ω when supply voltage were 5 V、4 V and 3 V ,respectively . The IC can output a maximum of 1 A dc current within a supply voltage range of 2 .5‐5 .5 V .

  20. 凸极式永磁无刷直流电机无位置传感型瞬时转矩观测%Instantaneous Torque Estimation in Sensorless Saliency Permanent Magnet Brushless DC Motors

    Institute of Scientific and Technical Information of China (English)

    周扬忠; 林启星; 马俊亭

    2013-01-01

    A key issue in the direct torque control (DTC) of permanent magnet brushless DC motor (BLDCM) is the estimation of the instantaneous electromagnetic torque.Additionally,some BLDCMs also have saliency phenomenon which augments the difficulty of torque estimation.A sensorless toque estimator was proposed in this paper.A stator current estimator with rotor back-electromotive-force (BEMF) self-adaptation was firstly constructed according to stator current state equations and the rotor BEMF was gained by adaptive law.Then,a lock-phase loop was used to output smooth rotor position angle estimation value on basic of identified rotor BEMF.At last,the torque was calculated to realize saliency BLDCM-DTC based on the estimated rotor position angle.The experimental results show the estimated torque is very close to the actual value,and the novel sensorless DTC drive has quick dynamic response and smooth operation with a minimum steady-state speed lowering to 33 r/min.%电磁转矩的准确观测是实现永磁无刷直流电机(brushless DC motor,BLDCM)直接转矩控制(direct torque control,DTC)的关键.另外,有些BLDCM还具有一定的凸极现象,增加了电磁转矩观测的难度.为此,该文针对凸极式BLDCM-DTC驱动提出一种无位置传感器型电磁转矩观测器.该观测器利用BLDCM定子电流状态方程构建一个转子反电动势自适应的定子电流观测器,利用自适应机制推导出转子反电动势辨识值;根据辨识的转子反电动势,采用锁相环输出平稳的转子位置角观测值;基于该观测角,计算出电磁转矩,实现凸极式BLDCM-DTC系统平稳运行.实验结果表明,所提观测器观测的电磁转矩与实际值非常接近;无位置传感器DTC系统动态响应迅速,稳态运行平稳,最低运行转速可达33 r/min.

  1. Comparing the efficiency of Denture brush and Ordinary brush in complete Denture cleaning

    Directory of Open Access Journals (Sweden)

    Amir Fayaz

    2013-11-01

    Full Text Available Please cite this article as: Fayaz A, Shakerian M, Ansari GH. Comparing the Efficiency of Denture brush and Ordinary brush in complete Denture cleaning. Novel Biomed 2013;1(2:62-65.Background & objective: Denture cleansing is a key element in retaining mucosa free of any inflammation. However, many denture users usually ignore this important factor. This investigation was designed to compare the efficacy of a denture brush and an ordinary brush in cleansing process of complete dentures.Materials & Methods: A group of 31 individuals aged 44-76 years were included in this study. Each patient was then instructed to use the denture brush for a period of 4 weeks while an ordinary brush was to be used for the following 4 weeks. Dentures were photographed and evaluated at every two week intervals using a computer photographic software assessment method. Pictures were compared using the image tool for plaque remaining on the denture surfaces. Student t-test was used to analyse data collected.Results: Comparison of the brush type efficacy at 2 and 4 weeks did not show any significant difference ( P>0.05 , however , clinical evaluation indicated that denture brush leaves much less plaque bio-film compare to the ordinary one, with mean plaque traced at 6.88 to 9.24 in 4 weeks.Conclusion: There were no significant differences found between the two brushes’ efficacy, with clinical evaluation significantly in favor of denture brush.

  2. PWM DC/DC Converter

    OpenAIRE

    Chen, Juan

    2008-01-01

    This report is the result of a Master Thesis work done at Seaward Electronics Inc. in Beijing, China from June to December in 2007. The main goal for this thesis is to verify and improve the performance of Honey-PWM DC-DC converter, which has been fabricated by a standard 0.6um CMOS processes. The project was started with studying of Buck converter structure. After the understanding of the converter structure, the project goes in to the analyses phase for each sub-cells, including the theory,...

  3. Touch- and Brush-Spinning of Nanofibers.

    Science.gov (United States)

    Tokarev, Alexander; Asheghali, Darya; Griffiths, Ian M; Trotsenko, Oleksandr; Gruzd, Alexey; Lin, Xin; Stone, Howard A; Minko, Sergiy

    2015-11-01

    Robust, simple, and scalable touch- and brush-spinning methods for the drawing of nanofibers, core-shell nanofibers, and their aligned 2D and 3D meshes using polymer solutions and melts are discussed.

  4. Water driven turbine/brush pipe cleaner

    Science.gov (United States)

    Werlink, Rudy J. (Inventor)

    1995-01-01

    Assemblies are disclosed for cleaning the inside walls of pipes and tubes. A first embodiment includes a small turbine with angled blades axially mounted on one end of a standoff support. An O-ring for stabilizing the assembly within the pipe is mounted in a groove within the outer ring. A replaceable circular brush is fixedly mounted on the opposite end of the standoff support and can be used for cleaning tubes and pipes of various diameters, lengths and configurations. The turbine, standoff support, and brush spin in unison relative to a hub bearing that is fixedly attached to a wire upstream of the assembly. The nonrotating wire is for retaining the assembly in tension and enabling return of the assembly to the pipe entrance. The assembly is initially placed in the pipe or tube to be cleaned. A pressurized water or solution source is provided at a required flow-rate to propel the assembly through the pipe or tube. The upstream water pressure propels and spins the turbine, standoff support and brush. The rotating brush combined with the solution cleans the inside of the pipe. The solution flows out of the other end of the pipe with the brush rotation controlled by the flow-rate. A second embodiment is similar to the first embodiment but instead includes a circular shaped brush with ring backing mounted in the groove of the exterior ring of the turbine, and also reduces the size of the standoff support or eliminates the standoff support.

  5. Research and application of dual-mode operation technology of brushless DC motor%无刷直流电机双模控制技术研究与应用

    Institute of Scientific and Technical Information of China (English)

    李凤祥; 朱伟进

    2013-01-01

    针对无刷直流电机的无位置传感器控制“三段式”起动技术的缺陷,以电动自行车为研究对象,采用反电动势过零点检测方法和相位补偿技术,通过改进反电动势检测电路,优化无位置传感器控制的起动方法,设计出基于相位补偿的双模式运行无刷直流电机控制方案,使无刷直流电机可运行在有位置传感器和无位置传感器两种模式下,当位置传感器信号输出正常时,电机默认运行在有位置传感器模式;若位置传感器信号输出不正常,电机自动切换运行在无位置传感器模式.实验证明,反电势检测电路灵敏度高,且很好的实现了相移补偿,两种模式切换过程平稳,运行状态平稳.%Aiming at overcoming shortcoming of " three-step" start method of the brushless DC motor (BLDCM) sensorless control, a dual-mode BLDCM controller was developed based on phase compensation technology by studying electric bicycle, using back electromotive force(back-EMF)detection method and improving the back-EMF detection circuit and position sensorless starting method. By using the technology , BLDCM can be run on position sensor mode and sensorless mode. When the position sensor signal output is normal, the motor is run on the position sensor mode in default; otherwise, when position sensor signal output is abnormal, the motor automatically switches to be run on the mode without position sensor. The experimental result proves that the detection circuit boasts high sensitivity and completely compensates the phase delay; two modes work steadily and the switching process is smooth.

  6. A Built-in Electric Cable Winch Driven by DC Motor%一种直流电机驱动的内装式电动电缆绞盘

    Institute of Scientific and Technical Information of China (English)

    杨少琴; 庄衍平

    2014-01-01

    介绍一种新型的直流电动机驱动的内装式电动电缆绞盘,这种电缆绞盘由直流电动机驱动,减速器为活齿减速器结构,把驱动装置和减速机构装在电缆绞盘滚筒里面。整体结构简单、紧凑,传动效率高,广泛应用于移动电源的电缆收放作业。%This paper introduces a new type built-in electric cable winch driven by DC motor .Decelerator structure is oscillating tooth decelerator , make the driving device and reducing mechanism installed in the roller of cable winch .The whole structure is simple and compact .Its transmission efficiency is high and widely used in twis-ted and released of the cable operation of mobile power supply .

  7. Structure Design and Strength Analysis of the Permanent DC Motor%永磁直流电动机电枢结构设计和强度分析

    Institute of Scientific and Technical Information of China (English)

    王峥; 原慧芳; 王桢楠

    2013-01-01

    以低惯量耐高冲击空心杯永磁式直流电动机电枢为工程研究对象,简要介绍了电枢的结构设计,对空心杯电枢的结构强度和耐冲击能力进行了详细的数值计算和有限元分析,最后,进一步优化电枢的结构设计和关键工艺.%The permanent-magnet cup-armature DC motor's rotor with a small inertia moment and high anti-shock ability was taken as the research object.The rotor's structure was introduced briefly.The structural strength and anti-shock ability of cup-armature rotor were calculated and analyzed with FEA(Finite Element Analysis) in detail.The rotor's structure and key process were optimized further.

  8. 基于无刷直流电机的执行器防堵转系统的设计%Design of electric actuator locked rotor protective system based on brushless DC motor

    Institute of Scientific and Technical Information of China (English)

    张寿春

    2012-01-01

    In order to protect the electric actuator driven by the brushless DC motor and controller for locked rotor,avoid the controller is damaged.The method of protection of taking LPC2132 central processing unit and hardware circuit of electric current collected of the control system,at same time intelligent judgment and treatment by using the method of software.Realization of intelligent control in the state of locked rotor,protect the controller.The experiment shows that: the system has reliability and the advantages of processing locked rotor in intelligent mode.%为了防止直流无刷电机驱动的执行器因电机堵转而损坏控制器,控制系统采用以LPC2132微处理器和电流采集等电路相结合的硬件保护方法,同时采用软件进行智能判断与处理。实现了电动执行器在堵转的状态下的智能控制,保护了控制器。实验结果表明:该系统具有可靠性高及智能处理堵转等优点。

  9. An Integrated Multifunctional Bidirectional AC/DC and DC/DC Converter for Electric Vehicles Applications

    Directory of Open Access Journals (Sweden)

    Liwen Pan

    2016-06-01

    Full Text Available This paper presents an on-board vehicular battery charger that integrates bidirectional AC/DC converter and DC/DC converter to achieve high power density for application in electric vehicles (EVs. The integrated charger is able to transfer electrical energy between the battery pack and the electric traction system and to function as an AC/DC battery charger. The integrated charger topology is presented and the design of passive components is discussed. The control schemes are developed for motor drive system and battery-charging system with a power pulsation reduction circuit. Simulation results in MATLAB/Simulink and experiments on a 30-kW motor drive and 3.3-kW AC/DC charging prototype validate the performance of the proposed technology. In addition, power losses, efficiency comparison and thermal stress for the integrated charger are illustrated. The results of the analyses show the validity of the advanced integrated charger for electric vehicles.

  10. Isolerad DC/DC-omvandlare

    OpenAIRE

    Andersson, Martin

    2011-01-01

    1 SammanfattningCrossControl är ett företag som bland annat tillverkar integrerade datorlösningar. Datorerna drivs normalt med 18-30 VDC och förbrukar som mest 50W. Datorerna säljs till flertalet olika kunder som monterar dem i allt från skogsmaskiner till tåg. I de olika fordonen varierar spänningen i de befintliga elnäten. Detta skapar behovet av att omvandla spänningen till en nivå som datorerna klarar av. En sådan apparat kallas DC/DC-omvandlare. Spänningsomvandling kan utföras genom linj...

  11. Simulation Research of Fault Model of Detecting Rotor Dynamic Eccentricity in Brushless DC Motor Based on Motor Current Signature Analysis%基于定子电流法监测无刷直流电动机转子动态偏心的故障模型仿真研究

    Institute of Scientific and Technical Information of China (English)

    赵向阳; 葛文韬

    2011-01-01

    The dynamic eccentricity fault model was implemented and the inductance and flux were resolved based on the finite element method (FEA) on Ansoft/Maxwell. That the simplified fault frequency of monitoring induction motor dynamic eccentricity could be used on brushless DC motor (BLDC) was demonstrated by simulation. The system of brushless DC motor was simulated on Ansoft/Simplorer. In steady state, the Fast Fourier Transform (FFT) analysis was used on the stator current. The simulated model of detecting dynamic eccentricity based on the stator current signature analysis (MCSA) method was investigated and implemented: The frequency to indentify dynamic eccentricity fault, the amplitude of frequency to estimate the dynamic eccentricity severity. Furthermore, the effect of speed pulsation of BLDC operating under steady state was investigated in this article. The results indicate that the severity of dynamic eccentricity fault increase, the amplitude of fault frequency increase.%基于Ansoft/Maxwell设置动态偏心故障,建立求解电机电感和磁链的有限元模型,通过仿真,证明了将感应电机动态偏心故障的特征频率经过简化后,同样适用于无刷直流电动机。基于Ansoft/Simplorer建立无刷直流电动机系统的仿真模型。在电机稳态运行下,对定子电流进行傅里叶分析,研究并建立基于定子电流监测动态偏心故障的仿真模型:动态偏心故障与特征频率的关系、动态偏心故障程度与特征频率幅值的关系。进而研究了无刷直流电动机稳态运行时转速波动对偏心故障监测的影响。仿真结果表明,转子偏心程度加大,特征频率的幅值增加。

  12. Research on the controlling of rare earth permanent magnet brushless DC motor based on TMS320C242%基于TMS320C242的稀土永磁无刷直流电机控制系统研究

    Institute of Scientific and Technical Information of China (English)

    董艺

    2012-01-01

    对用TMS320C242控制稀土永磁无刷直流电机(REPMBLDCM)进行了深入的探讨。作为驱动设备,稀土永磁无刷直流电机在很多方面性能优于普通直流电机;作为控制核心,TMS320C242无论是集成度还是控制速度都远超普通的单片机。所以用TMS320C242控制REPMBLDCM可获得极为优秀的控制效果和驱动性能。%A deep discussion has been made on how to control rare earth permanent magnet brushless DC motor with TMS320C242. As a driving device, rare earth permanent magnet brushless DC motor is superior to the common DC motor in many ways. As a core of the control system, TMS320C242 is far more superior to the common single chip microcontroller unit whether on its integration or its controlling speed. Therefore, excellent control effects and driving properties can be obtained by adopting TMS320C242 to control REPMBLDCM.

  13. Morphology and tribological properties of Ni/n-SiO2 composite coatings by pulse-reverse current brush-plating

    Institute of Scientific and Technical Information of China (English)

    TAN Jun; GUO Wen-cai; YANG Hong-jun; ZHOU Liang

    2005-01-01

    Ni/n-SiO2 composite coating was electrodeposited by brush-plating with pulse-reverse current(RC). The morphology, hardness, and tririological properties of the coating were investigated and compared with those of Ni and composite coatings electrodeposited with direct current (DC). The results indicate that Ni/n-SiO2 composite coating electrodeposited by RC, because of RC and the nano powders, has denser coating, finer crystal grains, high er hardness(HV650. 0, nearly 1.5 times higher than that of Ni coating electrodeposited by DC) and lower friction coefficient(nearly 0.62), as a result, in the wearing experiment, the Ni/n-SiO2 composite coating electrodeposited by RC has the least worn loss. So this kind of coating has better wear resistance. And RC electro brush-plating can be used as a new technology of brush-plating in the area of wear resistance.

  14. DC drive system for cine/pulse cameras

    Science.gov (United States)

    Gerlach, R. H.; Sharpsteen, J. T.; Solheim, C. D.; Stoap, L. J.

    1977-01-01

    Camera-drive functions are separated mechanically into two groups which are driven by two separate dc brushless motors. First motor, a 90 deg stepper, drives rotating shutter; second electronically commutated motor drives claw and film transport. Shutter is made of one piece but has two openings for slow and fast exposures.

  15. FreedomCAR Advanced Traction Drive Motor Development Phase I

    Energy Technology Data Exchange (ETDEWEB)

    Ley, Josh (UQM Technologies, Inc.); Lutz, Jon (UQM Technologies, Inc.)

    2006-09-01

    The overall objective of this program is to design and develop an advanced traction motor that will meet the FreedomCAR and Vehicle Technologies (FCVT) 2010 goals and the traction motor technical targets. The motor specifications are given in Section 1.3. Other goals of the program include providing a cost study to ensure the motor can be developed within the cost targets needed for the automotive industry. The program has focused on using materials that are both high performance and low costs such that the performance can be met and cost targets are achieved. In addition, the motor technologies and machine design features must be compatible with high volume manufacturing and able to provide high reliability, efficiency, and ruggedness while simultaneously reducing weight and volume. Weight and volume reduction will become a major factor in reducing cost, material cost being the most significant part of manufacturing cost at high volume. Many motor technology categories have been considered in the past and present for traction drive applications, including: brushed direct current (DC), PM (PM) brushless dc (BLDC), alternating current (AC) induction, switched reluctance and synchronous reluctance machines. Of these machine technologies, PM BLDC has consistently demonstrated an advantage in terms of power density and efficiency. As rare earth magnet cost has declined, total cost may also be reduced over the other technologies. Of the many different configurations of PM BLDC machines, those which incorporate power production utilizing both magnetic torque as well as reluctance torque appear to have the most promise for traction applications. There are many different PM BLDC machine configurations which employ both of these torque producing mechanisms; however, most would fall into one of two categories--some use weaker magnets and rely more heavily on reluctance torque (reluctance-dominant PM machines), others use strong PMs and supplement with reluctance torque

  16. Voltage Tracking of a DC-DC Flyback Converter Using Neural Network Control

    Directory of Open Access Journals (Sweden)

    Wahyu Mulyo Utomo

    2012-01-01

    Full Text Available This paper proposes a neural network control scheme of a DC-DC Flyback converter that will step up a 12V DC and applied it on brushless DC motor with 12 and 24V dc. In this technique, a back propagation learning algorithm is derived. The controller is designed to track the output voltage of the DC-DC converter and to improve performance of the Flyback converter during transient operations. Furthermore, to investigate the effectiveness of the proposed controller, some operations such as starting-up and reference voltage variations are verified. The numerical simulation results show that the proposed controller has a better performance compare to the conventional PI-Controller method.

  17. Two-stage eutectic metal brushes

    Science.gov (United States)

    Hsu, John S [Oak Ridge, TN

    2009-07-14

    A two-stage eutectic metal brush assembly having a slip ring rigidly coupled to a shaft, the slip ring being electrically coupled to first voltage polarity. At least one brush is rigidly coupled to a second ring and slidingly engaged to the slip ring. Eutectic metal at least partially fills an annulus between the second ring and a stationary ring. At least one conductor is rigidly coupled to the stationary ring and electrically coupled to a second voltage polarity. Electrical continuity is maintained between the first voltage polarity and the second voltage polarity. Periodic rotational motion is present between the stationary ring and the second ring. Periodic rotational motion is also present between the brush and the slip ring.

  18. Research of simulation for brushless DC motor with dual closed-loop cascade control system%无刷直流电机双闭环串级控制系统仿真研究

    Institute of Scientific and Technical Information of China (English)

    吕伟鹏

    2011-01-01

    In order to analyze and design the control system of BLDCM effectively,a new method of modeling and simulation for brushless DC motor under Matlab is proposed,this method is based on modular.Each module is described in detail.and then test the control system with a classic double-loop control method of modeling and simulation. The experimental results shows that the waveform of simulation consistent with analysis of theoretical The intergral separation which used in PI regulator makes zero-shoot on speed, and the system runs stability.It provides a great convenience for designing and debugging the system.%为了有效地分析和设计BLDCM控制系统,基于Matlab提出了一种新型的模块化的BLDCM控制系统仿真建模的方法。对各个模块进行了详细说明。最后,采用经典的速度、电流双闭环控制方法对该建模方法进行了仿真测试。结果表明仿真波形符合理论分析。转速环引入了积分分离的PI调节器使超调量为零,系统特性稳定,它为实际系统设计和调试工作提供了极大方便。

  19. 基于自适应DRNN的无刷直流电机控制方法研究%Study on Control Method of Brushless DC Motors Based on Self-adaptive DRNN

    Institute of Scientific and Technical Information of China (English)

    王立标; 李军; 范剑; 李绣峰

    2011-01-01

    针对无刷直流电机速度控制存在高度非线性特性,提出了基于自适应DRNN(diagonal re-current neural network)的"前馈+反馈"控制方法。反馈控制器以目标转速与实际转速的误差为输入量,采用PI控制来提高控制系统的稳定性。前馈控制器采用DRNN,以反馈控制器的输出作为性能误差进行自适应控制,以提高控制系统的瞬态响应性能。仿真和实验结果表明:该控制系统能较好地跟踪目标转速,在突变负载扰动下,能有效地改善相电流波形,降低电机电磁转矩脉动,而且该控制系统具有较强的鲁棒性。%In view of brushless DC motor speed control for highly nonlinear characteristics,a self-adaptive DRNN control system was proposed.The controller consisted of a PI feedback controller and a self-adaptive DRNN feed-forward controller.The PI feedback controller used target speed and actual speed error for input to improve the stability of control system.The feed-forward controller was trained by using feedback controller outputs as learning error to improve transient performance of control system.The simulation and experimental results illustrate that the control system can track the target speed,reduce the torque ripple and improve the current waveform under load disturbances,which has strong robustness.

  20. Analysis on the Operation Characteristics of Brushless DC Motor Using Bootstrap Driving Method%自举驱动方式下无刷直流电机运行特性分析

    Institute of Scientific and Technical Information of China (English)

    周西峰; 孙浩; 王丹; 郭前岗

    2011-01-01

    This paper analyzes the main problems of brushless DC motor(BLDCM) driving control system using bootstrap driving method. It is noted that PWM scheme is restricted when bootstrap driving method is adopted,thus initiated problems of more torque ripple, the diode freewheeling of the inactive phase, difficulties in sensorless BLDCM control and the heat generation of power switches.The basic reasons of those problems are profoundly analyzed through theoratical and mathmatical methods,and the correctness of the conclusion is also verified by experiment. Meanwhile, solution is also proposed for those which have requirements on more restricted specifications.%详细分析了自举驱动方式下无刷直流电机(BLDCM)控制系统中存在的主要问题,指出了因采用自举驱动带来的PWM调制方式受限问题以及由此引发的转矩脉动、非导通相续流、无位置传感器控制实施困难和开关管发热问题.在此通过原理分析和公式推导,深入分析了产生上述问题的根本原因,并通过实验验证了所推结论的正确性,同时给出了在控制指标要求较高的场合解决上述问题的方法.

  1. 非换相期间无刷直流电机转矩脉动分析与抑制%Analysis and Suppression of Torque Ripple During Non-commutation of Brushless DC Motor

    Institute of Scientific and Technical Information of China (English)

    李怀兵; 丑武胜; 冯震

    2011-01-01

    Torque ripple is an important factor affecting the performance of Brushless DC motor (BLDCM).In this paper, the non-commutation torque ripple was analyzed, focusing on the torque ripple caused by PWM_ON modulation.The main part of the torque ripple was caused by the PWM_OFF, and the diode freewheeling of inactive phase can compensate the torque ripple to some extent.Meanwhile, hysteresis current control was proposed to suppress the non-commutation torque ripple.The simulation and experiment show the difference between the method and the traditional method, and prove the validity of the method suppressing the torque ripple during non-commutation.%无刷直流电机的转矩脉动是影响其性能的重要因素.该文针对非换相期间的转矩脉动进行了分析,重点研究了PWM_ON调制方式时的转矩脉动.PWM信号为"OFF"时续流引起的转矩脉动占主要部分,非导通相续流在一定程度上可以补偿PWM关断时造成的转矩脉动.同时,提出使用滞环电流控制方法,采用该方法可以抑制非换相期间转矩脉动.通过仿真分析和实验验证了该方法和传统方法的差异,证明了该方法在非换相期间抑制转矩脉动的有效性.

  2. Dimeric assembly of enterocyte brush border enzymes

    DEFF Research Database (Denmark)

    Danielsen, E M

    1994-01-01

    The noncovalent, dimeric assembly of small intestinal brush border enzymes was studied by sedimentation analysis in density gradients of extracts of pulse-labeled pig jejunal mucosal explants. Like aminopeptidase N (EC 3.4.11.2), sucrase-isomaltase (EC 3.2.1.48-10), aminopeptidase A (EC 3...... appearance of the liposome-reconstituted enzyme [Norén et al. (1986) J. Biol. Chem. 261, 12306-12309], showing only the inner, membrane-anchored domains of the monomers to be in close contact with one another while the outer domains are far apart. In contrast to the other brush border enzymes studied...

  3. A DC Transformer

    Science.gov (United States)

    Youngquist, Robert C.; Ihlefeld, Curtis M.; Starr, Stanley O.

    2013-01-01

    A component level dc transformer is described in which no alternating currents or voltages are present. It operates by combining features of a homopolar motor and a homopolar generator, both de devices, such that the output voltage of a de power supply can be stepped up (or down) with a corresponding step down (or up) in current. The basic theory for this device is developed, performance predictions are made, and the results from a small prototype are presented. Based on demonstrated technology in the literature, this de transformer should be scalable to low megawatt levels, but it is more suited to high current than high voltage applications. Significant development would be required before it could achieve the kilovolt levels needed for de power transmission.

  4. Advanced DC Motor Drive for Haptic Devices

    OpenAIRE

    Miroslav Božić; Darko Todorović; Miloš Petković; Volker Zerbe; Goran S. Đorđević

    2012-01-01

    Haptics covers many different forms of mechanical interaction with human senses by engaging, touch, vibrations and forces/torques, established for the purpose of augmenting the feedback structure during human-machine interaction. A haptic device has mechanical part, moved by actuators from one and human hand or fingers from the other, actuators, drives, sensing elements, as well as algorithms designed to control the interaction between human and machine in positioning and motion control tasks...

  5. Scaling Relationships for Spherical Polymer Brushes Revisited.

    Science.gov (United States)

    Chen, Guang; Li, Hao; Das, Siddhartha

    2016-06-16

    In this short paper, we revisit the scaling relationships for spherical polymer brushes (SPBs), i.e., polymer brushes grafted to rigid, spherical particles. Considering that the brushes can be described to be encased in a series of hypothetical spherical blobs, we identify significant physical discrepancies in the model of Daoud and Cotton (Journal of Physics, 1982), which is considered to be the state of the art in scaling modeling of SPBs. We establish that the "brush" configuration of the polymer molecules forming the SPBs is possible only if the swelling ratio (which is the ratio of the end-to-end length of the blob-encased polymer segment to the corresponding coil-like polymer segment) is always less than unity-a notion that has been erroneously overlooked in the model of Daoud and Cotton. We also provide new scaling arguments that (a) establish this swelling (or more appropriately shrinking) ratio as a constant (less than unity) for the case of "good" solvent, (b) recover the scaling predictions for blob dimension and monomer number and monomer concentration distributions within the blob, and

  6. Spherical Polyelectrolyte Brushes and Their Films

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Nano-sized spherical polyelectrolyte brushes (SPB), which consist of a solid polystyrene core and linear poly(acrylic acid) (PAA) chains covalently attached on the core surface by one end with different lengths and grafting densities, were prepared by photo-emulsion polymerization and thermo- controlled emulsion polymerization.

  7. Curvature elasticity of a grafted polyelectrolyte brush

    Science.gov (United States)

    Lei, Zhen; Miao, Bing; Yang, Shuang; Chen, Er-Qiang

    2015-06-01

    The curvature elasticity of a polyelectrolyte brush monolayer attached to curved surface is investigated theoretically. An analytical method based on the strong-stretching theory for a Gaussian chain is developed to calculate the elastic modulus induced by a polyelectrolyte brush. In particular, the scaling relations for the bending or Gaussian modulus with respect to system parameters related to the electrostatic interaction (degree of ionization and salt concentration) are derived. Using the numerical self-consistent-field theory, the inner structural, free-energy, and elastic moduli are computed for the polyelectrolyte brush with excluded-volume interactions. Compared to the analytical result, the curvature elasticity has a weaker dependence on the system parameters, which is attributed to the linearization for the Poisson-Boltzmann equation in the analytical treatment. Furthermore, our results are compared to the curvature elasticity of a bare charged surface, wherefrom the unique polyelectrolyte brush effect on the surface elasticity is clarified clearly. The scaling relations derived in our paper can serve as a guide to experimental studies on the related systems.

  8. Chinese Brush Calligraphy Character Retrieval and Learning

    Science.gov (United States)

    Zhuang, Yueting; Zhang, Xiafen; Lu, Weiming; Wu, Fei

    2007-01-01

    Chinese brush calligraphy is a valuable civilization legacy and a high art of scholarship. It is still popular in Chinese banners, newspaper mastheads, university names, and celebration gifts. There are Web sites that try to help people enjoy and learn Chinese calligraphy. However, there lacks advanced services such as content-based retrieval or…

  9. Comparison of Carbon Brush Sliding Characteristics with Copper Ring and Steel Ring in Large Alternate Rotating Machine

    Science.gov (United States)

    Takanezawa, Makoto; Mori, Masami; Ueno, Takahiro; Morita, Noboru; Otaka, Toru; Arata, Masanori

    In the case of high speed and large capacity AC machines, such as turbine generators and large synchronous motors for industrial use, steel collector rings are generally applied to the brush/ring operation, where higher reliabilities are required, especially for large machines when compared to small machines. The brush/ring operation failures directly cause the service operation to shut down. Although steel ring application to those machines has been successful for almost sixty years, at present no one knows why “steel” is applied to the collector ring. It is considered that steel ring application technologies have never been disclosed or studied. In this study, the following points are investigated. 1) Consistency analysis for steel ring application 2) Experimental analysis for brush spark and collector ring hazard 3) Experimental analysis for brush contact V-I characteristics The above-mentioned points help in improving the reliabilities of the brush/collector ring operation, where the results of steel ring are completely compared with these of copper ring.

  10. Synthesis and characterization of metal oxide nanorod brushes

    Indian Academy of Sciences (India)

    Kalyan Raidongia; M Eswaramoorthy

    2008-02-01

    Nanorod brushes of -Al2O3, MoO3 and ZnO have been synthesized using amorphous carbon nanotube (-CNT) brushes as the starting material. The brushes of -Al2O3 and MoO3 are made up of single crystalline nanorods. In the case of ZnO brushes, the nanorod bristles are made by the fusion of 15–25 nm size nanoparticles and are porous in nature. Metal oxide nanorod brushes thus obtained have been characterized by XRD, FESEM, TEM and Raman spectroscopy. Single crystalline ruby nanorods were obtained by introducing chromium ions during the synthesis of alumina rods.

  11. A Multiport Isolated DC-DC Converter

    OpenAIRE

    Tran, Yan-Kim; Dujic, Drazen

    2016-01-01

    This paper presents a multi-port isolated DC-DC converter for DC applications. A three-port structure is presented, characterized with full bidirectional power flow and simple control. Galvanic isolation is achieved by means of a multi-winding medium frequency transformer which is a part of a resonant LLC converter. To provide controllable power exchange with external DC ports, two out of three ports are equipped with additional bidirectional buck/boost stages. They serve to provide active po...

  12. Multiport Resonant DC-DC Converter

    OpenAIRE

    Tran, Yan-Kim; Dujic, Drazen; Barrade, Philippe

    2015-01-01

    his paper presents a multiport galvanically isolated LLC resonant DC-DC converter suitable for DC applications. A three-port structure is analyzed, with full bidirectional power flow capabilities, simple control and behavior similar to that expected from a DC transformer. Each port is equipped with half-bridge modules accompanied with tuned resonant tank, partly realized with elements of a multi- winding high frequency transformer. With some restrictions that are explained in the paper, each ...

  13. VLSI Hybrid DC-DC Regulator

    OpenAIRE

    Cosp Vilella, Jordi; Martínez García, Herminio

    2015-01-01

    Hybrid DC-DC regulators are structures that combine both a linear voltage regulator and a switching DC-DC converter. The main objective of this hybrid topology is to converge, in a single circuit topology, the best of both alternatives: a small voltage output ripple, which is a common characteristic of linear regulator circuits, and good energy efficiency, as in switching alternatives. While the linear regulator fixes the required output voltage to a fixed value with negligible steady-state r...

  14. Design of Portable Garden Mowers Based on a Brushless Motor Control System%基于无刷电机控制系统的便携式园林割草机设计

    Institute of Scientific and Technical Information of China (English)

    段亚东

    2012-01-01

    Based on a thorough study of China's mower technologies,a simple and practical portable garden mower is designed.The mower uses a brushless motor and its technical performance parameters have improved substantially,compared with traditional brush motors.The mower uses the drive chip IR2130 dedicated for brushless DC motors as its control chip and uses power device MOSFET as its switch to realize the control of brushless DC motors.%在深入研究我国割草机技术的基础上,设计了简单实用的园林便携式割草机。该割草机采用无刷电动机,与传统有刷电动机相比,其主要技术性能大幅提升。以无刷直流电动机专用驱动芯片IR2130为控制芯片,以功率器件MOSFET为开关器件,可实现对无刷直流电动机的控制。

  15. Control analysis of PM brushless DC motor used in flywheel energy storage system%飞轮储能系统永磁无刷直流电机控制方法研究

    Institute of Scientific and Technical Information of China (English)

    程文星; 祝长生

    2012-01-01

    针对某高速飞轮储能系统中的永磁无刷直流电机在宽速范围内运行时出现的电流和转矩脉动问题,开展了换向期间的转矩脉动的分析,建立了转矩脉动和转速之间的关系,提出了在低速区功率开关管采用先脉宽调制后恒通,最后再脉宽调制(PWM-onPWM)的方法,在高速区功率开关管采用了带PWM的重叠换向调制的一种混合调制方法;在抑制换向期间的电流和转矩脉动的效果上对该调制方式进行了评价,并搭建了Matlab/Simulink仿真模型,进行了低速区的运行试验.研究结果表明,该混合控制方案能消除非换向期间非导通相上的续流现象,并可减小换向过程中的电磁转矩脉动,可以使无刷直流电机在相对较宽的速度范围内平稳运行.%Aiming at reducing the current and the torque ripple appeared in flywheel energy storage system running in wide-range speed, after the analysis of torque ripple in the commutation interval, the relation between the torque ripple and the speed was established. A hybrid method was presented that the PWM-on-PWM was chosen to control power devices during low-speed range, while during high-speed range, the overlapping commutation with PWM was used. The control method were evaluated on the effect of reducing the current and the torque ripple during the commutation interval, the Matlab/Simulink model was built, and the running test in low-speed range were tested. Hie experimental results show that the proposed method can eliminate diodes' free-wheeling phenomenon and reduce the torque ripple during the commutation interval, it adapts for brushless DC motor in wide speed-range.

  16. Backstepping high order sliding mode control for brushless DC motor speed servo control system%无刷直流电机转速伺服系统反步高阶滑模控制

    Institute of Scientific and Technical Information of China (English)

    张庆超; 马瑞卿

    2016-01-01

    针对无刷直流电机转速伺服系统高性能非线性鲁棒控制,提出一种新型的多滑模反步高阶滑模非线性控制方法。在控制律设计的每一步都引入二阶滑模Super-Twisting算法,无需计算变量导数,消除了滑模抖振,并在第1级子系统虚拟控制律设计中提出一种改进的二阶滑模Super-Twisting算法。与传统双闭环PI控制相比,能够令系统的动静态性能更好,转矩脉动更小,鲁棒性更强;与标准Super-Twisting算法相比,进一步提高了系统对阶跃负载扰动的抑制能力。最后通过仿真分析表明了所提出方法的有效性。%For higher performance speed servo robustness control of brushless DC motor(BLDCM), a novel multiple sliding mode backstepping high order sliding mode nonlinear control approach is proposed. The second order sliding mode Super-Twisting algorithm(STA) ,which needs no derivative of any variables and eliminates the sliding mode chattering, is used in each step design of the whole backstepping control law. And a self-adaption STA(SSTA) is proposed and used in the virtual control law of the first level subsystem. Compared with the traditional dual closed loop PI control, the proposed method makes the system have higher dynamic and static performance, smaller torque ripple and stronger robustness. Compared with the traditional STA, the proposed SSTA can futher improve the system’s robustness for the step load disturbance. Finally, simulation analysis shows the effectiveness of the proposed method.

  17. Strategy to Suppress Torque Ripple During Commutation of Brushless DC Motor%换相期间无刷直流电机转矩脉动的抑制策略

    Institute of Scientific and Technical Information of China (English)

    李怀兵; 丑武胜; 张延超

    2011-01-01

    Torque ripple was an important factor affecting the performance of brushless DC motor (BLDCM). The commutation torque ripple was analyzed, focusing on the torque ripple caused by non-ideal back EMF and the ascending speed of current in the upcoming phase and descending speed of current in the outgoing phase were not e-qual. The segment control strategy was proposed. The strategy which integrated the advantage of torque direct control and overlapping commutation method could effectively suppress the torque ripple caused by the two factors mentioned above. The simulation experiments showed the difference between the strategy and the two methods using alone, and prove the validity of the segment control strategy suppressing the torque ripple during commutation.%无刷直流电机的转矩脉动是影响其性能的重要因素.针对换相期间的转矩脉动进行了分析,重点研究了非理想反电势、关断相和开通相相电流变化速率不等这两个因素引起的转矩脉动,为了抑制这两个因素引起的转矩脉动,提出了分段控制的策略.该策略集成了转矩直接控制和重叠换相法的优点,可以有效抑制由非理想反电势、关断相和开通相相电流变化速率不等引起的转矩脉动.通过仿真分析验证了该方法和其中两种方法单独应用时的差异,证明了分段控制策略在换相期间抑制转矩脉动的有效性.

  18. 基于 BP 神经网络的无刷直流电机的自抗扰控制%Active Disturbance Rejection Control Based on BP Neural Network System for Brushless DC Motors

    Institute of Scientific and Technical Information of China (English)

    关学忠; 白云龙; 高哲

    2014-01-01

    Brushless DC motor speed servo system is multivariable ,nonlinear and strong coupling .Its performance is easily influenced by the parameter variation ,the cogging torque and the load disturbance .To solve the deficiency ,the paper presents the algorithm of active‐disturbance rejection control(ADRC) based on back‐propagation(BP) neural network .The ADRC is independent of accurate system and its extended‐state observer can estimate the disturbance of the system accurate‐ly .However ,the parameters of Nonlinear Feedback(NF) in ADRC are difficult to obtain .In this paper ,these parameters are self‐turned by the BP neural network .The simulation results indicate that the ADRC based on BP neural network can im‐prove the performances of the servo system in rapidity ,control accuracy ,adaptability and robustness .%无刷直流电机调速系统是多变量,非线性强耦合的非线性系统。它的齿槽转矩和负荷扰动性能很容易被参数的变化所影响。为了解决这个不足,论文将BP神经网络算法应用到自抗扰控制系统。自抗扰控制器是独立的精确的控制器,其扩张状态观测器可以准确地估计该系统的扰动。然而自抗扰控制器的非线性反馈参数是很难获得的,在文章中这些参数是来自BP神经网络。仿真结果表明,基于BP神经网络的自抗扰控制器能改善该伺服系统的快速性、控制精度适应性和鲁棒性。

  19. Inteilegent Optimizing Design of Permanent Magnet Brushless DC Motor Based on Finite Element%基于有限元的永磁无刷直流电机转矩优化设计

    Institute of Scientific and Technical Information of China (English)

    连军强; 谢顺依; 王鼎

    2011-01-01

    在分析永磁无刷直流电机电磁转矩的基础上,以抑制电机转矩脉动为目标,提出了有限元与最小二乘支持向量机( LS-SVM)及粒子群优化算法相结合的永磁无刷直流电机设计方法,建立了永磁无刷直流电机有限元模型.经有限元计算分析,得到了极弧系数、永磁体厚度和气隙长度对电机转矩脉动的影响曲线,生成了LS-SVM训练样本,经训练得到了永磁无刷直流电机LS-SVM模型,通过有限元计算和LS-SVM模型拟合结果的比较,验证了模型的准确性.利用粒子群优化算法对永磁无刷直流电机LS-SVM模型进行优化,得到了极弧系数、永磁体厚度和气隙长度的最优参数,经有限元计算结果验证了优化的有效性.%In order to keep down torque ripple. The thesis analyzed the torque of permanent magnet brushless DC motor (PMBLDCM) and put forward a new method of finite element and least squares support vector machine ( LS-SVM) and partide swarm optimization ( PSO). A infinite element model of PMBLDC has been found. After the anylisis of model, the influence of pole embrace and thickness of PM and gas length on torque ripple. The training sample has been gained. The LS-SVM model of PMBLDCM found. After contrast of two results, the accuracy of model was verified. Then optimizing model of PMBLDCM LS-SVM was obtained. The optimizing parameter of PMBLDCM has been found, the validity of model was verified.

  20. Power Electronic Systems for Switched Reluctance Generator based Wind Farms and DC Networks

    DEFF Research Database (Denmark)

    Park, Kiwoo

    . Under these circumstances, research on dc network connection with a novel wind power generator system is presented in this thesis, which mainly consists of two major parts: control of a Switched Reluctance Generator (SRG) system and development of dc-dc converters for a dc network system in a wind farm...... are presented to verify the feasibility and operational principles of the proposed converters. Finally, modelling and control of a dc-grid wind farm using one of the proposed dc-dc converters are presented. An average model provides insight into the overall performance of the system. Meanwhile, a switching....... The SRG, which eliminates permanent magnets, brushes, commutators, and coil winding in the rotor, could be a promising wind power generator. It has various desirable features, such as simple and solid structure, easiness of maintenance, fault tolerance, and low cost. These features are suitable...

  1. Sensorless Control of PM Synchronous Motors and Brushless DC Motors

    DEFF Research Database (Denmark)

    Montesinos, D.; Galceran, Samuel; Blaabjerg, Frede;

    2005-01-01

    This paper provides a review of the literature addressing sensorless operation methods of PM brushless machines. The methods explained are state-of-the-art of open and closed loop control strategies. The closed loop review includes those methods based on voltage and current measurements, those me...

  2. Sensorless Control of Electric Motors with Kalman Filters: Applications to Robotic and Industrial Systems

    OpenAIRE

    Gerasimos G. Rigatos; Pierluigi Siano

    2011-01-01

    The paper studies sensorless control for DC and induction motors, using Kalman Filtering techniques. First the case of a DC motor is considered and Kalman Filter-based control is implemented. Next the nonlinear model of a field-oriented induction motor is examined and the motor

  3. Energy saving dc-dc converter circuit

    International Nuclear Information System (INIS)

    An energy saving dc-dc converter circuit is disclosed having two energy efficient means which operate in tandem, an energy conserving means and a voltage doubling means. These energy efficient means are applied in combination with elements commonly found in dc-dc converter circuits, namely an ac voltage generator, a transformer for stepping up the generated ac voltage, and means for storing the converted dc voltage. The energy conserving means is connected to the dc voltage storage means. It comprises a resettable inhibit circuit which cuts off the provision of dc voltage for conversion for a predetermined interval when the output of the converter exceeds a predetermined level. The voltage doubling means is reponsive to outputs of the inhibit circuit of the energy conserving means and the ac voltage generator. It provides a phase inverted waveform of the generated ac voltage on one of two leads to the ac voltage step-up transformer

  4. Position-Sensorless Rotor Position Detection of Brushless DC Motor Based on H_PWM-L_PWM Modulation Model%基于H_PWM-L_PWM调制的无感无刷直流电机转子位置的检测

    Institute of Scientific and Technical Information of China (English)

    王宝忠; 孙健涛; 要丹

    2011-01-01

    Exactly detecting of rotor position was required during the control of brushless DC motor, and back EMF detecting method was a simple, effective way to detect the position-sensorless rotor position of brushless DC motor. A back EMF detecting method based on the H_PWM-L_PWM modulation model by analyzing the freewheeling condition of a non-conducted phase of this model was raised. This back EMF detecting method needed not to detect the center voltage of the three-phase winding, and gained a two times of the back EMF of a non-conducted phase. The simulation under MATLAB software environment and experimental results showed that this method had good performance in low speed control of brushless DC motor.%无刷电机的控制需要准确检测到转子的位置,反电动势法是检测无位置传感器无刷直流电机转子位置的一种简单、有效的方法.采用二相导通星形三相六状态的控制模式,通过分析在H_PWM-L PWM调制方式下不导通相的续流情况,提出了基于该调制方式的反电动势检测方法.该反电动势检测法不需要检测三相绕组中点电压,所获得的是不导通相的两倍的反电动势.MATLAB仿真和试验结果证明,该检测方法具有良好的低速控制性能.

  5. Fouling-resistant polymer brush coatings

    KAUST Repository

    Thérien-Aubin, Héloïse

    2011-11-01

    A major problem to be addressed with thin composite films used in processes such as coatings or water purification is the biofouling of the surface. To address this problem in a model system, functionalized polyaramide membranes containing an atom transfer radical polymerization (ATRP) initiator were synthesized as a versatile approach to easily modify the surface properties of the polyaramide. Poly(methacrylic acid) brushes were grown using surface initiated ATRP followed by the functionalization of the poly(methacrylic acid) brushes with different side-chains chosen to reduce adhesion between the membrane and foulant. The relation between membrane fouling and the physicochemical properties of the surface was investigated in detail. © 2011 Elsevier Ltd. All rights reserved.

  6. Novel Hyperbranched Polyurethane Brushes for Biomedical Applications

    Institute of Scientific and Technical Information of China (English)

    Ton; Loontjens; Bart; Plum

    2007-01-01

    1 Results The objective was to make hyperbranched (HB) polyurethane brushes with reactive end groups, to coat biomedical devices and to enable the introduction of various functionalities that are needed to fulfill biomedical tasks.Biomedical materials should fulfill at least three requirements: (1) good mechanical properties, (2) good biocompatibility and (3) provided with functionalities to perform the required tasks. Since polyurethanes are able to fulfill the first 2 requirements we focused in this w...

  7. CMOS Integrated Capacitive DC-DC Converters

    CERN Document Server

    Van Breussegem, Tom

    2013-01-01

    This book provides a detailed analysis of all aspects of capacitive DC-DC converter design: topology selection, control loop design and noise mitigation. Readers will benefit from the authors’ systematic overview that starts from the ground up, in-depth circuit analysis and a thorough review of recently proposed techniques and design methodologies.  Not only design techniques are discussed, but also implementation in CMOS is shown, by pinpointing the technological opportunities of CMOS and demonstrating the implementation based on four state-of-the-art prototypes.  Provides a detailed analysis of all aspects of capacitive DC-DC converter design;  Analyzes the potential of this type of DC-DC converter and introduces a number of techniques to unleash their full potential; Combines system theory with practical implementation techniques; Includes unique analysis of CMOS technology for this application; Provides in-depth analysis of four fabricated prototypes.

  8. DC-Link Compensation Method for Slim DC Link Drives Fed by Soft Grid

    DEFF Research Database (Denmark)

    Mathe, Laszlo; Rosendahl Andersen, Henrik; Lazar, Radu;

    2010-01-01

    harmonic distortion (PWHD) of the line current are degraded, if resonance between the line impedance and the DC-link capacitance occurs. Likewise, the motor performance is affected negatively giving extra torque ripple, vibration and acoustic-noise emission. This paper proposes a novel DC-link compensation...... method, which ensures the stability of the slim DC-link on a soft grid. The proposed compensation method may be used for open- and closedloop control schemes, requiring a small overhead in the digital implementation....

  9. Efficiency Characteristics of Low Power Hybrid Switched Reluctance Motor

    DEFF Research Database (Denmark)

    Jakobsen, Uffe; Ahn, Jin-Woo

    2009-01-01

    Switched reluctance motors (SRM) are usually considered inferior in terms of efficiency as compared to permanent magnet synchronous motors (PMSM) and brushless DC-motors (BLDC), but less costly. This article presents a test of a 70W hybrid switched reluctance motor (HSRM), that archieves a peak...... efficiency for the motor drive of more than 74%, and an efficiency for the motor of almost 80%....

  10. Speed Control of Induction Motor Fed from Wind Turbine via Particle Swarm Optimization Based PI Controller

    Directory of Open Access Journals (Sweden)

    A.S. Oshaba

    2013-05-01

    Full Text Available Three-phase Induction Motor (IM is widely used in the industry because of its rugged construction and absence of brushes. However, speed control of IM is required depending on the desired speed and application. This study proposes a design of a Proportional Integral (PI controller using Particle Swarm Optimization (PSO algorithm to control the speed of an IM supplied from wind turbine. The wind turbine acts as a prime mover to a connected DC generator. Pulse Width Modulation (PWM is used to obtain three phase AC voltage from the output of DC generator. The proposed design problem of speed controller is formulated as an optimization problem. PSO is employed to search for optimal controller parameters by minimizing the time domain objective function. The performance of the proposed technique has been evaluated with respect to the variation of load torque and speed wind turbine. Also the performance of the proposed controller has been evaluated with the performance of the PI controller tuned by Genetic Algorithm (GA in order to demonstrate the superior efficiency of the proposed PSO in tuning PI controller. Simulation results emphasis on the better performance of the optimized PI controller based on PSO in compare to optimized PI controller based on GA over a wide range of load torque and speed wind turbine.

  11. Speed Control of Bldc Motor Drive By Using Pid Controllers

    Directory of Open Access Journals (Sweden)

    Y.Narendra Kumar,

    2014-04-01

    Full Text Available This paper mainly deals with the Brushless DC (BLDC motor speed driving systems have sprouted in various small scale and large scale applications like automobile industries, domestic appliances etc. This leads to the development in Brushless DC motor (BLDCM. The usage of BLDC Motor enhances various performance factors ranging from higher efficiency, higher torque in low-speed range, high power density ,low maintenance and less noise than other motors. The BLDC Motor can act as an alternative for traditional motors like induction and switched reluctance motors. In this paper PID controller is implemented with speed feedback loop and it is observe that torque ripples are minimized. Simulation is carried out using MATLAB / SIMULINK. The results show that the performance of BLDC Motor is quite satisfactory for various loading conditions. Brushless DC motor drives are typically employed in speed controlled applications.

  12. 基于换相与电流控制对无刷直流电机非理想反电势转矩脉动的控制%The suppression to Torque Ripple of Brushless DC Motor under Non-Ideal Back-EMF Circumstance by Combining the Advance Angle Opened Commutation Method with Current Control Method

    Institute of Scientific and Technical Information of China (English)

    李劲松; 杨晓武; 李干蓉; 饶有祥

    2012-01-01

      从无刷直流电机转矩脉动产生的原理出发,分析了转矩脉动在非理想反电势情况下产生的原因,并提出通过提前角开通换相法与电流控制相结合的控制策略以减少电磁转矩脉动。仿真结果证明该控制策略能有效地控制由非理想反电势引起的无刷直流电机换向产生的电磁转矩脉动。%  Based on the principle of torque ripple produced brushless DC motor,the article analyzes the reasons for torque ripple under non-ideal Back-EMF circumstance,and puts forward the control strategy that combines the advance angle opened commutation method with current controlling to reduce the electromagnetic torque ripple. The simulation results prove that the control strategy can work effectively to control the electromagnetic torque ripple which produced by brushless DC motor under non-ideal Back-EMF circumstance.

  13. Effect of Frequency of Brushing Teeth on Plaque and Calculus Accumulation, and Gingivitis in Dogs.

    Science.gov (United States)

    Harvey, Colin; Serfilippi, Laurie; Barnvos, Donald

    2015-01-01

    The efficacy of brushing the teeth of beagle dogs in a randomized, controlled, blinded study design using a clearly-defined brushing technique was evaluated for 4 brushing frequencies: brushing daily, brushing every other day, brushing weekly and brushing every other week, compared with no brushing in a control group of dogs. All dogs were fed a standard dry kibble diet during the study. Standard plaque, calculus, and gingivitis indices were used to score the teeth. A 'clean tooth' model was used. No gingival or non-gingival lacerations or other signs of injury to oral tissues were found at the end of the 28 day trial period. Brushing more frequently had greater effectiveness in retarding accumulation of plaque and calculus, and reducing the severity of pre-existing gingivitis. Brushing daily or every other day produced statistically significant improved results compared with brushing weekly or every other week. Based on the results of this study, daily brushing is recommended.

  14. 日立J300变频器在PROTOS70主电机变频改造中的应用%Application of Hitachi J300 Inverter in the Frequency Transformation of the Main Motor PROTOS70

    Institute of Scientific and Technical Information of China (English)

    张海峰

    2015-01-01

    The PROTOS70 cigarette-making machine is easy to operate and the quality of the cigarette quality is stable. But its masterdrive adopts Direct Current Governor System, which has complex structure and high failure rate. So it needs frequent maintenance. Under continuous running, the carbon brush is easy to wear, thus shortening its service life. But it is not convenient to change the brush. The machine often fails to work because of the wear of copper head. Besides, the DC motor and carbon brush are quite expensive and their delivery time is long. Based on the reasons above, the author decides to use AC speed control system to replace the original DC speed control masterdrive system. Practice shows that this technology is worth promoting.%长春卷烟厂于1990年购买的PROTOS70卷接机组,具有操作方便、烟支质量稳定的特点,但其主驱动采用直流调速系统,结构复杂、故障率相对较高,需要经常维护,主要是在连续运行下,碳刷易磨损、使用周期短、更换又不方便,电机也常常因铜头磨损严重而不能使用,况且直流电机和碳刷价格昂贵、供货周期较长,基于上述原因,笔者决定采用交流变频调速系统替代原直流调速主驱动系统。通过验证,此项技术改造具有推广意义。

  15. EFFICACY OF BIOFILM DISCLOSING AGENT AND OF THREE BRUSHES IN THE CONTROL OF COMPLETE DENTURE CLEANSING

    OpenAIRE

    Cláudia Helena Lovato da Silva; Helena de Freitas Oliveira Paranhos

    2006-01-01

    OBJECTIVE: This report evaluated the efficacy of three brushes and one biofilm disclosing agent in complete denture cleansing. METHODS: Twenty-seven wearers of maxillary dentures were distributed into three groups and received different brushes: Oral B40, conventional toothbrush (Oral B); Denture, denture-specific brush (Condor); Johnson & Johnson, denture-specific brush (Johnson & Johnson). The 60-day experimental period was divided into two techniques: I - brushing (brush associated with a ...

  16. The Effects of a Brushing Procedure on Stereotypical Behavior

    Science.gov (United States)

    Davis, Tonya N.; Durand, Shannon; Chan, Jeffrey M.

    2011-01-01

    In this study we analyzed the effects of a brushing protocol on stereotyped behavior of a young boy with autism. First, a functional analysis was conducted which showed that the participant's stereotypy was maintained by automatic reinforcement. Next, the Wilbarger Protocol, a brushing intervention, was implemented. An ABA design was implemented…

  17. 16 CFR Figure 9 to Part 1610 - Brushing Device Template

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Brushing Device Template 9 Figure 9 to Part 1610 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FLAMMABLE FABRICS ACT REGULATIONS STANDARD FOR THE FLAMMABILITY OF CLOTHING TEXTILES Pt.1610, Fig. 9 Figure 9 to Part 1610—Brushing...

  18. 16 CFR Figure 8 to Part 1610 - Brush

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Brush 8 Figure 8 to Part 1610 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FLAMMABLE FABRICS ACT REGULATIONS STANDARD FOR THE FLAMMABILITY OF CLOTHING TEXTILES Pt.1610, Fig. 8 Figure 8 to Part 1610—Brush ER25MR08.007...

  19. 16 CFR Figure 7 to Part 1610 - Brushing Device

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Brushing Device 7 Figure 7 to Part 1610 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FLAMMABLE FABRICS ACT REGULATIONS STANDARD FOR THE FLAMMABILITY OF CLOTHING TEXTILES Pt.1610, Fig. 7 Figure 7 to Part 1610—Brushing Device ER25MR08.006...

  20. 75 FR 39706 - Natural Bristle Paint Brushes From China

    Science.gov (United States)

    2010-07-12

    ... the antidumping duty order on natural bristle paint brushes from China (75 FR 21347, April 23, 2010... revoke the order on June 16, 2010 (75 FR 34097). In light of these developments, the Commission is... COMMISSION Natural Bristle Paint Brushes From China AGENCY: United States International Trade...

  1. Carbazole functionalized isocyanide brushes in heterojunction photovoltaic devices

    NARCIS (Netherlands)

    Lim, E.; Gao, F.; Schwartz, E.; Cornelissen, J.J.L.M.; Nolte, R.J.M.; Rowan, A.E.; Greenham, N.C.; Do, L.M.

    2012-01-01

    In this work, carbazole-containing polyisocyanide (PIACz) brushes were used for photovoltaic devices. A photovoltaic device was fabricated on top of the brushes by spin-coating a suitable acceptor and evaporating an Al cathode. Devices with a poly(N-vinylcarbazole) (PVK) bulk polymer were also prepa

  2. FLYWHEEL AND A DC MACHINE

    Directory of Open Access Journals (Sweden)

    IVAN ALCALÁ

    2014-01-01

    Full Text Available Este artículo describe el análisis, modelado y simulación de un vehículo eléctrico (EV enfocado al desarrollo de un banco de pruebas para reproducir la dinámica del EV. El banco está formado por un drive de motor de inducción (IM acoplado directamente a una máquina de DC y a un volante de inercia a través de una transmisión. El volante de inercia y la máquina de DC reproducen la dinámica y las fuerzas que actúan en el vehículo. Se propone una metodología para diseñar un banco de pruebas de EV para estudiar el comportamiento de vehículos eléctricos cercano a las condiciones de operación reales. El análisis de las fuerzas en el EV en conjunto con la máquina DC define las condiciones de operación del EV. El modelado y la simulación son desarrollados en MATLAB/Simulink, el banco de pruebas implementado es controlado por un DSP. Finalmente, los resultados de simulación y experimentales obtenidos validan el funcionamiento del banco de prueba.

  3. A resonant dc-dc power converter assembly

    DEFF Research Database (Denmark)

    2015-01-01

    The present invention relates to a resonant DC-DC power converter assembly comprising a first resonant DC-DC power converter and a second resonant DC-DC power converter having identical circuit topologies. A first inductor of the first resonant DC-DC power converter and a second inductor...... of the second resonant DC-DC power converter are configured for magnetically coupling the first and second resonant DC-DC power converters to each other to forcing substantially 180 degrees phase shift, or forcing substantially 0 degree phase shift, between corresponding resonant voltage waveforms of the first...... and second resonant DC-DC power converters. The first and second inductors are corresponding components of the first and second resonant DC-DC power converters....

  4. Nanopatterned polymer brushes by reactive writing

    Science.gov (United States)

    Nawroth, Jonas F.; Neisser, Claudia; Erbe, Artur; Jordan, Rainer

    2016-03-01

    Polymer brush patterns were prepared by a combination of electron beam induced damage in self-assembled monolayers (SAMs), creating a stable carbonaceous deposit, and consecutive self-initiated photografting and photopolymerization (SIPGP). This newly applied technique, reactive writing (RW), is investigated with 1H,1H,2H,2H-perfluorooctyltriethoxysilane SAM (PF-SAM) on silicon oxide, which, when modified by RW, can be selectively functionalized by SIPGP. With the monomer N,N-dimethylaminoethyl methacrylate (DMAEMA), we demonstrate the straightforward formation of polymer brush gradients and single polymer lines of sub-100 nm lateral dimensions, with high contrast to the PF-SAM background. The lithography parameters acceleration voltage, irradiation dose, beam current and dwell time were systematically varied to identify the optimal conditions for the maximum conversion of the SAM into a carbonaceous deposit. The results of this approach were compared to patterns prepared by carbon templating (CT) under analogous conditions, revealing a dwell time dependency, which differs from earlier reports. This new technique expands the range of CT by giving the opportunity to not only vary the chemistry of the created polymer patterns with monomer choice but also vary the chemistry of the surrounding substrate.

  5. Surface grafted polymer brushes: potential applications in dengue biosensors

    International Nuclear Information System (INIS)

    A polymer brush membrane-based ultrasensitive biosensor for dengue diagnosis was constructed using poly(hydroxyethyl methacrylate) (PHEMA) brushes immobilized onto low density polyethylene (LDPE) films. LDPE surface films were initially modified by Ar+ ion irradiation to activate the polymer surface. Subsequently, graft polymerization of 2-hydroxyethyl methacrylate onto the activated LDPE surface was carried out under aqueous conditions to create patterned polymer brushes of PHEMA. The grafted PHEMA brushes were characterized by Fourier transform-infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and contact angle analysis. The SEM observations showed that selective surface activation with Ar+ implantation and graft polymerization on the selectively activated surface had occurred. The PHEMA brushes were electrically characterized in the presence of concentrations of human immunoglobulin (IgG). The proposed amperometric biosensor was successfully used for determination of IgG in physiologic samples with excellent responses. (author)

  6. Surface grafted polymer brushes: potential applications in dengue biosensors

    Energy Technology Data Exchange (ETDEWEB)

    Baratela, Fernando Jose Costa; Higa, Olga Zazuco, E-mail: ozahiga@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Faria, Henrique Antonio Mendonca de; Queiroz, Alvaro Antonio Alencar de, E-mail: alencar@unifei.edu.br [Universidade Federal de Itajuba (UNIFEI), Itajuba, MG (Brazil). Instituto de Fisica e Quimica

    2013-07-01

    A polymer brush membrane-based ultrasensitive biosensor for dengue diagnosis was constructed using poly(hydroxyethyl methacrylate) (PHEMA) brushes immobilized onto low density polyethylene (LDPE) films. LDPE surface films were initially modified by Ar{sup +} ion irradiation to activate the polymer surface. Subsequently, graft polymerization of 2-hydroxyethyl methacrylate onto the activated LDPE surface was carried out under aqueous conditions to create patterned polymer brushes of PHEMA. The grafted PHEMA brushes were characterized by Fourier transform-infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and contact angle analysis. The SEM observations showed that selective surface activation with Ar+ implantation and graft polymerization on the selectively activated surface had occurred. The PHEMA brushes were electrically characterized in the presence of concentrations of human immunoglobulin (IgG). The proposed amperometric biosensor was successfully used for determination of IgG in physiologic samples with excellent responses. (author)

  7. Virtual hairy brush for digital painting and calligraphy

    Institute of Scientific and Technical Information of China (English)

    XU Songhua; Lau Francis C. M.; XU Congfu; PAN Yunhe

    2005-01-01

    The design of user friendly and expressive virtual brush systems for interactive digital painting and calligraphy has attracted a lot of attention and effort in both computer graphics and human-computer interaction circles for a long time. Providing a digital environment for paper-less artwork creation is not only challenging in terms of algorithmic design, but also promising for its potential market values. This paper proposes a novel algorithmic framework for interactive digital painting and calligraphy based a novel virtual hairy brush model. The algorithms in the kernel of our simulation framework are built upon solid modeling techniques. Implementing the algorithms, we have developed a virtual hairy brush prototype system with which end users can interactively produce high-quality digital paintings and calligraphic artwork. (The latest progress of our virtual brush project is reported at the website "http://www.cs.hku.hk/~songhua/e-brush/".)

  8. Start-stop and recuperation: DC/DC current inverters with integrated double-layer condensers; Start-Stopp und Rekuperation: DC/DC-Wandler mit integrierten Doppelschichtkondensatoren

    Energy Technology Data Exchange (ETDEWEB)

    Igel, Juergen; Ollhaeuser, Helmut; Jeuck, Marc; Apfelbacher, Thomas [Alcoa/AFL Europe GmbH, Frickenhausen (Germany)

    2008-09-15

    Start-stop systems may be made more efficient, and energy recovery in regenerative brakes may be made more economical. The contribution describes a new DC/DC current inverter with integrated double-layer condensers developed by the electric/electronics department of Alcoa. The so-called Energy Conversion Module (ECM) will result in considerable fuel savings and also help to stabilize board grids which are nearing their limits because of the increasing number of electrified service aggregates. Motor car producers are currently testing the module. (orig.)

  9. System and method for determining stator winding resistance in an AC motor using motor drives

    Science.gov (United States)

    Lu, Bin; Habetler, Thomas G; Zhang, Pinjia

    2013-02-26

    A system and method for determining the stator winding resistance of AC motors is provided. The system includes an AC motor drive having an input connectable to an AC source and an output connectable to an input terminal of an AC motor, a pulse width modulation (PWM) converter having switches therein to control current flow and terminal voltages in the AC motor, and a control system connected to the PWM converter. The control system generates a command signal to cause the PWM converter to control an output of the AC motor drive corresponding to an input to the AC motor, selectively generates a modified command signal to cause the PWM converter to inject a DC signal into the output of the AC motor drive, and determines a stator winding resistance of the AC motor based on the DC signal of at least one of the voltage and current.

  10. DC source assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, Jeremy B; Newson, Steve

    2013-02-26

    Embodiments of DC source assemblies of power inverter systems of the type suitable for deployment in a vehicle having an electrically grounded chassis are provided. An embodiment of a DC source assembly comprises a housing, a DC source disposed within the housing, a first terminal, and a second terminal. The DC source also comprises a first capacitor having a first electrode electrically coupled to the housing, and a second electrode electrically coupled to the first terminal. The DC source assembly further comprises a second capacitor having a first electrode electrically coupled to the housing, and a second electrode electrically coupled to the second terminal.

  11. 75 FR 34097 - Natural Bristle Paint Brushes and Brush Heads From the People's Republic of China: Notice of...

    Science.gov (United States)

    2010-06-16

    ... Results of Antidumping Duty Changed Circumstances Review and Intent Not to Revoke, In Part, 73 FR 60214... Brushes and Paint Brush Heads from the People's Republic of China, 51 FR 5580 (Feb. 14, 1986) and Amended... China, 51 FR 8342 (March 11, 1986) (``Order''). The domestic industry submitted a letter to...

  12. Charge pump DC-DC converter comprising solid state batteries

    NARCIS (Netherlands)

    Reefman, D.; Roozeboom, F.; Notten, P.H.L.; Klootwijk, J.H.

    2013-01-01

    An electronic device is provided which comprises a DC-DC converter. The DC-DC converter comprises at least one solid-state rechargeable battery (B1, B2) for storing energy for the DC-DC conversion and an output capacitor (C2).

  13. Motor-operated valve (MOV) actuator motor and gearbox testing

    International Nuclear Information System (INIS)

    Researchers at the Idaho National Engineering and Environmental Laboratory tested the performance of electric motors and actuator gearboxes typical of the equipment installed on motor-operated valves used in nuclear power plants. Using a test stand that simulates valve closure loads against flow and pressure, the authors tested five electric motors (four ac and one dc) and three gearboxes at conditions a motor might experience in a power plant, including such off-normal conditions as operation at high temperature and reduced voltage. They also monitored the efficiency of the actuator gearbox. All five motors operated at or above their rated starting torque during tests at normal voltages and temperatures. For all five motors, actual torque losses due to voltage degradation were greater than the losses calculated by methods typically used for predicting motor torque at degraded voltage conditions. For the dc motor the actual torque losses due to elevated operating temperatures were greater than the losses calculated by the typical predictive method. The actual efficiencies of the actuator gearboxes were generally lower than the running efficiencies published by the manufacturer and were generally nearer the published pull-out efficiencies. Operation of the gearbox at elevated temperature did not affect the operating efficiency

  14. Fuel pump with brushless motor for high vibration applications; Kraftstoffpumpe mit buerstenlosen Motor fuer Anwendungen mit starken Vibrationen

    Energy Technology Data Exchange (ETDEWEB)

    Muenchow, Frank [Federal-Mogul, Bad Camberg (Germany). Geschaeftsbereich Vehicle Safety and Protection; Harvey, Richard; Richards, Michael [Federal-Mogul Corporation, Logansport, IN (United States). Business Unit Vehicle Safety and Protection

    2012-03-15

    Electrifying components in commercial vehicles can be a challenge. High vibration levels, for instance, amplify carbon brush and commutator erosion in a conventional electric motor. To offer a solution Federal-Mogul has developed the brushless fuel pump. This BLDC pump has successfully passed 10,000 h of operation in B100 fuel. (orig.)

  15. A New Phase Compensation Control System of Brushless DC Motor Based on Symmetric Line Voltage Difference%基于线电压差值对称的无刷直流电机换相信号相位补偿

    Institute of Scientific and Technical Information of China (English)

    姜志超; 廖勇

    2011-01-01

    When the precise commutation of brushless DC motor automatic control system was realized, the brushless DC motor could be running in the best performance. In this paper, the precise commutation, leading .commutation and delaying commutation of brushless DC motor with three-phase Y-connected windings was discussed. The relationship between line voltage difference and hall communication signal was analyzed and a new closed-loop compensation control method was presented. The compensation method used the difference of two line voltage as a semaphore and the asymmetric semaphore of line voltage bias as feedback signal. By this way the phase position deviation of hall commutation signal was corrected through the PI adjuster. The simulation and experimental results verify the effective of the proposed method.%无刷直流电机控制系统实现最佳换相可以使无刷直流电机发挥出最佳的性能.文章以无刷直流电机工作在三相星型六个状态模式为基础,详细分析了最佳换相、超前换相和滞后换相情况下线电压差值与霍尔换相信号相位之间的关系,据此提出一种补偿换相信号偏差的新型闭环控制方法.该补偿方法以两相线电压差作为信号量,前后两次换相时刻采集的非对称信号量偏差值作为反馈量,通过PI调节器达到补偿霍尔换相信号相位偏差的目的.仿真和实验证明该方法能够实时、有效地补偿换相信号的相位偏差.

  16. A norbornene polymer brush for electro-optic applications

    Energy Technology Data Exchange (ETDEWEB)

    Jia, Yue; Spring, Andrew M.; Yu, Feng; Yamamoto, Kazuhiro [Institute for Materials Chemistry and Engineering, Kyushu University, 6–1 Kasuga Fukuoka 816–8580 (Japan); Aoki, Isao; Otomo, Akira [National Institute of Information and Communications Technology, 588–2 Iwaoka, Nishi-ku, Kobe 651–2492 (Japan); Yokoyama, Shiyoshi, E-mail: s_yokoyama@cm.kyushu-u.ac.jp [Institute for Materials Chemistry and Engineering, Kyushu University, 6–1 Kasuga Fukuoka 816–8580 (Japan)

    2014-03-03

    Norbornene-dicarboximide derived polymer brushes containing Disperse Red 1 appended chromophores have been prepared by sequencial ring opening metathesis polymerization and atom transfer radical polymerization. This brush was then employed as an electro-optic polymer host for high molecular hyperpolarizability phenyl vinylene thiophene vinylene (FTC) bridge chromophores in a binary chromophore system. The r{sub 33} of the polymer brush/bi-chromophore network was evaluated via in situ poling and was measured as 94 pm/V compared to the benchmark polymethylmethacrylate (PMMA) system of 76 pm/V with an identical chromophore. Furthermore, our polymer brush/bi-chromophore network exhibited an enhanced poling efficiency of 1.37 (nm/V){sup 2} as compared to a simple PMMA - FTC host - guest 0.70 (nm/V){sup 2}. - Highlights: • Synthesis of a norbornene polymer brush. • Use of this polymer brush as a host for electro-optic materials. • The polymer brush enables a large electro-optic coefficient r{sub 33}.

  17. Efficiency of the surgical washing of hands with brush and without brush

    Directory of Open Access Journals (Sweden)

    Fresia Canales Carmona

    2013-10-01

    Full Text Available The purpose of this article is to establish the answer to a clinical question regarding the effectiveness ofpreoperative hygiene with hand washing brush or without it. This first technique has been performed on the skinto reduce transient bacteria and to inhibit the growth of resident microorganisms as a common and required actbefore any surgical procedure. Despite this measure and others such as prophylactic antibiotics, the mainoperative complication continues to be the surgical wound infection. Today, it is as prevalent as in the past withthe consequent negative effects derived from it, both for the institutions and for patients. Being controversialtoday which one is the most effective and safe surgical hand washing method for the binomial: professionalsurgical team/ patient, this study is done under the criteria of the Evidence-Based Nursing.A question was builtin PICO format (Personal, Intervention, Comparison and Outcome. After this is done, continues informationsearch in the databases GOOGLE ACADÉMICO, Pub Med, Cochrane y Base de Datos para la Investigación enEnfermería (BDIE We obtained 20 articles related to the topic of them 8, which fulfilled the set CASPe criteriato answer the clinical question, were analyzed. We conclude that washing hands with a brush is equally effectiveas without brush technique in terms of decreased of the superficial skin bacterial flora, although this technique hasadvantages over the traditional practice.

  18. Quantifying Fluctuations/Correlations in Polymer Brushes

    Science.gov (United States)

    Wang, Qiang; Zhang, Xinghua; Zhang, Pengfei; Li, Baohui

    2011-03-01

    Fast lattice Monte Carlo (FLMC) simulations with multiple occupancy of lattice sites and Kronecker δ -function interactions give orders of magnitude faster/better sampling of the configurational space of multi-chain systems than conventional lattice MC simulations with self- and mutual- avoiding walks and nearest-neighbor interactions. Using FLMC simulations with Wang-Landau -- Transition-Matrix sampling, we have studied polymer brushes in both an implicit and explicit solvent. The various quantities obtained from simulations (including the internal energy, Helmholtz free energy, constant-volume heat capacity, segmental distribution, and chain sizes) are compared with predictions from the corresponding lattice self-consistent field theory and Gaussian fluctuation theory that are based on the same Hamiltonian as in FLMC simulations (thus without any parameter-fitting) to unambiguously and quantitatively reveal the effects of system fluctuations and correlations neglected or treated only approximately in the theories. Q. Wang, Soft Matter, 5, 4564 (2009).

  19. Brushing abrasion of luting cements under neutral and acidic conditions.

    Science.gov (United States)

    Buchalla, W; Attin, T; Hellwig, E

    2000-01-01

    Four resin based materials (Compolute Aplicap, ESPE; Variolink Ultra, Vivadent; C&B Metabond, Parkell and Panavia 21, Kuraray), two carboxylate cements (Poly-F Plus, Dentsply DeTrey and Durelon Maxicap, ESPE), two glass-ionomer cements (Fuji I, GC and Ketac-Cem Aplicap, ESPE), one resin-modified glass ionomer cement (Vitremer, 3M) one polyacid-modified resin composite (Dyract Cem, Dentsply DeTrey) and one zinc phosphate cement (Harvard, Richter & Hoffmann) were investigated according to their brushing resistance after storage in neutral and acidic buffer solutions. For this purpose 24 cylindrical acrylic molds were each filled with the materials. After hardening, the samples were stored for seven days in 100% relative humidity and at 37 degrees C. Subsequently, they were ground flat and polished. Then each specimen was covered with an adhesive tape leaving a 4 mm wide window on the cement surface. Twelve samples of each material were stored for 24 hours in a buffer solution with a pH of 6.8. The remaining 12 samples were placed in a buffer with a pH of 3.0. All specimens were then subjected to a three media brushing abrasion (2,000 strokes) in an automatic brushing machine. Storage and brushing were performed three times. After 6,000 brushing strokes per specimen, the tape was removed. Brushing abrasion was measured with a computerized laser profilometer and statistically analyzed with ANOVA and Tukey's Standardized Range Test (p < or = 0.05). The highest brushing abrasion was found for the two carboxylate cements. The lowest brushing abrasion was found for one resin based material, Compolute Aplicap. With the exception of three resin-based materials, a lower pH led to a higher brushing abrasion.

  20. Antimicrobial penetration in a dual-species oral biofilm after noncontact brushing : an in vitro study

    NARCIS (Netherlands)

    He, Y.; Peterson, B. W.; Ren, Y.; van der Mei, H. C.; Busscher, H. J.

    2014-01-01

    Oral biofilm is inevitably left behind, even after powered brushing. As a special feature, powered brushing removes biofilm in a noncontact mode. When the brushing distance becomes too large, biofilm is left behind. We hypothesize that biofilm left behind after brushing has different viscoelastic pr

  1. Advanced AC Motor Control

    Energy Technology Data Exchange (ETDEWEB)

    Kazmierkowski, M.P. [Institute of Control and Industrial Electronics, Warsaw University of Technology, Warszawa (Poland)

    1997-12-31

    In this paper a review of control methods for high performance PWM inverter-fed induction motor drives is presented. Starting from the description of an induction motor by the help of the space vectors, three basic control strategic are discussed. As first, the most popular Field Oriented Control (FOC) is described. Secondly, the Direct Torque and Flux vector Control (DTFC) method, which - in contrast to FOC - depart from idea of coordinate transformation and analogy with DC motor, is briefly characterized. The last group is based on Feedback Linearization Control (FLC) and can be easy combined with sliding mode control. The simulation and experimental oscillograms that illustrate the performance of the discussed control strategies are shown. (orig.) 35 refs.

  2. An Overview of Non-Metallic Brush Seal Technology

    Science.gov (United States)

    Ruggiero, Eric J.

    2009-01-01

    Non-metallic brush seals are ultra-low flow sealing elements ideal for low pressure differentials (brush seal is advantageous in terms of sealing capability during transients. However, if not designed properly, the bristle pack compliance can be detrimental to the performance of the seal. GE GLobal Research has investigated the stiffness and heat generation properties of non-metallic brush seals made from Kevlar and Carbon Fiber. The presentation will review the progress made on the design points of the seals, as well as highlight some current commercial applications of the technology.

  3. A DC Transformer Project

    Data.gov (United States)

    National Aeronautics and Space Administration — During the period of this project three different possible DC transformer concepts were proposed, theoretically modeled, and then experimentally tested with the...

  4. Electric Tools Permanent Magnet Brushless DC Motor Hall Sensor Selection%电动工具用永磁无刷直流电机的霍尔传感器选型

    Institute of Scientific and Technical Information of China (English)

    古炯钧; 徐威群

    2014-01-01

    基于不同工艺霍尔传感器的磁特性与电特性,就电动工具用无刷电机的应用特点,介绍所需霍尔传感器的必要参数,提出合理选型建议,以期达到提高电机整体性能与可靠性的目的,为工程师设计电机时选择霍尔传感器提供参考。%Based on the magnetic properties and electrical characteristics of different processes Hall sensor, and on the application characteristics of electric tools brushless motor, introduce the necessary parameters of Hall sensor, put forward reasonable selection suggestions, in order to improve the overall performance and reliability, and to provide a reference for the engineers choosing Hall sensor when designing the motors.

  5. Radiation Effects on DC-DC Converters

    Science.gov (United States)

    Zhang, De-Xin; AbdulMazid, M. D.; Attia, John O.; Kankam, Mark D. (Technical Monitor)

    2001-01-01

    In this work, several DC-DC converters were designed and built. The converters are Buck Buck-Boost, Cuk, Flyback, and full-bridge zero-voltage switched. The total ionizing dose radiation and single event effects on the converters were investigated. The experimental results for the TID effects tests show that the voltages of the Buck Buck-Boost, Cuk, and Flyback converters increase as total dose increased when using power MOSFET IRF250 as a switching transistor. The change in output voltage with total dose is highest for the Buck converter and the lowest for Flyback converter. The trend of increase in output voltages with total dose in the present work agrees with those of the literature. The trends of the experimental results also agree with those obtained from PSPICE simulation. For the full-bridge zero-voltage switch converter, it was observed that the dc-dc converter with IRF250 power MOSFET did not show a significant change of output voltage with total dose. In addition, for the dc-dc converter with FSF254R4 radiation-hardened power MOSFET, the output voltage did not change significantly with total dose. The experimental results were confirmed by PSPICE simulation that showed that FB-ZVS converter with IRF250 power MOSFET's was not affected with the increase in total ionizing dose. Single Event Effects (SEE) radiation tests were performed on FB-ZVS converters. It was observed that the FB-ZVS converter with the IRF250 power MOSFET, when the device was irradiated with Krypton ion with ion-energy of 150 MeV and LET of 41.3 MeV-square cm/mg, the output voltage increased with the increase in fluence. However, for Krypton with ion-energy of 600 MeV and LET of 33.65 MeV-square cm/mg, and two out of four transistors of the converter were permanently damaged. The dc-dc converter with FSF254R4 radiation hardened power MOSFET's did not show significant change at the output voltage with fluence while being irradiated by Krypton with ion energy of 1.20 GeV and LET of 25

  6. Superhydrophilic Polyelectrolyte Brush Layers with Imparted Anti-Icing Properties

    DEFF Research Database (Denmark)

    Chernyy, Sergey; Järn, Mikael; Shimizu, Kyoko;

    2014-01-01

    This work demonstrates the feasibility of superhydrophilic polyelectrolyte brush coatings for anti-icing applications. Five different types of ionic and nonionic polymer brush coatings of 25-100 nm thickness were formed on glass substrates using silane chemistry for surface premodification follow......) that is enhanced in the presence of highly hydrated ions at the interface. It is suggested that the ability of ions to coordinate water is directly related to the efficiency of a given anti-icing coating based on the polyelectrolyte brush concept.......(-), SO4(2-), and C12SO3(-) ions. By consecutive measurements of the strength of ice adhesion toward ion-incorporated polymer brushes on glass it was found that Li(+) ions reduce ice adhesion by 40% at -18 °C and 70% at -10 °C. Ag(+) ions reduce ice adhesion by 80% at -10 °C relative to unmodified glass...

  7. Surface wave excitations and backflow effect over dense polymer brushes.

    Science.gov (United States)

    Biagi, Sofia; Rovigatti, Lorenzo; Sciortino, Francesco; Misbah, Chaouqi

    2016-01-01

    Polymer brushes are being increasingly used to tailor surface physicochemistry for diverse applications such as wetting, adhesion of biological objects, implantable devices and much more. Here we perform Dissipative Particle Dynamics simulations to study the behaviour of dense polymer brushes under flow in a slit-pore channel. We discover that the system displays flow inversion at the brush interface for several disconnected ranges of the imposed flow. We associate such phenomenon to collective polymer dynamics: a wave propagating on the brush surface. The relation between the wavelength, the amplitude and the propagation speed of the flow-generated wave is consistent with the solution of the Stokes equations when an imposed traveling wave is assumed as the boundary condition (the famous Taylor's swimmer). PMID:26975329

  8. Surface wave excitations and backflow effect over dense polymer brushes

    Science.gov (United States)

    Biagi, Sofia; Rovigatti, Lorenzo; Sciortino, Francesco; Misbah, Chaouqi

    2016-03-01

    Polymer brushes are being increasingly used to tailor surface physicochemistry for diverse applications such as wetting, adhesion of biological objects, implantable devices and much more. Here we perform Dissipative Particle Dynamics simulations to study the behaviour of dense polymer brushes under flow in a slit-pore channel. We discover that the system displays flow inversion at the brush interface for several disconnected ranges of the imposed flow. We associate such phenomenon to collective polymer dynamics: a wave propagating on the brush surface. The relation between the wavelength, the amplitude and the propagation speed of the flow-generated wave is consistent with the solution of the Stokes equations when an imposed traveling wave is assumed as the boundary condition (the famous Taylor’s swimmer).

  9. Virtual instrument for monitoring process of brush plating

    Institute of Scientific and Technical Information of China (English)

    JING Xue-dong; XU Bin-shi; WANG Cheng-tao; ZHU Sheng; DONG Shi-yun

    2004-01-01

    A virtual instrument(Ⅵ) was developed to monitor the technological parameters in the process of brush plating, including coating thickness, brush-plating current, current density, deposition rate, and brush plating voltage. Meanwhile two approaches were presented to improve the measurement accuracy of coating thickness. One of them aims at eliminating the random interferences by moving average filtering; while the other manages to calculate the quantity of electricity consumed accurately with rectangular integration. With these two approaches, the coating thickness can be measured in real time with higher accuracy than the voltage-frequency conversion method. During the process of plating all the technological parameters are displayed visually on the front panel of the Ⅵ. Once brush current or current density overruns the limited values, or when the coating thickness reaches the objective value, the virtual will alarm. With this Ⅵ, the solution consumption can be decreased and the operating efficiency is improved.

  10. Galectin-4 and small intestinal brush border enzymes form clusters

    DEFF Research Database (Denmark)

    Danielsen, E M; van Deurs, B

    1997-01-01

    Detergent-insoluble complexes prepared from pig small intestine are highly enriched in several transmembrane brush border enzymes including aminopeptidase N and sucrase-isomaltase, indicating that they reside in a glycolipid-rich environment in vivo. In the present work galectin-4, an animal lectin...... lacking a N-terminal signal peptide for membrane translocation, was discovered in these complexes as well, and in gradient centrifugation brush border enzymes and galectin-4 formed distinct soluble high molecular weight clusters. Immunoperoxidase cytochemistry and immunogold electron microscopy showed...... by a nonclassical pathway, and the brush border enzymes represent a novel class of natural ligands for a member of the galectin family. Newly synthesized galectin-4 is rapidly "trapped" by association with intracellular structures prior to its apical secretion, but once externalized, association with brush border...

  11. Role of gastric brush cytology in the diagnosis of giardiasis

    OpenAIRE

    Varma Deepali; Jain Shyama; Khurana Nita

    2008-01-01

    Background: Giardiasis, common in developing countries, has mostly nonspecific clinical symptoms, resulting in a limited role for preliminary tests. Aims: The present study aims to highlight the utility of endoscopic brush cytology (EBC) in the diagnosis of giardiasis in clinically unsuspected cases. Materials and Methods: Endoscopic brush smears (EBS) are routinely obtained in all patients presenting with gastric symptoms. The present study is a retrospective analysis of EBS, consis...

  12. Surface characterization of electron-beam irradiated polymer brushes

    International Nuclear Information System (INIS)

    Polymer brushes out of PS, P2VP, PNIPAMM and PAA were used to modify and control the surface potential of Si-wafers. The polymers brushes formed layers of thickness of less than 20 nm and significantly changed the surface potential of the substrate, which was investigated with contact angle measurements. Their chemical composition was studied by XPS. Electron irradiation was employed to modify the brushes by different radiation doses. With XPS and Zetapotential measurements we were able to specify the surface composition after electron beam treatment. Changes in surface composition and the structure of the grafted polymer brushes allowed to qualify cross-linkages and degradation processes. By varying the dose we could adjust on the one hand the decomposition of the polymer and on the other hand the amount of hydrophilic groups. We know that the adsorption of proteins on polymers highly depends on the surface potential. This work could be used to control the surface potential of the polymer brush as well as the adsorption of proteins, only by varying the radiation dose. The chosen substrate silicon is also attractive for lab-on-chip applications of those modified brushes. (orig.)

  13. The Unusual Conformational Behavior of Polyzwitterionic Brushes in Aqueous Solutions

    Science.gov (United States)

    Mao, Jun; Chen, Wei; Yuan, Guangcui; Yu, Jing; Tirrell, Matthew

    Polyzwitterions constitute a peculiar class of polyelectrolytes, which are electrically neutral polymers containing both a positive and a negative charge on each repeating unit. Surfaces coated with polyzwitterionic brushes are resistant to the nonspecific accumulation of proteins and microorganisms, making them excellent candidates for a wide range of antifouling applications, from biocompatible medical devices to marine coatings. The surrounding environment can dramatically influence the conformational behavior of polyzwitterionic brushes. High-density polyzwitterionic brushes poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC) were synthesized using surface initiated atom-transfer radical polymerization, and neutron reflectivity (NR) measurements were performed to investigate the ionic strength dependence of the conformational behaviors of PMPC brushes in monovalent salt solutions. Despite the numerous observations of normal pure polyelectrolyte brushes, NR results showed that both the densely concentrated layer near the substrate surface and the relatively swollen layer into the solution have been observed in different q range in a single neutron reflectivity profile. These results will definitely help us to better understand the relationship between the solution behaviors of zwitterionic polymer brushes and their antifouling properties.

  14. The Secretion and Action of Brush Border Enzymes in the Mammalian Small Intestine.

    Science.gov (United States)

    Hooton, Diane; Lentle, Roger; Monro, John; Wickham, Martin; Simpson, Robert

    2015-01-01

    Microvilli are conventionally regarded as an extension of the small intestinal absorptive surface, but they are also, as latterly discovered, a launching pad for brush border digestive enzymes. Recent work has demonstrated that motor elements of the microvillus cytoskeleton operate to displace the apical membrane toward the apex of the microvillus, where it vesiculates and is shed into the periapical space. Catalytically active brush border digestive enzymes remain incorporated within the membranes of these vesicles, which shifts the site of BB digestion from the surface of the enterocyte to the periapical space. This process enables nutrient hydrolysis to occur adjacent to the membrane in a pre-absorptive step. The characterization of BB digestive enzymes is influenced by the way in which these enzymes are anchored to the apical membranes of microvilli, their subsequent shedding in membrane vesicles, and their differing susceptibilities to cleavage from the component membranes. In addition, the presence of active intracellular components of these enzymes complicates their quantitative assay and the elucidation of their dynamics. This review summarizes the ontogeny and regulation of BB digestive enzymes and what is known of their kinetics and their action in the peripheral and axial regions of the small intestinal lumen.

  15. 桥堆整流电路在直流电机励磁电源中的应用%Application of the Bridge Pile Rectification Circuit in DC Motor Excitation Power

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    Aimed at the problem of the trigger line and the silicon controlled rectifier for 590 DC internal excitation in actual use, proposed the application of the bridge rectification circuit instead of the complicated trigger and excitation control circuit in order to achieve the simple structure,voltage stability and low maintenance cost.%  针对590直流调速器内部励磁触发线路及可控硅整流模块在实际使用中的问题,提出应用桥堆整流电路替代复杂的触发与励磁控制线路,使励磁电源控制电路达到结构简单、电压稳定、维护成本低的目的。

  16. 270 V高压无刷直流电动机速度闭环控制器%Speed Closed Loop Controller of 270 V High Voltage Brushless DC Motor

    Institute of Scientific and Technical Information of China (English)

    马瑞卿; 侯红胜; 杨白明

    2009-01-01

    介绍了一种270 V航空高压无刷直流电动机(BLDCM)速度闭环控制器.充分利用BLDCM自身三相Hall传感器的转子位置信息,对三相Hall信号进行逻辑处理来实现倍频,进而提高了电机速度检测的分辨率.给出了高压DC/DC隔离控制电源、Hall信号倍频逻辑和AT89C51单片机等关键电路的设计方法.试验结果表明:电机具有较为平直的机械特性及较好的速度稳定度.

  17. Adsorption of enzymes to stimuli-responsive polymer brushes: Influence of brush conformation on adsorbed amount and biocatalytic activity.

    Science.gov (United States)

    Koenig, Meike; Bittrich, Eva; König, Ulla; Rajeev, Bhadra Lakshmi; Müller, Martin; Eichhorn, Klaus-Jochen; Thomas, Sabu; Stamm, Manfred; Uhlmann, Petra

    2016-10-01

    Polyelectrolyte brushes can be utilized to immobilize enzymes on macroscopic surfaces. This report investigates the influence of the pH value of the surrounding medium on the amount and the activity of enzymes adsorbed to poly(2-vinylpyridine) and poly(acrylic acid) brushes, as well as the creation of thermoresponsive biocatalytically active coatings via the adsorption of enzymes onto a mixed brush consisting of a polyelectrolyte and temperature-sensitive poly(N-isopropylacryl amide). Spectroscopic ellipsometry and attenuated total reflection-Fourier transform infrared spectroscopy are used to monitor the adsorption process. Additionally, infrared spectra are evaluated in terms of the secondary structure of the enzymes. Glucose oxidase is used as a model enzyme, where the enzymatic activity is measured after different adsorption conditions. Poly(acrylic acid) brushes generally adsorb larger amounts of enzyme, while less glucose oxidase is found on poly(2-vinylpyridine), which however exhibits higher specific activity. This difference in activity could be attributed to a difference in secondary structure of the adsorbed enzyme. For glucose oxidase adsorbed to mixed brushes, switching of enzymatic activity between an active state at 20°C and a less active state at 40°C as compared to the free enzyme in solution is observed. However, this switching is strongly depending on pH in mixed brushes of poly(acrylic acid) and poly(N-isopropylacryl amide) due to interactions between the polymers. PMID:27447452

  18. Study on Starting Control for Sensorless Three-phase Permanent-magnet Brushless DC Motor%三相永磁无刷电机起动控制研究

    Institute of Scientific and Technical Information of China (English)

    吴强; 熊浩; 孟光伟; 让余奇; 李槐树

    2011-01-01

    本文分析了的120°导通三相逆变器的SVPWM控制特性,提出了基于SVPWM控制和电流调节控制的无位置传感器的三相永磁无刷直流电机(BLDCM)的起动控制方法。在Matlab/Simlink环境下,建立了三相永磁BLDCM起动控制系统的仿真模型并进行了仿真。仿真结果表明该起动控制方法不但能有效控制起动电流大小,而且能改善BLDCM开环起动性能。%The paper analyses the SVPWM control schema of three-phase inverter employing 120° switch-on mode,proposes a starting control method combining the SVPWM control schema with current regulation for a sensorless three-phase permanent-magnet(PM) brushless DC(BLDC) motor,establishes the simulation model of the starting control system in Matlab /Simlink environment,and implements the proposed starting control system through digital simulation.Simulation results verify that the proposed starting method can not only control the starting current effectively but also improve the open-loop starting performance of the BLDC motor.

  19. 基于 AVR 单片机的直流电机控制系统设计%Dc Motor Control System Based on AVR Single-chip Computer Design

    Institute of Scientific and Technical Information of China (English)

    姜颖韬

    2013-01-01

    MUC-controlled motor drive platform has been demanded widely in engineering field ,so the author designed a new scheme with AVR single chip microcomputer as main control chip .By using this scheme ,the motor drive platform has some advantages ,such as lightweight ,efficient ,low consumption ,good real-time performance ,which can be widely used in indus-trial and agricultural production ,civil life ,education ,scientific research and other fields .%针对在工程领域内具有广泛需求的MUC控制电动机驱动的动力平台,开发了一种以AVR单片机作为主控芯片的新方案。应用该方案设计的动力平台系统具有轻量化、高效低耗、实时性好等优点,可广泛应用于工农业生产、民用生活、教育科研等领域。

  20. Design of High-current DC Motor Driver Based Upon LM5106%基于LM5106的大电流直流电机驱动设计

    Institute of Scientific and Technical Information of China (English)

    姚善浪; 施国梁

    2014-01-01

    Aimed to realize the driving of the high-cur-rent motor, the PIC single chip LM5106 acted as hardware, was applied as main processor to control the on-off of the MOSFET, start the motor and fulfill clockwise, counter clockwise rotating and braking relying on the excellent driving performance of the single chip while the software was in charge of the intelligent test and control onto the sys-tem, in which the PWM signal was used to implement the motor’s speed-regulation with various kind of acceleration curves.%为实现驱动大电流电机的目标,以PIC单片机主处理器作为硬件,利用L M5106良好驱动性能,控制MOSFET导通,实现电机起动、正反转以及制动等操作。软件主要解决对系统的智能检测与控制,以PWM信号生成来实现多种加速度曲线的调速。试验证明本系统具有驱动能力强,可控性良好等优点。

  1. Radiation-Tolerant DC-DC Converters

    Science.gov (United States)

    Skutt, Glenn; Sable, Dan; Leslie, Leonard; Graham, Shawn

    2012-01-01

    A document discusses power converters suitable for space use that meet the DSCC MIL-PRF-38534 Appendix G radiation hardness level P classification. A method for qualifying commercially produced electronic parts for DC-DC converters per the Defense Supply Center Columbus (DSCC) radiation hardened assurance requirements was developed. Development and compliance testing of standard hybrid converters suitable for space use were completed for missions with total dose radiation requirements of up to 30 kRad. This innovation provides the same overall performance as standard hybrid converters, but includes assurance of radiation- tolerant design through components and design compliance testing. This availability of design-certified radiation-tolerant converters can significantly reduce total cost and delivery time for power converters for space applications that fit the appropriate DSCC classification (30 kRad).

  2. SIMULATION MODELS OF HEAVY TRUCKS TRAFFIC CONTROL WITH ELECTRIC DC DRIVE

    Directory of Open Access Journals (Sweden)

    N. N. Hurski

    2015-01-01

    Full Text Available A model of the straight course of movement of the mobile machine with a traction electric motor DC. Traffic management controller provides a closed classical scheme with feedback. The mathematical model of the electric DC motor with the energy dissipation in the rotor bearings. Design scheme of mobile machines include speed dial controller, traction electric motor, gearbox, transmission and progressively moving mass on the elastic­dissipative wheel. The results of the simulation of the machine in the form of temporary processes of change control signals, voltage and current in the windings of the motor and traction power developed on the wheel.

  3. Forback DC-to-DC converter

    Science.gov (United States)

    Lukemire, Alan T.

    1995-05-01

    A pulse-width modulated DC-to-DC power converter including a first inductor, i.e. a transformer or an equivalent fixed inductor equal to the inductance of the secondary winding of the transformer, coupled across a source of DC input voltage via a transistor switch which is rendered alternately conductive (ON) and nonconductive (OFF) in accordance with a signal from a feedback control circuit is described. A first capacitor capacitively couples one side of the first inductor to a second inductor which is connected to a second capacitor which is coupled to the other side of the first inductor. A circuit load shunts the second capacitor. A semiconductor diode is additionally coupled from a common circuit connection between the first capacitor and the second inductor to the other side of the first inductor. A current sense transformer generating a current feedback signal for the switch control circuit is directly coupled in series with the other side of the first inductor so that the first capacitor, the second inductor and the current sense transformer are connected in series through the first inductor. The inductance values of the first and second inductors, moreover, are made identical. Such a converter topology results in a simultaneous voltsecond balance in the first inductance and ampere-second balance in the current sense transformer.

  4. Research on DSP-based Asynchronous Motor Control Technology

    Directory of Open Access Journals (Sweden)

    Jun Yao

    2013-05-01

    Full Text Available The Motor in a variety of electrical transmission and position servo system occupies an extremely important position. After the DSP technology being applied to the motor control, the unification of the hardware and the flexibility of the software can be combined. Take the brushless DC motor for example, studied the mathematical model and the structure of the motor control system, also obtained the design scheme of the DSP-based asynchronous motor control system. With TI's 32 bit fixed point DSPTMS320F2812 as the core design of the hardware system, we wrote the system software, debug the motor control system and the results show that the system achieves the expected effect. The results of the research can be applied to brushless DC motor and other motor control, it will have a wide application prospects.

  5. Research on Mechanical Characteristics of AC Motor with Cascade DC Chopper Speed Control System%斩波串级调速系统电机机械特性曲线的研究

    Institute of Scientific and Technical Information of China (English)

    王归新; 裴合伟; 晓琼; 鲜万春

    2012-01-01

    In high power application, wound AC motor rotor loop cascade control system has very good speed performance and energy-saving effect. Based on the analysis that the equivalent internal impedance of three-phase rectifier bridge influence rectifier output,rectifier bridge and follow-up circuit equivalent to the mo-tor rotor loop resistance, inferred to the mechanical characteristics in the cascade control system.Came to con-clusion that two influence factors for mechanical characteristics. The rotor loop equivalent impedance is more serious than rotor leakage reactance effect commutation overlap angle to mechanical characteristics influence. The simulation and the experiment verify the theory.%绕线转子式交流电机转子回路串级调速系统具有很好的调速性能和节电效果,在中大功率领域应用较多.基于对三相整流电路电源等效内阻抗对桥路整流输出的影响分析,将整流桥及其后续电路等效为电机转子回路的电阻,推导出在有串级调速系统下电机的机械特性,得出了影响电机机械特性的两方面因素,其中转子回路的等效阻抗对机械特性的影响相对于转子漏抗影响换相重叠角对机械特性的影响尤为严重的结论.仿真结果证实了理论推导的结论,并进行了实验验证.

  6. 基于准Z源网络的永磁无刷直流电机换相转矩脉动抑制方法%Researches on the Method of Suppressing Commutation Torque Ripple for Brushless DC Motors Based on a Quasi-Z-Source Net

    Institute of Scientific and Technical Information of China (English)

    夏鲲; 朱琳玲; 曾彦能; 徐鑫悦; 杨益华

    2015-01-01

    Focusing on popular existed high commutation torque ripple of square waves driving brushless DC motors, this paper presented a new method of suppressing commutation torque ripple for brushless DC motors based on a Quasi-Z-Source net. The Quasi-Z-Source net was employed at the front of the three-phase bridge. The control strategy was to adjust the DC link voltage of the motor controller via the Quasi-Z-Source net to keep the incoming and outgoing phase currents changing at the same rate during commutation, hence to effectively suppress commutation torque ripple. The cause of commutation ripple was analyzed. A novel circuit topology and a control algorithm of suppressing commutation torque ripple employed a Quasi-Z-Source net before the inverter was introduced in detail. Finally, simulation and experimental results show that, the proposed method can effectively minimizing commutation torque ripple. Torque ripple can be reduced to below 4.6% of the average torque by using appropriate circuit parameters in a simulation mode. And torque ripple can also be reduced to below 12% of the average torque via experimentation in real situation.%针对方波驱动的无刷直流电机普遍存在的换相转矩脉动较大的问题,提出了一种基于准 Z 源网络抑制永磁无刷直流电机换相转矩脉动的方法。在三相桥臂前级增加准 Z源网络,换相期间由准 Z 源网络调整直流母线电压,使电机关断相电流下降速率与开通相电流上升速率相等,从而有效抑制换相转矩脉动。分析了换相转矩脉动产生的原因,详细介绍了通过增加前级功率变换电路抑制换相转矩脉动的电路拓扑与控制算法。仿真及实验结果表明,该方法能够有效抑制永磁无刷直流电机换相转矩脉动,如采用合适的电路参数,仿真模型中转矩脉动可减少到平均转矩的4.6%以下,实际设计的系统实验可将转矩脉动抑制在平均转矩的12%以下。

  7. Design of brushless DC motor control system for electric motorcycle based on PIC%基于单片机的电动摩托车无刷直流电机控制系统的设计

    Institute of Scientific and Technical Information of China (English)

    马洪雨; 帕孜来·马合木提; 李倩

    2016-01-01

    According to the controlling strategy of BLDCM, a brushless DC motorof electric motorcycle control system based on PIC16F737 microcontroller was designed, a detail ofhardware circuit andsoftware design methods were given, This system can realize regulation speed, speed limit and stationary speed and has perfect function of protection and assistance. Static and dynamic test of the control system were completed. Experiments show that the control system has a good performance , meet the requirements, the devise have definite practical value.%根据无刷直流电机的工作原理,设计了以PICl6F737单片机为核心的电动摩托车无刷直流电动机控制系统,给出了控制系统的硬件组成和软件设计方法,可以实现调速、限速、定速功能,保护及辅助功能完善.通过对控制系统的静态和动态调试表明系统性能良好,满足设计要求,具有广泛的现实意义.

  8. Specific ion modulated thermoresponse of poly(N-isopropylacrylamide) brushes.

    Science.gov (United States)

    Humphreys, Ben A; Willott, Joshua D; Murdoch, Timothy J; Webber, Grant B; Wanless, Erica J

    2016-02-17

    The influence of specific anions on the equilibrium thermoresponse of poly(N-isopropylacrylamide) (pNIPAM) brushes has been studied using in situ ellipsometry, quartz crystal microbalance with dissipation (QCM-D) and static contact angle measurements between 20 and 45 °C in the presence of up to 250 mM acetate and thiocyanate anions in water. The thickness and changes in dissipation exhibited a broad swelling transition spanning approximately 15 °C from collapsed (high temperatures) to swollen conformation (low temperatures) while the brush surface wettability changed over approximately 2 °C. In the presence of the kosmotropic acetate anions, the measured lower critical solution temperature (LCST) by the three techniques was very similar and decreased linearly as a function of ionic strength. Conversely, increasing the concentration of the chaotropic thiocyanate anions raised the LCST of the pNIPAM brushes with variation in the measured LCST between the three techniques increasing with ionic strength. The thickness of the pNIPAM brush was seen to progressively increase with increasing thiocyanate concentration at all temperatures. It is proposed that specific ion binding of the chaotropic thiocyanate anion with pNIPAM amide moieties increases the electrostatic intra- and intermolecular repulsion within and between pNIPAM chains. This allows the brush to begin to swell at higher temperatures and to an overall greater extent. PMID:26840183

  9. Effects of Geometry on Leakage Flow Characteristics of Brush Seal

    Institute of Scientific and Technical Information of China (English)

    Yuan Wei; Zhaobo Chen∗; Yinghou Jiao

    2015-01-01

    In order to better application of brush seal in rotating machinery, the leakage flow characteristics of the brush seal considering geometry effects are numerically analyzed using Reynolds⁃Averaged Navier⁃Stokes ( RANS) model coupling with a non⁃Darcian porous medium model. The reliability of the present numerical method is proved, which is in agreement with the experimental and numerical results from literatures. Three different bristle pack thicknesses, fence heights and initial clearances under different pressure ratios, rotational velocities and other operating conditions are utilized to investigate the effects of geometry modification on the brush seal leakage flow behaviors. It discusses the effectiveness of various geometry configurations outlining important flow features. The results indicate that the increase of fence height and clearance would lead to the increase of leakage rate. But the leakage is not linearly with respect to the bristle pack thickness, and the effect of rotational velocity is not obvious. Moreover, the detailed leakage flow fields and pressure distributions along the rotor surface, free bristle height, and fence height of the brush seals are also presented. The static pressure drop amplitude through the bristle pack and the pressure rise amplitude through the cavity would increase while the pressure differential increases. And the axial pressure is the main reason of bristle blow down. The results provide theoretical support for the brush seal structure optimal design.

  10. What information can frictional properties of polymer brushes tell us?

    Science.gov (United States)

    Zhang, Zhenyu; Moxey, Mark; Morse, Andrew; Armes, Steven; Lewis, Andrew; Geoghegan, Mark; Leggett, Graham

    2013-03-01

    We have used friction force microscopy (FFM) to quantitatively examine surface grown zwitterionic polymer brushes: poly(2-(methacryloyloxy)ethyl phosphorylcholine) (PMPC), and to establish the correlation between its frictional behaviour to other intrinsic properties. In a good solvent, it was found that the coefficient of friction (μ) decreased with increasing film thickness. We conclude that the amount of bound solvent increases as the brush length increases, causing the osmotic pressure to increase and yielding a reduced tendency for the brush layer to deform under applied load. When measured in a series of alcohol/water mixtures, a significant increase in μ was observed for ethanol/water mixtures at a volume fraction of 90%. This is attributed to brush collapse due to co-nonsolvency, leading to loss of hydration of the brush chains and hence substantially reduced lubrication. We show that single asperity contact mechanics is strongly dependent on solvent quality. Friction-load relationship was found linear in methanol (good solvent), but sub-linear in water and ethanol (moderate solvent).

  11. Intelligent dc-dc Converter Technology Developed and Tested

    Science.gov (United States)

    Button, Robert M.

    2001-01-01

    The NASA Glenn Research Center and the Cleveland State University have developed a digitally controlled dc-dc converter to research the benefits of flexible, digital control on power electronics and systems. Initial research and testing has shown that conventional dc-dc converters can benefit from improved performance by using digital-signal processors and nonlinear control algorithms.

  12. The Trail Inventory of DC Booth Historic NFH [Cycle 2

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The purpose of this report is to create a baseline inventory of all non-motorized trails on D.C. Booth Historic National Fish Hatchery. Trails in this inventory are...

  13. Macromolecular Brushes as Stabilizers of Hydrophobic Solute Nanoparticles.

    Science.gov (United States)

    Luo, Hanying; Raciti, David; Wang, Chao; Herrera-Alonso, Margarita

    2016-06-01

    Macromolecular brushes bearing poly(ethylene glycol) and poly(d,l-lactide) side chains were used to stabilize hydrophobic solute nanoparticles formed by a rapid change in solvent quality. Unlike linear diblock copolymers with the same hydrophilic and hydrophobic block chemistries, the brush copolymer enabled the formation of ellipsoidal β-carotene nanoparticles, which in cosolvent mixtures developed into rod-like structures, resulting from a combination of Ostwald ripening and particle aggregation. The stabilizing ability of the copolymer was highly dependent on the mobility of the hydrophobic component, influenced by its molecular weight. As shown here, asymmetric amphiphilic macromolecular brushes of this type may be used as hydrophobic drug stabilizers and potentially assist the shape control of nonspherical aggregate morphologies. PMID:27035279

  14. Numerical simulations of plasma brush behavior in hybrid armatures

    Science.gov (United States)

    Hawke, R. S.; Pincosy, P. A.

    1993-01-01

    Hybrid armatures used to accelerate projectiles in railguns are often the consequence of using a solid armature or in some cases the preferred armature type. Although hybrid armatures are often used, their design has been empirical and their performance sporadic. As a first step towards understanding hybrid design and performance, we have begun a combined numerical simulation and experimental verification effort. This paper will describe numerical simulations performed with a quasi 1-D MHD code (CONFUSE) which has been applied to simulate the behavior of plasma brushes used in hybrid armatures. The simulations have provided estimates of the plasma brush length, resistive voltage drop and temperatures corresponding to a range of; 1) brush gap size, 2) fuse thickness, and 3) magnetic pressure. The results of these simulations is presented and discussed.

  15. Numerical simulations of plasma brush behavior in hybrid armatures

    Energy Technology Data Exchange (ETDEWEB)

    Hawke, R.S.; Pincosy, P.A.

    1992-04-01

    Hybrid armatures used to accelerate projectiles in railguns are often the consequence of using a solid armature or in some cases the preferred armature type. Although hybrid armatures are often used, their design has been empirical and their performance sporadic. As a first step towards understanding hybrid design and performance, we have begun a combined numerical simulation and experimental verification effort This paper will describe numerical simulations performed with liquid 1-D MHD code (CONFUSE) which has been applied to simulate the behavior of plasma brushes used in hybrid armatures. The simulations have provided estimates of the plasma brush length, resistive voltage drop and temperatures corresponding to a range of; (1) brush gap size, (2) fuse thickness, and (3) magnetic pressure. The results of these simulations will be presented and discussed.

  16. A Nanosecond Pulsed Plasma Brush for Surface Decontamination

    Science.gov (United States)

    Neuber, Johanna; Malik, Muhammad; Song, Shutong; Jiang, Chunqi

    2015-11-01

    This work optimizes a non-thermal, atmospheric pressure plasma brush for surface decontamination. The generated plasma plumes with a maximum length of 2 cm are arranged in a 5 cm long, brush-like array. The plasma was generated in ambient air with plasma chamber at a rate varying between 1 to 7 SLPM. Optimization of the cold plasma brush for surface decontamination was tested in a study of the plasma inactivation of two common pathogens, Staphylococcus aureus and Acinetobacter baumannii. Laminate surfaces inoculated with over-night cultured bacteria were subject to the plasma treatment for varying water concentrations in He, flow rates and discharge voltages. It was found that increasing the water content of the feed gas greatly enhanced the bactericidal effect. Emission spectroscopy was performed to identify the reactive plasma species that contribute to this variation. Additional affiliation: Frank Reidy Research Center for Bioelectrics

  17. Colloidal lithography for fabricating patterned polymer-brush microstructures

    Directory of Open Access Journals (Sweden)

    Tao Chen

    2012-05-01

    Full Text Available We exploit a series of robust, but simple and convenient colloidal lithography (CL approaches, using a microsphere array as a mask or as a guiding template, and combine this with surface-initiated atom-transfer radical polymerization (SI-ATRP to fabricate patterned polymer-brush microstructures. The advantages of the CL technique over other lithographic approaches for the fabrication of patterned polymer brushes are (i that it can be carried out with commercially available colloidal particles at a relatively low cost, (ii that no complex equipment is required to create the patterned templates with micro- and nanoscale features, and (iii that polymer brush features are controlled simply by changing the size or chemical functionality of the microspheres or the substrate.

  18. A Robust Fuzzy Sliding Mode Controller Synthesis Applied on Boost DC-DC Converter Power Supply for Electric Vehicle Propulsion System

    Directory of Open Access Journals (Sweden)

    Boumediène Allaoua

    2013-01-01

    Full Text Available The development of electric vehicles power electronics system control comprising of DC-AC inverters and DC-DC converters takes a great interest of researchers in the modern industry. A DC-AC inverter supplies the high power electric vehicle motors torques of the propulsion system and utility loads, whereas a DC-DC converter supplies conventional low-power, low-voltage loads. However, the need for high power bidirectional DC-DC converters in future electric vehicles has led to the development of many new topologies of DC-DC converters. Nonlinear control of power converters is an active area of research in the fields of power electronics. This paper focuses on a fuzzy sliding mode strategy (FSMS as a control strategy for boost DC-DC converter power supply for electric vehicle. The proposed fuzzy controller specifies changes in the control signal based on the surface and the surface change knowledge to satisfy the sliding mode stability and attraction conditions. The performances of the proposed fuzzy sliding controller are compared to those obtained by a classical sliding mode controller. The satisfactory simulation results show the efficiency of the proposed control law which reduces the chattering phenomenon. Moreover, the obtained results prove the robustness of the proposed control law against variation of the load resistance and the input voltage of the studied converter.

  19. Effective Antisense Gene Regulation via Noncationic, Polyethylene Glycol Brushes.

    Science.gov (United States)

    Lu, Xueguang; Jia, Fei; Tan, Xuyu; Wang, Dali; Cao, Xueyan; Zheng, Jiamin; Zhang, Ke

    2016-07-27

    Negatively charged nucleic acids are often complexed with polycationic transfection agents before delivery. Herein, we demonstrate that a noncationic, biocompatible polymer, polyethylene glycol, can be used as a transfection vector by forming a brush polymer-DNA conjugate. The brush architecture provides embedded DNA strands with enhanced nuclease stability and improved cell uptake. Because of the biologically benign nature of the polymer component, no cytotoxicity was observed. This approach has the potential to address several long-lasting challenges in oligonucleotide therapeutics. PMID:27420413

  20. Study on Technology and Properties of Brush Plating Coatings

    Institute of Scientific and Technical Information of China (English)

    DI Ping

    2004-01-01

    A new brush plating process with a soluble anode of nickel was introduced. TDY112 brush plating solution was used on the No.20 carbon steel substrate. It has the higher deposit velocity, better properties and lower cost. Scanning electronic microscopy(SEM), optical microscope, microhardness test and wear test were adopted to detect the surface quality and the properties of the coating, such as micrograph, microstructure, micro-hardness wear resistance and adherence between the coating and the substrate. The experimental results showed that the suitable technological parameters to be used, the coatings had better the surface quality, higher hardness and wear resistance.

  1. Stimuli-Responsive Polyelectrolyte Brushes As a Matrix for the Attachment of Gold Nanoparticles: The Effect of Brush Thickness on Particle Distribution

    Directory of Open Access Journals (Sweden)

    Stephanie Christau

    2014-06-01

    Full Text Available The effect of brush thickness on the loading of gold nanoparticles (AuNPs within stimuli-responsive poly-(N,N-(dimethylamino ethyl methacrylate (PDMAEMA polyelectrolyte brushes is reported. Atom transfer radical polymerization (ATRP was used to grow polymer brushes via a “grafting from” approach. The brush thickness was tuned by varying the polymerization time. Using a new type of sealed reactor, thick brushes were synthesized. A systematic study was performed by varying a single parameter (brush thickness, while keeping all other parameters constant. AuNPs of 13 nm in diameter were attached by incubation. X-ray reflectivity, electron scanning microscopy and ellipsometry were used to study the particle loading, particle distribution and interpenetration of the particles within the brush matrix. A model for the structure of the brush/particle hybrids was derived. The particle number densities of attached AuNPs depend on the brush thickness, as do the optical properties of the hybrids. An increasing particle number density was found for increasing brush thickness, due to an increased surface roughness.

  2. Three-port DC-DC converter with new integrated transformer for DC Distribution Systems

    DEFF Research Database (Denmark)

    Ouyang, Ziwei; Andersen, Michael A. E.

    2014-01-01

    A new integrated transformer for three-port dc-dc converter is proposed to overcome the power coupling effect existed in some known multiple inputs dc-dc converters. Orthogonal primary windings arrangement and in series connection of diagonal secondary Windings enables a fully power decoupling...

  3. Tooth brushing among 11- to 15-year-olds in Denmark

    DEFF Research Database (Denmark)

    Bast, L. S.; Nordahl, H.; Christensen, L. B.;

    2015-01-01

    OBJECTIVE: Regular tooth brushing in adolescence predicts stable tooth brushing habits later in life. Differences in tooth brushing habits by ethnic background and socioeconomic position have been suggested. We investigated migration status and social class in relation to infrequent tooth brushin...

  4. 永磁同步电机直流母线能量互馈试验系统设计与实现%Design and Implementation of the DC Bus Reciprocal Power -Fed Testing System for the Permanent Magnet Synchronous Motor

    Institute of Scientific and Technical Information of China (English)

    邱忠才; 魏振兴; 肖建; 葛艳华

    2014-01-01

    A DC bus reciprocal power -fed testing system based on the incremental photoelectric encoder was de -signed in this paper,which included a double inverter and a double permanent magnet synchronous motor (PMSM) withid being 0 vector control.The construction and working principle of this system were discussed , and then the hard-ware design and the technological process of software control were proposed in this paper .The experimental results verified that this experiment system had excellent dynamic and static performances and ideal control effects , which could provide a very good research platform for the study of the PMSM control .%设计了基于增量式光电编码器,采用 id 等于0矢量控制双逆变器双永磁同步电机直流母线能量互馈牵引试验系统。讨论了整个系统的组成和运行原理,给出了硬件设计与软件控制流程。实验结果证明该系统具有良好的静、动态性能和比较理想的控制效果,可以为永磁同步电机控制研究提供研究平台。

  5. Motor neglect.

    OpenAIRE

    Laplane, D.; Degos, J D

    1983-01-01

    Motor neglect is characterised by an underutilisation of one side, without defects of strength, reflexes or sensibility. Twenty cases of frontal, parietal and thalamic lesions causing motor neglect, but all without sensory neglect, are reported. It is proposed that the cerebral structures involved in motor neglect are the same as those for sensory neglect and for the preparation of movement. As in sensory neglect, the multiplicity of the structures concerned suggests that this interconnection...

  6. Formation of surface-attached microstructured polyelectrolyte brushes

    Institute of Scientific and Technical Information of China (English)

    Hai Ning Zhang

    2008-01-01

    Surface-attached micropatterned polyelectrolyte brushes on planar solid surfaces are generated using free radical polymerization photo-initiated by self-assembled initiator monolayers. It is shown that the formed patterns can be either negative or positive with different patterning processes.

  7. Immunoelectrophoretic studies on pig intestinal brush border proteins

    DEFF Research Database (Denmark)

    Danielsen, Erik Michael; Sjöström, H; Norén, O;

    1977-01-01

    Brush borders were prepared from pig intestinal mucosa and the membrane proteins solubilized with either Triton X-100 or papain. Proteins, thus released, were used as antigens to raise antisera in rabbits. The immunoglobulin G fractions were isolated and shown by the double layer immunofluorescence...

  8. Keep Kids' Mouths Healthy: Brush 2min2X

    Science.gov (United States)

    ... More about BRUSHING Visit a Dentist Visit a Dentist Take your kids to see a dentist no ... and freshen breath. Visit a dentist Visit a Dentist Kids and parents – it’s important to visit ...

  9. Badger hair in shaving brushes comes from protected Eurasian badgers

    NARCIS (Netherlands)

    Domingo-Roura, X.; Marmi, J.; Ferrando, A.; López-Giráldez, F.; Macdonald, D.W.; Jansman, H.A.H.

    2006-01-01

    The Eurasian badger (Meles meles) is included in Appendix III of the Bern Convention and protected by national laws in many European countries. Badger hair is used to manufacture luxury shaving brushes, although it is frequently argued that the hog badger (Arctonyx collaris), which in Europe is an i

  10. AN INTERDISCIPLINARY APPROACH TO VALUING WATER FROM BRUSH CONTROL

    Science.gov (United States)

    An analytical methodology utilizing models from three disciplines is developed to assess the viability of brush control for wate yield in the Frio River Basin, TX. Ecological, hydrologic, and economic models are used to portray changes in forage production and water supply result...

  11. Controlled Synthesis of Polymer Brushes via Polymer Single Crystal Templates

    Science.gov (United States)

    Zhou, Tian

    A novel synthetic method of polymer brushes using polymer single crystals (PSCs) as solid-state templates is introduced in this study. PSC has a quasi-2D lamellae structure with polymer chains fold back-and-forth perpendicular to the lamellae surfaces. During crystallization, the chain ends are excluded from the unit cell onto the lamellae surfaces, which makes the material extremely versatile in its functionality. Such structure holds the unique capability to harvest nanoparticles, or being immobilized onto macroscopic flat surfaces. After dissolving PSCs in good solvent, polymer brushes are chemically tethered on either nanoparticles or flat macroscopic surfaces. Because the chain-folding structure can be conveniently tailored by changing the molecular weight of polymer and the crystallization temperature, the thickness, grafting density and morphology of resulted polymer brushes can be precisely controlled. As a model system, poly(?-caprolactone) with thiol or alkoxysilane terminal groups was used, and polymer brushes were successfully prepared on both nanoparticles and glass/Au flat surfaces. The structure-property relationships of the as-prepared polymer brushes were studied in detail using multiple characterization techniques. First of all, when functionalizing nanoparticles, by engineering the chain-folding structure of the PSCs, interesting complex nanostructures can be formed by nanoparticles including Janus nanoparticles and nanoparticle dimers. These unique structures render hybrid nanoparticles very interesting responsive behavior which have been studied in detail in this dissertation. When grafted onto a flat surface on the other hand, not only the molecular weight and grafting density can be precisely controlled, the tethering points of a single polymer chain can also be conveniently tailored, resulting polymer brushes with either tail or loop structures. Such difference in brush structure can significantly alter the properties of functional surface

  12. Design optimization of a brush turbine with a cleaner/water based solution

    Science.gov (United States)

    Kim, Rhyn H.

    1995-01-01

    Recently, a turbine-brush was analyzed based on the energy conservation and the force momentum equation with an empirical relationship of the drag coefficient. An equation was derived to predict the rotational speed of the turbine-brush in terms of the blade angle, number of blades, rest of geometries of the turbine-brush and the incoming velocity. Using the observed flow conditions, drag coefficients were determined. Based on the experimental values as boundary conditions, the turbine-brush flows were numerically simulated to understand first the nature of the flows, and to extend the observed drag coefficient to a flow without holding the turbine-brush.

  13. Comparison of bronchial brushing and sputum in detection of pediatric pulmonary tuberculosis.

    Science.gov (United States)

    Chen, Qiao-Pei; Ren, Shi-Feng; Wang, Xin-Feng; Wang, Mao-Shui

    2016-01-27

    The retrospective study aimed to evaluate the diagnostic value of bronchial brushing and sputum using acid fast bacilli smear, mycobacterial culture and real-time PCR in detection of pediatric pulmonary tuberculosis, sensitivity and specificity of bronchial brushing and sputum examined by the three methods were calculated and compared to each other. Data showed there were no significant difference in sensitivity between bronchial brushing and matched sputum using each method. But the specificity of real-time PCR on bronchial brushing was lower than on sputum. Compared with bronchial brushing, sputum was better specimen in detection of pediatric pulmonary tuberculosis.

  14. DC-DC powering for the CMS pixel upgrade

    Science.gov (United States)

    Feld, Lutz; Fleck, Martin; Friedrichs, Marcel; Hensch, Richard; Karpinski, Waclaw; Klein, Katja; Rittich, David; Sammet, Jan; Wlochal, Michael

    2013-12-01

    The CMS experiment plans to replace its silicon pixel detector with a new one with improved rate capability and an additional detection layer at the end of 2016. In order to cope with the increased number of detector modules the new pixel detector will be powered via DC-DC converters close to the sensitive detector volume. This paper reviews the DC-DC powering scheme and reports on the ongoing R&D program to develop converters for the pixel upgrade. Design choices are discussed and results from the electrical and thermal characterisation of converter prototypes are shown. An emphasis is put on system tests with up to 24 converters. The performance of pixel modules powered by DC-DC converters is compared to conventional powering. The integration of the DC-DC powering scheme into the pixel detector is described and system design issues are reviewed.

  15. DC-DC Powering for the CMS Pixel Upgrade

    CERN Document Server

    Feld, Lutz Werner; Marcel Friedrichs; Richard Hensch; Karpinski, Waclaw; Klein, Katja; Rittich, David Michael; Sammet, Jan Domenik; Wlochal, Michael

    2013-01-01

    The CMS experiment plans to replace its silicon pixel detector with a new one with improved rate capability and an additional detection layer at the end of 2016. In order to cope with the increased number of detector modules the new pixel detector will be powered via DC-DC converters close to the sensitive detector volume. This paper reviews the DC-DC powering scheme and reports on the ongoing R and D program to develop converters for the pixel upgrade. Design choices are discussed and results from the electrical and thermal characterisation of converter prototypes are shown. An emphasis is put on system tests with up to24 converters. The performance of pixel modules powered by DC-DC converters is compared to conventional powering. The integration of the DC-DC powering scheme into the pixel detector is described and system design issues are reviewed.

  16. New propulsion components for electric vehicles

    Science.gov (United States)

    Secunde, R. R.

    1983-01-01

    Improved component technology is described. This includes electronically commutated permanent magnet motors of both drum and disk configurations, an unconventional brush commutated motor, ac induction motors, various controllers, transmissions and complete systems. One or more of these approaches to electric vehicle propulsion may eventually displace presently used controllers and brush commutated dc motors. Previously announced in STAR as N83-25982

  17. Hydrologic Effects of Brush Management in Central Texas

    Science.gov (United States)

    Banta, J. R.; Slattery, R.

    2011-12-01

    Encroachment of woody vegetation into traditional savanna grassland ecosystems in central Texas has largely been attributed to land use practices of settlers, most notably overgrazing and fire suppression. Implementing brush management practices (removing the woody vegetation and allowing native grasses to reestablish in the area), could potentially change the hydrology in a watershed. The U.S. Geological Survey, in cooperation with several local, State, and Federal cooperators, studied the hydrologic effects of ashe juniper (Juniperus ashei) removal as a brush management conservation practice in the Honey Creek State Natural Area in Comal County, Tex. Two adjacent watersheds of 104 and 159 hectares were used in a paired study. Rainfall, streamflow, evapotranspiration (Bowen ratio method), and water quality data were collected in both watersheds. Using a hydrologic mass balance approach, rainfall was allocated to surface-water runoff, evapotranspiration, and groundwater recharge. Groundwater recharge was not directly measured, but estimated as the residual of the hydrologic mass balance. After hydrologic data were collected in both watersheds for 3 years, approximately 80 percent of the woody vegetation (ashe juniper) was selectively removed from the 159 hectare watershed (treatment watershed). Brush management was not implemented in the other (reference) watershed. Hydrologic data were collected in both watersheds for six years after brush management implementation. The resulting data were examined for differences in the hydrologic budget between the reference and treatment watersheds as well as between pre- and post-brush management periods to assess effects of the treatment. Preliminary results indicate there are differences in the hydrologic budget as well as water quality between the watersheds during pre- and post-treatment periods.

  18. Charge-driven and reversible assembly of ultra-dense polymer brushers: Formation and antifouling properties of a zipper brush

    NARCIS (Netherlands)

    Vos, de W.M.; Meijer, G.; Keizer, de A.; Cohen Stuart, M.A.; Kleijn, J.M.

    2010-01-01

    We investigated a new type of polymer brushes: the zipper brush. By adsorbing a diblock-copolymer with one charged block and one neutral block to an oppositely charged polyelectrolyte brush, a neutral polymer brush is formed on top of an almost neutral complex layer of polyelectrolytes. This neutral

  19. Overview of Multi-DC-Bus Solutions for DC Microgrids

    DEFF Research Database (Denmark)

    Ricchiuto, D.; Mastromauro, R.A.; Liserre, Marco;

    2013-01-01

    DC Microgrids have recently received a lot of attention in the last years due to high penetration of renewable energy sources as well as distributed energy storage systems. In the future DC microgrids could be preferable respect to AC microgrids in terms of redundancy since multi-DC-Bus solutions...

  20. Droplet:A Virtual Brush Model to Simulate Chinese Calligraphy and Painting

    Institute of Scientific and Technical Information of China (English)

    XiaoFeng Mi; Min Tang; Jin-Xiang Dong

    2004-01-01

    This paper proposes a virtual brush model based on droplet operation to simulate Chinese calligraphy and traditional Chinese painting in real time. Two ways of applying droplet model to virtual calligraphy and painting are discussed in detail. The second droplet model is more elaborated and can produce more vivid results while being slightly more time-consuming. The novel feature of the proposed droplet virtual brush model successfully enables the simulation painting system to overcome the poor expressional ability of virtual brush based on particle system and avoids the complex evaluation of physical brush with solid model. The model,derived from the actual calligraphy and painting experience, due to the simplicity of the droplet operation and its powerful expressive ability, considerably improves the performance of the simulation system and maintains painting effect comparable with real brush by supporting special Chinese brush effect such as dry brush, feng and stroke diffusion.

  1. Impact of self-tongue brushing on taste perception in Thai older adults: A pilot study.

    Science.gov (United States)

    Madiloggovit, Jirakate; Chotechuang, Nattida; Trachootham, Dunyaporn

    2016-01-01

    Oral hygiene influences taste, affecting appetite and nutrition in older adults. However, the impact of self-administered tongue brushing on their taste perceptions was unclear. This pilot study (N = 44) was aimed to observe the changes in taste thresholds using Filter Paper Disc after tongue brushing in Thai older adults. Based on the results, continuous tongue brushing for 3 months reduced tongue coat (p taste in 74% of participants. Sweet and salty recognition thresholds were reduced in both anterior and posterior tongue, while sour and bitter thresholds were reduced only in posterior tongue. No changes in umami (savory) were observed. Daily brushing was more effective than weekly brushing in improving the sweet and bitter tastes. The data suggested that tongue brushing could improve perception of multiple tastes and daily tongue brushing was recommended as routine personal care for older adults. This study supports further investigation in a randomized-controlled setting. PMID:26747405

  2. Evaluation of multi-brush anode systems in microbial fuel cells

    KAUST Repository

    Lanas, Vanessa

    2013-11-01

    The packing density of anodes in microbial fuel cells (MFCs) was examined here using four different graphite fiber brush anode configurations. The impact of anodes on performance was studied in terms of carbon fiber length (brush diameter), the number of brushes connected in parallel, and the wire current collector gage. MFCs with different numbers of brushes (one, three or six) set perpendicular to the cathode all produced similar power densities (1200±40mW/m2) and coulombic efficiencies (60%±5%). Reducing the number of brushes by either disconnecting or removing them reduced power, demonstrating the importance of anode projected area covering the cathode, and therefore the need to match electrode projected areas to maintain high performance. Multi-brush reactors had the same COD removal as single-brush systems (90%). The use of smaller Ti wire gages did not affect power generation, which will enable the use of less metal, reducing material costs. © 2013 Elsevier Ltd.

  3. Evaluation of multi-brush anode systems in microbial fuel cells.

    Science.gov (United States)

    Lanas, Vanessa; Logan, Bruce E

    2013-11-01

    The packing density of anodes in microbial fuel cells (MFCs) was examined here using four different graphite fiber brush anode configurations. The impact of anodes on performance was studied in terms of carbon fiber length (brush diameter), the number of brushes connected in parallel, and the wire current collector gage. MFCs with different numbers of brushes (one, three or six) set perpendicular to the cathode all produced similar power densities (1200 ± 40 mW/m(2)) and coulombic efficiencies (60% ± 5%). Reducing the number of brushes by either disconnecting or removing them reduced power, demonstrating the importance of anode projected area covering the cathode, and therefore the need to match electrode projected areas to maintain high performance. Multi-brush reactors had the same COD removal as single-brush systems (>90%). The use of smaller Ti wire gages did not affect power generation, which will enable the use of less metal, reducing material costs. PMID:24063821

  4. Droplet: A Virtual Brush Model to Simulate Chinese Calligraphy and Painting

    Institute of Scientific and Technical Information of China (English)

    Xiao-FengMi; MinTang; Jin-XiangDong

    2004-01-01

    This paper proposes a virtual brush model based on droplet operation to simulate Chinese calligraph yand traditional Chinese painting in real time. Two ways of applying droplet model to virtual calligraphy and painting are discussed in detail. The second droplet model is more elaborated and can produce more vivid results while being slightly more time-consuming. The novel feature of the proposed droplet virtual brush model successfully enables the simulation painting system to overcome the poor expressional ability of virtual brush based on particle system and avoids the complex evaluation of physical brush with solid model. The model, derived from the actual calligraphy and painting experience, due to the simplicity of the droplet operation and its powerful expressive ability, considerably improves the performance of the simulation system and maintains painting effect comparable with real brush by supporting special Chinese brush effect such as dry brush, feng and stroke diffusion.

  5. Scientific Laboratory Platform for Testing the Electric Vehicle Equipped with DC Drive

    Directory of Open Access Journals (Sweden)

    Brazis V.

    2014-12-01

    Full Text Available The authors present a test platform for the low-power DC electric motor of a traction vehicle or a high-power motor scaled in the traction and braking modes. The load emulator of the traction drive is made using an induction motor controlled by a frequency converter. A microcontroller controls the bi-directional DC/DC converter and sends a speed reference signal to the frequency converter. The test bench is meant for determination of the power consumption by motor in various speed cycles, and will be used to demonstrate the operation of electric vehicle to students and to investigate the charging/discharging strategies of energy sources.

  6. DC Power System of Electric Vehicle

    Directory of Open Access Journals (Sweden)

    Zhang Liwei

    2013-11-01

    Full Text Available In recent years, environmental and energy problem has become one of the world's hot spot problems. Today, the road cars not only consume a lot of oil resource, but also cause serious pollution to human survival environment. Therefore, to save energy and protect environment, a green environmental friendly electric car instead of fuel car will be needed for sustainable development of the society. Electric vehicle has no pollution, low noise, high efficiency, diversification, simple structure and convenient maintaining; the development of green cleaning electric vehicle is the trend, and the inevitable choice. The power supply system of electric vehicle can be divided into three parts, the battery charging system, motor drive system and dc load power supply system. This paper mainly studies the dc load power supply system. Main function is to convert the high-voltage of the battery in the electric vehicle into low voltage output, provide the power supply for the low voltage dc load, including the car safety system, windshield wiper system, audio system. On the basis of the analysis of the parameters, this article designs the converter, sets up the principle prototype, analyzes the experimental results and finally makes conclusion. The vehicle power supply is green, environment friendly, high-efficiency, digital and intelligent.    

  7. Motor homopolar

    OpenAIRE

    2007-01-01

    Mostramos la construcción de un modelo de motor homopolar, uno de los más antiguos tipos de motores eléctricos. Se caracterizan porque el campo magnético del imán mantiene siempre la misma polaridad (de ahí su nombre, del griego homos, igual), de modo que, cuando una corriente eléctrica atraviesa el campo magnético, aparece una fuerza que hace girar los elementos no fijados mecánicamente. En el sencillísimo motor homopolar colgado (Schlichting y Ucke 2004), el imán puede girar ...

  8. Control of improved full-bridge three-level DC/DC converter for wind turbines in a DC grid

    DEFF Research Database (Denmark)

    Deng, Fujin; Chen, Zhe

    2013-01-01

    This paper presents an improved full-bridge three-level (IFBTL) dc/dc converter for a wind turbine in a dc grid by inserting a passive filter into the dc/dc converter to improve the performance of the converter. The passive filter can effectively reduce the voltage stress of the medium frequency...... transformer in the IFBTL dc/dc converter. A modulation strategy, including two operation modes, is proposed for the IFBTL dc/dc converter. Then, a voltage balancing control strategy is proposed for the IFBTL dc/dc converter. Furthermore, the control of the wind turbine based on the IFBTL dc/dc converter...... in a dc-grid system is presented. Finally, a small-scale IFBTL dc/dc converter prototype was built and tested in the laboratory, and the results verify the theoretical analysis....

  9. Application of stepping motor

    International Nuclear Information System (INIS)

    This book is divided into three parts, which is about practical using of stepping motor. The first part has six chapters. The contents of the first part are about stepping motor, classification of stepping motor, basic theory og stepping motor, characteristic and basic words, types and characteristic of stepping motor in hybrid type and basic control of stepping motor. The second part deals with application of stepping motor with hardware of stepping motor control, stepping motor control by microcomputer and software of stepping motor control. The last part mentions choice of stepping motor system, examples of stepping motor, measurement of stepping motor and practical cases of application of stepping motor.

  10. Novel motor design for rotating anode x-ray tubes operating in the fringe field of a magnetic resonance imaging system

    International Nuclear Information System (INIS)

    Purpose: Using hybrid x-ray/MR (XMR) systems for image guidance during interventional procedures could enhance the diagnosis and treatment of neurologic, oncologic, cardiovascular, and other disorders. The authors propose a close proximity hybrid system design in which a C-arm fluoroscopy unit is placed immediately adjacent to the solenoid magnet of a MR system with a minimum distance of 1.2 m between the x-ray and MR imaging fields of view. Existing rotating anode x-ray tube designs fail within MR fringe field environments because the magnetic fields alter the electron trajectories in the x-ray tube and act as a brake on the induction motor, reducing the rotation speed of the anode. In this study the authors propose a novel motor design that avoids the anode rotation speed reduction. Methods: The proposed design replaces the permanent magnet stator found in brushed dc motors with the radial component of the MR fringe field. The x-ray tube is oriented such that the radial component of the MR fringe field is orthogonal to the cathode-anode axis. Using a feedback position sensor and the support bearings as electrical slip rings, the authors use electrical commutation to eliminate the need for mechanical brushes and commutators. A vacuum compatible prototype of the proposed motor design was assembled, and its performance was evaluated at various operating conditions. The prototype consisted of a 3.1 in. diameter anode rated at 300 kHU with a ceramic rotor that was 5.6 in. in length and had a 2.9 in. diameter. The material chosen for all ceramic components was MACOR, a machineable glass ceramic developed by Corning Inc. The approximate weight of the entire assembly was 1750 g. The maximum rotation speed, angular acceleration, and acceleration time of the motor design were investigated, as well as the dependence of these parameters on rotor angular offset, magnetic field strength, and field orientation. The resonance properties of the authors’ assembly were also

  11. Novel motor design for rotating anode x-ray tubes operating in the fringe field of a magnetic resonance imaging system

    Energy Technology Data Exchange (ETDEWEB)

    Lillaney, Prasheel; Pelc, Norbert [Department of Radiology, Stanford University, Stanford, California 94305 and Department of Bioengineering, Stanford University, Stanford, California 94305 (United States); Shin Mihye [Department of Radiology, Stanford University, Stanford, California 94305 and Department of Mechanical Engineering, Stanford University, Stanford, California 94305 (United States); Hinshaw, Waldo; Fahrig, Rebecca [Department of Radiology, Stanford University, Stanford, California 94305 (United States); Bennett, N. Robert [Department of Radiology, Stanford University, Stanford, California 94305 and Qualcomm MEMS Technologies, San Jose, California 95134 (United States)

    2013-02-15

    Purpose: Using hybrid x-ray/MR (XMR) systems for image guidance during interventional procedures could enhance the diagnosis and treatment of neurologic, oncologic, cardiovascular, and other disorders. The authors propose a close proximity hybrid system design in which a C-arm fluoroscopy unit is placed immediately adjacent to the solenoid magnet of a MR system with a minimum distance of 1.2 m between the x-ray and MR imaging fields of view. Existing rotating anode x-ray tube designs fail within MR fringe field environments because the magnetic fields alter the electron trajectories in the x-ray tube and act as a brake on the induction motor, reducing the rotation speed of the anode. In this study the authors propose a novel motor design that avoids the anode rotation speed reduction. Methods: The proposed design replaces the permanent magnet stator found in brushed dc motors with the radial component of the MR fringe field. The x-ray tube is oriented such that the radial component of the MR fringe field is orthogonal to the cathode-anode axis. Using a feedback position sensor and the support bearings as electrical slip rings, the authors use electrical commutation to eliminate the need for mechanical brushes and commutators. A vacuum compatible prototype of the proposed motor design was assembled, and its performance was evaluated at various operating conditions. The prototype consisted of a 3.1 in. diameter anode rated at 300 kHU with a ceramic rotor that was 5.6 in. in length and had a 2.9 in. diameter. The material chosen for all ceramic components was MACOR, a machineable glass ceramic developed by Corning Inc. The approximate weight of the entire assembly was 1750 g. The maximum rotation speed, angular acceleration, and acceleration time of the motor design were investigated, as well as the dependence of these parameters on rotor angular offset, magnetic field strength, and field orientation. The resonance properties of the authors' assembly were also

  12. Comparative analysis of some brushless motors based on catalog data

    Directory of Open Access Journals (Sweden)

    Anton Kalapish

    2005-10-01

    Full Text Available Brushless motors (polyphased AC induction, synchronous and brushless DC motors have no alternatives in modern electric drives. They possess highly efficient and very wide range of speeds. The objective of this paper is to represent some relation between the basic parameters and magnitudes of electrical machines. This allows to be made a comparative analysis and a choice of motor concerning each particular case based not only on catalogue data or price for sale.

  13. Wettability and antifouling behavior on the surfaces of superhydrophilic polymer brushes.

    Science.gov (United States)

    Kobayashi, Motoyasu; Terayama, Yuki; Yamaguchi, Hiroki; Terada, Masami; Murakami, Daiki; Ishihara, Kazuhiko; Takahara, Atsushi

    2012-05-01

    The surface wettabilities of polymer brushes with hydrophobic and hydrophilic functional groups were discussed on the basis of conventional static and dynamic contact angle measurements of water and hexadecane in air and captive bubble measurements in water. Various types of high-density polymer brushes with nonionic and ionic functional groups were prepared on a silicon wafer by surface-initiated atom-transfer radical polymerization. The surface free energies of the brushes were estimated by Owens-Wendt equation using the contact angles of various probe liquids with different polarities. The decrease in the water contact angle corresponded to the polarity of fluoroalkyl, hydroxy, ethylene oxide, amino, carboxylic acid, ammonium salt, sulfonate, carboxybetaine, sulfobetaine, and phosphobetaine functional groups. The poly(2-perfluorooctylethyl acrylate) brush had a low surface free energy of approximately 8.7 mN/m, but the polyelectrolyte brushes revealed much higher surface free energies of 70-74 mN/m, close to the value for water. Polyelectrolyte brushes repelled both air bubbles and hexadecane in water. Even when the silicone oil was spread on the polyelectrolyte brush surfaces in air, once they were immersed in water, the oil quickly rolled up and detached from the brush surface. The oil detachment behavior observed on the superhydrophilic polyelectrolyte brush in water was explained by the low adhesion force between the brush and the oil, which could contribute to its excellent antifouling and self-cleaning properties. PMID:22500465

  14. pH-Responsive Behavior of Poly(acrylic acid) Brushes of Varying Thickness

    Science.gov (United States)

    Yadav, Vivek; Robertson, Megan; Conrad, Jacinta

    2015-03-01

    We have investigated the pH-dependent response of polyelectrolyte brushes of varying thickness. Our model system consists of poly(acrylic acid) brushes, which change from hydrophobic and neutral at low pH to hydrophilic and negatively charged at high pH, synthesized using a grafting-from approach at constant grafting density. As the polymer brush thickness increased, the brushes exhibited greater hysteresis in static water contact angle as a function of pH. We extracted the pKa of the polymer brushes from contact angle measurements. The relationship between the pKa and brush thickness depended on the order in which the brushes were exposed to solutions of varying pH: pKa decreased on increasing brush thickness when going from basic to acidic medium whereas pKa increased on increasing brush thickness when going from acidic to basic medium. We speculate that the origin of hysteresis can be explained by pH-dependent conformational changes in these polyelectrolyte brushes.

  15. CORRELATION OF FINE NEEDLE ASPIRATION CYTOLOGY WITH BRONCHOALVEOLAR LAVAGE AND BRUSH SMEAR CYTOLOGY IN PULMONARY LESIONS

    Directory of Open Access Journals (Sweden)

    Surabhi

    2014-06-01

    Full Text Available BACKGROUND: Fine Needle Aspiration Cytology (FNAC, Bronchoalveolar Lavage (BAL and Brush Cytology are important diagnostic tools for evaluation of pulmonary lesions. Considering the limitations of these procedures correlation of these cytological techniques may help in improving accuracy and increasing the diagnostic yield. AIM: To determine the role of FNAC, Brush and BAL Cytology in pulmonary lesions and to correlate the efficacy of FNAC with Brush and BAL Cytology. MATERIALS AND METHODS: This prospective study was conducted on 78 patients with radiologically demonstrable pulmonary lesions in the department of pathology and Dr ML Chest Hospital, GSVM Medical College, Kanpur over a period from nov2011-july2013. The cases selected had to give consent for the procedure. Bronchoalveolar lavage, bronchial brush sample were taken and FNAC was done in the cases. RESULTS: In present study 78 cases of pulmonary lesions were subjected to FNAC and/ or Bronchoalveolar lavage and brush cytology. Among them 49 cases were selected in which all three procedures were done. The sensitivity and specificity for detecting lung tumors by FNAC was 96.29% and 95.45% which was more than that of BAL cytology (84.61%, 91.30% and Brush cytology (81.48%, 95.45%. FNA correlates with Brush and BAL cytology in 78.57% of malignant lesions. Among malignant lesions 84.61% of BAL and Brush cytology correlates with FNA for diagnosis of squamous cell carcinoma. FNA correlates with 66.67% of brush and 83.37% of BAL fluid cytology for diagnosis of adenocarcinoma. BAL and Brush both correlates with FNA in 83.33% cases of small cell carcinoma. Overall 85.71% of BAL and 82.14% of brush smear cytology correlates with FNA cytology for diagnosis of lung cancers. CONCLUSIONS: FNA, BAL and Brush cytology provide a high yield for evaluation of pulmonary lesions. BAL fluid and brush cytology correlated well with FNAC for diagnosis of lung cancers.

  16. Usage of polymer brushes as substrates of bone cells

    Institute of Scientific and Technical Information of China (English)

    Sabine A.LETSCHE; Annina M.STEINBACH; Manuela PLUNTKE; Othmar MARTI; Anita IGNATIUS; Dirk VOLKMER

    2009-01-01

    Implant methcal research and hssue eagmeer-ing both target the design of novel biomaterials for the improvement of human health and clinical applications. In order to develop improved surface coatings for hard tissue (bone)replacement materials and implant devices,we are developing micropartemed coatings consisting of polymer brushes. These are used as organic templates for the mineralization of calcium phosphate in oraer to improve adhesion of bone cells. First we give a shortaccount of the current state-of-the-art in this particular field of blomaterial development,while in the second part the preliminary results of cell culture experiments are presented,in which the biocompatibility of polymer brushes are tested on human mesenchvmal stem cells.

  17. Cholinergic urethral brush cells are widespread throughout placental mammals.

    Science.gov (United States)

    Deckmann, Klaus; Krasteva-Christ, Gabriela; Rafiq, Amir; Herden, Christine; Wichmann, Judy; Knauf, Sascha; Nassenstein, Christina; Grevelding, Christoph G; Dorresteijn, Adriaan; Chubanov, Vladimir; Gudermann, Thomas; Bschleipfer, Thomas; Kummer, Wolfgang

    2015-11-01

    We previously identified a population of cholinergic epithelial cells in murine, human and rat urethrae that exhibits a structural marker of brush cells (villin) and expresses components of the canonical taste transduction signaling cascade (α-gustducin, phospholipase Cβ2 (PLCβ2), transient receptor potential cation channel melanostatin 5 (TRPM5)). These cells serve as sentinels, monitoring the chemical composition of the luminal content for potentially hazardous compounds such as bacteria, and initiate protective reflexes counteracting further ingression. In order to elucidate cross-species conservation of the urethral chemosensory pathway we investigated the occurrence and molecular make-up of urethral brush cells in placental mammals. We screened 11 additional species, at least one in each of the five mammalian taxonomic units primates, carnivora, perissodactyla, artiodactyla and rodentia, for immunohistochemical labeling of the acetylcholine synthesizing enzyme, choline acetyltransferase (ChAT), villin, and taste cascade components (α-gustducin, PLCβ2, TRPM5). Corresponding to findings in previously investigated species, urethral epithelial cells with brush cell shape were immunolabeled in all 11 mammals. In 8 species, immunoreactivities against all marker proteins and ChAT were observed, and double-labeling immunofluorescence confirmed the cholinergic nature of villin-positive and chemosensory (TRPM5-positive) cells. In cat and horse, these cells were not labeled by the ChAT antiserum used in this study, and unspecific reactions of the secondary antiserum precluded conclusions about ChAT-expression in the bovine epithelium. These data indicate that urethral brush cells are widespread throughout the mammalian kingdom and evolved not later than about 64.5millionyears ago. PMID:26044348

  18. Cholinergic urethral brush cells are widespread throughout placental mammals.

    Science.gov (United States)

    Deckmann, Klaus; Krasteva-Christ, Gabriela; Rafiq, Amir; Herden, Christine; Wichmann, Judy; Knauf, Sascha; Nassenstein, Christina; Grevelding, Christoph G; Dorresteijn, Adriaan; Chubanov, Vladimir; Gudermann, Thomas; Bschleipfer, Thomas; Kummer, Wolfgang

    2015-11-01

    We previously identified a population of cholinergic epithelial cells in murine, human and rat urethrae that exhibits a structural marker of brush cells (villin) and expresses components of the canonical taste transduction signaling cascade (α-gustducin, phospholipase Cβ2 (PLCβ2), transient receptor potential cation channel melanostatin 5 (TRPM5)). These cells serve as sentinels, monitoring the chemical composition of the luminal content for potentially hazardous compounds such as bacteria, and initiate protective reflexes counteracting further ingression. In order to elucidate cross-species conservation of the urethral chemosensory pathway we investigated the occurrence and molecular make-up of urethral brush cells in placental mammals. We screened 11 additional species, at least one in each of the five mammalian taxonomic units primates, carnivora, perissodactyla, artiodactyla and rodentia, for immunohistochemical labeling of the acetylcholine synthesizing enzyme, choline acetyltransferase (ChAT), villin, and taste cascade components (α-gustducin, PLCβ2, TRPM5). Corresponding to findings in previously investigated species, urethral epithelial cells with brush cell shape were immunolabeled in all 11 mammals. In 8 species, immunoreactivities against all marker proteins and ChAT were observed, and double-labeling immunofluorescence confirmed the cholinergic nature of villin-positive and chemosensory (TRPM5-positive) cells. In cat and horse, these cells were not labeled by the ChAT antiserum used in this study, and unspecific reactions of the secondary antiserum precluded conclusions about ChAT-expression in the bovine epithelium. These data indicate that urethral brush cells are widespread throughout the mammalian kingdom and evolved not later than about 64.5millionyears ago.

  19. Brush Wellman公司的先进Cu/W技术

    Institute of Scientific and Technical Information of China (English)

    JuanSeputveda; 李学芳; 龙建国

    1999-01-01

    Brush Weltman陶瓷产品分公司已经用粉末冶金技术开发出了一种生产Cu/W复合材料的新型、低成本方法。这些材料有一系列的用途,包括用作微电子工业的基片和散热片,Juan Sepulveda和Lisa Valenzuela介绍了这种技术。

  20. Hybrid electric system based on fuel cell and battery and integrating a single dc/dc converter for a tramway

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, Luis M., E-mail: luis.fernandez@uca.e [Department of Electrical Engineering, EPS Algeciras, University of Cadiz, Avda. Ramon Puyol, s/n. 11202 Algeciras (Cadiz) (Spain); Garcia, Pablo, E-mail: pablo.garcia@uca.e [Department of Electrical Engineering, EPS Algeciras, University of Cadiz, Avda. Ramon Puyol, s/n. 11202 Algeciras (Cadiz) (Spain); Garcia, Carlos Andres, E-mail: carlosandres.garcia@uca.e [Department of Electrical Engineering, EPS Algeciras, University of Cadiz, Avda. Ramon Puyol, s/n. 11202 Algeciras (Cadiz) (Spain); Jurado, Francisco, E-mail: fjurado@ujaen.e [Department of Electrical Engineering, EPS Linares, University of Jaen, C/Alfonso X, No. 28. 23700 Linares (Jaen) (Spain)

    2011-05-15

    Research highlights: {yields} Hybrid electric power system for a real surface tramway. {yields} Hybrid system based on PEM fuel cell with dc/dc converter and Ni-MH battery. {yields} New control strategy for the energy management of the tramway. {yields} Hybrid system demonstrated to meet appropriate driving cycle of the tramway. -- Abstract: This paper presents a hybrid electric power system for a real surface tramway. The hybrid system consists of two electrical energy sources integrating a single dc/dc converter to provide the power demanded by the tramway loads (four electric traction motors and auxiliary services): (1) a Polymer Electrolyte Membrane (PEM) fuel cell (FC) as the primary and (2) a rechargeable Ni-MH battery as electrical energy storage to supplement the FC over the driving cycle. According to the requirements of the real driving cycle of the tramway, it was considered a 200 kW PEM FC system with two FCs connected in parallel and a 34 Ah Ni-MH battery. The PEM FC and Ni-MH battery models were designed from commercially available components. The power conditioning system provides the appropriate power for the tramway. It is composed of: (1) a unique dc/dc boot converter which adapts the FC output voltage to the 750 V traction standard dc bus; (2) three phase inverters to drive properly each electric motors; and (3) a braking chopper to dissipate excess of regenerative braking energy. Suitable state machine control architecture is presented for the hybrid system, its objective being to provide demanded power by the driving cycle, optimizing the energy generated. Following this objective, a new state machine control strategy based on eight states decides the operating point of each component of the system and a cascade control structure allows achieving the operating points determined by the strategy. Simulation results of the real driving cycle of the tramway check the adequacy of the hybrid electric power system.

  1. Role of gastric brush cytology in the diagnosis of giardiasis

    Directory of Open Access Journals (Sweden)

    Varma Deepali

    2008-01-01

    Full Text Available Background: Giardiasis, common in developing countries, has mostly nonspecific clinical symptoms, resulting in a limited role for preliminary tests. Aims: The present study aims to highlight the utility of endoscopic brush cytology (EBC in the diagnosis of giardiasis in clinically unsuspected cases. Materials and Methods: Endoscopic brush smears (EBS are routinely obtained in all patients presenting with gastric symptoms. The present study is a retrospective analysis of EBS, consisting of 12 cases whose smears had revealed trophozoites of Giardia lamblia . Biopsy correlation was available in five cases. Results: The patients ranged in age from 15 to 78 years (mean age: 34.08 years with a 1:1 sex ratio. Stool examination in all 12 cases yielded negative results for giardiasis. Upper gastrointestinal endoscopy was normal in all these cases. EBS from these cases revealed Giardia trophozoites, which were identified by their typical morphology. Conclusions: Endoscopic brush cytology can be used as a reliable screening tool in the diagnosis of gastro-duodenal giardiasis in clinically unsuspected cases, especially in developing countries where parasitic infections are common.

  2. Hierarchical structure formation of cylindrical brush polymer-surfactant complexes.

    Science.gov (United States)

    Cong, Yang; Gunari, Nikhil; Zhang, Bin; Janshoff, Andreas; Schmidt, Manfred

    2009-06-01

    The complex formation of cylindrical brush polymers with poly(l-lysine) side chains (PLL) and sodium dodecyl sulfate (SDS) can induce a helical conformation of the cylindrical brush polymer in aqueous solution (Gunari, N.; Cong, Y.; Zhang, B.; Fischer, K.; Janshoff, A.; Schmidt, M. Macromol. Rapid Commun. 2008, 29, 821-825). Herein, we have systematically investigated the influence of surfactant, salt, and pH on the supramolecular structure formation. The cylindrical brush polymers and their complexes with surfactants were directly visualized by atomic force microscopy in air and in aqueous solution. The alkyl chain length (measured by the carbon number, n) of the surfactant plays a key role. While helical structures were formed with n=10, 11, and 12, no helices were observed with n13. Addition of salt destroys the helical structures as do pH conditions below 4 and above 6, most probably because the polymer-surfactant complexes start to disintegrate. Circular dichroism was utilized to monitor the PLL side chain conformation and clearly revealed that beta-sheet formation of the side chains induces the helical conformation of the atactic main chain. PMID:19326944

  3. PIEZOELECTRIC PROPERTIES OF SINGLE-STRAND DNA MOLECULAR BRUSH BIOLAYERS

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The paper is devoted to investigations on nanomechanical behaviors of biochips in label-free biodetections. The chip consists of Si-layer, Ti-layer, Au-layer and single-strand DNA (ssDNA) molecular brush biolayer immobilized by self-assembly technology of thiol group. Unlike previous viewpoints, such as force-bending, entropy-bending and curvature electricity effect, etc.,the piezoelectric effect of the biopolymer brush layer is viewed as the main factor that induces nanomechanical bending of biochips, and a classical macroscopic piezoelectric constitutive relation is used to describe the piezoelectric effect. A new laminated cantilever beam model with a piezoelectric biolayer in continuum mechanics, the linearized Poisson-Boltzmann equation in statistical mechanics and the scaling method in polyelectrolyte brush theory are combined to establish a relationship between the nanomechanical deflection of DNA chips and the factors such as nanoscopic structural features of ssDNA molecules, buffer salt concentration, macroscopic mechanical/piezoelectric parameters of DNA chips etc. Curve fitting of experimental data shows that the sign of the piezoelectric constant of the biolayer may control the deflection direction of DNA chips during the packaging process.

  4. Development of a DC propulsion system for an electric vehicle

    Science.gov (United States)

    Kelledes, W. L.

    1984-01-01

    The suitability of the Eaton automatically shifted mechanical transaxle concept for use in a near-term dc powered electric vehicle is evaluated. A prototype dc propulsion system for a passenger electric vehicle was designed, fabricated, tested, installed in a modified Mercury Lynx vehicle and track tested at the contractor's site. The system consisted of a two-axis, three-speed, automatically-shifted mechanical transaxle, 15.2 Kw rated, separately excited traction motor, and a transistorized motor controller with a single chopper providing limited armature current below motor base speed and full range field control above base speed at up to twice rated motor current. The controller utilized a microprocessor to perform motor and vehicle speed monitoring and shift sequencing by means of solenoids applying hydraulic pressure to the transaxle clutches. Bench dynamometer and track testing was performed. Track testing showed best system efficiency for steady-state cruising speeds of 65-80 Km/Hz (40-50 mph). Test results include acceleration, steady speed and SAE J227A/D cycle energy consumption, braking tests and coast down to characterize the vehicle road load.

  5. Modeling helical polymer brushes using self-consistent field theory (SCFT)

    Science.gov (United States)

    Mahalik, Jyoti; Sumpter, Bobby; Kumar, Rajeev

    We investigate structure of helical polymer brushes in terms of segment density distribution and local helical ordering using SCFT. A flexible chain model with vector potential was used to model liquid crystalline-like ordering in the brushes. The effects of surface grafting density, polymer molecular weight and the solvent quality on the brush structure were investigated. For densely grafted polymer brushes or the brushes made up of high molecular weight polymers, immersed in good quality solvent, stronger orientational ordering was found near the edge of the brushes (i.e., far from the grafting surface). Furthermore, an increase in the orientational ordering near the grafted end was found with decrease in solvent quality or decrease in molecular weight and decrease in surface grafting density. Computer Science and Mathematics Division, Oak Ridge National Laboratory.

  6. A Novel Current Sensor Technique for Brushless DC Motor Drives

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    1 Introduction Itiswellknownthatthetorquedevelopedbyapermanentmagnetbrushlessdcmotorisproportionaltothemagnitudeofmotorphasecurrents.ThislinearrelationshipmakesitconvenienttocontrolBLDCMtorqueproductionbyregulatingthemotorphasecurrents[1].Inthispaper,theinstantaneoustorquereferstotherealtorqueproducedatanytimeinstant,whereasthestatictorquereferstothetorqueproducedwhenonlytwoofthethreephasewindingscarrycurrents[2,3]. Instantaneoustorquecontrolstrategiesareusuallyimplementedonsuchservoapplicationsthatareexpec...

  7. Permanent magnet synchronous and brushless DC motor drives

    CERN Document Server

    Ramu, Krishnan

    2009-01-01

    Presents an introduction to machines, power devices, inverters, and control. This book covers pm synchronous machines, including modeling, implementation, control strategies, flux weakening operations, parameter sensitivity, sensorless control, and intelligent control applications.

  8. Design and Simulation of Dc-Dc Converter for Fuel Cell Operated Vehicle with Single Reference Six Pulse Modulation

    Directory of Open Access Journals (Sweden)

    1V.Chaitanya,P.G.scholar,

    2015-10-01

    Full Text Available : Even though electrical vehicle concept is introduced in early 1800’s, it gained importance in past couple of decades due to growing conscience on environmental aspects. Different types of electrical vehicles are manufactured in the past centuries and now onboard generation is seems to be promising by fulfilling the needs of a vehicle. Fuel cells or fuel cell stack produces typically 32-68V of EMF, which has to be conditioned before it fed to motor. The conditioning involves two stages DCDC conversion and then to DC-AC conversion .DC-AC conversion is done through inverter. For DC-DC to conversion various topologies are proposed such as fly back, forward, buck-boost are proposed. This paper deals with the front end DC-DC converter and inverter switching. A hybrid modulation scheme is used to produce pulses to switch the source end full bridge rectifier and inverter at load end. In this modulation scheme high frequency pulses given to full bridge rectifier and 33% modulation scheme based pulses are produced for inverter switching.

  9. On and off controlled resonant dc-dc power converter

    DEFF Research Database (Denmark)

    2015-01-01

    output voltage and connection to a converter load. The resonant DC-DC power converter further comprises a rectification circuit connected between an output of a resonant network and the output side circuit. The resonant network is configured for alternatingly being charged from the input voltage...... or current and discharged through the rectification circuit by a first controllable switch arrangement in accordance with a first switch control signal. A second controllable switch arrangement of the resonant DC-DC power converter is configured to select a first impedance characteristic of the resonant...

  10. Step-Up DC-DC Power Converter

    DEFF Research Database (Denmark)

    2015-01-01

    The present invention relates to a step-up DC-DC power converter which comprises a primary side circuit and a secondary side circuit coupled through a galvanic isolation barrier. The primary side circuit comprises a positive and a negative input terminal for receipt of an input voltage and an input...... being charged from the input voltage and discharged to the output capacitor through the galvanic isolation barrier in accordance with a switch control signal to produce the converter output voltage. The step-up DC-DC power converter comprises an electrical short-circuit connection across the galvanic...

  11. A Novel FPSM Controller for DC-DC Switching Converters

    Institute of Scientific and Technical Information of China (English)

    Yong Feng; Shun-Ping Wang; Ping Luo; Quan-Ming Niu; Zhao-Ji Li

    2007-01-01

    This paper presents a novel fuzzy pulse skip modulation (FPSM) controller for switching direct current to direct current (DC-DC) converters based on fuzzy ratiocination modeling approach. Owing to the optimal consideration during the design and the nonlinear characteristics of the controller, improved dynamic responses of the FPSM controller can be achieved over conventional controllers. Compared with conventional proportion integral derivative (PID) control, FPSM control has 60% lower overshoot and 10% lower setting time under the same input voltage and output load change. The presented approach is general and can be applied to other types of DC-DC converters.

  12. High performance dc-dc conversion with voltage multipliers

    Science.gov (United States)

    Harrigill, W. T.; Myers, I. T.

    1974-01-01

    The voltage multipliers using capacitors and diodes first developed by Cockcroft and Walton in 1932 were reexamined in terms of state of the art fast switching transistors and diodes, and high energy density capacitors. Because of component improvements, the voltage multiplier, used without a transformer, now appears superior in weight to systems now in use for dc-dc conversion. An experimental 100-watt 1000-volt dc-dc converter operating at 100 kHz was built, with a component weight of about 1 kg/kW. Calculated and measured values of output voltage and efficiency agreed within experimental error.

  13. Improved DC Gun Insulator

    Energy Technology Data Exchange (ETDEWEB)

    M.L. Neubauer, K.B. Beard, R. Sah, C. Hernandez-Garcia, G. Neil

    2009-05-01

    Many user facilities such as synchrotron light sources and free electron lasers require accelerating structures that support electric fields of 10-100 MV/m, especially at the start of the accelerator chain where ceramic insulators are used for very high gradient DC guns. These insulators are difficult to manufacture, require long commissioning times, and have poor reliability, in part because energetic electrons bury themselves in the ceramic, creating a buildup of charge and causing eventual puncture. A novel ceramic manufacturing process is proposed. It will incorporate bulk resistivity in the region where it is needed to bleed off accumulated charge caused by highly energetic electrons. This process will be optimized to provide an appropriate gradient in bulk resistivity from the vacuum side to the air side of the HV standoff ceramic cylinder. A computer model will be used to determine the optimum cylinder dimensions and required resistivity gradient for an example RF gun application. A ceramic material example with resistivity gradient appropriate for use as a DC gun insulator will be fabricated by glazing using doping compounds and tested.

  14. Tooth brushing, tongue cleaning and snacking behaviour of dental technology and therapist students

    Directory of Open Access Journals (Sweden)

    Clement C. Azodo

    2010-08-01

    Full Text Available Objective: To determine the tooth brushing, tongue cleaning and snacking behaviour of dental technology and therapist students. Methods: A descriptive cross-sectional study of students of Federal School of Dental Therapy and Technology Enugu, Nigeria. Self-administered questionnaire was used to obtain information on demography, frequency, duration and technique of tooth brushing and tongue cleaning as well as information on consumption of snacks. Results: A total of 242 students responded. Dental technology students made up 52.5% of the respondents and dental therapist in training made up 47.5%. Majority (63.2% of the respondents considered the strength of tooth brush when purchasing a tooth brush and 78.9% use tooth brushes with medium strength. Seven-tenth (71.9% of the respondents brush their teeth twice daily and 52.1% brush for 3–5 minutes. About one-third (30.2% brush their teeth in front of a mirror. Chewing stick was used by 51.7% of respondents in addition to the use of tooth brush. Tongue cleaning was done by 94.2% with only 9.5% using a tongue cleaner. Only 20.2% reported regular snacks consumption. Nine-tenth (90.4% of respondents were previously involved in educating others, apart from their colleagues, on tooth brushing. Conclusion: This survey revealed that most of the dental therapy and technology students had satisfactory tooth-brushing behaviour. The zeal to educate others about proper tooth brushing revealed in this study suggests that the students may be helpful in oral health promotion.

  15. Anion-specific effects on the behavior of pH-sensitive polybasic brushes.

    Science.gov (United States)

    Willott, Joshua D; Murdoch, Timothy J; Humphreys, Ben A; Edmondson, Steve; Wanless, Erica J; Webber, Grant B

    2015-03-31

    The anion-specific solvation and conformational behavior of weakly basic poly(2-dimethylamino)ethyl methacrylate (poly(DMA)), poly(2-diethylamino)ethyl methacrylate (poly(DEA)), and poly(2-diisopropylamino)ethyl methacrylate (poly(DPA)) brushes, with correspondingly increasing inherent hydrophobicity, have been investigated using in situ ellipsometric and quartz crystal microbalance with dissipation (QCM-D) measurements. In the osmotic brush regime, as the initial low concentration of salt is increased, the brushes osmotically swell by the uptake of solvent as they become charged and the attractive hydrophobic inter- and intrachain interactions are overcome. With increased ionic strength, the brushes move into the salted brush regime where they desolvate and collapse as their electrostatic charge is screened. Here, as the brushes collapse, they transition to more uniform and rigid conformations, which dissipate less energy, than similarly solvated brushes at lower ionic strength. Significantly, in these distinct regimes brush behavior is not only ionic strength dependent but is also influenced by the nature of the added salt based on its position in the well-known Hofmeister or lyotropic series, with potassium acetate, nitrate, and thiocyanate investigated. The strongly kosmotropic acetate anions display low affinity for the hydrophobic polymers, and largely unscreened electrosteric repulsions allow the brushes to remain highly solvated at higher acetate concentrations. The mildly chaotropic nitrate and strongly chaotropic thiocyanate anions exhibit a polymer hydrophobicity-dependent affinity for the brushes. Increasing thiocyanate concentration causes the brushes to collapse at lower ionic strength than for the other two anions. This study of weak polybasic brushes demonstrates the importance of all ion, solvent, and polymer interactions. PMID:25768282

  16. Gallium-containing polymer brush film as efficient supported Lewis acid catalyst in a glass microreactor

    OpenAIRE

    Rajesh Munirathinam; Roberto Ricciardi; Egberink, Richard J.M.; Jurriaan Huskens; Michael Holtkamp; Herbert Wormeester; Uwe Karst; Willem Verboom

    2013-01-01

    Polystyrene sulfonate polymer brushes, grown on the interior of the microchannels in a microreactor, have been used for the anchoring of gallium as a Lewis acid catalyst. Initially, gallium-containing polymer brushes were grown on a flat silicon oxide surface and were characterized by FTIR, ellipsometry, and X-ray photoelectron spectroscopy (XPS). XPS revealed the presence of one gallium per 2–3 styrene sulfonate groups of the polymer brushes. The catalytic activity of the Lewis acid-function...

  17. Piperazine-containing polymer brush layer as supported base catalyst in a glass microreactor

    OpenAIRE

    Munirathinam, Rajesh; Huskens, Jurriaan; Verboom, Willem

    2014-01-01

    The covalent attachment of piperazine onto the inner walls of a microreactor using glycidyl methacrylate polymer brushes has been demonstrated. The piperazine-containing polymer brushes were first grown on a flat silicon oxide surface and were characterized by contact angle, Fourier transform infrared (FT-IR), ellipsometry, and X-ray photoelectron spectroscopy (XPS). The applicability of the catalytic polymer brushes in a microreactor was demonstrated for the Knoevenagel and nitroaldol conden...

  18. Protein microarrays based on polymer brushes prepared via surface-initiated atom transfer radical polymerization.

    Science.gov (United States)

    Barbey, Raphael; Kauffmann, Ekkehard; Ehrat, Markus; Klok, Harm-Anton

    2010-12-13

    Polymer brushes represent an interesting platform for the development of high-capacity protein binding surfaces. Whereas the protein binding properties of polymer brushes have been investigated before, this manuscript evaluates the feasibility of poly(glycidyl methacrylate) (PGMA) and PGMA-co-poly(2-(diethylamino)ethyl methacrylate) (PGMA-co-PDEAEMA) (co)polymer brushes grown via surface-initiated atom transfer radical polymerization (SI-ATRP) as protein reactive substrates in a commercially available microarray system using tantalum-pentoxide-coated optical waveguide-based chips. The performance of the polymer-brush-based protein microarray chips is assessed using commercially available dodecylphosphate (DDP)-modified chips as the benchmark. In contrast to the 2D planar, DDP-coated chips, the polymer-brush-covered chips represent a 3D sampling volume. This was reflected in the results of protein immobilization studies, which indicated that the polymer-brush-based coatings had a higher protein binding capacity as compared to the reference substrates. The protein binding capacity of the polymer-brush-based coatings was found to increase with increasing brush thickness and could also be enhanced by copolymerization of 2-(diethylamino)ethyl methacrylate (DEAEMA), which catalyzes epoxide ring-opening of the glycidyl methacrylate (GMA) units. The performance of the polymer-brush-based microarray chips was evaluated in two proof-of-concept microarray experiments, which involved the detection of biotin-streptavidin binding as well as a model TNFα reverse assay. These experiments revealed that the use of polymer-brush-modified microarray chips resulted not only in the highest absolute fluorescence readouts, reflecting the 3D nature and enhanced sampling volume provided by the brush coating, but also in significantly enhanced signal-to-noise ratios. These characteristics make the proposed polymer brushes an attractive alternative to commercially available, 2D microarray

  19. Pericellular Brush and Mechanics of Guinea Pig Fibroblast Cells Studied with AFM.

    Science.gov (United States)

    Dokukin, Maxim; Ablaeva, Yulija; Kalaparthi, Vivekanand; Seluanov, Andrei; Gorbunova, Vera; Sokolov, Igor

    2016-07-12

    The atomic force microscopy (AFM) indentation method combined with the brush model can be used to separate the mechanical response of the cell body from deformation of the pericellular layer surrounding biological cells. Although self-consistency of the brush model to derive the elastic modulus of the cell body has been demonstrated, the model ability to characterize the pericellular layer has not been explicitly verified. Here we demonstrate it by using enzymatic removal of hyaluronic content of the pericellular brush for guinea pig fibroblast cells. The effect of this removal is clearly seen in the AFM force-separation curves associated with the pericellular brush layer. We further extend the brush model for brushes larger than the height of the AFM probe, which seems to be the case for fibroblast cells. In addition, we demonstrate that an extension of the brush model (i.e., double-brush model) is capable of detecting the hierarchical structure of the pericellular brush, which, for example, may consist of the pericellular coat and the membrane corrugation (microridges and microvilli). It allows us to quantitatively segregate the large soft polysaccharide pericellular coat from a relatively rigid and dense membrane corrugation layer. This was verified by comparison of the parameters of the membrane corrugation layer derived from the force curves collected on untreated cells (when this corrugation membrane part is hidden inside the pericellular brush layer) and on treated cells after the enzymatic removal of the pericellular coat part (when the corrugations are exposed to the AFM probe). We conclude that the brush model is capable of not only measuring the mechanics of the cell body but also the parameters of the pericellular brush layer, including quantitative characterization of the pericellular layer structure. PMID:27410750

  20. Modeling of an oscillatory freely-rotating cutting brush for street sweeping

    OpenAIRE

    Vanegas-Useche, Libardo V; ABDEL-WAHAB, MAGD M.; Graham A. Parker

    2012-01-01

    A dynamic model of a novel oscillatory cutting brush for street sweeping in free rotation is developed. The bristles are modelled as cantilever beams. The equation of motion is determined through the theory of forced transverse vibrations of beams, and the solution is based on the normal-mode method. A sinusoidal angular speed function and a novel function, named VAP, are studied. The model is validated through finite element analyses. The effects of brush parameters on brush dynamics are ide...

  1. Preparation of End Grafted Polyacrylonitrile Brushes through Surface Confined Radical Chain Transfer Reaction

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    End grafted polyacrylonitrile (PAN) brush was prepared through surface initiated polymerization via the chain transfer process. The thiol-terminated monolayer and PAN brushes were characterized by FTIR, X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), ellipsometry and contact angle measurements ete. It is demonstrated that radical chain transfer reaction and surface initiated precipitate polymerization can be used to prepare end-grafted polymer brushes.

  2. Endocytic trafficking from the small intestinal brush border probed with FM dye

    DEFF Research Database (Denmark)

    Hansen, Gert H; Rasmussen, Karina; Niels-Christiansen, Lise-Lotte;

    2009-01-01

    The small intestinal brush border functions as the body's main portal for uptake of dietary nutrients and simultaneously acts as the largest permeability barrier against pathogens. To enable this, the digestive enzymes of the brush border are organized in lipid raft microdomains stabilized by cross...... localized deeper into the cytoplasm of the enterocytes. Two major raft-associated brush border enzymes, alkaline phosphatase and aminopeptidase N, were excluded from endocytosis. We propose that the terminal web cytoskeleton, by inhibiting traffic from apical early endosomes further into the cell......, contributes to the overall permeability barrier of the gut. Key words: FM dye, small intestine, brush border, endocytosis....

  3. Analysis of carbon fiber brush loading in anodes on startup and performance of microbial fuel cells

    KAUST Repository

    Hutchinson, Adam J.

    2011-11-01

    Flat carbon anodes placed near a cathode in a microbial fuel cell (MFC) are adversely affected by oxygen crossover, but graphite fiber brush anodes placed near the cathode produce high power densities. The impact of the brush size and electrode spacing was examined by varying the distance of the brush end from the cathode and solution conductivity in multiple MFCs. The startup time was increased from 8 ± 1 days with full brushes (all buffer concentrations) to 13 days (50 mM), 14 days (25 mM) and 21 days (8 mM) when 75% of the brush anode was removed. When MFCs were all first acclimated with a full brush, up to 65% of the brush material could be removed without appreciably altering maximum power. Electrochemical impedance spectroscopy (EIS) showed that the main source of internal resistance (IR) was diffusion resistance, which together with solution resistance reached 100 Ω. The IR using EIS compared well with that obtained using the polarization data slope method, indicating no major components of IR were missed. These results show that using full brush anodes avoids adverse effects of oxygen crossover during startup, although brushes are much larger than needed to sustain high power. © 2011 Elsevier B.V.

  4. SIMULATION AND IMPLEMENTATION OF PID-ANN CONTROLLER FOR CHOPPER FED EMBEDDED PMDC MOTOR

    Directory of Open Access Journals (Sweden)

    M. Madheswaran

    2012-04-01

    Full Text Available The closed loop control of PMDC drive with an inner current controller and an outer PID-ANN (Proportional Integral Derivative – Artificial Neural Network based speed controller is designed and presented in this paper. Motor is fed by DC / DC buck converter (DC Chopper. The controller is used to change the duty cycle of the converter and thereby, the voltage fed to the PMDC motor to regulate the speed. The PID-ANN controller designed was evaluated by computer simulation and it was implemented using an 8051 based embedded system. This system will operate in forward motoring with variable speed.

  5. Very High Frequency Half Bridge DC/DC Converter

    DEFF Research Database (Denmark)

    Madsen, Mickey Pierre; Knott, Arnold; Andersen, Michael A. E.

    2014-01-01

    This paper presents the first, off chip, class DE (resonant half bridge) converter working in the Very High Frequency (VHF) range. The benefits of using half bridge circuits both in the inverter and rectifier part of a VHF resonant dc/dc converter are analyzed and design equations for all...

  6. A Plasma-Based DC-DC Electrical Transformer

    Science.gov (United States)

    Nebel, Richard; Finn, John

    2013-10-01

    Previous work has indicated that it may be possible to make DC-DC electrical transformers using plasmas. The mechanism is an MHD electromagnetic relaxation process induced by helical electrodes. This process is now being tested on the Bismark device at Tibbar Technologies.

  7. Power flow analysis for DC voltage droop controlled DC microgrids

    DEFF Research Database (Denmark)

    Li, Chendan; Chaudhary, Sanjay; Dragicevic, Tomislav;

    2014-01-01

    This paper proposes a new algorithm for power flow analysis in droop controlled DC microgrids. By considering the droop control in the power flow analysis for the DC microgrid, when compared with traditional methods, more accurate analysis results can be obtained. The algorithm verification is ca...

  8. Dc-To-Dc Converter Uses Reverse Conduction Of MOSFET's

    Science.gov (United States)

    Gruber, Robert P.; Gott, Robert W.

    1991-01-01

    In modified high-power, phase-controlled, full-bridge, pulse-width-modulated dc-to-dc converters, switching devices power metal oxide/semiconductor field-effect transistors (MOSFET's). Decreases dissipation of power during switching by eliminating approximately 0.7-V forward voltage drop in anti-parallel diodes. Energy-conversion efficiency increased.

  9. THE MOTOR

    DEFF Research Database (Denmark)

    Gammelgaard Nielsen, Anders

    2011-01-01

    MOTOR is the first assignment that students at Unit 1a of the School of Architecture are introduced to. The purpose of the assignment is to shake up the students and their preconceptions of what architec- ture is. This is done by introducing them to a working method that al- lows them to develop...

  10. Motor Magnates

    Institute of Scientific and Technical Information of China (English)

    ISABEL DING

    2008-01-01

    @@ The automotive industry is often seen as a man's world. Wang Fengying (王风英) begs to differ. The 38-year-old has presided over Great Wall Motors (长城汽车), the leading pick-up truck and Sport Utility Vehicle(SUV) manufacturer in China for the past five years.

  11. Motor radiculopathy

    OpenAIRE

    Khan, Afsha; Camilleri, Jeremy

    2012-01-01

    A 48-year-old immunosuppressed woman presented to a rheumatology follow-up clinic after suffering from herpes zoster infection. She had manifestations of foot drop 3 months after the initial infection. She was diagnosed with motor radiculopathy following herpes zoster infection that was effectively managed by physiotherapy and amitriptyline.

  12. A Feed-Forward Control Realizing Fast Response for Three-Branch Interleaved DC-DC Converter in DC Microgrid

    DEFF Research Database (Denmark)

    Wang, Haojie; Han, Minxiao; Yan, Wenli;

    2016-01-01

    It is a common practice for storage batteries to be connected to DC microgrid buses through DC-DC converters for voltage support on islanded operation mode. A feed-forward control based dual-loop constant voltage PI control for three-branch interleaved DC-DC converters (TIDC) is proposed...

  13. Molecular interaction forces generated during protein adsorption to well-defined polymer brush surfaces.

    Science.gov (United States)

    Sakata, Sho; Inoue, Yuuki; Ishihara, Kazuhiko

    2015-03-17

    The molecular interaction forces generated during the adsorption of proteins to surfaces were examined by the force-versus-distance (f-d) curve measurements of atomic force microscopy using probes modified with appropriate molecules. Various substrates with polymer brush layers bearing zwitterionic, cationic, anionic, and hydrophobic groups were systematically prepared by surface-initiated atom transfer radical polymerization. Surface interaction forces on these substrates were analyzed by the f-d curve measurements using probes with the same polymer brush layer as the substrate. Repulsive forces, which decreased depending on the ionic strength, were generated between cationic or anionic polyelectrolyte brush layers; these were considered to be electrostatic interaction forces. A strong adhesive force was detected between hydrophobic polymer brush layers during retraction; this corresponded to the hydrophobic interaction between two hydrophobic polymer layers. In contrast, no significant interaction forces were detected between zwitterionic polymer brush layers. Direct interaction forces between proteins and polymer brush layers were then quantitatively evaluated by the f-d curve measurements using protein-immobilized probes consisting of negatively charged albumin and positively charged lysozyme under physiological conditions. In addition, the amount of protein adsorbed on the polymer brush layer was quantified by surface plasmon resonance measurements. Relatively large amounts of protein adsorbed to the polyelectrolyte brush layers with opposite charges. It was considered that the detachment of the protein after contact with the polymer brush layer hardly occurred due to salt formation at the interface. Both proteins adsorbed significantly on the hydrophobic polymer brush layer, which was due to hydrophobic interactions at the interface. In contrast, the zwitterionic polymer brush layer exhibited no significant interaction force with proteins and suppressed

  14. EUS-Guided Pancreatic Cyst Brushing: A Comparative Study in a Tertiary Referral Centre

    Directory of Open Access Journals (Sweden)

    Titus Thomas

    2010-03-01

    Full Text Available Context Fluid analysis obtained by EUS guided FNA is used to aid in diagnosis and management of cystic lesions in the pancreas. Complementing fluid aspiration with brushing of cyst wall may increase the cellular yield. Objective To compare cellular yield of pancreatic cyst FNA with and without wall brushing. Design Comparative study. Setting Tertiary referral centre. Patients Fifty-one patients with cystic pancreatic lesions referred for EUS-guided aspiration/sampling were included (median age 69 years; interquartile range: 49-77 years. Main outcome measures Comparing adequacy of cellular yield between EUS-guided aspiration alone vs. EUS-guided aspiration and cyst wall brushing. Intervention EUS-guided FNA and/or wall brushing (aspiration only: No. 27; brushing: No. 24. Results There was no significant difference in age (P=0.496 cyst size (P=0.084 or cyst location (P=0.227 between groups. Overall 29.5%; (15/51 of samples were acellular/insufficient with no significant difference between the two groups (22.2% in the aspiration only group vs. 37.5% in the brushing group; P=0.356. The remaining samples were adequate for cytological evaluation (77.8% vs. 62.5%; aspiration only vs. brushing groups. Seventeen cases were neoplastic (8 benign, 9 malignant. The diagnostic accuracy was 61.9% and 55.0% in aspiration only and brushing groups, respectively. Two out of 4 (50.0% patents were diagnosed as having cancer in the brushings group compared to 1/5 (20.0% in the FNA only group (P=0.524. Limitations Non-randomised series. Conclusions The cellular yield was similar in FNA and brushing group. Greater proportion of patients with malignant cystic pancreatic lesions diagnosed by EUS sampling was in the brushing group, but this did not reach statistical significance.

  15. Design And Construction Of A Miniaturized Motor Controller For Interplanetary Rover

    Science.gov (United States)

    Lofgren, Henrik; Lijemark, Tomas; Lamoureux, Enrique; Bruhn, Fredrik; Hagstrom, Maria; Hall, Karin; Ljunggren, Anders; Habinc, Sandi; Gruener, Gabriel; Rusconi, Andrea; Boyes, Ben; Wagenbach, Susanne; Poulakis, Pantelis; Kohler, Johan

    2011-10-01

    providing the software for the MCC, which includes PID position, velocity, and torque control for brushed and brushless DC motors, as well as telecommand, telemetry and housekeeping through SpaceWire and CAN bus. Astrium UK is in charge of the definition of requirements for rover locomotion applications of the MCC. Astrium UK has experience from the Beagle project and is responsible for the Exomars rover development. Selex Galileo is in charge of the definition of requirements for three major applications of the MCC: robotic arms, complex motorized payloads (as drills and sample distribution systems) and exoskeletons. DLR Institute of Space Systems contributes to the definition of requirements related to rover locomotion drives and is furthermore in charge of environmental testing of the MCC prototype.

  16. Investigation of brush seals for application in steam turbines

    International Nuclear Information System (INIS)

    Brush seals have high potential for efficiency increase compared to conventional labyrinth seals in steam turbines. Due to less experience in operation today there is a lot of scepticism with customers of steam turbine manufacturers. Therefore this thesis is investigating characteristics of this type of seal. Experiments and numerical models will be presented, which lead to better knowledge about leakages and influence of flow through seal onto dynamics of rotor in comparison to labyrinth seals. This thesis is increasing area of experience and one more positive reference.

  17. Electrochemical redox responsive polymeric micelles formed from amphiphilic supramolecular brushes.

    Science.gov (United States)

    Feng, Anchao; Yan, Qiang; Zhang, Huijuan; Peng, Liao; Yuan, Jinying

    2014-05-11

    The end-decorated homopolymer poly(ε-caprolactone)-ferrocene threaded onto a β-cyclodextrin-functionalized main-chain polymer can form a class of amphiphilic noncovalent graft copolymers based on the host-guest interactions of the terminal groups on the side chains. These new supramolecular polymer brushes can further self-assemble into micellar aggregates that exhibit reversible assembly and disassembly behavior under an electrochemical redox trigger, which opens up a new route to building dynamic block copolymer topologies. PMID:24681929

  18. Parents experiences of tooth brushing with children: a qualitative study

    OpenAIRE

    Marshmann, Z; Ahern, SM; McEachen, RRC; Rogers, HJ.; Gray-Burrows, KA; Day, PF

    2016-01-01

    Globally, dental caries is one of the most prevalent diseases and is more common in children living in deprived areas. Dental caries is preventable, and guidance in the United Kingdom recommends parental supervised brushing (PSB): a collection of behaviors—including twice-daily toothbrushing with fluoridated toothpaste—that should begin upon eruption of the first tooth (approximately 6 to 12 mo of age) and for which children need to be helped or supervised by an adult until at least 7 y of ag...

  19. A Modified Tactile Brush Algorithm for Complex Touch Gestures

    Energy Technology Data Exchange (ETDEWEB)

    Ragan, Eric [Texas A& M University

    2015-01-01

    Several researchers have investigated phantom tactile sensation (i.e., the perception of a nonexistent actuator between two real actuators) and apparent tactile motion (i.e., the perception of a moving actuator due to time delays between onsets of multiple actuations). Prior work has focused primarily on determining appropriate Durations of Stimulation (DOS) and Stimulus Onset Asynchronies (SOA) for simple touch gestures, such as a single finger stroke. To expand upon this knowledge, we investigated complex touch gestures involving multiple, simultaneous points of contact, such as a whole hand touching the arm. To implement complex touch gestures, we modified the Tactile Brush algorithm to support rectangular areas of tactile stimulation.

  20. Electric motor drive selection issues for HEV propulsion systems: A comparative study

    OpenAIRE

    Zeraoulia, Mounir; Benbouzid, Mohamed; Diallo, Demba

    2006-01-01

    International audience This paper describes a comparative study allowing the selection of the most appropriate electric propulsion system for a parallel Hybrid Electric Vehicle (HEV). This study is based on an exhaustive review of the state of the art and on an effective comparison of the performances of the four main electric propulsion systems that are the dc motor, the induction motor, the permanent magnet synchronous motor, and the switched reluctance motor. The main conclusion drawn b...