Evaluating generalized predictive control for a brushless DC drive

This paper proposes a new control approach for a brushless DC motor drive using the generalized predictive control (GPC) algorithm. Based on the same least-squares framework as in the controller design, we further develop the method to design an observer. The GPC algorithm uses the receding horizon approach whereby the control signals are determined by minimizing a quadratic cost function. Our study shows that the rise time and settling time of the servo system have an approximate linear relationship with the prediction horizon. Thus, it is used to tune the controller of the drive. Moreover, the control weighting factor can be used to smooth the controller output. The proposed algorithm has been implemented using a digital signal processor (DSP) and tested in real time with a prototype system. The performance and robustness of the algorithms have been evaluated both in simulation and experiment. The results show that the drive performs reasonably well despite load changes and step changes in the position setpoint. Furthermore, it is fairly robust against motor parameters change     

A SPICE model for a novel brushless adjustable-speed drive

A SPICE circuit model was developed to accurately simulate the i-v characteristics of a brushless AC motor commutated by semiconductor switches. The model is based on Fourier curve fits to measured mutual inductance interactions between all combinations of field and armature windings, as well as coil resistance and inductance. The model is able to accurately predict current and voltage characteristics, both statically, and dynamically when interfaced with a commutation model. The model has been demonstrated to agree with electrical tests of an inverted motor on a large time scale. It has also given reliable predictions of small time-scale details, where it is desirable to predict power MOSFET switch behavior after a command to open or close. Data were collected and analyzed for simulations of the motor model combined with a commutation model containing MOSFET switches. Metrics were compared to data collected from an inverted brushless motor with good agreement.     

A discrete time variable structure controller for a brushless DCmotor drive

The design and the microprocessor-based implementation of a variable-structure-strategy (VSS) controller for a brushless DC motor drive are described. The controller is a conventional variable-structure design in the continuous-time domain. However, the microprocessor implementation using a constant sample period implies that full sliding mode is not achieved. The properties of the quasi-sliding that results are explored. It is shown that the sliding line expands into a sliding region, which can be described as a sector. The size of this sector is related to the sampling period and the switching gains. A modified design procedure is proposed for discrete-time VSS design. The design was verified on an experimental set-up, which generated variations in system parameters as well as external load disturbances     

A novel space-vector current regulation scheme for afield-oriented-controlled induction motor drive

The system performance of an AC variable-speed drive directly depends on the current regulation. In this paper, a novel space-vector current regulation scheme for a field-oriented controller (FOC) is developed. Motor currents are regulated by generating appropriate inverter output voltage vectors via software-implemented comparators and a switching table. A switching table based on the angular coordinate enables the inverter to generate optimal voltage vectors. By introducing an additional triangular carrier signal to the output of original hysteresis comparators, a user-selectable high and fixed switching frequency can be obtained, further improving the driver performance. Experiments are made to verify the effectiveness and correctness of this proposed method. According to the experimental results, both simple hardware design and good current response can be attained     

双闭环无刷直流电机驱动电路的设计与实现

在对无刷直流电动机控制系统的发展及应用综述的基础上,介绍了无刷直流电动机的结构和工作原理,给出了其数学模型,并重点分析了无刷直流电机控制技术中简单易用且鲁棒性较好的PID控制算法。对无刷直流电动机控制系统的硬件和软件设计做了详细论述。该电路是基于微芯公司的电机驱动电路专用驱动芯片DSPic30f4011而设计开发的,其中主体电路架构包括电源电路,三相逆变桥电路、转速闭环、电流闭环、线电压闭环和保护电路等。系统的软件设计中,主要包括微控制器的初始化程序、开环起动、换向控制、电流、速度采样时刻控制等。     

Novel resonant pole inverter for brushless DC motor drive system

The brushless dc motor (BDCM) has been widely used in industrial applications because of its low inertia, fast response, high power density, high reliability, and maintenance-free reputation. It is usually supplied by a hard-switching pulse width modulation inverter, which normally displays relative low efficiency since the power losses across the switching devices are high. In order to reduce the losses, many soft switching inverters have been designed. However, these inverters have such disadvantages as high device voltage stress, large dc link voltage ripple, discrete pulse modulation, and complex control scheme. This paper introduces a novel resonant pole inverter, which is unique to a BDCM drive system, and is easy to implement. The inverter possesses the advantages of low switching power loss, low inductor power loss, low device voltage stress, and simple control scheme. The operation principle of the inverter is analyzed. Simulation and experimental results are proposed to verify the theoretical analysis.     

Integrated fault-tolerant scheme for a DC speed drive

In this paper, an active fault-tolerant control (FTC) scheme is presented with disturbance compensation. Fault-detection and compensation are merged together to propose a robust algorithm against model uncertainties. The GIMC control architecture is used as a feedback configuration for the active fault-tolerant scheme. The synthesis procedure for the parameters of the fault-tolerant scheme is carried out by using tools of robust control theory. A detection filter is designed for fault isolation taking into account uncertainties and disturbances in the mathematical model. Finally, the fault compensation strategy incorporates an estimate of the disturbances into the system to improve the performance of the closed-loop systems after the fault is detected. In order to illustrate these ideas, the speed regulation of a dc motor is selected as a case study, and experimental results are reported.     

The optimal control of a constrained drive system with brushless DCmotor

The optimal (according to the quadratic performance index) control method of a drive position system with an electronically commutated brushless DC motor is discussed. Initially developed for linear, unconstrained, and undistributed systems, this optimal control method is now applied to a system having constrained state and input variables (e.g. armature voltage, armature current, rotor speed) and unknown disturbances (e.g. load torque). The method uses an undisturbed and unconstrained model for a model-following adaptive control of the real system. The control method is verified through computer simulation using the data from a real drive position system. Results show that the controlled system operates effectively at the limiting state variables, which represent the real system. In addition, the final position is reached without overshoots     

Novel soft-switching inverter for brushless DC motor variable speed drive system

Brushless DC motor has been widely used in industrial applications because of its low inertia, fast response, high power density, high reliability and maintenance-free. It is usually supplied by a hard-switching PWM inverter, which normally has low efficiency since the power losses across the switching devices are high. In order to reduce the losses, many soft switching inverters have been designed. Unfortunately, there are many drawbacks, such as high device voltage stress, large DC link voltage ripple, complex control scheme and so on. This paper introduces a novel soft-switching inverter which generates notches of the DC bus voltage becomes to zero during chopping switches commutation to guarantee all switches working in zero voltage state. The result of this investigation will be very useful for industrial applications.     

Microprocessor-based primary current control for a cage inductionmotor drive

A novel approach for primary current vector control of a current-source inverter induction motor (CSI-IM) drive with an improved estimation of slip angular frequency is described. Accurate digital control of the current vector orientation is achieved. Advanced software control logic provides the drive with rapid speed reversal and regenerative braking. A simple variable-structure current controller improves the system stability and robustness in performance. System large-signal operation and optimization are briefly discussed. Experimental results verify system development and design     

Integrated design of speed-sensorless and adaptive speed controller for a brushless DC motor

The study develops a design of an integrated new speed-sensorless approach that involves a torque observer and an adaptive speed controller for a brushless dc motor (BLDCM). The system is based on the vector control drive strategy. The speed-sensorless approach first employs a load observer to estimate the disturbed load torque, and then the estimated load torque is substituted into the mechanical dynamic equation to determine the rotor speed, and thus develop a speed-sensorless algorithm. Additionally, the mechanical rotor inertia constant and the friction coefficient, which are the inputs of the load observer, are estimated using the recursive least-square rule. Therefore, the proposed speed-sensorless approach is unaffected by the time-variant motor parameters nor is affected by the integrator drift problem. It also has a simpler computing algorithm than the extended Kalman filter for estimating the speed. The modified model reference adaptive system algorithm, an adaptive control algorithm, is adopted as a speed controller of the BLDCM to improve the performance of the speed-sensorless approach. Simulation and experimental results confirm that the performance of the design of a new integrated speed-sensorless approach and the adaptive speed controller is good.     

利用DSP控制直流无刷电机

直流无刷电机实际属于永磁同步电机,一般转子为永磁材料,随定子磁场同步转动。这种电机结构简单,而且由于移去了物理电刷,使得电磁性能可靠,维护简单,从而被广泛应用于办公自动化、家电等领域。直流无刷电机运行过程要进行两种控制,一种是转速控制,也即控制提供给定子线圈的电流;另一种是换相控制,在转子到达指定位置改变定子导通相,实现定子磁场改变,这种控制实际上实现了物理电刷的机制。因此这种电机需要有位置反馈机制,比如霍尔元件、光电码盘,或者利用梯形反电动势特点进行反电动势过零检测等。利用光电编码器的系统在软件实现上更方便…     

A new topology for unipolar brushless DC motor drive with high power factor

A new converter topology is proposed for driving a permanent magnet brushless DC (BLDC) motor with unipolar currents. It is based on a front-end single-ended primary inductance converter (SEPIC) and a switch in series with each phase. All the switches are ground-referenced, which simplifies their gate drives. The available input voltage can be boosted for better current regulation, which is an advantage for low voltage applications. For operation with an AC supply, the SEPIC converter is designed to operate in the discontinuous conduction mode. In this operation mode, it approximates a voltage follower and the line current follows the line voltage waveform to a certain extent. The reduction in low-order harmonics and improved power factor is achieved without the use of any voltage or current sensors. The simplicity and reduced parts count of the proposed topology make it an attractive low-cost choice for many variable speed drive applications.     

A sliding mode current control scheme for PWM brushless DC motordrives

This paper proposes a sliding mode current control scheme for pulsewidth modulation (PWM) brushless DC motor drives. An improved “equivalent control” method is used in this scheme. A simple algorithm is proposed that differs from the original equivalent control method, which requires extensive calculation to estimate the load parameters. This algorithm can be implemented using logic circuits. Moreover, using autotuning, the proposed algorithm can be applied without load information. An operating principle for the power stage switching devices called single-side firing is also proposed. Single-side firing solves the dead-time problem, allowing the PWM frequency to be increased and the sampling rate to be raised. This paper explains the current control algorithm, single-side firing principle, and implementation of the proposed scheme in detail. Simulations and experimental results are given to show the validity of this scheme     

基于IR2136与MOSFET的无刷直流电机驱动电路设计

针对传统驱动电路的设计,需要采用相互独立的电源为功率开关管供电,使得硬件结构复杂,可靠性下降,为此,基于功率驱动芯片IR2136与场效应管MOSFET,从信号隔离、三相逆变驱动、过流保护电路等方面,对无刷直流电机驱动电路进行设计。重点阐述了三相逆变驱动电路中的自举电路设计和功率管的驱动保护优化设计。采用TMS570控制板,对该驱动电路进行功能测试,结果表明,设计的驱动电路能够驱动电机平稳运行,且工作稳定可靠。     

Gate drive level intelligence and current sensing for matrixconverter current commutation

This paper is concerned with the process of current commutation in matrix converters. The mechanisms involved in the commutation process are described and practical waveforms are presented. A novel commutation strategy is described that uses gate drive level intelligence in the form of a field-programmable gate array. Current direction is determined using device voltages and, therefore, the measurement problems associated with all other commutation methods are overcome. Practical results from an 18-kW matrix converter induction motor drive are presented     

Profiled current drive for pulsed bipolar transistor switching

Preliminary investigations have been made of the profiling of base current drive to obtain fast turn-on without lifetime pulse stretching and turn-off delays.<>     

基于AVR的纯电动车无刷直流电机驱动系统

根据整车参数要求。设计一种基于AVR单片机控制的纯电动汽车无刷直流电机驱动系统。该系统以MEGA48单片机作为控制芯片．进行了电源电路设计、系统硬件保护电路设计、三相全桥逆变电路设计、逆变器驱动电路设计,利用PI控制器进行电机电流速度的双闭环控制,并采用C语言进行模块化编程和结构化编程。该系统可以实现欠压、过流和堵转保护。在系统出错情况下具有自检功能,同时具有升级空间,便于用户二次开发。     

A fast current drive circuit for injection lasers

An inexpensive solid-state circuit for fast-driving injection laser diodes is described. The high current pulses are generated by paralleling conventional (nonselected) transistor switches and operating them at avalanche breakdown.     

限流技术在无刷直流电机控制器中的应用

限流是无刷直流电机控制器系统中的关键点和难点,是保证整个系统正常工作的前提条件,设计中的AD对齐采样技术是整个限流工作的关键。该技术应用在一种以PSoC为主控芯片的电动车用无刷直流电机控制器,给出了整体的方案以及关键技术的具体设计方案。经实验验证是一种较好的限制控制器电流的方案。