Low-cost battery-powered switched reluctance drives with integral battery-charging capability

This paper presents a low-cost battery-powered drive using switched reluctance motors. The converter topology proposed in this paper is cost effective while still maintaining an energy-efficient system for battery-powered drives. The proposed drive not only achieves cost-effective and efficient battery motoring, but also battery charging with minimal additional power semiconductor components. Charging is achieved through the windings of the switched reluctance motor, thus eliminating the need of external bulky transformers and separate charging units.     

Theory and operation of a four-quadrant switched reluctance motor drive with a single controllable switch-the lowest cost four-quadrant brushless motor drive

Low-cost motor drives are being sought for high-volume energy-efficient home appliances. Key to the realization of such low-cost motor drives is the reduction of the power electronic converter to the barest in terms of its components, particularly the active devices, finding the motor with the least complexity for manufacturing and a controller that can extract the desired performance from the machine and converter combination. These and other factors such as self-starting, speed control over a wide range, and, most of all, the crowning aspect of four-quadrant operation with a bare minimum number of controllable switches remain as formidable challenges for low-cost motor drive realization. An innovative four-quadrant switched reluctance motor (SRM) drive with only one controllable switch is realized in this paper, for the first time, in the opinion of the authors. The motor drive is realized using a two-phase machine and a single controllable switch converter. The theory and operation of the proposed four-quadrant SRM drive with the proposed control algorithm for its realization are described. The motor drive is modeled, simulated, and analyzed to verify its feasibility for self-starting, speed control, and for four-quadrant operation, and the simulation results are presented. Experimental results confirm the validity of the proposed control algorithm for four-quadrant control of the SRM drive. The focus of the paper is mainly directed toward the control algorithm for realizing the four-quadrant operation of the two-phase SRM drive with a single controllable switch converter.     

Compensation strategy of matrix converter fed induction motor drive under input voltage and load disturbances using internal model control

The Matrix Converter (MC) is well known for its diverse advantages and applications but the output characteristics are adversely affected by the input voltage disturbances because there is no energy storage elements present in the dc link. Hence the matrix converter fed drive performance is affected. In this paper, Internal Model Control (IMC) based controller which is capable of achieving perfect set point tracking and disturbance rejection is proposed for compensating the voltage disturbances and load disturbances of matrix converter fed vector controlled Induction Motor (IM) drives. Modeling of matrix converter with input voltage disturbances and parameter estimation of IMC based speed and current controllers for vector controlled induction motor drive are described in this paper. The simulation results validate the input voltage disturbance rejection and improved dynamic performance of matrix converter fed induction motor drive obtained using IMC based controller.     

Analysis of a novel stator winding structure minimizing harmoniccurrent and torque ripple for dual six-step converter-fed high power ACmachines

Many attempts have been made to expand the application of AC motor drives to high-power levels. One way to use AC motor drives at high-power levels is to use multiple power converters together to supply power to a large machine. For a multiple converter combination scheme, the six-step power converter is competitive due to its robust structure and simplicity of control. In a previous study, an AC motor drive with dual stator windings fed by dual six-step converters was proposed. Two sets of electrically isolated windings are placed in the stator slots, and one set is shifted from the other by 30° in space. Two converters are used to power the dual windings, and the phase voltages from the two converters are also shifted 30° from each other in time. The 5th and 7th harmonics of the airgap flux and rotor currents are reduced dramatically, and the output torque from the drive is superior to that of the drive which is singly fed from a six-step converter. However, for each individual six-step converter, the 5th and 7th harmonic currents are found to be substantial and the functioning of the power converter evidently is deteriorated. In this paper, the authors propose a novel stator winding structure and control strategy to solve the power converter problem. Principles associated with the new stator winding are discussed and a practical implementation presented     

Power converter control based on neural and fuzzy methods

The new power converter control approaches based on neural network techniques and fuzzy logic theorems are briefly reviewed and discussed in this paper. Current-controlled voltage source inverters offer substantial advantages in improving motor system dynamics for high-performance AC drive systems. The controller switches follow a set of reference current waveforms. Fixed-band and sinusoidal-band hysteresis current controllers have been studied. The first part of this paper develops neural network and fuzzy logic based current-controlled voltage source inverters. The models and learning techniques have been investigated by simulation. The implementation of neural networks is described and simulation results are presented. In the second part of this paper, the new UPS (uninterruptible power supply) with fuzzy logic compensator is proposed. The proposed fuzzy logic compensator is used to prevent voltage drop from nonlinear loads. The total harmonic distortion (THD) of the proposed scheme is better than that of conventional deadbeat control methods for linear and nonlinear loads. The applications of fuzzy and neural network control to DC-DC converters operating at finite switching frequency are studied in the third part of this paper. The fuzzy logic and neural network controller for unity power factor rectifiers, half-bridge DC-DC ZVZCS converters, DC motor drives, induction motor drives and permanent-magnet motor drives are also discussed. Some simulations are presented in this paper.     

级联式并联有源电力滤波器的控制

本文提出了一种新的级联式并联有源电力滤波器(CSAPF)的控制算法.传统的两电平拓扑结构的有源滤波器由于其功率开关耐压水平的限制,难以实现对高压大容量非线性负载的谐波补偿.在高压大容量传动系统中,H桥级联式逆变器得到了广泛的应用.然而,这种逆变器独立电容电压的不平衡问题限制了其在有源滤波领域的应用.本文针对这一问题设计了一种新的参考电流提取算法和电容电压平衡PWM算法.实验结果表明了所提出算法的正确性和有效性.     

Control of c-dump converters fed switched reluctance motor on an automotive application

This paper deals with the analysis of switched reluctance motor drives for different drive circuit topologies used in automobile. Therefore, we attempt to improve the weaknesses associated with the asymmetric bridge converter in the limited internal environment of automotive application. Two kinds of c-dump converters are tested in terms of dump capacitor voltage, speed response according to the variation of advance angle and efficiency for the radiator cooling-fan drive of an automobile. They enable more economical and efficient converter topology for automobile industries. This paper describes the performance characteristics of 12 V–250 W–3000 rpm SRM drives for automobiles. Computer simulation and experiment results are then presented to verify the performance of the two kinds of c-dump converters.     

SRM inverter topologies: a comparative evaluation

Several inverter power circuits suitable for switched reluctance motor (SRM) drives are analyzed and compared. Five inverter circuits are considered with the objective of establishing the most appropriate topology for an SRM drive. The comparison is based on the peak voltage and peak current ratings of the DC link components. Because the power converter choice depends on the motor design, the converter analysis and selection are done for a high-speed, 6/2 SRM suitable for a spindle drive and a high-torque 8/6 motor. Experimental results obtained for a high-torque drive are included     

无刷直流电机电容储能型变换器的参数设计

:建立了c dump变换器的等效电路模型 ,分析了由这种变换器供电的无刷直流电机的控制特性 ,在此基础上对c dump变换器主要参数选取进行了详细的讨论 ,推导出了计算公式。以实验室一台永磁无刷直流电机作为设计实例 ,说明了变换器主要参数的选择过程并简要分析了对系统的影响 ,最后给出了实验结果。可为无刷直流电动机c dump变换器提供设计依据     

A Series-Connected Three-Level Inverter Topology for Medium-Voltage Squirrel-Cage Motor Drive Applications

The application of pulsewidth-modulated (PWM) voltages using two-level high-voltage inverters to a squirrel-cage induction motor (SQIM) can cause heating of rotor shaft, voltage spike across the motor terminals, etc. The increase in the number of steps of the motor voltage and hence decreasing the $dv/dt$ applied to the machine terminals can be a solution to this problem. The existing topologies that generate this multistep voltage include cascading of a number of single-phase inverters or use of higher order multilevel inverters. In this paper, a topology with series connection of three-phase three-level inverters is proposed, which addresses the problems of medium-voltage drives. The design of the inverter topology and its various PWM techniques are presented in this paper. This inverter topology and its control are verified on a 7.5-hp SQIM drive. Experimental results validate the steady-state and dynamic performances of the drive.      

A linear switched reluctance motor: converter and control

The converter topology with a minimum number of power devices and control implementations to facilitate the pulsation-free force control of the linear switched reluctance machines are investigated for the first time in this paper. The minimization of the devices offers cost reduction, compact packaging, and enhanced overall reliability. With that in view, a topology with 3N_sc+3 devices is chosen where N_sc is the number of sectors in the linear machine. The propulsion force with conventional control of single-phase excitation has high-commutation torque pulsation and it is overcome with a multiphase excitation strategy, proposed in this paper. Further, the proposed control strategy reduces the normal force pulsation. A systematic step-by-step design procedure of the switching strategy for the converter known as unipolar switching strategy, proportional plus integral current controller, and gating control strategy of a long linear switched reluctance machine is presented. Experimental correlation of the proposed converter arrangement and control strategy is presented with a 4.8 m-long linear switched reluctance machine in achieving the stated objectives     

无刷直流电机电容储能型变换器的参数设计

The c-dump converter is a new converter topology developed recently for brushless DC motors. The equivalent circuit model is developed and the control characteristics of the brushless DC motor based on the c-dump converter are studied in this paper. Then, guidelines for the design of the converter are given and some related formulas are derived for the choices of its important parameters. Finally, experimental results from a laboratory prototype are presented to validate the feasibility of the proposed guidelines for the design of c-dump converters.     

An improved CSI fed induction motor drive

Current source inverter (CSI) drives are preferred over voltage source inverter (VSI) drives in high power applications where fast dynamic response is not required. Conventional CSI drives have drawbacks such as resonance, instability at low speeds and high torque ripple, due to which their applications are restricted. This paper presents an improved CSI fed drive configuration that addresses these major drawbacks, as well as other power quality issues associated with the conventional drives. Two active power filters (APFs) are used in the proposed drive. The drive ensures sinusoidal waveforms at both the input and the output terminals. A simple CSI power circuit switching at fundamental frequency is used. Further, the use of a standard six-pulse SCR based rectifier eliminates the bulky and expensive input transformer, thus reducing the overall system cost. The proposed configuration is verified for a high power rating vector controlled induction motor drive. The design of the controllers and operation of the APFs are explained. Simulation results for the entire operating region of the drive including low speed operation and the field weakening region are presented. Finally, an important result regarding the presence of undesired circulating currents with the common DC bus for the two APFs, is also reported. The solution to avoid this problem is presented.     

Improved Weighting Factor Selection for Predictive Torque Control of Induction Motor Drive Based on a Simple Additive Weighting Method

A predictive torque control (PTC) technique is emerging as an effective alternative for induction motor drives because of its simple structure, ability to include control parameters directly into the cost function, and fast dynamic response. To implement PTC for induction motor drive, both stator flux and torque errors are predicted for each switching state of the converter and the combined error is determined with the help of cost function using a suitable stator flux weighting factor. However, the selection of suitable weighting factor is a tedious and complex task. In this paper, a simple additive weighting method is introduced in the cost function optimization to simplify the weighting factor selection process. To observe the effectiveness of the proposed control algorithm, both simulation and experimental results are presented for a two-level voltage-source-inverter-fed induction motor drive and compared with conventional PTC under various operating conditions. The proposed control technique achieves low-torque ripple along with reduced switching frequency.     

Demand-side management opportunities through the use ofenergy-efficient motor systems

The key issues related to efficient motor systems operation are presented, with a particular emphasis on electronic adjustable speed drives (ASD), due to their comparatively larger potential for savings. The potential for savings associated with the use of ASD in the residential, commercial, and industrial sectors are presented. With ASD it is estimated that one-fifth of the drive power consumption can be saved, that, is over 250 TWh/yr. The combined use of ASD with other efficient motor technologies can increase the savings to 30%. Research, development, demonstration, and training options are proposed which can significantly expand the cost effectiveness, performance, and scope of efficient motor systems applications     

Excitation of Variable-Reluctance Motor Drives

ABSTRACT

This paper focuses on two major issues which need careful consideration when designing an excitation for variable-reluctance motor (VRM( drives. The drive is comprised of a VRM, an inverter and an excitation and control strategy. The controller acts to enforce the excitation. The specific issues addressed here include the modeling of the drive and selecting a topology Toe the drive. These issues were found to be important during the design of an optimal-efficiency excitation for a high-power (60 kW( VRM drive. The drive used for the running example was designed for electric vehicle propulsion using a bifilar wound VRM.

The importance of drive modeling is examined through an example. The example uses two magnetic models for the same VRM to generate current waveforms for drive operation at a specific speed. The attributes of the current waveforms are then compared and their influence on excitation design is discussed. The comparison shows that meaningful excitation design requires accurate models of drive operation. The implications of the magnetic model on the design of the VRM are discussed.

With regard to inverter topology, a detailed efficiency comparison between a bifilar and a monofilar high-power VRM drive is presented. Each drive is comprised of a motor with identical geometries and the same number of turns per pole, a switching inverter, an excitation strategy and a control algorithm. After examining drive efficiency at several operating points over the intended duty, the paper concludes that the monofilar drive offers increased efficiency over the bifilar drive.     

High Performance Control of Matrix Converter Fed Induction Motor Drive System

I Introduction Matrix converter(MC)is a modern energyconversion device that has been developed over the lastthree decades[1~5].Matrix converter fed motor drive issuperiorto pulse width modulation(PWM)inverter drivessince it provides bi-directional power f…     

一种电机驱动用大功率网侧变流系统研究

提出了一种电机驱动用高性价比大功率网侧变流系统。主电路采用二极管整流器与PWM整流器并联,充分利用二极管整流器简单可靠、成本低,以及PWM整流器能量双向流动、功率因数高的优点,不仅能够省去传统电机驱动中的制动电阻,节约电能,还能提高交流系统功率因数。控制上通过对二极管整流器输出特性的研究,并调节PWM整流器输出特性,实现了PWM整流器与二极管整流器的协调工作。仿真和试验验证了主电路方案及控制方法的有效性。