Direct Torque and Flux Control of a Four-Switch Three-Phase Inverter-Fed Synchronous Reluctance Motor Drives

This paper presents an application of direct torque and flux control (DTFC) for a four-switch three-phase inverter (FSTPI)-fed synchronous reluctance motor (SynRM) in which the saturation and iron losses' effects are involved in the machine control modeling. The DTFC switching technique for the SynRM fed by FSTPI in low-power and low-cost applications is implemented by imitating the six-switch three-phase inverter (SSTPI). By considering equal effective vectors depicted in SSTPI, the αβ stationary reference frame is represented by using six sectors. Similarly, the voltage space vector formation is constructed in FSTPI. Accordingly the SynRM performance under DTFC is precisely analyzed by considering the saturation and iron losses' effects. The DTFC behavior based on SSTPI- and FSTPI-fed SynRM is evaluated using Simulink benchmark. At different operating conditions, further simulation and experimental results of DTFC based on FSTPI dynamically confirm the effectiveness of the proposed control application on the SynRM.     

Fuzzy-logic-controller-based cost-effective four-switch three-phase inverter-fed IPM synchronous motor drive system

This paper investigates the performance of a fuzzy-logic-controller (FLC)-based cost-effective drive system of interior permanent-magnet synchronous motor (IPMSM) for high-performance industrial applications. In this paper, the FLC is used as a speed controller and the motor is fed from a four-switch three-phase (4S3Ph) pulsewidth-modulation (PWM) inverter instead of a conventional six-switch three-phase (6S3Ph) inverter. This reduces the cost of the inverter, the switching losses, and the complexity of the control algorithms and interface circuits to generate six PWM logic signals. Furthermore, the proposed control approach reduces the computation for real-time implementation. The closed-loop vector control scheme of the proposed 4S3Ph-inverter-fed IPMSM drive incorporating the FLC is implemented in real time using the digital signal processor (DSP) TI TMS320C31 for a prototype 1-hp motor. The robustness of the proposed FLC-based 4S3Ph-inverter-fed IPMSM drive is verified by theoretical and experimental results at different operating conditions. A comparison of the proposed 4S3Ph-inverter-fed IPM drive with a conventional 6S3Ph inverter system is also made in terms of performance and harmonic analysis of the stator current. The proposed inverter-fed IPMSM drive is found quite acceptable considering its performance, cost reduction, and other inherent advantageous features.     

Sensorless Control of a Permanent Magnet Synchronous Motor Using Artificial Neural Network Based Estimator—An Application of the Four-Switch Three-Phase Inverter

This article presents a space vector pulse width modulation based three-phase four-switch inverter for the sensor-less control of a three-phase permanent-magnet synchronous motor (PMSM). The PMSM was modeled in MATLAB SIMULINK using the dynamic model to extract signals required for the sensor-less control. The calculation of time for gate signals of the switches in the four-switch three-phase inverter has been explained in detail and implemented using the artificial neural networks. The ANN based SVPWM block takes reference voltage, frequency and modulation index as commands and provides three-phase voltages with variable frequency. An ANN based speed and position estimator was also implemented for the PMSM to eliminate mechanical sensors. The proposed system was implemented using the Texas Instruments' TMS320F2812 development kit and the National Instruments data acquisition module USB-6259. The results have been presented for the permanent magnet synchronous motor drive in under-modulation region.     

Design and implementation of a new four-switch modified quasi Z-source inverter with improved space vector control method

This paper proposes a novel cost-effective feature as a three-phase four-switch inverter utilizing a modified quasi Z-source (MQZs) network. This inverter exploits a pulse-width modulation (PWM) control strategy based on developed space vectors to provide balanced three-phase output voltages and currents. It also has many applications such as the three-phase induction motor (IM) with adjustable speed drive (ASD) fed by a DC and/or rectified AC supply. Unlike some other similar four-switch inverters or converters, which can only work in step down (buck) mode or step up (boost) mode, this inverter can operate in both modes that depend on switching signals and due to adjusting the zero shoot-through (Zsh-th) duty cycle. It also decreases the total harmonic distortions (THD) of output voltages and currents. The MQZs inverter reduces the switching losses and the cost of topology in comparison with the conventional six-switch topologies. The utilized control strategy can work well without any extra filtering circuit in DC side to eliminate the effect of the DC-bus voltage ripples on the inverter output currents and voltages. The experimental results are found closely analogous and confirm the aforementioned features of the proposed topology compared with other traditional topologies, although the inverter output filter is a conventional LC filter.     

三电平异步电机的无速度传感器矢量控制系统研究

为解决在中高压领域无速度传感器矢量控制速度辨识差的缺点,基于三电平电压源型逆变器,提出了一种异步电机无速度传感器矢量控制方案.该方案采用间接矢量控制(IFOC)策略,以模型参考自适应(MRAS)方法构造速度辨识系统,并在新型三电平空间矢量脉宽调制(SVPWM)简化算法基础上,运用MATLAB/Simulink实现对三电平异步电机无速度传感器矢量控制系统的仿真研究.仿真结果表明,所述控制方法正确有效,该系统具有较好的稳态特性和动态响应能力.     

四开关三相方波无刷直流电机的磁链跟踪控制

在分析传统六开关三相无刷直流电机运行原理的基础上,提出四开关三相方波无刷直流电机的磁链跟踪控制策略.系统外环为转速环,通过转速环输出和电流形状函数分别相乘实现三相电流的给定,借助坐标变换在两相静止坐标系下构建电流闭环,采用磁链跟踪型调制策略实现对四开关逆变器的控制,从而克服了滞环调制的开关频率不固定问题,实现了四开关三...     

基于全阶观测器的三电平逆变器异步电机无速度传感器矢量控制系统

采用全阶观测器的方法在三电平逆变器平台上实现了异步电机的无速度传感器矢量控制。针对观测器中增益矩阵选择困难的问题,采用解析推导的方法借助数学软件完整地得出了六组增益矩阵,并指出了采用不同状态变量时增益矩阵之间的联系。全阶观测器只需要两路直流母线电压和两路电机电流信号,可以在全速域范围内准确的观测磁链和转速,并成功的将观测得到的转速和磁链用于闭环矢量控制中。仿真和实验表明基于全阶观测器的矢量控制系统动静态性能良好,对电机参数变化具有较好的鲁棒性。采用预励磁的方法可以在减小起动电流的同时增大起动转矩,保证系统的低速稳定运行。     

四开关逆变器直流母线电容电压均衡控制

当传统三相两电平六开关逆变器的某个功率管发生开路或短路故障时,四开关逆变器作为一种容错拓扑结构可以维持三相系统继续运行.然而,由于有一相负载电流从电容中点流入流出,势必导致母线中点上下两个电容的电压波动.对需要经常改变运行工况的场合,两电容电压甚至会向相反方向漂移,严重影响系统的可靠运行.首先通过电路分析给出电容电压波...     

四开关空间矢量脉宽调制控制算法及母线电容电压不平衡问题的研究

三相四开关逆变器采用"五段式"空间矢量脉宽调制(SVPWM)方案可有效减小电机的转矩脉动,而四开关逆变器的母线电容电压不平衡将直接影响SVPWM的效果,导致电机三相电流不平衡,使电机的转矩脉动加剧。在深入分析四开关逆变器SVPWM原理的前提下,分析了直流母线电压不平衡对电机运行的影响,提出了一种有效的补偿办法。仿真结果表明,补偿后的异步电机VVVF系统具有较好的性能。     

容错型三相四开关有源电力滤波器及其控制策略

有源电力滤波器(APF)多基于三相六开关拓扑,为提高其运行可靠性,提出一种基于元件冗余的三相四开关容错型APF。针对三相六开关APF的故障判别,应用功率器件承受电压变化识别桥路开路故障;研究了基于谐波检测APF补偿算法与控制电源电流跟踪电网电压APF补偿算法的关系,指出容错型APF切换控制中更适合采用电源电流直接跟踪补偿算法;在三相四开关APF数学模型基础上,研究了直流母线中点偏移对三相四开关APF补偿性能的影响,提出一种直流中点电压差值前馈补偿方法。扩展了配置直流侧储能的情况下,容错型APF的有功调节实现方法;设计了APF容错控制切换策略和硬件实现的电流滞环跟踪控制电路,在建立的三相四开关APF平台上,实验验证了所提方法的有效性。     

电压型逆变器电流实时检测质量改善研究

交流调速系统在取消机械传感器后,其速度的估计依靠实时检测逆变器端电压、电流来完成,因而电流检测质量的好坏至关重要。良好的滤波是系统实现无速度传感器稳定运行的前提,而传统模拟和数字滤波在宽调速范围内面临难以克服的困难。为此,提出采用跟踪-微分法对逆变器电流进行滤波,并研究了跟踪-微分器各参数对滤波性能的影响。以一个4 kW普通三相异步电机为控制对象了进行仿真试验,对比分析了新旧电流检测滤波方案下的电机运行性能。分析结果表明,采用新的电流滤波方案后,调速系统在宽调速范围内均有更好的运行性能。     

一种新的无刷直流电动机驱动系统

提出了一种新的低成本四开关无刷直流电动机驱动系统。为了有效地利用该系统,设计了一种直接电流控制的脉宽调制(PWM)方案,以得到良好的动、静态的速度-转矩特性。该四开关变换器的可行性可推广到二相无刷直流电动机驱动以及用于功率因数校正和速度控制的六开关变换器。从理论上分析了该无刷直流电动机四开关变换器的工作原理,并通过仿真和试验演示了其性能。     

PMSM比例谐振自抗扰电流谐波抑制方法

基于扩展状态观测器的永磁同步电机转子位置和速度估算中,由于死区效应、电气元件误差、逆变器非线性因素会产生大量的电流谐波,影响位置和速度估计精度。本文提出一种基于比例谐振与自抗扰控制的PR-ADRC电流环控制策略,可以有效抑制dq坐标系下6次电流谐波,从而降低静止坐标系下5、7次谐波含量。基于MATLAB和HiGale平台对提出方法进行仿真和实验验证,结果表明改进后的电流环降低了三相电流谐波,估算反电动势波形良好,转子位置和速度估算误差降低,无位置传感器控制系统控制精度得到提高。     

PERFORMANCE ANALYSIS OF LOAD COMMUTATED INVERTER FED CAGE INDUCTION MOTOR DRIVE

ABSTRACT

An approach, to analyse the performance of a variable speed cage induction motor drive fed from load commutated inverter (LCI), is presented. Induction motor with an appropriate capacitor across its stator terminals constitutes the load on the inverter. A fully controlled bridge converter, supplied by a variable dc voltage source, commutated with the back emf of the motor, acts as an inverter. An algorithm to compute the motor performance, is developed using equivalent circuit representation of the system. Strategies for the selection of control variables, in order to achieve the desired speed range for satisfactory performance of the drive are given. The performance of a 3-hp, cage induction motor fed from LCI is computed, using the developed algorithm for wide range of speed; and is verfied experimentally.     

三相四开关容错逆变器的PMSM驱动系统FCS-MPC策略

针对三相四开关容错逆变器的永磁同步电机(PMSM)驱动系统,基于模型参考自适应(MRAS)观测器,提出一种有限控制集模型预测控制(FCS-MPC)策略。考虑温度变化对永磁磁链影响,采用MRAS技术,实现了对永磁磁链的在线辨识;同时考虑降低逆变器开关频率的需求,设计开关频率可优化的FCS-MPC系统目标函数。与常规FCS-MPC方法比较,本方法可以有效减小系统控制过程的计算量,与此同时,本方法中的电流反馈特性可对四开关逆变器直流母线电容分压不平衡形成的不利影响实现自动抑制。仿真结果表明,本方法能够保证四开关容错逆变器驱动的PMSM系统持续稳定运行、具有良好运行性能,并能明显降低逆变器功率管的开关频率。     

Sensorless IPMSM position estimation based on multi SVPWM with elimination of inverter nonlinear effects

This paper presents a position‐sensorless interior permanent magnet synchronous motor (IPMSM) control system at low and zero speed based on a multi‐space‐vector pulse‐width modulation (MSVPWM) pattern with the elimination of nonlinear inverter effects. In conventional sensorless methods based on the MSVPWM pattern, the high‐frequency (HF) components of voltage and current are used to estimate the rotor position information. However, the inverter nonlinear effects, such as forward voltage drops and deadtime, distort the HF components of the voltage and current so that an error occurs in the position estimation. Therefore, an improved position estimation scheme is developed in this paper. The compensated HF components of the voltage taking account of the inverter nonlinear effects can be used to decrease the estimation error. The proposed method can be implemented without increasing any hardware cost. Experimental results confirm the effectiveness of the proposed method. © 2014 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

三相四开关逆变器供电的IPMSM直接转矩控制系统建模与分析

为获得较高的转矩响应速度和较低的转矩脉动,将基于比例-积分控制器和空间矢量调制的直接转矩控制(PI-SVM DTC)引入到由三相四开关逆变器供电的凸极式永磁同步电机(IPMSM)驱动系统中。鉴于电机的强耦合性,同时为便于分析其定子磁链环,建立了IPMSM在静止坐标系下以定子磁链为状态变量的状态空间模型。为改善系统的稳态性能,构建无差拍全阶状态观测器,实现对定子磁链的闭环观测。揭示了传统定子磁链环极点放置位置存在的问题,并利用一种简单的方法对定子磁链环极点位置进行优化。对PI-SVM DTC的转矩环进行建模分析,为PI控制器的设计提供依据。另外,为抑制三相四开关逆变器直流母线中性点电压偏移,根据其偏移量生成合适的补偿量,并将其添加到定子磁链控制环中。实验结果验证了该模型的有效性。     

四开关逆变器供电永磁同步电机直接转矩控制系统转矩脉动抑制

永磁同步电机直接转矩控制(PMSM DTC)系统的转矩脉动问题一直被广泛关注，特别是在四开关逆变器供电系统中，由于可用电压矢量减少，转矩脉动更加严重。空间矢量调制(SVM)是一种常用的消除电力谐波的调制技术，更可用于电机控制中转矩脉动的削减。该文针对四开关逆变器供电PMSM DTC系统的特殊性，采用了一种新型SVM方法，分析了等效零矢量模拟技术，将传统SVPWM调制中的劈零思想引入到空间矢量的合成上。仿真及实验结果验证了该新型SVM DTC方法大大减小了转矩脉动，且仍保持了DTC系统固有的快速转矩动态响应。     

三电平逆变器异步电动机直接转矩控制系统(I)--单一矢量法

三电平中点钳位逆变器(NPC)广泛应用于中压变频调速系统,具有对器件耐压要求低,输出谐波含量低,控制性能好等优点.其主要问题是如何避免中点电压的漂移,以及防止输出电压有过高的瞬时跳变.提出一种三电平异步电动机直接转矩控制(DTC)系统,即基于单一矢量的控制算法.该方法有效地控制了三电平逆变器的中点电压,并抑制了输出电压的跳变,从而满足了实际运行的要求.仿真结果表明,本文的方法在三电平逆变器供电的异步电动机上有效地实现了DTC系统,并能达到较好的控制性能.     

三相六开关容错逆变器驱动PMSM的预测转矩控制

为提高电动汽车用永磁同步电机驱动系统性能,设计了新型的三相六开关容错逆变器拓扑结构,以达到降低驱动系统故障发生率的目的;针对所用到的模型预测转矩控制策略,提出了新型的目标函数构造方法,避免了权重系数的整定,对传统模型预测控制策略中的电压矢量选择方法进行了改进与优化,以达到降低整体控制算法计算量,增加算法实用性的目的,仿真结果表明,采用新型的三相六开关容错逆变器驱动的PMSM的MPTC改进优化策略具有较强的故障容错能力,有良好的动静态性能。