Novel Antiwindup of a Current Regulator of a Surface-Mounted Permanent-Magnet Motor for Flux-Weakening Control

This paper proposes a novel antiwindup method of current regulator for the drive system of a surface-mounted permanent-magnet synchronous motor at flux-weakening region. It is designed in conjunction with the synchronous-frame proportional and integral current regulator and the space vector pulse width modulation. The difference between the regulator output voltage and the saturated voltage on the$q$-axis of the regulator is used for flux-weakening control, which modifies the$d$-axis current reference. With this method, the antiwindup and the flux-weakening control can be achieved simultaneously. Since the proposed method utilizes the dc-link voltage more efficiently, it makes the motor generate higher output torque than the conventional antiwindup and/or flux-weakening control methods under the same voltage and current limitation. The effectiveness of this method is confirmed by computer simulations and experiments.     

Six-step Voltage Control of PM Brushless AC Motors under High Speed Flux-weakening Operation for EV/HEV Applications

The torque-speed characteristics of brushless motor having an interior permanent magnet rotor and a sinusoidal back-emf waveform are compared experimentally when it is operated in brushless AC(BLAC) mode and brushless DC (BLDC) modes with both 2-phase,120° conduction(BLDC-120) and 3-phase,180° conduction(BLDC-180).Particular emphasis is on high-speed,six-step voltage controlled,flux-weakening operation.It is shown that for EV/HEV applications,even for interior PM brushless motors which have sinusoidal back-emf waveforms,in order to achieve maximum torque per ampere capability over wide operation speed range,it is advantageous to employ a hybrid operation mode-BLAC operation in the constant torque region and six-step voltage control(BLDC-180 operation,together with current phase control) in the flux-weakening region.     

A Method of Voltage Unbalance Compensation in a Y‐Connected Modular Multilevel Converter

A STATCOM is expected to be suitable for use as voltage control equipment for a distribution system that needs to be controlled to suppress the voltage deviation caused by an increase in the number of photovoltaic energy sources. A Y‐connected MMC is a promising alternative for the STATCOM circuit topology. However, it is known that the Y‐connected MMC cannot achieve capacitor voltage balance between phases with unbalance current output in order to compensate system voltage unbalance. To solve this problem, we propose a novel method to control the capacitor voltage for unbalance current output. The proposed control involves feedforward and feedback zero sequence voltage control. The feedforward control prevents capacitor voltage unbalance between phases, which is caused by the unbalance current that the Y‐connected MMC outputs. The feedback control cancels the remaining control error of the feedforward control. We verified the performance of this control through transient simulation. The Y‐connected MMC with the proposed control can realize capacitor voltage balance between phases even when the Y‐connected MMC outputs an unbalance current. Additionally, we determined the maximum unbalance current output produced by the Y‐connected MMC in relation to the rated capacitor voltage.     

Flux-Weakening Regime Operation of an Interior Permanent-Magnet Synchronous Motor Drive

The interior permanent magnet (IPM) synchronous motor is compatible with extended-speed-range constant-power operation by means of flux-weakening control. Flux weakening uses stator current components to counter the fixed-amplitude magnetic airgap flux generated by the rotor magnets, performing a role similar to field weakening in a separately excited dc motor. The nature of current regulator saturation caused by the finite inverter dc source voltage is described, marked by premature torque and power degradation at high speeds in the absence of flux-weakening control. This is followed by presentation of a new flux-weakening control algorithm developed as a modification of an established feedforward IPM torque control algorithm described previously in the literature. Attractive features of this new algorithm include smooth drive transitions into and out of the flux-weakening mode, fast response, as well as automatic adjustment to changes in the dc source voltage. Simulation and empirical test results from a 3-hp laboratory IPM motor drive are used to confirm the constant-power operating envelope achieved using the new flux-weakening control algorithm.     

新型的内嵌式永磁同步电机弱磁转速控制

在基本转矩前馈控制系统的基础上,提出了一种新型的永磁同步电机的弱磁控制算法。由于电流调节器的饱和使得定子电流进入弱磁控制,因此在这种新的弱磁控制算法的基础上,设计出一种新的定子电流误差观测器用以辨识电流调节器的饱和情况。另外,在弱磁区利用转速观测器观测定子电流变化,利用差值控制器以达到使定子电流矢量由常规的弱磁控制轨迹转向最大输出的电压极限轨迹（VLMO）的目的。仿真结果表明：相应产生的VLMO控制模式能够优化弱磁控制策略,控制算法能有效实现弱磁控制下的转速调节。     

基于改进下垂控制的微网协调控制策略

微源间的无功环流是由其输出电压幅值的差异引起的。在深入分析并联运行微源间输出电压幅值差异与无功功率出力分配偏差关系的基础上,将电压幅值反馈的控制策略引入到传统下垂控制中,降低微源间输出电压的幅值差,从而抑制无功环流的形成。仿真结果验证了该控制策略的可行性,同时仿真结果还表明该策略可以有效提高微网运行的稳定性。最后将该控制策略应用到并网过程中,仿真结果表明电压幅值反馈控制策略可以有效抑制并网过程中频率和电压的震荡。     

电动汽车IPMSM单电流调节器弱磁控制技术

针对电动汽车IPMSM在弱磁扩速时交直轴电流强耦合的问题,采用单电流调节器的弱磁控制方式,通过选择开关对最大转矩电流比(MTPA)控制方式和弱磁控制方式在不同运行状态下进行切换。在弱磁控制中直轴电压指令由直轴电流调节器获得,交轴电压指令则根据直轴电压值通过调节器直接给出。该方法能够对电机直流电压充分利用,使电机工作在最优工作点。建立该控制系统的Matlab/Simulink仿真模型,仿真结果分析证明该方法的可行性。最后搭建以英飞凌TC 1782为主控芯片的电动汽车驱动控制系统平台,对所提的控制策略的实际应用能力进行验证。     

基于子模块电压波动估计的MMC双环二倍频环流抑制策略

模块化多电平变换器以其优越的性能在大功率电能变换领域得到了广泛应用和研究。推导了MMC子模块电容电压波动和桥臂投入模块数的表达式,针对MMC环流控制器性能分析的多样性、复杂性和电压波动的计算问题,提出一种基于子模块电容电压波动估计前馈+电压电流双闭环反馈的复合环流控制策略,有效结合前馈控制的快速跟踪性和反馈控制的闭环跟踪性能,同时优化计算环节。所提方法包括四部分:子模块电容电压的前馈估算;基于小信号模型的二倍频环流电压指令计算;投入模块数的计算;子模块电容电压的排序及其投切。其中二倍频环流电压指令通过电压电流双闭环控制器获得,并通过等效闭环阻抗分析其动态性能,选取达到最佳抑制效果时合适的控制参数。仿真和实验结果验证了所提方法的有效性。     

混合励磁同步电机新型矢量控制算法研究

在速度分区控制的基础上提出一种混合励磁电机矢量控制算法,该方法综合考虑了负载转矩、励磁电流及母线电压对弱磁基速的影响,在线动态计算弱磁基速。在弱磁区,保持气隙合成反电势恒定,利用励磁电流和d轴电流共同弱磁升速。采用Matlab/Simulink仿真软件建立混合励磁同步电机控制系统,对所提算法进行验证。仿真结果表明该算法可实现混合励磁电机低速大转矩和高速宽调速范围运行。     

低输入电流纹波大升压比差动Boost型逆变器研究

为减少功率变换级数以及低频纹波对输入直流电源的影响,具有大升压能力和低输入纹波的单相逆变器具有重要的研究意义。深入研究了大升压比差动Boost逆变器电路拓扑、纹波抑制策略、电流纹波回路、输入电流反馈和输出电压复合控制策略。在传统波形控制基础上,通过输入电流反馈在输出滤波电容上叠加低频偶次电压,进一步减小输入电流中相应偶次谐波分量,使逆变器输出侧低频脉动功率在输出滤波电容与负载之间传递,阻断其向输入源传递;采用前馈与比例积分控制策略提高输出电压质量和输入电流质量。不同负载下的实验结果验证了此变换器的可行性。     

感应电机弱磁调速时SVPWM过调制策略研究

以提高感应电机弱磁调速时逆变器输出电压为目标,提出了一种新的空间矢量脉宽调制(SVPWM)线性过调制策略。结合交流异步电机磁场定向闭环控制的特点,在SVPWM过调制区域Ⅱ中采用一种线性幅值跟随过调制策略,而在过调制区域Ⅲ中采用了6步法,从而保证SVPWM在整个过调制区域都能获得最大调制比。实验结果表明,该方法能有效提高逆变器输出电压,有利于扩大弱磁调速系统基速以上的调速范围。     

Wide-speed operation of interior permanent magnet synchronousmotors with high-performance current regulator

Interior permanent magnet synchronous motors can be applied to applications requiring wide-speed operation. The current vector control algorithm of an interior permanent magnet synchronous (IPM) motor for constant power operation over the base speed is proposed. As the available voltage controlling the armature current vector is small in the flux-weakening constant power region, the current vector sometimes becomes uncontrollable in transient operations because of the current regulator saturation. The high-performance current regulator is also proposed to improve the current responses in the flux-weakening region, which includes the decoupling current controller and the voltage command compensator. The control performances are confirmed by several drive tests with respect to the prototype IPM motor     

复合控制型低纹波PWM AC/DC-DC变换器

在PWM AC／DC-DC变换器中,通常采用大电容滤除前级整流产生的纹波。但在某些应用场合,滤波电容不能太大。如果只用较小的电容滤波,变换器输出电压的纹波较大。本文提出了前馈及局部负反馈控制方案,即利用变换器直流中间环节的纹波移相控制芯片UC3875的移相角,使输出电压产生与采用这种方式前反相的纹波,调节这种纹波的幅度就可以减小输出电压纹波,在此基础上,本文增加了局部负反馈环节,进一步降低纹波。仿真和实验结果表明了方案的可行性。     

基于多模式SVPWM算法的永磁同步牵引电机弱磁控制策略

弱磁控制技术可以降低逆变器的容量、拓宽调速范围,对提高轨道交通永磁同步牵引系统的性能有着重要而现实的意义。性能优异的调制方式更能保证弱磁系统输出良好的控制性能,而大功率传动系统开关器件的开关频率较低,使得传统的空间电压矢量异步调制方法已不能满足控制策略需要,本文在分析空间电压矢量多模式调制算法原理以及永磁同步电机弱磁原理的基础上,提出了新型的基于多模式空间电压矢量调制算法的永磁同步牵引电机弱磁控制策略,保证永磁同步牵引电机弱磁控制系统能充分利用开关频率,且在异步调制和分段同步调制段都具有良好的输出特性,仿真和试验验证了本方案的可行性和有效性。     

基于多环复合控制的岸电电源的研究与实现

详细介绍了一种基于前馈的多环复合控制设计及硬件实现.采用输出电压有效值反馈和输出电流前馈及直流母线电压前馈的多环复合控制系统,搭建仿真模型和分析仿真的波形.同时也详细介绍了逆变单元所采用的SKiiP类型IPM的优点,逆变器输出端LC滤波器参数的设计方法.简要介绍了一下岸电变频电源的硬件结构.最后在样机上进行实验,结果表...     

Design and Control of an Axial-Flux Machine for a Wide Flux-Weakening Operation Region

This paper describes the strategy to design and control an axial-flux (AxF) surface-mounted permanent-magnet machine for achieving a wide flux-weakening (FW) operating region. By using a slotted stator with fractional-slot windings and additional cores enclosing end windings, the AxF machine satisfies the specification of a wide constant-power speed range. The design procedure is presented for increasing FW capability while obtaining low-harmonic back electromotive force and low cogging torque. This technique is applied to design an 8-Nldrm AxF prototype machine that exhibits about 3 : 1 FW range. To the aim of exploiting full capability of the machine, an FW controller is designed and implemented. This controller utilizes the voltage difference between the current regulator and the output voltage, limited by a voltage source inverter. With this method, the output torque in the FW region is higher than that achieved using the conventional FW method based on the voltage-magnitude feedback. The goodness of both design and control algorithm is proved by experimental tests on a prototype.     

永磁同步风力发电系统输出功率最佳控制

讨论了内嵌式永磁同步变速风力发电系统输出功率最大的控制方法.为了从风中获得的功率最大,对IPMSG采用最大功率点跟踪(MPTT)控制,根据发电机速度来控制发电机的转矩.同时控制IPMSG电流矢量以降低发电机损耗,使输出功率最大.电压极限时使用弱磁控制.在高速区域,变换器控制从正弦PWM控制转换到六脉冲方波运行以增加输出功率.试验结果证明了该控制方法的效果.     

带有源缓冲的单级单相电流型逆变器

为了实现单级升压逆变,提出了一种带有源缓冲的单级单相电流型PWM逆变器,及其状态量限定下的输出电压反馈复合单周期控制策略,并对构成这种逆变器的电路拓扑、控制策略、关键电路参数设计、系统建模和仿真等进行了深入分析和研究,获得了重要结论。该逆变器电路拓扑主要由储能电感、有源缓冲电路、电流型单相逆变桥构成,存在三种工作模式和四种电路模态,通过三种工作模式的灵活切换达到限定储能电感电流和缓冲电容电压等状态量的目的,通过前馈储能电感电流和反馈输出电压的复合单周期控制实现输出正弦电压的稳定。1 kVA 100 V DC/220 V 50 Hz AC逆变器的原理实验结果表明,所提出逆变器能实现单级升压逆变,具有输出电压波形质量高、负载适应能力强和动态性能好的优点。     

基于电感辨识的电流解耦算法在内置式永磁同步电机弱磁控制中的应用

电流耦合效应在内置式永磁同步电机的弱磁高速运行中尤为突出,造成了较大的电流跟踪误差,导致转矩输出性能变坏。提出基于电感辨识的电流解耦算法,采用带遗忘因子的递推最小二乘法对电感参数进行在线辨识,并将辨识的结果应用到基于电压前馈补偿的电流解耦算法中,既实现了电流的完全解耦,也提高了系统对电感参数变化的鲁棒性。仿真和实验结果表明,所提算法在弱磁区能够获得较好的电流控制效果,使实际电流能快速准确地跟踪给定电流,提高了转矩输出能力,增强了系统的动态性能。     

基于微分平坦理论的双有源桥式变换器的单移相控制

针对双有源桥式(Dual Active Bridge,DAB)变换器系统受到扰动时动态响应速度慢,基于微分平坦理论,结合单移相控制,提出了一种平坦控制策略。设计DAB变换器平坦控制系统,包括前馈控制和非线性误差反馈控制两部分:前馈控制利用期望输出来规划状态变量轨迹;非线性误差反馈对平坦输出进行校正,消除误差。证明了平坦控制的稳定性,最后在仿真平台上分别对DAB变换器平坦控制和PI控制进行仿真,结果表明:在DAB变换器输出电压给定值改变、输入电压波动以及负载突变时,平坦控制策略下DAB系统可以更快达到输出稳定,系统具有更好的动态性能。