基于复矢量调节器的低开关频率同步电机控制

为提高中压大功率变频器出力,需要降低器件的开关频率,这会导致脉宽调制(pulse width modulation,PWM)响应滞后,影响定子电流磁化分量和转矩分量间的动态解耦效果。受低开关频率制约,常规的比例积分(proportionalintegral,PI)及前馈补偿PI调节器难以满足系统要求。为改善这一问题,在对电励磁同步电机进行复矢量信号建模的基础上,充分考虑信号采样的延迟和开关器件在低开关频率下的惯性特性,结合经典的控制理论分析方法,设计了一种新颖的基于复矢量的电流调节器。该调节器能在低开关频率下实现对定子电流磁化分量和转矩分量的有效解耦,动稳态性能良好。Matlab仿真及DSP实验验证了该调节器的有效性与可行性。

A Novel Complex State Current Controller for Synchronous Motor at Very Low Switching Frequency

High-power pulse width modulation(PWM) inverters for medium voltage applications operate at low switching frequency to keep the dynamic losses at permitted level.Also the sampling rate of the digital signal processing system is then low,which introduces considerable signal delays.These have adverse effects on the dynamics of the current control system and aggravate undesired cross-coupling between the stator current magnetization components and torque component.Due to low switching frequency,proportional integral(PI) regulator and PI with feed-forward compensation could not meet system requirements.To overcome this problem,a novel current controller with complex state variables was proposed based on the classical control tool,which also considering the delay introduced by the switching device and the time-discrete sampling.This kind of current controller with complex state variables can realize decoupling between current magnetization components and torque component as well as the perfect dynamic and steady response.The simulation and experimental results verify the availability of the novel current controller at low switching frequency.