低开关频率下电励磁同步电机的MATLAB仿真研究

MATLAB Simulation for Electrically Excited Synchronous Motors with Low Switching Frequency

功率器件的开关损耗是大功率变频调速系统的主要能耗之一,低开关频率运行是改善能耗问题的有效措施,但会造成变频器输出谐波畸变严重、控制效果不佳的问题。以电励磁同步电机为对象,研究了一种适用于低开关频率运行的特定谐波消除的脉冲调制策略,给出了基于MATLAB软件的开关角求解算法。针对该策略特定谐波消除、整体谐波能量迁移的特点,提出了一种简单LC电路进行谐波能量滤除的方法。基于MATLAB仿真环境搭建了电励磁同步电机的控制系统,验证了所设计方案的有效性与可行性。

Switch loss is one of the main energy consumption of the high power transmission system, while the low switching frequency approach is an effective way to improve above issues. However, it will result in a severe harmonic distortion and further affect the control performance. A selective harmonic elimination pulse width modulation（SHEPWM） strategy has been used to ensure the low energy consumption operation of a diode clamped three-level converter whose load is a high power electrically excited synchronous motors（EESM）. For the SHEPWM＇s characteristics of specific harmonic elimination and harmonic energy moving on the high order, a simple high-pass harmonic filter is designed. The whole control system of the EESM is established based on the MATLAB/Simulink to verify the effectiveness of the designed strategy.