阻抗不匹配引起的逆变器-IPMSM系统直流侧振荡抑制方法对比

摘要

随着逆变器-内置式永磁同步电机(IPMS M)系统输出功率的增加,其输入阻抗与直流供电端LC滤波环节输出阻抗不再匹配,引发逆变器直流侧电压、电流振荡.针对IPMSM,推导了逆变器-电机系统采样双电流调节器控制时的输入导纳模型,用于系统稳定性分析.参考异步电机系统振荡抑制方法,根据IPMSM转矩公式,提出直轴电流补偿法和直轴电压补偿法两种振荡抑制办法.结合交轴电流补偿法、交轴电压补偿法思想,推导了分别加入四种振荡抑制方法后的逆变器-IPMSM系统输入阻抗,采用奈奎斯特判据,分析各振荡抑制方法的有效性.依据电机模型与控制系统模型,分析不同方法的优劣,提出电压补偿法优于电流补偿法、交轴补偿法优于直轴补偿法的观点.通过实验验证了各振荡抑制方法的有效性和交轴电压补偿法的优势.%Due to mismatch of output impedances of LC and input impedance of inverter-motor system,inverter-IPMSM(Interior Permanent Magnet Synchronous Motor) system will lose stability with a large output power.That means DC current and voltage oscillation.For stability analysis,input admittance formulas of inverter-IPMSM system under double current control are derived.Reference induction motor system oscillation suppression methods and combined with IPMSM torque formula,two oscillation suppression methods based on daxis voltage and current command separately are proposed.These two methods are compared with the existing oscillation suppression methods based on q-axis voltage and current command separately.Input admittance formulas of inverter-IPMSM system with oscillation suppression are derived.The Nyquist theorem is adopted to verify the validity of the oscillation suppression methods.According to the motor model and control system model,the oscillation suppression method based on q-axis voltage is considered to be the best.Experimental verification of the viewpoints is carried out.