高速低载频比下电流型逆变器有源阻尼策略研究

Research on active damping scheme for current source inverter at high speed and low carrier ratio

针对高速低载频比下数字控制电流型逆变器谐振尖峰抑制的问题,通过对电流环复系数传递函数的频域分析,比较了反馈型有源阻尼策略和陷波器型有源阻尼策略受控制延迟的影响,得出了电容电压反馈有源阻尼策略在时间延迟影响下会出现电压反馈环失稳的结论,并提出了带角度误差补偿的分段陷波器有源阻尼策略。该方法解决了谐振尖峰问题,同时补偿了角度误差和谐振频率随转速变化引起的电流环性能下降。最后,搭建了仿真及实验平台,对数字控制电流型逆变器的电流环动稳态性能进行实验,实验结果表明,反馈型有源阻尼策略会造成电流环失稳,不适合针对高速样机设计的电流型逆变器驱动系统;而带角度误差补偿的分段陷波器能够实现全速域鲁棒控制,验证了对高速低载频比下电流型逆变器有源阻尼策略的分析。

To address the issue of resonance peak suppression of digitally controlled current source inverter under high speed and low carrier frequency ratio,frequency domain analysis of complex coefficient transfer function of current loop is carried out,the influence of control delay on feedback active damping strategy and notch active damping strategy is compared.It is concluded that the voltage feedback loop will lose stability under the influence of time delay.The active damping strategy of segmented notch filter with angle error compensation is proposed.This method not only solves the problem of resonance peak,but also compensates the performance degradation of current loop caused by angle error and vibration of resonant frequency with speed.Finally,simulation and experimental platform was built to verify the dynamic and steady-state performance of the current loop of the digitally controlled current source inverter.The experiment shows that the feedback active damping strategy will cause the instability of the current loop and is not suitable for the current source inverter drive system designed for the high-speed prototype.The segmented notch filter with angle error compensation can achieve full speed domain robust control,which verifies the analysis of active damping strategy of current source inverter under high speed and low carrier frequency ratio.