基于傅里叶变换的有源阻尼器虚拟电阻自适应方法

Virtual Resistance Adaptive Method for Active Dampers Based on Fourier Transform

为解决虚拟电阻值固定导致的有源阻尼器工作容量大、损耗大的问题,提出基于傅里叶变换的虚拟电阻自适应控制策略。以发生谐振稳定性现象的并网逆变器为对象,分析逆变器出现谐振的原因,通过设计有源阻尼器的虚拟电阻来校正系统的稳定性,最后根据傅里叶变换提取公共耦合点谐振电压分量,动态调节虚拟电阻值,使有源阻尼器在较低容量下工作,同时为系统提供合适的阻尼。仿真实验结果表明,采用所提策略能有效抑制公共耦合点电压的谐振,同时有效降低有源阻尼器的工作容量,提高有源阻尼器解决谐振问题的能力。

In order to solve the problem of large working capacity and high loss of active damper caused by the fixed virtual resistance value,the virtual resistance adaptive control strategy based on Fourier transform is proposed.Taking the grid-connected inverter with the resonance stability as the object,the reason of resonance in the inverter is analyzed,the stability of the system is corrected by designing the virtual resistance of the active damper.Finally,the magnitude of the resonance voltage component is extracted at the common coupling point according to the Fourier transform,and the value of the virtual resistance dynamically is adjusted,so as to make the active damper work at a lower capacity and provide the suitable damping for the system at the same time.Simulation shows that the proposed strategy can effectively suppress the resonance of the voltage at the point of common coupling,effectively reduce the working capacity of the active damper at the same time,and improve the ability of the active damper to solve the resonance problem.