多台微电网逆变器并联的改进软件锁相技术

Improved software phase-locked technique with multiple micro-grid inverters in parallel

在多台无互连线逆变器构成的微电网系统中,为了防止环流,必须准确、快速的检测出逆变器输出电压的相位。在逆变器输出电压发生畸变或不对称时,传统锁相技术受到高次谐波和负序电压分量的影响,导致频率振荡,相位检测不准确。提出了一种基于降阶谐振(ROR)级联二阶广义积分(SOGI)的改进软件锁相模型,通过ROR和SOGI能有效地从基波电压中消除高次谐波、提取正序分量,达到响应迅速、波动小、相位准确的目标。基于Matlab/Simulink搭建仿真模型,验证了该方法的可行性。

In the micro-grid system with multiple non-interconnection inverters , it is necessary to detect the output voltage phase of the inverters accurately and quickly in order to avoid circular current.When distortion or asymmetry of the inverters’ output voltage occur, the traditional phase-locked loop technology will lead to oscillation frequency and inaccurate phase detection due to the influence of higher harmonics and negative sequence voltage components.This paper put forward an improved software phase-locked loop model based on Reduced Order Resonant （ ROR） combined with Second Order Generalized Integral （SOGI）.By using this technique, higher harmonics could be effectively elim-inated from the fundamental voltage and the positive sequence components could be extracted to achieve the purposes of quick response, small fluctuation and accurate phase.The simulation model based on Matlab/Simulink was con-structed and the feasibility of the method was verified.