基于移相变压器的直驱风机次同步振荡抑制

Subsynchronous Oscillation Mitigation of Permanent Magnet Synchronous Generator Based on Phase Shifting Transformer

针对直驱风机接入弱交流电网引发严重的次同步振荡问题,建立了并网系统的小信号模型。首先,利用特征值分析法得出系统的次同步振荡模态,通过参与因子分析揭示了直驱风机接入弱交流电网的次同步振荡机理;然后,在分析移相变压器应用原理的基础上,提出了基于移相变压器可实现直驱风机并网系统负电阻补偿的次同步振荡抑制方法;最后,在Matlab/Simulink上搭建了基于移相变压器的直驱风机并网系统仿真模型,通过改变系统运行参数验证了次同步振荡抑制方法的适应性。

Aimed at the serious subsynchronous oscillation problem caused by a permanent magnet synchronous generator(PMSG)connected to weak AC power grid,a small signal model of the grid-connected system is established.First,the subsynchronous oscillation(SSO)modes of the system are obtained by means of the eigenvalue analysis method,and the SSO mechanism of PMSG connected to weak AC power grid is revealed through the participation factor analysis.Then,based on the analysis of the application principle for phase shifting transformer(PST),a SSO mitigation method based on PST is put forward,which can realize negative resistance compensation of PMSG connected to power grid.Finally,a simulation model of the grid-connected system based on PST is built in Matlab/Simulink,and the adaptability of the proposed SSO mitigation method is verified by changing the system’s operation parameters.