电力电子换流器的惯性与稳定性分析

Inertia and Stability Analysis of Power Electronic Converter

针对电力电子换流器引起电力系统振荡问题,该文以双馈风机转子侧换流器为例,推导换流器件的惯性表达式并解释其惯性的物理意义,同时将其与电力系统的传统惯性:转子的转动惯量和电感电容的电磁惯性进行类比,得到了描述电力系统惯性元件的统一微分方程式,进而根据微分方程推导出换流器的失稳判据。最后通过PSCAD/EMDTC仿真验证所求结论。所提出电力电子换流器的惯性为研究电力电子化电力系统稳定性问题,提供了一种新的求解思路。

In order to solve the problem of power system oscillation caused by power electronic converter,this paper took the rotor-side converter of doubly-fed induction generator as an example,derived the inertia expression of the converter and explanation of physical meaning of inertia,meanwhile compared it with the traditional inertia of power system:rotor inertia and electromagnetic inertia of inductance and capacitance,and a unified differential equation describing the inertial elements of power system was obtained.At the same time,the criterion of converter instability was deduced according to the differential equation.Finally,the conclusions were verified by PSCAD/EMDTC simulation.The inertia of power electronic converter proposed in this paper provides a new idea for studying the stability of power electronized power systems.