基于改进型同步逆变器技术的微电网变换器

摘要

针对风光储等分布式电源接入配电网(微电网)造成系统“低惯量、欠阻尼”进而导致的稳定性问题,对模拟同步发电机外特性的虚拟同步发电机(Virtual Synchronous Generator,VSG)技术进行了研究.在下垂控制的基础上,通过对电磁方程和机械方程的设计,使得电力电子装置的变换器具有同步发电机的转子转动惯量和阻尼特性,同时具备一次调频调压的能力.同时,对VSG输出功率的动态和稳态特性的矛盾性,提出一种改进型VSG方案.最后,利用MATLAB/Simulink仿真工具,验证所提模型和控制策略的正确性与有效性.%Aimed at the stability problem of distribution network (micro-grid) caused by "low inertia and underdamping",while distributed power integrated in,such as wind energy,photovoltaic,energy storage and so on,virtual synchronous generator (VSG) simulated synchronous generator characteristic had been studied.Based on the droop control,the converter power electronic device would have synchronous generator rotor inertia and damping characteristics by the design of the electromagnetic equation and the mechanical equation,so it had the capability of primary frequency and voltage regulation.In view of the contradiction between dynamic and steady state characteristics of VSG output power,an improved VSG scheme was proposed.Finally,the correctness and effectiveness of the proposed model and control strategy were verified by MATLAB/Simulink simulation.