分布式发电系统中四桥臂逆变器控制策略

摘要

A grid formed with distribution generators is a weak grid, and supplies power energy to all sorts of loads. According to characteristics of distribution generation grid and status of loads, a four-leg inverter has been used as an interface device for forming distribution generation system. A decomposing sequence method with band pass filter has been proposed, and a decomposing sequence control algorithm has been applied to control the four-leg inverter. The parameters of a current controller and a voltage controller have been tuned. Static-state performance of a four-leg inverter controlled by a double loop control method in synchronous rotor frame is poor, and this problem has been solved. Associated control scheme for the distributed generation system based on a four-leg inverter has been designed and constructed so as to confirm the feasibility of the proposed method. Control system static-state performance of a four-leg inverter has been thoroughly improved, and the operation ability of the distributed generation system under the unbalanced loads has been greatly enhanced.%由分布式电源构成的电网是弱电网,并且给各类负载供电,针对这类电网的特点和电网中负载的状况,本文提出采用四桥臂逆变器作为分布式发电系统的并网接口,提出基于带通滤波器的分序方法和分序控制策略,解决了四桥臂逆变器基于单同步旋转坐标的双环控制系统稳态性能差的问题,在此基础上搭建了实验平台,实验结果表明,本文提出的方案彻底改善了逆变器控制系统的稳态特性,极大地提高了分布式发电系统在不对称负载下的运行能力.