不平衡及非线性负载下的三相逆变器控制方法

A Control Method for Three-phase Inverters with Unbalanced and Nonlinear Loads

围绕孤立微电网中不平衡及非线性负载下三相逆变器的控制问题,提出一种包含基波电压跟踪、谐波电压抑制、有源阻尼和输出电流限制功能的逆变器控制方法。针对逆变器运行系统建立了传递函数模型,并分析主要硬件回路及控制系统参数对系统稳定性的影响。通过仿真和实验,验证系统传递函数模型的准确性,结果表明:所提出的逆变器控制方法能够在不平衡和非线性负载条件下保证逆变器端电压质量,实现不平衡过载时的限流运行,并具有较好的动态响应特性。

Focusing on three-phase inverter control with unbalanced and nonlinear loads in islanded microgrids,an inverter control method including fundamental voltage tracking,harmonic voltage suppression,active damping and output current limiting is proposed. A transfer function model for the inverter operation system is established,and the influence of main hardware circuit and control system parameters on the system stability is analyzed. Simulations and experiments verify the accuracy of the system transfer function model,indicating that the proposed inverter control method can ensure the voltage quality on the inverter side under unbalanced and nonlinear load conditions and achieve current-limiting operation under unbalanced overload conditions with excellent dynamic response characteristics.