为使多功能并网逆变器能够在传输有功功率的同时实现电能质量治理的功能,提出一种基于改进型重复控制算法的内环控制器设计方法。为提高内环控制系统的动态响应能力,改进型重复控制器采用比例控制器与传统重复控制器并联的形式。通过对内环传递函数的分析,提出等效被控对象的概念,将并联的比例控制器等效成系统被控对象的一部分,由此分析了内环系统的稳定性、稳态误差以及动态性能,并在此基础上对重复控制器的参数进行设计。最后,通过仿真和实验验证了所设计的内环控制器能够实现对参考电流的快速精确跟踪,基于改进型重复控制算法的多功能并网逆变器具有优良的电能质量治理能力。
The multi-functional grid-connected inverter can improve power quality while used to transmit active power.To make the inner loop controller track reference current fast and accurately,a new design method of inner loop controller based on the modified repetitive control algorithm is proposed.The modified repetitive controller is composed of a proportional controller and a traditional repetitive controller connected in parallel,and an equivalent controlled object is used for analyzing the stability,steady state error and dynamic performance of the inner loop control system and designing the parameters of the modified repetitive controller.Finally,simulations and experiment results show that the proposed inner loop controller can track reference current fast and accurately,and multi-functional grid-connected inverter based on the modified repetitive control algorithm has an excellent ability to enhance power quality.