Abstract：The control strategy of the converter station is extremely important in the DC grid based on modular multilevel converter(MMC). Aiming at the shortcomings of current control methods, a new control strategy is proposed for the converter stations, improving controller respond speed and adjusting speed. In the novel control strategy, the improved proportional integral(PI) control is introduced into the outer loop controller, and the voltage droop control is combined for active power control, which can not only deal with the requirement of one slave station switching to the master station quickly when the master station loses due to faults, but also satisfy the requirements of active power balance and DC-side voltage stability during active power or DC voltage fluctuation. Based on the PSCAD/EMTDC software, a four-terminal MMC based DC grid model is built to simulate different conditions. The results show that the proposed control strategy is correct and effective.
标题：基于MMC的直流电网换流站控制策略
title:Control Strategy for Converter Station in DC Grid Based on MMC
作者：李慧, 范新桥
authors:LI Hui, FAN Xinqiao
关键词：模块化多电平换流器(MMC),柔性直流电网,电压下垂控制,主从控制,
keywords:modular multilevel converter(MMC),flexible direct current grid,voltage droop control,master-slave control,
