HIL platform design and controller verification for MMC based HVDC networks

摘要

High Voltage DC systems are gaining widespread attention due to the advances in power electronic devices and converters. MMCs are very popular nowadays in this type of application. This paper first revisits the dynamic equations of the circulating current of a MMC to incorporate a disturbance term. Based on the modified equations, a disturbance rejection controller is proposed to eliminate the double fundamental ac part of this current. In a larger scale, a platform for the offline and real time simulation of MMC based HVDC is designed. Hardware-in-the Loop (HIL) simulations are then conducted to validate the circulating current controller and a case study on the Lower Churchill project is illustrated to show the feasibility of an actual MMC implementation.