A New Type Real-Time Simulation Platform for Modular Multilevel Converter Based HVDC

This paper focused on a new type simulation platform. Restricted by the number of network nodes and time step, traditional all digital simulation platform is not fast enough for the modular multilevel converter Based HVDC (MMC-HVDC). This paper presented a real-time digital-analog hybrid simulation platform including 49-level MMC, described the method of calculating the proportion of the platform to the original system. The characteristics of the simulation platform were designed according to the dynamic response features of actual system and its converter was simulated by analog devices. Depending on the special communication interface the simulation platform can also be used to verify the function of converter valve based controller (VBC) used in the Nanhui MMC-HVDC project. Experiment results of severe bipolar short circuit fault are compared with that by off-line digital simulation platform PSCAD, showing that most of the dynamic characteristics are basically identical. Thus the simulation system is verified available for optimization of dynamic parameters and real-time test of control system in planning of MMC-HVDC system.