Hardware-in-the-Loop Simulation of Grid Connected Modular Multilevel Converter Using Real Time Simulators

The process of designing and controlling modular multilevel converter (MMC) poses numerous challenges.So, hardware-in-the-loop (HIL) simulation and transient analysis are necessary to test the efficacy and reliability of MMC in different operational conditions.This paper presents transient analysis of MMC using MATLAB/Simulink, and results are verified using HIL simulation to validate the performance of decoupled current and circulating current controllers in real-time (RT).The decoupled current control enables the independent control of real and reactive power in AC system, and circulating current control minimizes the circulating currents in MMC phase-legs.The transient analysis is performed on the study system with a rating of 1000 MVA, 220 kV in MATLAB/Simulink.The analysis is carried out for a step perturbation of 100 MW in the real power and 2.0 kA in reactive current references, and results show the satisfactory responses with MMC controllers.The simulation results are validated with HIL simulation of MMC using two RT simulators.The HIL simulation results show the satisfactory responses with closely matching responses to MATLAB/Simulink results.