OVERVOLTAGE SUPPRESSION OF MMC-HVDC OFFSHORE WIND FARM UNDER VALVE-SIDE SPG FAULT BASED ON MODEL PREDICTIVE CONTROL

Abstract

In the midst of the world's rapidly accelerating energy transition, offshore wind power is one of the forefront technologies to be developed and implemented. With the advantage of having an extensive coastline, the potential for offshore wind power systems in Vietnam is enormous. To ensure a reliable and efficient power delivery system, modular multilevel converter high-voltage direct current (MMC-HVDC) transmission systems are being increasingly preferred. Considering onshore converter stations, occurrence of single-phase to ground (SPG) faults can cause DC line overvoltage, which triggers circuit breakers and interrupts the power transmission process. This paper proposes a method to suppress the overvoltage based on a model predictive control (MPC) controller for the onshore converter station. The simulated results are directly compared with a previously proposed zero-sequence voltage control method and show the superiority of the MPC model on controlling the DC line and the sub-modules’ voltages. Simulations were performed using Simulink/MATLAB software.