Diode rectifier?based hybrid high?voltage direct current converter for offshore wind farms

This paper presents a diode rectifier (DR)-based hybrid converter topology for high-voltage direct current (HVDC) transmission system with offshore wind farms (OWFs). The consists of DR and an auxiliary converter. A high conversion ratio ac/dc is designed as the converter, which can form grid voltage OWFs to achieve black-start. Under steady state, all active power output from delivered through DR. Meanwhile, able compensate reactive harmonic currents system. Comparing conventional modular multilevel (MMC), number submodules (SM) proposed significantly reduced, decreases construction cost size operation principle HVDC are introduced. Then corresponding control strategy energy balance transmission. Based on mathematic model, design method parameters proposed. Finally, feasibility verified by both simulation hardware-in-the-loop experiment results.