Research on Harmonic Characteristics of UHVDC

Based on PSCAD/EMTDC, the authors build a harmonic analysis model for a bi-pole dual 12-pulse ±1000kV Ultra-High Voltage Direct Current (UHVDC) converter and the interconnected AC system. The control strategy for UHVDC employs the current margin control from CIGRE HVDC Benchmark. The AC system includes the equipments above 500kV and the equivalent circuit under 500kV. The harmonic interaction of DC and AC system and the propagation of harmonics in AC system are studied with different operation mode. Simulation results illustrate the existence of harmonic amplification. Following the guidelines on harmonic control in HVDC system, the authors suggest the harmonic filter deployment in the proposed paper.