Mechanism analysis and suppression method of high frequency harmonic resonance in VSC-HVDC.

• Mechanism of high frequency harmonic resonance of Luxi VSC-HVDC project is analyzed. • Time delay and system impedance will influence the high frequency harmonic resonance. • A method to suppress the high frequency harmonic resonance is proposed. This paper introduces the basic situation of high frequency harmonic resonance in Guangxi on April 10, 2017, which is based on the Luxi back-to-back voltage source converter based high voltage direct current transmission (VSC-HVDC) project in China. Firstly, the harmonic amplification mechanism and its key links in the event are analyzed in detail and verified by simulation. Secondly, the relationship among high frequency harmonic resonance, voltage feedforward control loop and system harmonic impedance is obtained, and the formulas among voltage feedforward control parameters, system harmonic impedance and high frequency harmonic resonance frequency amplitude are deduced. Then, a method to suppress high frequency harmonic resonance by adding a reasonably filter to the voltage feedforward control loop is proposed. Finally, the effectiveness of the proposed method in this paper is verified by simulation and field operation. [ABSTRACT FROM AUTHOR]