LOW VOLTAGE APPARATUS ›› 2021, Vol. 0 ›› Issue (3): 68-75.doi: 10.16628/j.cnki.2095-8188.2021.03.013

• Power Quality • Previous Articles     Next Articles

Harmonic Analysis of MMC-HVDC System in Asymmetric AC Power Grid

CHEN Heyang1, GUO Feng2, YE Rong3   

  1. 1. State Grid Longyan Power Supply Company, Longyan 364000, China
    2. State Grid Quanzhou Power Supply Company, Quanzhou 362000, China
    3. State Grid Fuzhou Power Supply Company, Fuzhou 350009, China
  • Received:2020-12-27 Online:2021-03-30 Published:2021-04-14

Abstract:

When an asymmetrical fault occurs in the AC system connected to the MMC-HVDC,the AC bus voltage of the converter station is no longer balanced,and there are negative sequence components and zero sequence components,which makes the distribution of harmonic on the AC-DC side of MMC-HVDC more complicated.In order to study the transmission law of harmonic voltage and harmonic current on the AC-DC side of the system,as well as the instantaneous power fluctuations of the bridge arm in this case,this paper firstly derives theoretically based on the symmetrical component method and dynamic phasor,and then builds the simulation model in PSCAD/EMTDC.Finally,the voltage and current harmonic distribution in the steady state and the fault state are analyzed according to the simulation results,and it verifies the transmission of harmonics on the AC-DC side and the law of bridge arm power fluctuations in the asymmetric fault state which provides references for related suppression and control strategies.

Key words: asymmetric fault, MMC-HVDC, harmonic analysis, power fluctuation, negative sequence component

CLC Number: