Research on Power Modulation to Suppress Low Frequency Oscillation by Asynchronous Interconnection HVDC System

Abstract

when the Generator run in parallel through the transmission line, the relative swing between the motor rotors will occur under the disturbance. If there is insufficient damping, it will cause the occurrence of low frequency oscillation (LFO). HVDC transmission system has the advantages of fast regulation speed and high control accuracy and it can be used to suppress the LFO. In this paper, the mechanism of asynchronous interconnected HVDC transmission to suppress inter regional LFO is studied. Then the strategy of power modulation to suppress LFO is proposed. In the end, the suppression strategy is verified by simulation based on an actual power grid simulation model. The simulation results show that when LFO occurs, the proposed strategy can effectively increase the system damping, suppress the generation of LFO and improve the dynamic stability of AC/DC interconnected system.