基于故障行波差异性的柔性直流输电线路纵联保护OA北大核心CSTPCD

Flexible HVDC transmission is of great significance to solve the problem of long-distance consumption of large-scale new energy,and its traveling wave protection is the key to ensuring system safety.However,the existing traveling wave amplitude comparison protection is not rigorous in analyzing the relationship on traveling wave amplitude,and the traveling wave reflection relationship is only valid in the complex frequency domain.If this relationship is extended to the time domain,it may affect the protection action performance and bury hidden dangers for the system safety.To solve this problem,this paper first theoretically analyzes the shortcomings of the existing traveling wave amplitude comparison protection,and verifies the time period when the amplitude of the forward traveling wave is greater than that of the backward traveling wave.In order to reveal the difference of traveling waves,the polarity of voltage backward traveling wave and current traveling wave is quantitatively analyzed,and then a voltage traveling wave fault identification criterion using multi-point mean is proposed.A large number of simulation results indicate that the proposed protection is not affected by the fault resistance,and it can quickly and reliably discriminate internal fault from external faults,as well as has strong sensitivity and anti-interference ability.