An Enhanced Instantaneous Calculation Method of Commutation Voltage Magnitude for Predicting CF in HVDC System

Commutation failure (CF) is one of the most common issue in traditional high voltage direct current (HVDC) transmission system. It will threat the safe and stable operation of the system. Therefore, accurate and fast prediction of CF is a necessary premise to suppress commutation failure. One of the methods for predicting CF is the critical voltage prediction method. However, it has some problems such as slow speed, single sampling point and complex control. This paper proposes an enhanced instantaneous calculation method of communication voltage magnitude by fitting. The proposed considers multiple time quantities, improves the prediction speed and accuracy of the traditional method, and has more engineering significance. Finally, the proposed method is verified in the standard model of CIGRE HVDC transmission system and compared with the widely-used method. The accuracy and rapidity of the proposed method are proved by simulation results.