Study on the optimization of CFPREV by adapative threshold

Commutation failure is a common fault in HVDC transmission systems. In order to reduce the risk of commutation failure, commutation failure predictive control is often configured in engineering.After detecting the fault, the criterion is triggered by a given threshold, output trigger offset angle to increase commutation margin. Because the threshold is often given in the actual project, it can only meet part of the failure conditions. For most other fault conditions, the given threshold cannot suppress the commutation failure. This paper presents an adaptive threshold selection method. By analyzing the relationship between AC bus voltage and commutation failure, an adaptive criterion is established to reduce the probability of commutation failure. In PSCAD/EMTDC, based on CIGRE Benchmark model is used for calculation and analysis. The simulation shows that the optimized threshold can suppress the commutation failure in short-circuit fault.