A Feasible Region Analysis Method for Continuous Commutation Failure in HVDC

In order to mitigate continuous commutation failure that often occurs in High Voltage Direct Current (HVDC) systems, the concept of the feasible region of continuous commutation is proposed combined with the principle of commutation failure and the feasible region theory, which can be used as a criterion for continuous commutation failure. Through the analysis of the fault transient process and DC control system, the continuous commutation failure is predicted. Based on this, the feasible region of continuous commutation in the pre-fault operating parameter space of HVDC system is established. According to the positional relationship between the current operating point and the feasible region of continuous commutation, control strategy can be formed to provide help for operators in operation parameter selection and mitigation of continuous commutation failure. In the end of the paper, the validity of the proposed theory is verified by means of simulation carried out on the PSCAD/EMTDC platform.