A Commutation Failure Prediction Criterion Based on Feasible Region Theory

Aiming at the problem of commutation failure often occurring in high voltage direct current (HVDC) system, the shortcomings of existing commutation failure prediction criterion applied in the commutation failure prevention control strategies are analyzed. The basic reason of commutation failure is studied in the way of mechanism. Combined with feasible region theory which is widely used in power system and many other fields, a concept of commutation feasible region is put forward in this paper which can improve the accuracy of commutation failure prediction to some extent. Both commutation feasible regions in the pre-fault and post-fault parameter spaces are described in definition. The relative parameters are analyzed in each parameter space. In order to make it more intuitive and convenient, the method for constructing the section of commutation feasible region in the control parameter space of regular HVDC system is proposed. 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.