A method of detecting commutation failure in multi-infeed HVDC systems based on critical failure impedance boundary

摘要

A fast distinguish method to discriminate the critical commutation failure region of multi-infeed HVDC system is proposed in this paper. Based on the nodal impedance matrix and nodal voltage interaction factor (VIF), the extinction angles of convert stations under the single-phase or three-phase to ground fault happening at any bus in AC system is first calculated. If the calculated extinction angle with regard to a certain bus is greater than the critical extinction angle, the single-phase or three-phase to ground fault at that bus will cause commutation failure of the HVDC system. The critical failure impedance boundaries on topology diagram can be therefore delimited by examining every bus in the AC system. The simulation results of a two-infeed HVDC test system verifies the effectiveness and accuracy of the proposed method which detects the commutation failure of multi-infeed HVDC system based on critical failure impedance boundaries.