A High Voltage DC Commutation Failure Judgment Method Considering DC Current Variation

Abstract

The invention discloses a high voltage direct current commutation failure judging method considering the change of direct current. The method includes: step 1: respectively obtaining the expression of the turn-off angle of the inverter and the expression of the direct current; step 2: calculating the turn-off angle under the single-phase ground fault and the turn-off angle under the three-phase short-circuit fault respectively; Step 3: If only one phase voltage changes after a fault occurs, go to step 4; if all three phase voltages change after a fault occurs, go to step 5; When the inverter has the minimum turn-off angle of commutation failure, it is judged as commutation failure; otherwise, it is judged as commutation success; Step 5: When the turn-off angle under three-phase short-circuit fault is less than or equal to that of inverter, commutation failure occurs When the minimum turn-off angle of , it is judged as commutation failure; otherwise, it is judged as commutation success. The high-voltage direct current commutation failure discrimination method provided by the present invention can accurately identify the commutation failure risk.

Description

technical field [0001] The invention relates to the technical field of power system operation and control, in particular to a method for judging commutation failure of high-voltage direct current considering changes in direct current. Background technique [0002] Due to its advantages of long distance, large capacity, low loss, quick and flexible power regulation, etc., HVDC transmission is widely used in AC asynchronous networking and long-distance large-capacity power transmission all over the world. my country's energy and load centers present a reverse distribution trend, so HVDC transmission has an extremely broad application background in my country. [0003] Commutation failure is one of the most common faults in HVDC transmission systems, which will cause instantaneous interruption of system transmission power. At the same time, if it is not properly controlled, it will cause continuous commutation failures, which will eventually lead to DC system blocking and affec...

AI Technical Summary

Problems solved by technology

[0003] Commutation failure is one of the most common faults in HVDC transmission systems, which will cause instantaneous interruption of system transmission power. At the same time, improper control will cause continuous commutation failures, which will eventually lead to DC system blocking, affecting the safe and stable operation of the system.

Images