UHV hybrid direct current system receiving end VSC fault exit method, equipment and medium

Abstract

The invention discloses a VSC fault exit method, equipment and medium of a UHV hybrid direct current system receiving end, which blocks the faulty receiving end inverter station and generates a fault signal by receiving an emergency shutdown command sent by the faulty receiving end inverter station ; Send the fault signal to the non-faulty inverter station and the rectifier station, so that the non-faulty inverter station enters into the negative voltage control mode, and the rectifier station performs phase-shifting operation; when the current flowing through the DC switch connected to the fault receiving inverter station meets When the opening condition is preset, control the DC switch to open and isolate the inverter station at the fault receiving end; when the DC switch is opened, control the non-faulty inverter station to establish a DC voltage at a predetermined speed, and when the DC voltage returns to the preset When the first voltage value is reached, control the rectifier station to release the phase shift to quickly recover the DC power; the present invention can avoid misjudgment when the DC switch fails to open or other low-voltage and low-current conditions, and avoid the process of exiting the faulty converter station Damage to equipment due to overstress.

Description

technical field [0001] The invention relates to the technical field of direct current transmission, in particular to a method, equipment and medium for withdrawing from VSC failure at a receiving end of an ultra-high voltage hybrid direct current system. Background technique [0002] Multi-terminal DC transmission is the trend of future power system development. Among them, the fault exit technology of a certain converter station is one of the key technologies for its development. The main technical difficulty lies in quickly isolating the faulty converter station and maintaining the continuous operation of the non-faulty converter station. Especially for the hybrid multi-terminal DC system based on LCC and VSC, how to coordinate the control strategies of LCC and VSC is a difficult and complicated problem when isolating the faulty station and restoring the power of the non-faulty station. [0003] At present, the methods of isolating faulty converter stations in multi-termi...

AI Technical Summary

Problems solved by technology

[0004] However, if the above-mentioned second exit strategy of the faulty converter station does not fully set the opening conditions of the HSS according to the technical level of the current DC switch HSS, it will cause the HSS opening time to be too long or even open overtime and fail to exit the station , or prone to misjudgment in other low-voltage and low-current situations

In addition, if the timing of the exit of the faulty converter station is improper, it will cause overstress during the exit process, such as overvoltage, overcurrent, and damage to devices or equipment.

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