Control method and device for inhibition of overvoltage of sending end power grid during commutation failure

Abstract

The present invention discloses a control method for inhibition of overvoltage of sending end power grid during commutation failure. The method comprises the steps of: when it is detected that a direct current system generates commutation failure, inputting a by-pass pair at an inverter side after commutation failure signals are obtained at the inverter side, and regulating parameters of the inverter side VDCOL according to a current instruction value during the commutation failure; emitting the commutation failure signals at the inverter side; after the commutation failure signals emitted bythe inverter side are received at a rectifier side, reducing the trigger angle limiting value at the rectifier side to 95 degrees, and regulating parameters of the rectifier side VDCOL according to acurrent instruction value during commutation failure; and after it is detected that the alternating voltage at the inverter side returns to normal, withdrawing the by-pass pair at the inverter side, cancelling the trigger angle limiting value at the rectifier side, and recovering setting of original parameters of the inverter side VDCOL and the rectifier side VDCOL. The problem is solved that a new energy device such as a fan is off-line due to generation of an overvoltage of the sending end power grid when the direct current system generates commutation failure.

Description

technical field [0001] The application relates to UHV DC transmission control and protection technology, in particular to a control method for suppressing the overvoltage of the sending-end power grid during commutation failure, and to a control device for suppressing the over-voltage of the sending-end power grid during commutation failure. Background technique [0002] my country's energy centers and load centers are located in the western and central eastern regions respectively, and the distribution of energy loads is extremely uneven. With the continuous growth of my country's electricity demand, the contradiction between energy and demand distribution has become increasingly prominent. Therefore, DC transmission technology has gradually exerted greater and greater advantages in large-capacity long-distance transmission. As of the end of 2018, as the ±1100kV Jiquan UHV DC transmission project with the highest voltage level and the largest capacity in the world and the ±...

AI Technical Summary

Problems solved by technology

[0003] This application provides a control method for suppressing the overvoltage of the power grid at the sending end during commutation failure, which solves the problem that the overvoltage of the power grid at the sending end occurs when the commutation fails in the DC system, which leads to the off-grid of new energy equipment such as wind turbines.

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