Method and device for calculating overvoltage stage of direct-current blocking sending-end power grid by considering influence of phase modifier

Abstract

The invention provides a method and device for calculating the overvoltage stage of a direct-current blocking sending-end power grid by considering the influence of a phase modifier, wherein the method comprises the steps: step 1, judging whether a power grid fault is a receiving-end alternating-current system fault or a direct-current system fault or not according to direct-current control protection information, and executing the step 2 if the receiving-end alternating-current system fault exists, and executing the step 3 if the direct-current system fault exists; step 2, determining whethera stability device is switched off or not according to the stability device switching time, and determining a before-switching-off overvoltage calculation model and an after-switching-off overvoltagecalculation model of the stability device after direct-current locking caused by the receiving-end alternating-current system fault; and step 3, determining whether the stability device is switched off or not according to the switching-off time of the stability device, and determining a before-switching-off overvoltage calculation model and a after-switching-off overvoltage calculation model of the stability device after direct current locking caused by the direct-current system fault. Theoretical analysis of the sending end overvoltage under the direct-current blocking working condition is achieved, and a guiding effect is provided for sending end power grid structure optimization and operation mode adjustment.

Description

Technical field[0001]The invention relates to the technical field of power systems, in particular to a method and device for calculating an overvoltage stage of a DC blocking transmission end power grid considering the influence of a power adjustment camera.Background technique[0002]With the continuous completion and commissioning of DC projects in my country, the problem of "strong direct and weak alternating current" of power grid companies has become increasingly prominent, and higher demands have been placed on dynamic reactive power support of the power grid. To this end, the State Grid Corporation of China has built a number of large-scale tuning cameras at the UHV converter station to improve the system voltage stability level. For the sending-end power grid, UHV large-capacity DC blocking may cause transient overvoltage problems in the sending-end AC power grid, which may cause large-scale disconnection of wind turbines at the sending-end. The access of the new generation of...

AI Technical Summary

Problems solved by technology

For the sending-end power grid, the UHV large-capacity DC block may cause the transient overvoltage problem of the sending-end AC power grid, which may lead to large-scale off-grid of sending-end wind turbines

The access of a new generation of condensers may effectively suppress the overvoltage level at the sending end, but the existing research on its impact on the overvoltage at the sending end lacks relevant analysis, especially when the safety control system cut-off and DC blocking at the sending end occur at the same time, the Multiple overvoltage phenomena may occur, and it is urgent to evaluate the research of the regulator on the stable overvoltage level of the sending end, so as to provide guidance for the configuration of the reactive power compensation device of the sending end power grid and the calculation of the system operation mode.

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