Phase modifier field loss protection method and system based on multi-dimensional electrical quantity

Abstract

The invention discloses a phase modifier field loss protection method and system based on multi-dimensional electrical quantity, and belongs to the technical field of power systems and automation thereof. The method comprises the steps: determining rated parameters of a phase modifier, and collecting electrical quantity information of the phase modifier in the current operation state; establishing a field loss protection starting criterion and a field loss protection action criterion according to the rated parameters; determining whether the electrical quantity information of the phase modifier in the current motion state meets the excitation loss protection starting criterion or not, and if so, starting excitation loss protection; and after the field loss protection is started, if the electrical quantity information of the phase modifier in the current motion state meets the field loss protection action criterion within the preset delay threshold, performing field loss protection action. According to the method, starting is carried out through the reactive variable quantity, the total field loss fault and the partial field loss fault of the phase modifier are recognized through the relative change of the generator terminal voltage and the steady-state relation between the generator terminal voltage and the exciting voltage and the reactive power, and the field loss protection action is started.

Description

technical field [0001] The present invention relates to the technical field of electric power system and automation thereof, and more specifically, relates to a method and system for demagnetization protection of a condenser based on multi-dimensional electrical quantities. Background technique [0002] The condenser can provide reactive power support for the sending and receiving ends of the DC system, improve the dynamic reactive power reserve, and effectively solve the problem of transient overvoltage caused by commutation failure. At present, the State Grid Corporation has fully started the construction of the condenser project of the UHV DC converter station. [0003] The excitation system of the condenser provides excitation current for the excitation coil, so as to provide the condenser unit with the synchronous rotating magnetic field required to establish the machine terminal voltage and the reactive power of the condenser unit. The excitation system of the condens...

AI Technical Summary

Problems solved by technology

However, after research and analysis, it is found that the original loss-of-excitation protection is not sensitive enough to partial loss-of-excitation faults, and the I-stage of the original loss-of-excitation protection operates in phase advance under the condition that the controller is controlled by AVC and the machine terminal voltage is at the action boundary. There is a risk of misoperation in the event of a fault disturbance

In order to prevent this risk, most of the condensers currently in operation have withdrawn from the loss-of-excitation protection section I. As a result, the protection cannot act in time when a partial loss of excitation occurs in the excitation system of the condenser, which may be detrimental to the system operation.

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