Cooperative setting method and device for low excitation limit and loss of excitation protection of salient pole machines

Abstract

The present invention provides a coordinative setting method and device for low excitation limitation and loss-of-excitation protection of a salient-pole machine to ensure reasonable cooperation between low-excitation limitation and loss-of-excitation protection of a salient-pole machine. The method includes: changing the low-excitation limit curve from Transform the power plane to the impedance plane, and compare the low-excitation limit curve transformed to the impedance plane with the static stability limit curve of the salient pole machine in the positive semi-axis area of ​​the R-axis; when the low-excitation limit curve of the positive semi-axis of the R-axis When the limit curve is stable, readjust the low excitation limit curve. The technical scheme of the invention ensures the reasonable cooperation of salient pole machine low excitation limitation and loss of excitation protection, which is beneficial to provide technical basis for power dispatching production management, fully exerts generator control and protection functions, improves network source coordination level, and realizes energy safety and high efficiency operation to ensure the safe and economical delivery of electricity.

Description

technical field [0001] The invention relates to the technical field of generators, in particular to a method and device for coordinating setting of low-excitation limitation and loss-of-excitation protection of a salient-pole machine. Background technique [0002] Motor loss of excitation refers to the sudden partial or complete loss of excitation of the generator, which is a common fault in the excitation circuit of the generator. Especially for large-scale generator sets, the excitation system has many links and complex structure, which increases the probability of loss-of-excitation faults. Statistics show that loss-of-excitation faults account for more than 60% of the total generator faults. After the generator is demagnetized, it will transition to asynchronous operation, the rotor will slip, the stator current will increase, the stator voltage will decrease, the active power will decrease, and the reactive power will reverse and increase; the differential frequency cur...

AI Technical Summary

Problems solved by technology

[0011] It can be seen that although the existing literature has discussed the cooperation between low-excitation limitation and loss-of-excitation protection, it generally only analyzes specific experiments and lacks a general method. The relation of low excitation limit does not take into account the particularity that the static stability limit curve of a salient pole machine is a drop-shaped curve

Images