Method of limiting low excitation

Abstract

Method of limiting low excitation, calculating measured impedance of generator terminal by detecting generator terminal voltage and terminal current, when the measured impedance entering low excitation limited impedance circle, the low excitation limits prolong action of 40-60 ms on amplifying excitation current to maintain generator in stable operation situation, the low excitation limited impedance impedance circle covers static stable loss of excitation protection impedance circle to implement seamless connection with generator loss of excitation protection impedance criterion, and preventthe generator in low excitation operation, the low excitation is limited lagging behind the loss of excitation protection action, thereby generator error jump is caused. The invention is used in generator excitation regulation, comparing with former low extitation limiting method, the invention is more visualized, the loss of excitation protection and low excitation are all R-X impedance plane coordinate description and easy to cooperate with each other.

Description

Technical field [0001] The invention relates to a low excitation limit method based on a static stability impedance circle, which realizes seamless coordination with the generator loss-of-excitation protection impedance criterion and prevents the low-excitation limit from lagging behind the loss-of-excitation protection action when the generator is running under low excitation, resulting in power generation Machine loss of magnetism protection trips by mistake. Background technique [0002] In order to prevent insufficient excitation of the generator to affect the safe operation of the generator, a low excitation limit is set in the excitation regulator to limit the minimum value of the excitation current. The previous low excitation limit methods mainly include P-Q plane linear low excitation limit methods, such as figure 1 , P-Q plane broken line type low excitation limit method, such as figure 2 , And P-Q plane simulation statically stable circular low excitation limit method...

AI Technical Summary

Problems solved by technology

The domestic literature "Analysis of Coordination of Low Excitation Limitation and Loss of Excitation Protection" (Hao Xueping, North China Electric Power Technology, No. 07, 2005) proposed that both the low excitation limitation and the loss of excitation protection be attributed to the R-X impedance circular plane Comparative analysis method, but does not directly use the low excitation limit method of the R-X impedance circular plane, that is, it still needs to coordinate the different coordinates used, and does not solve the fundamental problem

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