The Operation Analysis And Solution Study For The Excitation Loss Relay Of The Generator In Large-scale Power Plant

With the development of power industry and the capacity of single generator grows, the large generator-transformer units play more important roles in power system, and the demands for higher performance of large generator protection is necessary.For synchronous generator, loss of excitation is a serious fault and the corresponding protection often refuse to operate. It's important for us to analyze the dynamic excitation-loss process precisely. In this paper, by use of theselected blocks from Power System Library in Matlab, the author sets up agenerator-infinite system and simulates the loss of excitation fault.It introduces the domestic existing partial or total loss of excitation protection criterion, analyzed the problem of existing criterion. The multianalysis used according to the asynchronous boundary setting caculation principle and according to the static stability boundary setting caculation principle and through the comparison analysis provide generator model generator protection according to the asynchronous boundary impedance setting caculation principle.This paper also introduced the constitution loss of excitation protection , the exportation logic as well as the disposition plan. Lost the excitation protection regarding the different principle generator by mistake moves carries on analyzes and proposes the improvement measure.By using the Simulink power system Simuliation module of Matlab, uses the single generator - single system and the double generator - double system model establishes the equivalent mathematical model and the module, considers the influence of transmission line, hydraulic turbine rotational speed adjustment as well as automatic excitation control system establishes simulation model includes generator , transformer, connects line, infinity system . In view of partial or total loss of excitation, the magnetism situation, according to the difference of output active power as well as the generator mark , carried on the simulation to it. and analyzed partial or total loss of excitation, the dynamic process, tcarried on the theory analysis through contrast the change of various electrical quantity .