Method for analyzing turn-to-turn fault of generator rotor based on multiloop model

Abstract

The invention relates to a method for analyzing turn-to-turn faults of a generator rotor based on a multiloop model, belonging to the technical problem of analysis and research of asymmetric fault problems of alternating current motor windings and relay protection of power system master devices. In the invention, based on a multiloop analysis method of an alternating current motor, a voltage and flux linkage equation is listed according to actual connection conditions of all stator and rotor loops in consideration of various space harmonics of air gap magnetic field caused by rotor faults, unbalance current inside a stator phase winding and the change of a topological structure of an excitation winding circuit; various loop parameters, particularly induction parameters related to an excitation winding generating turn-to-turn short circuit faults are accurately calculated, and a transient state calculation method and a stable state calculation method for the turn-to-turn short circuit faults of the excitation winding are provided. Experimental results prove the correctness and the accuracy of the two calculation methods and provide a quantified basis for designing turn-to-turn short circuit protection.

Description

technical field [0001] The invention belongs to the field of analysis and research on asymmetrical faults of AC motor windings and the technical field of relay protection for main equipment in power systems, and in particular relates to analysis, calculation and protection methods for inter-turn short circuits of excitation windings of synchronous generator rotors. Background technique [0002] Turn-to-turn short circuit of generator excitation winding is a common electrical fault. Generally, a slight inter-turn short circuit of the rotor will not directly have a serious impact on the operation of the generator, and the existing inter-turn short circuit protection principle is not perfect, so it is not required to install the inter-turn short circuit protection of the rotor winding at present. However, if the fault continues to develop, the excitation current will increase significantly, the output reactive power of the generator will decrease, the vibration of the unit will...

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Problems solved by technology

[0007] The multi-loop analysis method can not only analyze the internal faults of the stator winding, but also go deep into the interior of the rotor winding to analyze the current and voltage distribution of all branches of the stator and each winding of the rotor, and can take into account various harmonics of the air gap magnetic field, so it can It is applied to the calculation and analysis of the inter-turn short circuit fault of the generator excitation winding, but it will encounter many new problems that are different from the normal operation and the internal fault of the stator winding

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