Synchronous generator de-excitation circuit based on thermistor

Abstract

A synchronous generator de-excitation circuit based on a thermistor comprises a generator rectification circuit, a magnetic field breaker and a synchronous generator excitation winding, wherein the synchronous generator excitation winding is further connected with the de-excitation circuit in parallel. The de-excitation circuit comprises a thermistor and a nonlinear field suppression resistor, wherein the thermistor and the nonlinear field suppression resistor are connected in series. The thermistor (PTC) with positive temperature characteristics is selected as a closed switch of a de-excitation circuit. The de-excitation circuit solves the problems of high manufacturing cost, complex control loop, low reliability and the like of a de-excitation device in the traditional de-excitation method of the synchronous generator, is one of important safeguard measures for safe and stable operation of the synchronous generator, and has important practical significance for power generation engineering in China.

Description

technical field [0001] The invention relates to the technical field of demagnetization of a synchronous generator rotor circuit, in particular to a synchronous generator demagnetization circuit based on a thermistor. Background technique [0002] The excitation system is an important part of the synchronous generator, which not only directly affects the operating characteristics of the synchronous generator, but also plays an important role in the stability of the power system. Among them, the demagnetization is the most critical part in the excitation system, and the theory and technology are also the most complicated. [0003] The traditional method of de-excitation of synchronous generators usually uses two devices, power electronic devices (also known as electronic switches) and circuit breakers (or load switches, also known as mechanical switches), as the closing switch devices of the main circuit of de-excitation. As a result, the current The synchronous generator dem...

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Problems solved by technology

[0003] The traditional method of demagnetization of synchronous generators usually uses two devices, power electronic devices (also known as electronic switches) and circuit breakers (or load switches, also known as mechanical switches), as the closing switch devices of the main circuit of demagnetization. As a result, the current The current synchronous generator demagnetization device generally has many problems such as high cost, complex control loop, low reliability, etc.

The reliability problem will lead to the lack of de-excitation function of the excitation system of the synchronous generator, which will directly endanger the safe and stable operation of the synchronous generator.

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