Controllable two-phase zero reactance shunt excitation system

Abstract

The invention discloses a controllable two-phase zero reactance shunt excitation system. The excitation system of the invention is composed of a two-phase zero excitation system and a double-winding reactance shunt self-excitation constant voltage system. The two-phase zero excitation system adjusts the excitation current of the double-winding reactance shunt self-excitation constant voltage system, so as to control the voltage at the generator end. An excitation mode combining the advantages of the two-phase zero excitation system and the double-winding reactance shunt self-excitation constant voltage system is adopted in the invention. Automatic adjustment of the magnitude of the excitation current is realized mainly through measurement of the voltage and current components at the generator end during grid connection, adjuster synchronization signal shaping, measurement comparison, stabilization and amplification, a trigger circuit, pulse formation and thyristor control, and then, the voltage at the generator end can be controlled, stable grid connection can be achieved, and a controllable closed loop can be formed. The system has the technical advantages such as simple transformation, low cost, reliable grid-connected operation and high safety.

Description

technical field [0001] The invention belongs to the field of generator excitation control systems, and relates to an excitation system suitable for grid connection of small generator sets, in particular to a controllable two-phase zero-type reactance shunt excitation system. Background technique [0002] The double-winding reactance shunt self-excited constant voltage system has a series of advantages such as small excitation power, good strong excitation performance, fast dynamic response, simple structure, low cost, easy operation and maintenance, etc. It is the main generator commonly used in small hydropower stations in my country. One of the excitation methods, especially the most common in small hydropower stations in rural areas. [0003] However, after adopting this excitation method, the external characteristics of the generator are different from those of the grid voltage adjustment when the generator is connected to the grid, which is prone to oscillation or loss o...

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Problems solved by technology

[0003] However, after adopting this excitation method, the external characteristics of the generator are different from those of the grid voltage adjustment when the generator is connected to the grid, which is prone to oscillation or loss of excitation, and even causes out-of-step and decoupling of the generator, which brings difficulties to grid-connected operation. Unable to connect to the grid, resulting in waste of hydropower station resources and economic losses

This shortcoming of the double-winding reactance shunt self-excited constant voltage system is the main problem that the domestic manufacturers and the hydropower stations that install this system have not yet solved satisfactorily and urgently need to be solved.

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