A brushless excitation black excitation circuit

Abstract

The invention discloses a brushless excitation black excitation circuit. The brushless excitation black excitation circuit is applied to a non-auxiliary-power remote hydropower station or a movable diesel generating set, and under the condition that no external power supplies are provided, the automatic black excitation of a brushless excitation generating set is realized. The brushless excitation black excitation circuit comprises a voltage setting unit, a power tube array unit, a power tube driving unit and an optical coupler. The voltage setting unit comprises a short-range voltage setting variable resistor and a remote voltage setting variable resistor. According to the invention, a large power power tube parallel connection technology is adopted, the working state is started and stopped at a high speed, no mechanical contacts exist, and the reliability is high; in addition, according to the magnitude of the excitation current of the generating set, the number of the power tube can be increased or decreased flexibly. The brushless excitation black excitation circuit provided by the invention has an over-current protection function. When the excitation current is detected to be larger than a setting value, a protection circuit acts immediately, the output of power tubes is stopped, and the generating set is effectively protected against an excitation over-current and over-voltage.

Description

technical field [0001] The invention relates to a brushless excitation black excitation circuit which utilizes the residual voltage of a brushless excitation generator to automatically start excitation. It is applied to remote hydropower stations or mobile diesel generators without factory power, and realizes automatic black-start excitation of brushless excitation generators without any external power supply. Background technique [0002] In some remote small hydropower stations at home and abroad, most of them use low-voltage brushless excitation generator sets. In order for the generator to generate electric energy, when the prime mover drives the rotor to rotate, direct current must be passed into the rotor winding to establish a rotating magnetic field, so that three-phase alternating current can be induced in the stator, and its voltage depends on the magnitude of the rotor excitation current. The brushless excitation generator mostly adopts the self-excitation magnet...

AI Technical Summary

Problems solved by technology

However, before the unit has established the rotor magnetic field, the residual magnetism of the rotor only maintains a very low residual voltage (2% to 5% of the rated value) of the generator stator output.

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