Alternating current excitation system based on full control device

Abstract

The invention discloses an alternating current excitation system based on a full control device. The alternating current excitation system comprises an excitation power unit and an excitation regulator, wherein the excitation regulator controls the excitation current output of the excitation power unit, the excitation power unit comprises an excitation machine excitation system, an excitation machine excitation winding, an excitation machine and a current converter, the output end of the excitation machine excitation system is connected with the excitation machine excitation winding, the input end of the current converter is connected with the machine end of the excitation machine, the excitation machine excitation system provides excitation current for the excitation machine, the excitation power unit also comprises a chopper, the current converter adopts a full control current converter, the output end of the full control current converter is connected with the input end of the chopper, and the output end of the chopper is used for being connected with an excitation winding of a power generator. The alternating current excitation system adopts the full control current converter, the phase shifting failure problem does not exist, the reliability is high, the excitation capability is good, the power generator capacity is improved, the deexcitation failure is effectively prevented, the system manufacturing cost is reduced, the equivalent time constant of a regulating system is reduced, and the response speed is improved.

Description

technical field [0001] The invention belongs to the technical field of generator excitation, and in particular relates to an AC excitation system based on a full control device. Background technique [0002] With the development of grid capacity and scale, the power system has higher and higher requirements on the reliability and dynamic performance of excitation control. Modern power systems require that the excitation system of synchronous generators can suppress low-frequency / ultra-low-frequency oscillations of 0.1Hz to 3Hz. However, it is difficult for conventional thyristor rectifier excitation systems to suppress low-frequency oscillations in a wide range of 0.1Hz to 3Hz. When low-frequency / ultra-low-frequency oscillation occurs in the power grid, the terminal voltage of the synchronous generator will also oscillate greatly at low-frequency / ultra-low frequency, and the terminal voltage may continue at a low level for a long time. During the oscillation period, if a sh...

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Problems solved by technology

[0004] However, the three-machine system has the following defects: (1) The generator, exciter and sub-exciter are installed coaxially, so the main shaft of the generator is longer, which affects the stability of the shafting of the unit, the system cost is high, and the maintenance workload is heavy; (2) Excitation The regulator controls the excitation voltage of the exciter, and it needs to pass through the exciter when it acts on the excitation winding of the generator. Therefore, the equivalent time constant of the excitation system is relatively large, and the response speed of the regulating system is slow, which makes the power system stable. have been affected to a certain extent

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