Device and method for modulating frequency of generator set

Abstract

The invention discloses a device and a method for modulating the frequency of a generator set of the device. According to the device, an isolation cascaded transformer and a cascaded convertor are additionally arranged between a machine end of a generator and a low-voltage side of a boosting transformer of a grid connection point, a shunt-wound convertor is additionally arranged on a low-voltage side of the machine end of the generator or the low-voltage side of the boosting transformer of the grid connection point, the cascaded convertor and the shunt-wound convertor are connected together through a public bus, and the cascaded convertor is used for dynamically regulating a cascading compensation output voltage according to the real-time response of technical requirements on the frequencymodulation of the generator set so as to realize the active power regulation of the frequency modulation requirements; and the shunt-wound convertor is used for stabilizing a direct current bus voltage and timely responding to reactive power control requirements of a system. The device has the advantages that various problems during the frequency modulation of the generator set at present can besolved, the comprehensive response speed is high, the modulation precision is high, the device has good coordination control capability with an existing automatic generation control AGC system, the equipment maintenance amount is reduced, the service life of a machine set is prolonged, and the device has very good economic benefits.

Description

Technical field [0001] The invention relates to the field of power generation, in particular to a device and a method for frequency modulation of a generator set. Background technique [0002] In the domestic and international scope, most of coal-fired units and thermal power units, hydroelectric units, nuclear power units and other generating units undergoing steam turbine flow reformation adopt the digital electro-hydraulic regulation system DEH instead of synchronizer control, and corresponding frequency modulation The function is completed by the Distributed Control System (DCS), Coordinated Control System (CCS), and Electro-hydraulic Control System (DEH). In accordance with the technical specifications of the steam turbine or hydraulic turbine manufacturer, step by step adjust and test the frequency modulation function of the control system of the ESC unit, so that the unit can better meet the load requirements of the grid operation. [0003] When the grid frequency fluctuate...

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Problems solved by technology

[0004] (1) The primary frequency regulation of some units has not been put into use, and the action effect of the units that have been put into operation cannot fully meet the requirements, mainly due to insufficient adjustment amount and short stabilization time.

[0005] (2) At present, the cooperation between the primary frequency regulation and the automatic generation control system (AGC) is insufficient, and there may be situations where the AGC reverses the adjustment according to the strategy after the frequency regulation action adjusts the output, causing fluctuations in the system frequency and tie line power

[0006] (3) Frequent action of frequency modulation will cause unit instability and increase the degree of wear of mechanical devices;

[0007] (4) The load adjustment accuracy of thermal power units is low, and the load adjustment accuracy in a small range is poor

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