Reactive compensation device and method for partially regulating voltages and capacitance of three-phase four-wire power grid

Abstract

The invention discloses a reactive compensation device and method for partially regulating voltages and capacitance of a three-phase four-wire power grid. The reactive compensation device comprises a U-phase voltage and capacitance regulating reactive compensation unit, a V-phase voltage and capacitance regulating reactive compensation unit, a W-phase voltage and capacitance regulating reactive compensation unit and a control unit. Each phase of voltage and capacitance regulating reactive compensation unit is mainly composed of a current detection element, a voltage detection element, a full-voltage compensation capacitor bank, an auto-transformer and a voltage-regulating capacitor bank. The control mode of independent reactive compensation in each phase is used in the three-phase four-wire power grid, total capacitance in each phase is uniform, the capacitance in each phase is evenly divided into n sets, wherein one set of the capacitance is subjected to voltage and capacitance regulation through the auto-transformer which totally has m levels of output voltages, each phase has n*m grades of compensation, and multi-level fine compensation for the power grid is achieved.

Description

technical field [0001] The invention relates to reactive power compensation of a three-phase four-wire power grid, and belongs to the technical field of automatic reactive power compensation of parallel capacitors controlled by thyristors, in particular to a reactive power compensation device and method for partial voltage regulation and capacity adjustment of a three-phase four-wire power grid. Background technique [0002] The three-phase four-wire power grid has the disadvantages of serious three-phase load imbalance, frequent load changes, and low load power factor, which is not conducive to the safe and efficient operation of the power grid. Reactive power compensation is an important means to maintain grid voltage stability and maintain the safe operation of the power system, and shunt capacitors are an important means of reactive power compensation for the grid. The conventional capacitor compensation device adopts the simultaneous switching mode of three equal capaci...

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Problems solved by technology

[0002] The three-phase four-wire power grid has the disadvantages of serious three-phase load imbalance, frequent load changes, and low load power factor, which is not conducive to the safe and efficient operation of the power grid.

This reactive power compensation technology generally uses an autotransformer as a voltage regulating device, but the autotransformer itself is a device that consumes energy and generates reactive power. The large capacity of the autotransformer is extremely unfavorable to economic operation.

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