Novel series-parallel system compensation load reactive power demand control method and system

Abstract

The invention discloses a novel series-parallel system compensation load reactive power demand control method and system, and the method comprises the steps: obtaining a DC component of reactive powerneeded by a load, and determining the reactive power needing to be compensated by a series inverter, i.e., the reactive power vacancy exceeding the rated capacity value of a parallel inverter; calculating a power angle according to the reactive power required to be additionally compensated by the series inverter; generating a three-phase reference voltage signal injected into the series inverteraccording to the power angle; comparing the three-phase reference voltage signal with the actually measured three-phase series injection voltage to generate a switching signal required by switching ofthe series inverter, and controlling the series inverter to compensate the reactive vacancy exceeding the rated capacity value of the parallel inverter. According to the invention, the parallel inverters and the series inverters are controlled to provide load reactive power demands together, so sharing of the load reactive power demands is facilitated, reduction of rated values of the parallel inverters is facilitated, and the total cost of the novel series-parallel system is reduced.

Description

technical field [0001] The invention relates to a novel series-parallel system (UPQC) control method for compensating reactive power demands of loads, and belongs to the field of electric power conversion. Background technique [0002] Power system load reactive power compensation is one of the common problems in power transmission. Parallel capacitor banks are used to compensate load reactive power, which is the simplest load reactive power compensation method, but this method has some disadvantages, such as fixed compensation amount and possible load resonance. The newly researched series-parallel system can be used for load reactive power compensation, in which load reactive power compensation is completed through parallel inverters, while series inverters are usually used to compensate voltage-related problems, not for load reactive power compensation. When the reactive power demand of the load is large, the reactive power compensation of the parallel side inverter alon...

AI Technical Summary

Problems solved by technology

When the reactive power demand of the load is large, the reactive power compensation of the parallel side inverter alone is too large, and the reactive power compensation pressure of the parallel side inverter is too large, which is easy to exceed its rated reactive power capacity, causing inverter failure and affecting system stability.

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