Dynamic voltage compensator adopting 3 phase structure

Abstract

The invention relates to a dynamic voltage compensator adopting a three-single phase structure, wherein three-phase alternating voltage of electric grid is inputted to a rectification module; the rectification module adopts a PWM control three single phase full bridge circuit with rectification controlling unit output; the direct current voltage of the rectification module is inputted to a directcurrent energy storage module formed by direct current capacitances; the direct current of the direct current energy storage module is inputted to an inversion module; the inversion module adopts thePWM control three single phase full bridge circuit with inversion controlling unit output; the inversion module is inputted to a filtering synchronization module; the filtering synchronization moduleformed by an LC circuit is directly connected with the electric grid in series by capacitances; a detection module is inputted with voltage-current analog quantity signals of a system, and the outputof the detection module, which is used as a reference wave component, is sent to the inverter controlling unit. The dynamic voltage compensator has the advantages that the compensator thoroughly resolves the problem of unbalanced compensation of three phase voltage, and three phases can also independently work and other two phases can continue to work normally even if one phase is out of work.

Description

technical field [0001] The invention relates to a dynamic voltage compensator, in particular to a dynamic voltage compensator adopting a three-phase structure. Background technique [0002] Dynamic Voltage Restorer (DVR) is a voltage source type power electronic compensation device, which is connected in series between the power supply and important loads. It has very good dynamic performance, and when a voltage sag or swell occurs, it can restore the voltage at the fault to the normal value within a short time (several milliseconds). DVR usually consists of an energy storage device, an inverter device, a filter device, and a series transformer, and its control circuit is mostly composed of a single-chip microcomputer. [0003] Depend on figure 1 It can be seen that the rectifier module is implemented by a three-phase rectifier circuit, and its DC side voltage is uncontrollable, and it is difficult to ensure the stability of the DC side voltage when the voltage drops; the ...

AI Technical Summary

Problems solved by technology

Since my country's power grid mostly adopts a three-phase four-wire system structure, there are many unbalanced three-phase situations, so the traditional DVR structure is difficult to meet the compensation requirements

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