Unbalance and reactive compensation control device for low-voltage power grid

Abstract

The invention relates to an unbalance and reactive compensation control device for a low-voltage power grid. The control device comprises a data processing module, a CPU module and a communication module. Switching of a control capacitor bank is achieved with network loss as the control target. After the data processing module samples currents and voltages of the low-voltage power grid, the effective values of the collected currents and voltages, the active factor, the reactive factor, the power factor and the current unbalance degree are calculated according to the collected currents and voltages. The CPU module calculates compensation amount according to the deviation between the reactive power and the set value of the reactive power and the deviation between the current unbalance degree and the set value of the current unbalance degree, and outputs three-phase compensation and single-phase separate compensation switching control signals according to the compensation amount. The switching control signals are transmitted to a switching device of the capacitor bank, and the switching device carries out switching according to the switching control signals and compensates for the low-voltage power grid. According to the unbalance and reactive compensation control device, reactive compensation can be carried out, the three-phase current unbalance problem can be solved at the same time, and therefore the optimum compensation effect can be achieved.

Description

technical field [0001] The invention relates to a device for compensating three-phase unbalance and reactive power of a low-voltage power grid. Background technique [0002] Most of the existing low-voltage line reactive power compensation devices in China use power factor as the control target controller to control the automatic switching of capacitors in groups. The switches for switching capacitors mostly use contactors. Star-shaped sub-compensation and delta-star mixed compensation, the controller switching judgment is based on the power factor. However, most of the low-voltage distribution network is a three-phase four-wire system, and the reactive power compensation that improves the power factor of the line alone cannot solve the problem of unbalanced load of transformers in the existing distribution network. In the final analysis, the existing low-voltage line reactive power compensation device for the purpose of supplementing the power factor cannot solve the probl...

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to provide a low-voltage power grid unbalance and reactive power compensation co

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