Energy feedback unit and energy feedback method

Abstract

The invention discloses an energy feedback unit and an energy feedback method. The energy feedback unit comprises a three-phase input wire voltage sampling module, a current sampling module, a busbar voltage sampling module and a control module, wherein the three-phase input wire voltage sampling module is used for sampling the voltage of a power grid and transmitting the voltage to the control module, the current sampling module is used for sampling the current of the power grid and transmitting the current to the control module, the busbar voltage sampling module is used for sampling the busbar side voltage of the energy feedback unit and transmitting the busbar side voltage to the control module, and the control module is used for performing an automatic phase distinguishing and locking algorithm according to a signal transmitted by the three-phase input wire voltage sampling module and performing a double-closed-loop control algorithm and a zero sequence current compensation control algorithm according to signals transmitted by the current sampling module and the busbar voltage sampling module so as to generate a PWM driving signal for driving a first inverter bridge. The energy feedback unit and the energy feedback method have the advantages that the zero sequence current compensation algorithm is adopted for eliminating loop current, the power supply reliability is improved, the phase position of power grids can be automatically identified, and indifference grid connection is achieved.

Description

technical field [0001] The present invention relates to the field of electric power technology, and more specifically, relates to an energy feedback unit and an energy feedback method. Background technique [0002] With the continuous improvement of national energy conservation and emission reduction policies and the continuous improvement of the legal system, the concept of energy conservation and environmental protection has been deeply rooted in the hearts of the people. As a product of the development of power electronics technology, frequency converters have been widely used in various fields of the national economy such as metallurgy, petrochemical, tap water, electric power and other industries. Wide range of applications, and play an increasingly important role. The frequency converter is a power conversion device that converts the power frequency power supply into an adjustable frequency by using the on and off functions of semiconductor power devices. The device f...

AI Technical Summary

Problems solved by technology

Since the parallel energy feedback unit is connected in parallel with the inverter bus and power input, the traditional double closed-loop control is prone to loop current, causing distortion of the grid voltage and feedback current

On the other hand, the parallel energy feedback unit feeds energy back to the grid when it is in use, and the traditional electric energy meter cannot realize the measurement of the reverse current, so the feedback power cannot be accurately measured

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