Inverter droop control method capable of achieving secondary frequency modulation and pressure regulation

Abstract

The invention discloses an inverter droop control method capable of achieving secondary frequency modulation and pressure regulation and belongs to the technical field of distributed power supply inverter output control. According to the inverter droop control method capable of achieving secondary frequency modulation and pressure regulation, aiming at the defect that a traditional local inverter droop control method can not achieve secondary frequency modulation and pressure regulation, with the restriction of the purpose of meeting the upper limit, the lower limit and the specified working point of power output of an inverter, an S-shaped droop control curve is constructed based on a traditional droop control curve with the specified working point as a middle transition point; modeling is achieved by means of a cubic function or a piecewise function, traditional droop control constant coefficients are replaced with a quadratic function, so that power output can be adjusted dynamically along with load change; due to the fact that when a traditional electric generator operates under the control of a frequency modulator / pressure regulator, the movement track of the intersection point of the secondary frequency modulation and pressure regulation power output curve of the electric generator and a load characteristic curve is an S-shaped curve, the curve can be directly used for controlling the inverter, and then secondary frequency modulation and pressure regulation are achieved, and operation performance of the inverter is better than that when the inverter is under traditional droop control.

Description

technical field [0001] The invention relates to an inverter droop control method with secondary frequency modulation and voltage regulation characteristics, which belongs to the field of distributed power inverter output control technology and micro power grid system output control field. Background technique [0002] The microgrid system can flexibly switch between the grid-connected mode and the island mode according to the different operating conditions of the main grid, making it an important part of the smart grid. The stable realization of micro-grid operation mode switching depends on the adjustment of the operation mode or output of the underlying micro-power supply. Among them, the control methods of the underlying micro-power supply mainly include master-slave control and droop control. The master-slave control requires fast switching of the control mode during the grid-connected / islanding switching process, and the accuracy of the islanding detection and the requ...

AI Technical Summary

Problems solved by technology

This method can effectively solve the problem of large frequency deviation caused by the inverter adapting to the large-scale fluctuation of the load, and is suitable for the parallel connection of multiple micro power sources

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