Three-phase four-bridge-arm photovoltaic grid-connected inverter and multi-target cooperative fault control method

Abstract

The invention discloses a three-phase four-bridge-arm photovoltaic grid-connected inverter and a multi-target cooperative fault control method. The photovoltaic grid-connected inverter comprises a power distribution network equivalent circuit, a common coupling point, a three-phase four-bridge-arm grid-connected inverter main circuit and a control system. The control system respectively acquires avoltage signal of the common coupling point and an output current signal of the three-phase four-bridge-arm grid-connected inverter, and calculates and analyzes the voltage signal and the output current signal to finally obtain a driving signal; and the driving signal drives the main circuit of the three-phase four-bridge-arm grid-connected inverter to work and performs multi-target cooperative fault control. By the adoption of the method, the problem that active power fluctuation, reactive power fluctuation and output current quality are difficult to control at the same time is solved, cooperative control over multiple targets is achieved, and the design difficulty of a control algorithm is reduced.

Description

technical field [0001] The invention relates to the technical field of new energy grid-connected power generation, in particular to a three-phase four-arm photovoltaic grid-connected inverter and a multi-objective collaborative fault control method. Background technique [0002] As large-scale distributed photovoltaic, wind power and other power generation units are connected to the power grid, the interaction between power generation units and the power grid has become increasingly significant. In order to improve the reliability of distributed energy access to the grid, the existing grid-connected guidelines require that when a short-term fault occurs in the grid, the new energy grid-connected inverter must maintain non-off-grid operation, that is, it has fault ride-through control capabilities. [0003] Most of the existing technologies take the three-phase three-wire grid-connected inverter as the research object, focusing on solving the problems of output active power f...

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Problems solved by technology

[0004] The purpose of this application is to solve the problem of simultaneous control of active power fluctuations, reactive power fluctuations, and output current quality, to achieve coordinated control among multiple objectives, and to reduce the difficulty of designing control algorithms

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