Self-checking method and system applied to network side relay topology in energy storage inverter

Abstract

The invention discloses a self-checking method and system applied to network side relay topology in an energy storage inverter, and belongs to the technical field of power electronics and electricians. A relay combination detection method is adopted. When a power grid is normal, the network side relay topology needs to be self-checked before the energy storage inverter operates normally, and the inverter in a main circuit of the energy storage inverter does not work at the moment, and the method comprises the following three steps: 1, detecting whether a short-circuit fault and an open-circuitfault happen to a contact of a first bridge arm of the network side relay topology or not; 2, detecting whether a short-circuit fault and an open-circuit fault happen to a contact of a second bridgearm of the network side relay topology or not; 3, detecting whether a short-circuit fault and an open-circuit fault happen to a contact of a third bridge arm of the network side relay topology or not;the method is simple and reliable, can be applied to a digitally controlled energy storage inverter system, and is easy to program and implement.

Description

technical field [0001] The invention relates to an energy storage inverter system, in particular to a grid-side relay circuit in the energy storage inverter system, which belongs to the technical field of power electronics and electric engineering. Background technique [0002] The main working modes of the photovoltaic energy storage inverter system include grid-connected operation mode and off-grid operation mode, which have both the characteristics of photovoltaic power generation and UPS. The grid-connected operation mode includes enabling the energy of the inverter to flow to the grid, and the energy of the grid to flow to the backup load; when the grid fails and enters the off-grid operation mode, the photovoltaic energy storage inverter system needs to cut off the grid and control the energy of the inverter to flow to the backup load. Realize the uninterrupted power supply of backup load. This requires placing a relay network on the grid side of the energy storage in...

AI Technical Summary

Problems solved by technology

[0003] The current grid-connected inverter already has a mature relay self-inspection scheme, but insufficient attention has been paid to the self-inspection method of the photovoltaic energy storage inverter that has just emerged in my country, especially the relatively complex relay topology network in the energy storage system. The current technology only focuses on the UPS function, and the relay is designed to provide uninterrupted power supply for the backup load, and rarely considers the high reliability required in the certification standard, that is, the design of the grid side from the perspective of the fault detection of the relay itself Relay topology, and give the corresponding self-test control method

Images