Method for increasing loading capacity of three-phase energy storage inverter system and three-phase energy storage inverter system using same

Abstract

The invention relates to a method for increasing the loading capacity of a three-phase energy storage inverter system. The method is applied to the three-phase energy storage inverter system comprising an energy storage inverter, a power grid side relay, an off-grid relay and bypass relays. The output side of the energy storage inverter forms a power grid end after passing through the power grid side relay and is connected to a power grid; the output side of the energy storage inverter forms an off-grid end used for being connected with a load after passing through the off-grid relay; and thebypass relays are connected between the power grid end and the off-grid end. The method for increasing the loading capacity of the three-phase energy storage inverter system comprises the following steps: connecting the load after short circuiting two or three live wires at the off-grid end; in the presence of the power grid, closing the power grid side inverter and one phase of bypass relay corresponding to any one of the short-circuited live wires; and in the absence of the power grid, closing the off-grid relay, and controlling the corresponding inverter power module to perform current-sharing output according to the phase of the short-circuited live wire. According to the invention, the loading capacity of the three-phase energy storage inverter system can be improved, and the flexibility of off-grid end in load connection is improved.

Description

technical field [0001] The invention belongs to the technical field of power electronic converters, and in particular relates to a three-phase energy storage inverter system and a method for increasing load capacity adopted therefor. Background technique [0002] At present, there are many demands for off-grid load applications based on three-phase energy storage inverters, and users need more load-carrying methods to improve load-carrying capacity and easier use. [0003] Currently using three-phase energy storage inverters, users can connect three-phase loads and single-phase loads for off-grid applications. When the user uses three-phase loads or single-phase loads off-grid, it is necessary to pay attention to the calculation of the load power. The off-grid three-phase load power is the power of the inverter, and the off-grid single-phase load power is 1 / 3 of the total power. . When using off-grid single-phase loads that exceed the off-grid single-phase rated power of t...

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Problems solved by technology

When using off-grid single-phase loads that exceed the off-grid single-phase rated power of the three-phase energy storage inverter (that is, the load power is 1 / 3 of the overall power), even if the three-phase energy storage inverter Single-phase load power that needs to be used off-grid, but it cannot be used because it exceeds the rated power of off-grid single-phase. If you want to use it, you need to purchase a three-phase energy storage inverter with single-phase off-grid power that can meet the single-phase load power In this way, the number of solar panels installed will be increased, and the power of the three-phase energy storage machine cannot be fully utilized, resulting in energy waste

The current technology cannot increase the single-phase load capacity of the off-grid end

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