Three-phase current type multi-level converter photovoltaic power generation grid-connection device

Abstract

The invention discloses a three-phase current type multi-level converter photovoltaic power generation grid-connection device. The three-phase current type multi-level converter photovoltaic power generation grid-connection device comprises a photovoltaic cell array I, a constant current circuit I based on maximum power tracking, a photovoltaic cell array II, a constant current circuit II based on maximum power tracking, an MCU (Micro Controller Unit) circuit, a driving / photoelectric isolating circuit I, a three-phase current type multi-level converter, a converter controller, a filter circuit and a power grid, wherein the photovoltaic cell array I is connected with the constant current circuit I based on maximum power tracking; the photovoltaic cell array II is connected with the constant current circuit II based on maximum power tracking; the constant current circuit I based on maximum power tracking and the constant current circuit II based on maximum power tracking are both connected with the three-phase current type multi-level converter; the three-phase current type multi-level converter is connected with the filter circuit; the filter circuit is connected with the power grid. The three-phase current type multi-level converter photovoltaic power generation grid-connection device is free of a boosted circuit, and is quick in dynamic response and convenient for regenerative braking.

Description

technical field [0001] The invention relates to a grid-connected device for photovoltaic power generation of a three-phase current-type multilevel converter. Background technique [0002] Solar power generation is a beneficial supplement to traditional power generation. In view of its importance to environmental protection and economic development, all developed countries are fully promoting solar power generation. At present, small and medium-scale solar power generation has formed an industry. There are two ways of solar power generation: photovoltaic power generation and solar thermal power generation. Among them, photovoltaic power generation has outstanding advantages such as simple maintenance and variable power, and is widely used as a medium and small grid-connected power supply. [0003] A converter is provided in the grid-connected device for photovoltaic power generation. A converter is an electrical device that changes the voltage, frequency, number of phases, a...

AI Technical Summary

Problems solved by technology

Since the current research results of three-phase current-type inverters are not mature enough compared with three-phase voltage-type inverters, the inverters in the converters of photovoltaic power generation grid-connected devices in the prior art are generally three-phase Voltage Source Multilevel Inverter

However, when the three-phase voltage-type multi-level inverter is applied to the converter of the photovoltaic power generation grid-connected device, the voltage output from the photovoltaic panel needs to be boosted before it can be input into the inverter. Adding a booster circuit to the photovoltaic power generation grid-connected device not only makes the structure of the photovoltaic power generation grid-connected device more complicated, but also increases the cost

Moreover, compared with the three-phase current-type inverter, the three-phase voltage-type inverter has disadvantages such as insufficient dynamic response and inconvenient feedback braking.

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