Three-port converter system applied to independent photovoltaic power generation occasion

Abstract

The invention relates to the independent photovoltaic power generation technology, and simultaneously realizes the functions of large-scale boosting, three-port grounding and storage battery charging.Furthermore, the invention provides a control strategy corresponding to a converter, wherein a TPC can be safely and reliably applied to an independent photovoltaic power generation system. Accordingto the technical scheme adopted by the invention, a three-port converter system applied to an independent photovoltaic power generation occasion comprises three parts: a buck-boost bidirectional DC converter, a boost DC converter and a switch capacitor unit. In the buck-boost bidirectional DC converter, a Vpv and an ipv serve as the port voltage and the port current of a photovoltaic array respectively. The output of the photovoltaic array is applied to the parallel voltage-stabilized capacitor Cpv of the photovoltaic array as the input of the three-port converter. S1 and S2 are switching tubes which are connected in series. The system is is mainly applied to independent photovoltaic power generation occasions.

Description

technical field [0001] The present invention relates to the application of combining an independent photovoltaic power generation system with an energy storage unit, in particular to a novel high-gain non-isolated DC converter and its corresponding control strategy. Specifically, it relates to a three-port converter system applied to independent photovoltaic power generation occasions. Background technique [0002] In recent years, with the aggravation of environmental pollution and energy crisis, new energy generation technologies represented by solar energy and wind energy have become research hotspots. When the light intensity and temperature of the outside world change, the power output provided by the photovoltaic (Photovoltaic, PV) array alone often has problems of instability and discontinuity. Therefore, an energy storage unit such as a battery must be equipped in an independent photovoltaic power generation system to store and adjust electric energy to meet the req...

AI Technical Summary

Problems solved by technology

Nowadays, there are many problems in the research of non-isolated TPC, such as: the topological boost capability is low; the battery charging circuit cannot be formed, and it is not suitable for independent photovoltaic power generation systems; photovoltaics, batteries, and output ports are not shared, which affects system stability. The corresponding control strategy requires various controllers to compete, the control is complicated, and the battery cannot be protected; while the photovoltaic port realizes Maximum Power Point Tracking (Maximum Power Point Tracking, MPPT), it cannot guarantee a constant output voltage and cannot meet constant voltage requirements. complex needs

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