Miniature photovoltaic grid-connected inverter with optimized DC (Direct Current) bus capacitor and control method

Abstract

The invention belongs to the field of photovoltaic power generation, applies a power decoupling circuit to reduce the capacity of a capacitor at the side of a DC (Direct Current) bus for prolonging the service life and improving the reliability of the inverter, replaces an electrolytic capacitor with high capacity and a short service life with a thin film capacitor with low capacity and a long service life and designs a miniature photovoltaic grid-connected inverter. To fulfill the aims, the invention adopts the technical scheme that the miniature photovoltaic grid-connected inverter with an optimized DC bus capacitor comprises a main circuit and a control and driving circuit, wherein the main circuit is formed by a photovoltaic cell panel, a phase-shift full-bridge circuit, a high frequency transformer, a full-bridge rectifying circuit, the DC bus capacitor, the power decoupling circuit and an inverter circuit which are sequentially connected; the control and driving circuit comprises a photovoltaic output current sampling circuit, a photovoltaic output voltage sampling circuit, a power MOSFET (Metal Oxide Semiconductor Field Effect Transistor) driving circuit, a capacitor voltage sampling circuit, a grid-connected current sampling circuit, a phase-locked loop circuit and a DSP (Digital Signal Processor) controller. The miniature photovoltaic grid-connected inverter is mainly applied to photovoltaic power generation.

Description

technical field [0001] The invention belongs to the field of photovoltaic power generation, and more specifically relates to a micro-inverter for photovoltaic power generation using a power decoupling circuit and a control method thereof, that is, a micro-photovoltaic grid-connected inverter with optimized DC bus capacitance and a control method thereof. technical background [0002] As a pollution-free and renewable new energy source, solar energy has very broad application and development prospects. With the increasing shortage of natural resources such as oil and natural gas, and the severe situation of abnormal global climate change, clean renewable energy has become increasingly popular. Pay attention to. Photovoltaic power generation occupies an important position in it, and it provides a reliable way to solve the energy supply of production and life and improve environmental pollution. [0003] Due to its advantages of high efficiency, simple and convenient expansion...

AI Technical Summary

Problems solved by technology

However, the introduction of electrolytic capacitors not only increases the volume of the entire solar photovoltaic grid-connected power generation system, but also greatly shortens the service life of the solar photovoltaic grid-connected power generation system and reduces the reliability of the solar photovoltaic grid-connected power generation system.

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