A Micro Photovoltaic Grid-Connected Inverter Based on Flyback Circuit and Active Ripple Suppression

Abstract

The invention discloses a miniature photovoltaic grid-connected inverter based on a flyback circuit and active ripple suppression. The main circuit typology of the miniature photovoltaic grid-connected inverter comprises a DC power supply, an input capacitor, a primary side switching tube, an auxiliary switching tube, an auxiliary diode, an auxiliary capacitor, an isolation transformer, a secondary side diode, a secondary side switching tube, a filtering circuit and a power grid. According to the miniature photovoltaic grid-connected inverter, an active ripple suppression circuit composed of an auxiliary winding of the isolation transformer, the auxiliary switching tube, the auxiliary diode and the auxiliary capacitor is arranged in a flyback converter, and power pulsation caused by a grid-connected side is transferred onto the auxiliary capacitor, so that input power is kept flat, the use of an electrolytic capacitor is avoided, the service life of the miniature photovoltaic grid-connected inverter is prolonged, and the system reliability is improved.

Description

technical field [0001] The invention relates to a miniature photovoltaic grid-connected inverter based on a flyback circuit and active ripple suppression, which belongs to an isolated, miniature, and grid-connected inverter. It realizes grid-connected inverter based on a flyback circuit, and utilizes the increased An active ripple suppression circuit is used to suppress the secondary ripple current on the DC input side. Background technique [0002] Due to the massive use of non-renewable energy sources such as fossils, the global energy crisis and serious environmental pollution problems have been caused. New energy sources such as solar energy and wind energy have a series of advantages such as cleanness and sustainability, and have become one of the hot spots that people pay attention to at present. The rapid development of the industry. As we all know, in order to make the photovoltaic panel output the maximum power, the maximum power tracking technology needs to be ado...

AI Technical Summary

Problems solved by technology

It is the simplest way to connect a large-capacity electrolytic capacitor in parallel on the DC side of the photovoltaic power generation system to filter the secondary ripple current. However, electrolytic capacitors have problems such as large volume and low reliability, which not only affect the power density of the system, but also affect the maintenance cost. also higher

Parallel connection of an LC resonant circuit with a resonant frequency twice the power grid frequency in the circuit can also filter out the secondary current ripple and reduce the capacitance value, but the inductance and capacitance values ​​required by this method are still relatively large, to a certain extent influence on system power density

All in all, the method of using passive devices to suppress the secondary ripple in the inverter input current has problems such as large volume and low reliability.

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