Photovoltaic grid-connected inverter with active power decoupling function

Abstract

The invention discloses a photovoltaic grid-connected inverter with the active power decoupling function. The photovoltaic grid-connected inverter comprises a main flyback converter, a power decoupling converter, an inverter circuit and an output filter circuit. Decoupling between the output power of the photovoltaic grid-connected inverter and the output power of a photovoltaic module is achieved, the direct current voltage stabilization function of output of the photovoltaic module can be achieved by applying a non-electrolytic capacitor with small capacity to the direct current input side of the photovoltaic grid-connected inverter, and MPPT efficiency of the photovoltaic module is improved. An electrolytic capacitor is replaced by the non-electrolytic capacitor with high reliability, so that the problem that the overall service life of the photovoltaic grid-connected inverter is short due to use of the electrolytic capacitor is solved. Meanwhile, leakage inductance energy of a transformer can be absorbed and fed back, soft switching of a high-frequency operating switching tube of the main flyback converter is achieved, and conversion efficiency of the inverter is improved.

Description

technical field [0001] The invention relates to a photovoltaic grid-connected inverter, in particular to a photovoltaic grid-connected inverter with an active power decoupling function. Background technique [0002] Solar energy is inexhaustible and inexhaustible. In the 21st century when there is an urgent need for green energy, solar photovoltaic power generation will develop more rapidly. With the rapid development of distributed photovoltaic grid-connected applications and smart grids, the home roof and commercial roof markets are growing rapidly. In small and medium-sized photovoltaic grid-connected systems, the low-power photovoltaic grid-connected inverter that directly inverts the DC power output by a single photovoltaic module into AC power and injects it into the grid is called a photovoltaic grid-connected micro-inverter. Photovoltaic grid-connected micro-inverters are especially suitable for low-power applications. Micro-inverters can realize component-level mon...

AI Technical Summary

Problems solved by technology

At present, a commonly used power decoupling method is to connect a large electrolytic capacitor in parallel on the DC input side of the photovoltaic grid-connected inverter, but the electrolytic capacitor is a bottleneck of the service life of the whole machine

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