Flyback type miniature photovoltaic grid connected inverter with power decoupling circuit and control method thereof

Abstract

A purpose of the present invention is disclosing a flyback type miniature photovoltaic grid connected inverter with a power decoupling circuit and a control method thereof. The inverter comprises a flyback converter and a power frequency polarity conversion circuit. The flyback converter is provided with a power decoupling circuit, a decoupling capacitance voltage grade is higher than output voltage of a solar energy photovoltaic array, decoupling capacitance voltage is allowed to fluctuate in a large range, thus decoupling capacitance capacity is decreased, power decoupling can be realized by only using a non-electrolytic capacitor, using an electrolytic capacitor is avoided, a service life of the miniature photovoltaic grid connected inverter is prolonged, and reliability is raised. Through the control method, not only is decoupling of miniature photovoltaic grid connected inverter output power and solar energy photovoltaic array output power realized, but also direct current voltage and current waveform outputted by the solar energy photovoltaic array can maintain smooth, a service life of the solar energy photovoltaic array is guaranteed, and realization of maximum power point tracking (MPPT) is facilitated.

Description

technical field [0001] The invention relates to a flyback miniature photovoltaic grid-connected inverter with a power decoupling circuit and a control method thereof. Background technique [0002] Micro photovoltaic grid-connected inverters have attracted more and more attention because of their advantages such as high energy utilization rate, good system scalability, and easy installation. In particular, when combining a microinverter with a single solar photovoltaic array to form an AC module, the inverter needs to have a lifespan that matches that of the photovoltaic array. [0003] In the miniature photovoltaic grid-connected inverter, the solar photovoltaic array generates smooth DC power due to the effect of MPPT, and the power measured by the grid-connected grid is the power pulsation of twice the grid frequency. Usually, large-capacity electrolytic capacitors are connected in parallel at both ends of the solar photovoltaic array to solve the problem of instantaneous...

AI Technical Summary

Problems solved by technology

However, the life of electrolytic capacitors is very short, much lower than the life of solar photovoltaic arrays

Therefore, the e...

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