Dual H-bridge high-frequency isolation type photovoltaic grid-connected inverter

Abstract

The invention relates to a dual H-bridge high-frequency isolation type photovoltaic grid-connected inverter which comprises an H-bridge chopper circuit, wherein an input end of the H-bridge chopper circuit is connected with an output end of a photovoltaic battery board, an output end of the H-bridge chopper circuit is connected with an input end of a high-frequency transformer T1, an output end of the high-frequency transformer T1 is connected with an input end of an H-bridge inverter circuit through a rectification filter circuit, and an output end of the H-bridge inverter circuit is connected with an input end of an output filter circuit. The inverter further comprises a digital signal processor (DSP) controller, an input end of the DSP controller is connected with output ends of a photovoltaic detection sampling circuit, a grid-connection sampling circuit and a protective circuit, and an output end of the DSP controller and a driving circuit are respectively connected with input ends of the H-bridge chopper circuit and the H-bridge inverter circuit. The dual H-bridge high-frequency isolation type photovoltaic grid-connected inverter achieves complete isolation of photovoltaic battery direct current and power grid alternating current through the high-frequency transformer T1 and achieves high efficiency of system operation by adopting of controlling of two-stage high-frequency pulse-width modulation (PWM). The dual H-bridge high-frequency isolation type photovoltaic grid-connected inverter can conduct comprehensive monitoring and protection for a system by adopting of a protective circuit, and effectively ensures safety and reliability of grid-connected operation of a photovoltaic inverter.

Description

technical field [0001] The invention relates to the field of photovoltaic grid-connected inverters, in particular to a double H-bridge high-frequency isolation photovoltaic grid-connected inverter. Background technique [0002] The large-scale application of clean energy such as solar energy will be an important symbol of the development and progress of human society in the 21st century. With the increasingly serious problems of power shortage and environmental pollution, photovoltaic grid-connected power generation inverters that are connected to the public grid have shown out of its growing competitiveness. With the gradual increase in the installation scale of photovoltaic power generation systems, the market for photovoltaic inverters will maintain a rapid growth trend. In 2012, my country's photovoltaic installed capacity will exceed 4GW, of which photovoltaic building installed capacity will reach 1.7GW. It is estimated that by 2020, the cumulative installed photovolt...

AI Technical Summary

Problems solved by technology

The power frequency transformer isolation type has a single-stage structure, good stability, electrical isolation, and no DC component, but it is bulky and heavy, and the power frequency transformer has high cost and large loss

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