Isolated high-gain quasi-Z-source DC-DC converter for photovoltaic power generation

Abstract

The invention provides an isolated high-gain quasi-Z source DC-DC converter, including mainly the input DC voltage source, by the first inductor, first capacitance, first diode, a quasi-Z source network composed of a second inductor and a second capacitor, by the second diode, a quasi-switching boost unit composed of a third diode, a third capacitor, a third MOS transistor and a fourth MOS transistor, a first MOS transistor, a second MOS transistor, a high-frequency transformer T with a conversion ratio of 1: n, a voltage doubling rectifier composed of a fourth capacitor, a fifth capacitor, afourth diode and a fifth diode, and a load resistance R (i) L ( / i). The whole circuit is simple, The input current of the power supply is continuous, which combines the single step-up and step-down voltage characteristics of the quasi-Z source impedance network and the quasi-switching boost network respectively, so that the output voltage gain is higher, and the electrical isolation between the output and input of the converter is realized by a high-frequency transformer, and the circuit does not have the start-up impulse current and the impulse current of the switching transistor at the turn-on time.

Description

technical field [0001] The invention relates to the technical field of power electronic converters, in particular to an isolated high-gain quasi-Z source DC-DC converter suitable for photovoltaic power generation. Background technique [0002] With the development of the economy, the problem of energy shortage and environmental pollution has become increasingly serious. In order to achieve sustainable development, the development and utilization of renewable energy is one of the effective ways to solve this problem. Renewable energy power generation mainly includes water conservancy, solar energy, wind energy, and fuel cells. Among them, solar photovoltaic power generation has become one of the most widely implemented renewable energy power generation methods today. However, due to the low output voltage level of solar photovoltaic panels, it cannot meet the requirements of some existing electrical equipment and grid connection, so the output voltage of photovoltaic panels...

AI Technical Summary

Problems solved by technology

However, due to the low output voltage level of solar photovoltaic panels, it cannot meet the requirements of some existing electrical equipment and grid connection, so the output voltage of photovoltaic panels must be used after a high-gain step-up DC / DC converter.

In recent years, relevant scholars have proposed Z-source DC-DC converters and switch boost DC-DC converters. Although they respectively use the Z-source impedance network and switch boost network to increase the output voltage, their corresponding There is still a lot of room for improvement in voltage gain, and in many applications, there is often a need for electrical isolation between the output and input of the converter, so the research and development of isolated high-gain DC-DC converters has become more and more important. more important

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