Isolated type high-gain quasi Z-source DC-DC converter applicable to photovoltaic generation

Abstract

The invention provides an isolated type high-gain quasi Z-source DC-DC converter applicable to photovoltaic generation. The DC-DC converter mainly comprises an input direct current voltage source; a quasi Z-source network formed by a first inductor, a first capacitor, a first diode, a second inductor and a second capacitor; a quasi switch boosting unit formed by a second diode, 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 transformation ratio of 1:n; a voltage-doubling rectifier formed by a fourth capacitor, a fifth capacitor, a fourth diode and a fifth diode; and a load resistor RL. According to the converter, the whole circuit structure is simple, a current input by a power supply is continuous, higher output voltage gain is achieved with the combination of respective single-stage boosting and voltage-reducing characteristics of the quasi Z-source impendencenetwork and the quasi switch boosting network, electrical isolation between output and input of the transformer is realized through the high-frequency transformer, and the circuit avoids a starting impulse current and an impulse current at the instant of switch-on of a switch tube.

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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