High-gain quasi-Z-source switch boost inverter suitable for fuel-cell power generation

Abstract

The present invention provides a high-gain quasi-Z-source switch boost inverter suitable for fuel-cell power generation. The inverter comprises a voltage source, a quasi-Z-source network formed by a first inductor, a second inductor, a first capacitor, a second capacitor and a first diode, a switch boost unit formed by a second diode, a third diode, a third capacitor and an MOS tube S7, a three-phase inverter bridge, an output filtering inductor, a filter capacitor and a load. A whole circuit combines single-stage buck-boost features of a quasi-Z-source unit and a switch boost unit and outputshigher output voltage gain, output and input are commonly earthed, voltage stress of a switch device in the inverter bridge is reduced, and the circuit does not have a starting impact current and animpact current at the opening instant of a switch tube.

Description

technical field [0001] The invention relates to the technical field of power electronic circuits, in particular to a high-gain quasi-Z source switch boost inverter suitable for fuel cell power generation. Background technique [0002] With the development of modern society and the development and utilization of renewable new energy, the application of fuel cells to achieve clean power generation has been more and more popularized. However, due to the low DC voltage provided by a single fuel cell, it cannot meet the power demand of existing electrical equipment, and the AC output voltage of the three-phase inverter cannot meet the needs of grid connection, so it is often necessary to connect multiple batteries in series up to achieve the desired output voltage level. On the one hand, this method increases the volume of the entire system and greatly reduces the reliability of the entire system; on the other hand, the corresponding series voltage equalization problem needs to ...

AI Technical Summary

Problems solved by technology

The Z-source boost converter and switching boost converter proposed in recent years are both high-gain converter circuits, but because the traditional Z-source converter circuit has a high impedance network capacitive voltage stress, the power supply current is discontinuous, The output and input do not share the same ground, and there is a large start-up inrush current when the circuit is started, and the output voltage gain of the switching boost converter is relatively low, which limits the extended application of these two converter circuits in actual production and life.

Images