Enhanced and high-performance Z-source inverter

Abstract

The invention discloses an enhanced and high-performance Z-source inverter. The enhanced and high-performance Z-source inverter comprises a DC power supply V0, a diode D7, an input capacitor C3, a switch tube SW7 and a three-phase inverter, also comprises a Z-source network and is characterized in that the Z-source network comprises a switch inductor, a diode, an inductor and a capacitor, a singleinductor of a traditional Z-source network is substituted by the switch inductor, the Z-source network is connected in series between the power diode SW7 and the three-phase inversion bridge, a positive electrode of the diode D7 is connected with a positive electrode of the DC power supply V0, a positive electrode of the power diode SW7 is connected with a negative electrode of the diode D7 and one end of the capacitor C3, and the other pole of the capacitor C3 is connected with a negative electrode of the DC power supply V0 and the Z-source network. Compared with a traditional Z-source inverter, the enhanced and high-performance Z-source inverter has the advantages that DC chain voltage distortion caused by relatively small inductance value of the Z-source network or a light-load mode can be eliminated, so that the abnormal working state of the traditional Z-source inverter is eliminated; the adaptive capacity of a load is high, and large-range change of the load can be adapted; theboost capability of the inverter can be remarkably improved, high modulation factor is achieved, and the output quality of the whole inverter is improved; and meanwhile, the capacitance voltage stressof the Z-source network is effectively reduced, so that the volume and the weight of the inverter are reduced.

Description

technical field [0001] The invention relates to the field of power electronics, in particular to an enhanced high-performance Z-source inverter. Background technique [0002] People are paying more and more attention to clean energy. Wind power generation, photovoltaic power generation and fuel cells are favored by the industry, but the DC voltage output by wind power generation, photovoltaic power generation and fuel cell systems fluctuates greatly and cannot directly supply power to users. In order to achieve stable power output for step-up and step-down, a DC / DC boost circuit is added to the front stage of the inverter bridge, but the link of the DC / DC converter increases the cost of the system and reduces the efficiency of the system, and the two-stage structure increases the complexity of the system control. The literature (F. Z. Peng, "Z-source Inverter," IEEE Trans. on Industry Applications, vol. 39, no. 2, pp, 504-510, March / April, 2003) proposes a Z-source inverter...

AI Technical Summary

Problems solved by technology

The Z-source inverter solves the problem that the upper and lower sides of the bridge arm of the traditional inverter cannot be conducted at the same time, and the dead time control needs to be added.

And it can increase the DC link voltage, simplify the system structure, and improve the efficiency. However, the capacitor voltage stress in the Z source network of the traditional Z source inverter is too large, resulting in large capacitor volume and high cost in practical applications.

In light-load mode, it is prone to abnormal working conditions, resulting in DC link voltage distortion, and its low boost capacity cannot meet some conditions

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