Full-bridge current-source high-frequency isolation-type three-level inverter

Abstract

The invention provides a full-bridge current-source high-frequency isolation-type three-level inverter. The full-bridge current-source high-frequency isolation-type three-level inverter consists of an input direct-current power supply, voltage-dividing capacitors, a full-bridge current-source high-frequency isolation-type three-level conversion unit, a cyclic wave converter, an output filter and an output alternating-current load which are sequentially connected with one another, wherein on the basis of the traditional full-bridge current-source inverter, two capacitors are connected to two ends of the input direct-current voltage source in parallel to divide the voltage, so that three levels of Ui, Ui / 2, minus N1U0 / N2 can be generated on the front end of a transformer, the voltage stress on a switch tube can be reduced, and the application range of the current-source high-frequency isolation inverter can be enlarged. The full-bridge current-source high-frequency isolation-type three-level inverter has two levels of power transformation (direct-current (DC)-high-frequency alternating-current (HFAC)-low frequency alternating current (LFAC)) and has the advantages of bi-directional power flow, low voltage stress on a switch device, good spectrum characteristics on the front end of the filter, small size of the output filter, high power density and capability of realizing the high-frequency electrical isolation between the alternating-current load and the direct-current power supply.

Description

technical field [0001] The invention belongs to the technical field of power electronic conversion, in particular to a full-bridge current source type high-frequency isolated three-level inverter. Background technique [0002] Direct-to-AC (DC-AC) conversion technology is a static conversion technology that uses power semiconductor devices to convert DC power into constant voltage and constant frequency AC power, which is used for AC load power or grid-connected power generation. Technology is widely used in industrial production and daily life. [0003] The development of high-power power electronic devices provides technical support for the research and development of multi-level inverter devices. In 1977, the German scholar Holtz first proposed the main circuit of a three-level inverter using a switch tube to assist the neutral point clamp. Inverter (Neutral-Point-Clamped Inverter, NPC inverter). After decades of development, the current multi-level inverter technology...

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Problems solved by technology

However, due to the limitation of the flyback topology and the shortcomings of the two-level circuit itself, the switching tube of the inverter has low power and low voltage withstand capability, so it can only be used in occasions with low voltage and power.

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