Soft switching of three-phase inverter circuit and method thereof

Abstract

The invention relates to the technical field of inverter switching, and discloses soft switching of a three-phase inverter circuit and a method thereof. Three levels are output by adopting the three-phase inverter controlled by a microprocessor; a three-phase symmetrical sine wave power supply is provided for a motor M by using a three-phase filter; a single-phase inverter of the three-phase inverter can be used for converting bus direct current voltage into three levels through a capacitor C1 and a capacitor C2; the three levels form an oscillating condition by using the switch-on / off states of resonant capacitors C12 and C13, a resonant inductor and a main power switch device and an auxiliary power switch device; the auxiliary power switch device is a switch device; and three switch-on / off states of zero-voltage switch-on and zero-current switch-off conditions are provided, so that each phase of inverter outputs three types of levels.. The soft switching and the method are suitable for the application of high-voltage large-power inversion; by adopting the soft switching and the method, the insulation breakdown of a motor winding can be effectively prevented, the EMI (Electromagnetic Interference) characteristic of an inverter device can be improved, the service life of the switch device can be prolonged, the equipment reliability can be increased, and the energy saving efficiency is high.

Description

technical field [0001] The invention relates to the technical field of inverter switches, in particular to a soft switch and method for a three-phase inverter circuit for power conversion. Background technique [0002] In the power conversion technology to realize the transformation of high-voltage electric energy by low withstand voltage switching elements, the traditional method adopts the series connection of switching elements, and the typical application is a two-level hard switching structure. Its input current has serious harmonics and low power factor. The sharply changing voltage and current cause electromagnetic interference to the surrounding electrical equipment, and also make the power switching devices bear great voltage stress. Contents of the invention [0003] In order to solve the hard switching structure of traditional switching devices, there is serious distortion of input current, serious harmonic content, low power factor, and sharply changing voltage...

AI Technical Summary

Problems solved by technology

Its input current has serious harmonics and low power factor. The sharply changing voltage and current cause electromagnetic interference to the surrounding electrical equipment, and also make the power switching devices bear great voltage stress.

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