Isolation buffer two-level inversion circuit

Abstract

The invention discloses an isolation buffer two-level inversion circuit, which comprises a direct current unit, an inversion unit and a controller, wherein the direct current unit is connected with the inversion unit; an isolation buffer driving unit is arranged between the inversion unit and the controller; the inversion unit is connected with the controller through the isolation buffer driving unit; the isolation buffer driving unit comprises a buffer unit, a conditioning unit and a driving unit; a control signal output end of the controller is connected with a gate pole of an IGBT switching tube of the inversion unit through the buffer unit, the conditioning unit and the driving unit in turn; and one control signal output end correspondingly controls one gate pole of the IGBT switching tube. The isolation buffer two-level inversion circuit has safe and reliable insulated isolation and flexible and convenient overall layout, reduces the requirement on the voltage stress of isolation devices on the premise of not losing the performance, reduces the requirement of the whole circuit isolation security on the devices, and is a product design with low cost and high performance.

Description

technical field [0001] The invention relates to a two-level inverter circuit, in particular to an isolation buffer type two-level inverter circuit which uses the middle point of the DC circuit voltage to reduce the voltage stress of the isolation device. Background technique [0002] High-voltage two-level inverters have shown good application prospects in the field of inverters due to the advantages of fewer components required, bidirectional energy flow, small size, and light weight, especially integrated gate commutated thyristors (IGCTs). The advent of the medium and high voltage frequency converter has added another ideal choice for switching devices. According to the current withstand voltage level of IGCT and high-voltage IGBT, the output voltage level of the two-level inverter in the frequency converter is getting higher and higher, which greatly expands the application range of the two-level inverter. However, This places higher requirements on the isolation device...

AI Technical Summary

Problems solved by technology

The voltage stress borne by the devices in the direct coupling connection unit 400 in the two-level inverter constructed in this direct coupling manner should be considered according to the full bus voltage. Therefore, low withstand voltage devices cannot be used in the direct coupling connection unit 400 . High requirements for devices, high requirements for insulation safety of the entire device, high design and manufacturing costs

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