High-voltage frequency converter, IGBT isolation driver and common-mode suppression circuit thereof

Abstract

The invention provides a high-voltage frequency converter, an IGBT isolation driver and a common-mode suppression circuit thereof, and the common-mode suppression circuit is applied to a signal transformer in the IGBT isolation driver, wherein when the signal transformer generates a common-mode voltage signal, a common-mode suppression unit at a dotted terminal of a secondary winding and a common-mode suppression unit at a non-dotted terminal of the secondary winding are used for bypassing common-mode current on the dotted terminal and the non-dotted terminal of the secondary winding by taking the low output level of a corresponding comparator in the IGBT isolation driver as a control target, namely, the common-mode suppression circuit provided by the invention can bypass common-mode current on the dotted terminal and the non-dotted terminal of the secondary winding through the corresponding common-mode suppression units when the common-mode voltage signal appears in the signal transformer, so that a signal processing unit on the high-voltage side of the signal transformer is prevented from receiving two pulses with the same height; and the normal work of the signal processing unit in the IGBT isolation driver is ensured.

Description

technical field [0001] The invention relates to the technical field of circuit electronics, in particular to a high-voltage frequency converter, an IGBT isolation driver and a common-mode suppression circuit thereof. Background technique [0002] In high-voltage inverters, such as figure 1 As shown, the controller (CONTROL CIRCUITRY in the figure) transmits the control signal on the low-voltage side to the IGBT on the high-voltage side through the IGBT isolation driver (GATE DRIVE in the figure), thereby realizing IGBT switching. IGBT isolated drivers usually use optocouplers, capacitive couplers, transformers and other isolators for isolated signal transmission. [0003] Take the signal transformer as an example, such as figure 2 As shown, the input and output of the signal transformer are on the high-voltage side and the low-voltage side respectively. The IGBT on the high-voltage side will generate a VCM (common mode voltage, common mode voltage) signal when switching. ...

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Problems solved by technology

[0004] In this regard, the present application provides a high-voltage frequency converter, an IGBT isolation driver and its common-mode suppression circuit to solve the common-mode voltage signal generated when the IGBT on the high-voltage side switches, which will form a common-mode current between the high-voltage side and the low-voltage side , causing the signal processing unit on the high voltage side to receive two pulses of the same high level, thus affecting the normal operation of the signal processing unit

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