IGBT module internal defect monitoring method and circuit based on gate charge change

Abstract

The invention discloses an IGBT module internal defect monitoring method and circuit based on gate charge change. The method is based on the characteristic that a gate electric signal of an IGBT module in a switching process is affected by the internal parameter change of the IGBT module due to the aging of the IGBT module; a health state of the IGBT module at the current period is evaluated by monitoring a gate pole electric signal of the IGBT module in the switching process; specifically, the gate charge of the IGBT module is taken as a monitoring object, and the internal defect condition ofthe current IGBT module is evaluated by monitoring the change of the gate charge of the IGBT module in the operation process; and the gate charge information obtained in a plurality of switching periods is continuously accumulated to amplify defects in the IGBT module. According to the method, the IGBT module can be conveniently monitored under the condition that the IGBT module is not disassembled, meanwhile, it can be ensured that the health state of the IGBT module can be accurately evaluated under normal work of the IGBT module, and reliability of the module and the system is improved.

Description

technical field [0001] The invention relates to the technical field of power electronics, in particular to a method for monitoring defects in an internal branch of an IGBT module, in particular to a method and a circuit for monitoring internal defects in an IGBT module based on gate charge changes. Background technique [0002] Power electronic devices have been widely used in new energy power generation, traffic traction, aerospace and other fields. Improving the reliability of power electronic devices can meet stricter safety and cost requirements. As a general-purpose power semiconductor device, an insulated gate bipolar transistor (insulated gate bipolar transistor, IGBT) module is widely used in power electronic devices with wide power levels. In order to improve the flow capacity of the power module and reduce the cost of use, the bonded wire packaged IGBT module is considered to be a promising solution to increase the capacity of the power module. However, complex an...

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Problems solved by technology

For multi-chip IGBT modules, due to the inconsistency of the temperature of each chip, this method of ensuring a constant current during monitoring and obtaining the junction temperature of the module during the monitoring process has certain limitations on the monitoring of bonding wire defects in IGBT modules. The short-circuit current method is to use the same short-circuit current at each temperature point in the transfer characteristics of the IGBT module. The short-circuit current decreases with the increase of the IGBT module bonding wire defect and is not affected by temperature, but the short-circuit current Whether it is a potential hazard to the IGBT module or the power electronic equipment is relatively large; the gate switch signal can be used to monitor the defect state of the bonding wire of the multi-chip IGBT module, but these switch characteristic quantities are easily affected by noise, and require Sampling equipment has a high sampling frequency, which is not conducive to practical application in industrial sites

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