Temperature prediction method for igbt module with ntc thermistor

Abstract

The invention discloses a temperature prediction method of an IGBT module with an NTC thermistor. The method includes the following steps that: the present operating current I of the IGBT module is detected through a current sensor; the current loss PLOSSER of the IGBT module is calculated on the basis of the operating current I through a formula; temperature difference Tth-jnt between the NTC thermistor and the IGBT module chip is obtained through conversion on the basis of the current loss; and the predicted temperature Tj of the IGBT module is obtained according to the sum of the temperature difference Tth-jnt and the current temperature Tht of the IGBT module detected by the NTC thermistor. With the method of the invention adopted, the defect of traditional IGBT module over-temperatureprotection can be eliminated; the operating temperature of the IGBT module can be obtained accurately; and therefore, the more accurate over-temperature protection of the IGBT module can be realized,and the normal operation of a device provided with the IGBT module can be ensured.

Description

technical field [0001] The invention relates to a temperature prediction method of an IGBT module with an NTC thermistor. Background technique [0002] The IGBT module is a semiconductor module packaged by insulated gate bipolar transistor and freewheeling diode through a specific circuit bridge. The packaged IGBT module is directly applied to inverters, UPS uninterruptible power supplies and other equipment; the operating temperature of the IGBT module It is a very important parameter, which is related to the normal operation of the equipment. Such as figure 1 As shown, the IGBT module 1 is usually composed of six bridge-connected insulated gate bipolar transistors 11 and an NTC thermistor 12. The operating temperature of the IGBT module 1 is detected in real time through the NTC thermistor 12 to realize the overtemperature of the IGBT module 1. Protect. However, in practical applications, due to the difference in the setting position of the NTC thermistor on the IGBT mo...

AI Technical Summary

Problems solved by technology

However, in practical applications, due to the difference in the setting position of the NTC thermistor on the IGBT module, there is a certain error between the detected temperature and the actual operating temperature of the IGBT module. There is a certain hysteresis in the temperature detection of the IGBT module, which leads to deviations in the over-temperature protection of the IGBT module, which affects the normal operation of the IGBT module equipment, and may damage the IGBT module in severe cases.

Images