A kind of igbt module life monitoring method

Abstract

The invention discloses a method for monitoring the life of an IGBT module, which is characterized in that the method comprises the following steps: performing offline calibration on samples of the IGBT module to obtain a calibration sample; performing data analysis on the calibration sample to obtain reference data and determine A preset deviation value; before the operation of the IGBT module, detect the IGBT module and obtain detection data; compare the detection data with the reference data, and judge the deviation between the detection data and the reference data Whether the value is greater than the preset deviation value, if yes, it is judged that the life of the IGBT module is about to end. Using the IGBT module life monitoring method of the present invention, a simple and efficient detection method can be used to realize the monitoring of its life and the warning of the end of life; the monitoring method fully considers the module difference through calibration and statistics; and the detection method is under low pressure. Detection, and the influence of different junction temperatures are considered, which greatly improves the safety and accuracy of life monitoring.

Description

A kind of IGBT module life monitoring method technical field [0001] The present invention relates to the field of IGBT modules, in particular to a method for monitoring the life of an IGBT module. Background technique [0002] At present, in practical applications of IGBT modules, under the influence of various operating conditions, there are frequent power cycles. worked During the process, the chip is continuously heated and cooled, resulting in changes in the structure of the metal cladding on the surface of the chip. Gradually accumulate, resulting in the breakage, displacement or falling off of the bonding wire connected to the chip, and finally the IGBT module is terminated due to its service life. failure, which in turn can cause unintended equipment downtime or lead to a larger accident. Therefore, the aging of the IGBT modules is monitored, and the It is very important to issue a warning before its end of life, and it is also a technical problem in this fiel...

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Problems solved by technology

This method requires power cycle data, loss and junction temperature calculation models, and life models under application conditions, and there are problems such as difficult data acquisition, high modeling requirements, and complex calculations.

[0004] A parameter that characterizes end-of-life for power cycling is the IGBT saturation voltage drop V cesat or diode forward voltage drop V f The change exceeds the allowable value, and some methods will also directly detect V cesat or V f Realize life detection, but this method will have the following problems: For example, when the detection is carried out when there is high voltage, if there is a short circuit in the upper IGBT at this time, and then the lower IGBT is turned on for detection, it may cause the bridge arm to pass through and cause device damage ;Even if the above risks are taken into account, trying to avoid it by shortening the turn-on time will still cause the problem of high requirements for the response time and precision of the detection circuit; in addition, V cesat and V f The value is very small, and the detection is easily disturbed under high pressure

In addition, existing methods simply detect V cesat or V f , the sensed value is compared with a fixed limit, without taking into account the effect of junction temperature on V cesat or V f effects, and differences between modules, can affect the accuracy of lifetime warnings

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