IGBT online state monitoring method and measuring system based on Miller platform delay

Abstract

The invention discloses an IGBT online state monitoring method and measuring system based on Miller platform delay. One end of a drive signal pre-processing circuit is connected with one end of a controller through a time measuring circuit. The other end of the controller and the drive chip of an IGBT device drive circuit are connected. The drive chip is divided into two paths. One is connected with an IGBT device, and the other is connected with the drive signal pre-processing circuit. The drive signal pre-processing circuit extracts the Miller platform delay in a drive voltage signal of an IGBT turn-on process as the characteristic parameter of IGBT state monitoring to carry out initial state calibration and real-time online monitoring. The health and reliability of the IGBT device during an aging process are evaluated. According to the invention, online monitoring and parameter extraction do not affect the operation of a main circuit, and are sensitive to various typical failure modes; and the method and the system can be directly used for health monitoring and service life evaluation of the IGBT, and solve the problem of lack of effective characteristic parameters in the existing state monitoring technology of power electronic devices.

Description

technical field [0001] The invention belongs to the technical field of reliability of power electronic devices, and in particular relates to an IGBT online state monitoring method and measurement system based on Miller platform time delay. Background technique [0002] IGBT (Insulated Gate Bipolar Transistor, insulated gate bipolar transistor) is the core device of national strategic industries such as energy conversion and transmission. It is widely used in rail transit, smart grid, aerospace, electric vehicles and new energy equipment. IGBT is the most widely used power device and plays an indispensable role. [0003] With the wide application of IGBT, its power level and system integration are getting higher and higher, the working environment is more harsh, the service conditions are becoming more and more harsh, and the requirements for reliability are becoming more and more stringent. In power electronic equipment, due to various reasons such as improper use of IGBT o...

AI Technical Summary

Problems solved by technology

Conventionally, the IGBT conduction tube voltage drop VCE,ON is used as the characteristic parameter for state monitoring, but the change of this parameter during the aging process is relatively small. When the bus voltage value is hundreds of volts or even thousands of volts, the millivolt The level of change has extremely high requirements on the sampling system, and VCE, ON is only related to the aging effect of the package level, ignoring the aging effect of the chip level, and the comprehensive health status information of the IGBT cannot be obtained completely.

Aiming at chip-level aging effects, the state monitoring is usually carried out with the characteristic parameters of IGBT threshold voltage or collector leakage current. However, the measurement of these parameters can only be done offline, which requires shutdown testing, which is obviously not suitable for field applications.

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