IGBT module health state monitoring method based on natural frequency of thermal network

Abstract

The invention discloses an IGBT module health state monitoring method based on a natural frequency of a thermal network. The IGBT module health state monitoring method comprises the steps of: establishing a fourth-order equivalent Cauer thermal network model according to physical performance parameters of an IGBT module and a radiator; establishing a mapping relationship between the natural frequency of the thermal network and parameters of each order in the thermal network model according to an order-of-magnitude difference between the thermal parameters of each order; fitting a measured junction temperature cooling curve of the IGBT module to obtain the natural frequency of the thermal network; and monitoring a health state of the IGBT module according to the natural frequency. The IGBTmodule health state monitoring method can monitor the aging degree of the IGBT module under the condition that the power loss of the IGBT module is not measured.

Description

technical field [0001] The invention relates to a method for monitoring an IGBT module, in particular to a method for monitoring the health state of an IGBT module based on the natural frequency of a thermal network. Background technique [0002] IGBT modules are widely used in new energy systems, such as traction of high-speed trains, wind power and photovoltaic power generation, etc. However, with the continuous improvement of power density levels, the thermal fatigue aging problem of IGBT modules has become increasingly prominent. Due to the fluctuation and intermittency of the processing power of the IGBT module and the change of task conditions, the IGBT module is vulnerable to thermal cycle shocks during long-term use. And because the thermal expansion coefficients of the multi-layer physical materials inside the IGBT module do not match, there will be extrusion deformation between the physical layers, especially the chip solder layer and the substrate solder layer ar...

AI Technical Summary

Problems solved by technology

However, since the IGBT module usually works in the switching state, and the voltage and current change rapidly, how to accurately measure the conduction loss of the IGBT module is still an unsolved problem.

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