Optimized power loss equivalent modeling method for IGBT junction temperature estimation

Abstract

The invention discloses an optimized power loss equivalent modeling method for IGBT junction temperature estimation, and the method specifically comprises the steps: collecting an external variable needed by the calculation of power loss, calculating the average loss in a single fundamental wave period, and converting the average loss into half-sine loss; performing first-order square wave equivalence on the half-sine loss curve, and calculating an initial junction temperature value of a steady-state fundamental wave period in combination with a thermal network model; discretizing the half-sine loss curve, and deriving a junction temperature expression at any time point in a single steady-state fundamental wave period in combination with the thermal network model and the initial junction temperature value; deriving the junction temperature expression to obtain the maximum junction temperature time point and the minimum junction temperature time point, and performing discrete equivalence on the half-sine loss based on an equal-area rule; and calculating a discretized rectangular pulse loss value, substituting the discretized rectangular pulse loss value into the thermal network model, and calculating the junction temperature of the IGBT. According to the method, the discretization of power loss is more reasonable, the estimated junction temperature is more accurate, and meanwhile, the calculated amount in junction temperature estimation can be effectively reduced.

Description

technical field [0001] The invention belongs to the technical field of reliability evaluation of power semiconductors in power electronic converters, and in particular relates to an equivalent modeling method for optimizing power loss used for IGBT junction temperature estimation. Background technique [0002] In power electronic converter systems, insulated gate bipolar transistors (insulated gate bipolar transistors, IGBTs) are widely used in many industrial fields due to their excellent power conversion performance. As the working conditions change, the IGBT module will continue to age and be damaged over time. Relevant studies have shown that temperature fluctuation is the most critical factor affecting the reliability of IGBT modules, and the current reliability evaluation of converter IGBT modules is mainly based on junction temperature, so accurate junction temperature estimation is a key step in reliability analysis. [0003] For junction temperature calculation, th...

AI Technical Summary

Problems solved by technology

[0004] The existing power loss modeling methods mostly use the equidistant division criterion based on the time point of 1 / 4 fundamental wave cycle, which estimates that the time point of the maximum junction temperature will change with the change of the discrete level, and does not exist within the fundamental wave cycle The minimum junction temperature, which is inconsistent with the actual junction temperature curve characteristics, and further leads to a large error in the estimation of the junction temperature and a high amount of calculation

Images