TEMPERATURE ESTIMATION IN POWER SEMICONDUCTOR DEVICE IN ELECTRIC DRVIE SYSTEM

摘要

Estimating junction temperature in a power semiconductor includes monitoring electrical current direction so as to determine which of a first and a second power semiconductor is in an on-state, and sensing a voltage drop across the one of the power semiconductors. Voltage drop may be correlated with temperature according to a gain dependent upon a level of the electrical current.

主权项

1. A method of operating an electric drive system comprising:
alternately conducting electrical current through a first power semiconductor and a second power semiconductor in the electric drive system, dependent upon an alternating direction of flow of the electrical current; monitoring the direction of flow of the electrical current so as to determine which one of the first and the second power semiconductors is in an on-state conducting the electrical current; monitoring a voltage drop across the one of the first and the second power semiconductors in the on-state; calculating a value indicative of an estimated junction temperature in the one of the first and the second power semiconductors in the on-state responsive to the voltage drop; and outputting a temperature warning signal responsive to the determined value.