Switching element having temperature monitoring and method for temperature monitoring

Patent metadata

Field	Value
Publication number	US-2019137347-A1
Application number	US-201716096128-A
Country	US
Kind code	A1
Filing date	Mar 9, 2017
Priority date	Apr 29, 2016
Publication date	May 9, 2019
Grant date	—

Abstract

The present invention relates to a temperature monitoring for switching elements, in particular for a module having bipolar transistors with an insulated gate. For this purpose, the current operating parameters of the IGBT module are detected and, on the basis of said operating parameters, an expected temperature of the switching element is determined at a predetermined position. Said expected temperature is compared with a temperature detected at this position. If the actual temperature exceeds the expected temperature, then this is an indication of a malfunction.

First claim

1 . A switching element having temperature monitoring, the switching element comprising:
an IGBT module ( 1 ) including a first plurality of IGBT chips and a second plurality of IGBT chips, wherein the collector terminals of the first plurality of IGBT chips are electrically coupled to a first terminal (A 1 ) of the IGBT module ( 1 ), and the emitter terminals of the first plurality of IGBT chips are electrically coupled to a node (K), and wherein the collector terminals of the second plurality of IGBT chips are electrically coupled to the node (K), and the emitter terminals of the second plurality of IGBT chips are electrically coupled to a second terminal (A 2 ) of the IGBT module ( 1 ); a first temperature sensor ( 11 ) which is designed to detect a chip temperature at a predetermined position of the IGBT module ( 1 ); a second temperature sensor ( 12 ) which is designed to detect an ambient temperature in the vicinity of the IGBT module ( 1 ); a current sensor ( 10 ) which is designed to detect an electric current which flows into the IGBT module ( 1 ) at the node (K) of the IGBT module ( 1 ); and a monitoring device ( 20 ) which is designed to
ascertain a limit temperature, using the electric current detected via the current sensor ( 10 ) and the ambient temperature detected via the second temperature sensor ( 12 ), and
to detect a malfunction of the IGBT module ( 1 ), based on a comparison of the ascertained limit temperature to the chip temperature detected via the first temperature sensor ( 11 ).

2 . The switching element as claimed in claim 1 , wherein the IGBT module ( 1 ) comprises a cooling device ( 14 ) which may be cooled by means of a fluid, wherein the cooling device ( 14 ) comprises a third temperature sensor ( 13 ) which is designed to detect a coolant temperature of the fluid; and
wherein the monitoring device ( 20 ) is furthermore designed to ascertain the limit temperature, using the detected coolant temperature.

3 . The switching element as claimed in claim 1 , wherein the monitoring device ( 20 ) comprises a memory ( 21 ) which is designed to store a predetermined set of characteristic curves for the limit temperature to be ascertained, as a function of current flowing into the IGBT module ( 1 ) and temperature.

4 . The switching element as claimed in claim 1 , wherein the monitoring device ( 20 ) is designed to calculate the limit temperature, based on a predetermined function which is stored in monitoring device ( 20 ).

5 . The switching element as claimed in claim 1 , wherein the monitoring device ( 20 ) is designed to carry out the ascertainments of the limit temperature and the comparison of the ascertained limit temperature to the chip temperature only if an electric machine ( 3 ) which is connected to the node (K) of the IGBT module ( 1 ) is in a predefined operating state.

6 . A drive system, including:
an electric machine ( 3 ) having a plurality of phase terminals; a rectifier ( 2 ) including a switching element as claimed in claim 1 .

7 . The drive system as claimed in claim 6 , including a control device which is designed to short-circuit the phase terminals of an electric machine ( 3 ) by controlling the rectifier ( 2 ) in an active short circuit;
wherein the monitoring device ( 20 ) is designed to carry out the ascertainment of the limit temperature and the comparison of the ascertained limit temperature to the chip temperature only if the phase terminals of the electric machine ( 3 ) are short-circuited.

8 . A method for monitoring the temperature of an IGBT module ( 1 ) including a first plurality of IGBT chips and a second plurality of IGBT chips, wherein the collector terminals of the first plurality of IGBT chips are electrically coupled to a first terminal (A 1 ) of the IGBT module ( 1 ), and the emitter terminals of the first plurality of IGBT chips are electrically coupled to a node (K), and wherein the collector terminals of the second plurality of IGBT chips are electrically coupled to the node (K), and the emitter terminals of the second plurality of IGBT chips are electrically coupled to a second terminal (A 2 ) of the IGBT module ( 1 ), the method comprising:
detecting (S 1 ) a chip temperature at a predetermined position of the IGBT module ( 1 ); detecting (S 2 ) an ambient temperature in the vicinity of the IGBT module ( 1 ); detecting (S 3 ) an electric current which flows into the IGBT module ( 1 ) at the node (K) of the IGBT module ( 1 ); ascertaining (S 5 ) a limit temperature, using the detected electric current and the detected ambient temperature; comparing (S 6 ) the ascertained limit temperature to the detected chip temperature; and detecting (S 7 ) a malfunction of the IGBT module ( 1 ) if the detected chip temperature exceeds the ascertained limit temperature.

9 . The method as claimed in claim 8 , further comprising a step (S 4 ) for detecting a coolant temperature of a fluid via which the IGBT module ( 1 ) is cooled;
wherein the step (S 5 ) for ascertaining the limit temperature furthermore ascertains the limit temperature, using the detected coolant temperature.

10 . The method as claimed in claim 8 , wherein the limit temperature is ascertained using a previously determined set of characteristic curves.

Assignees

• Bosch Gmbh Robert

Inventors

• Jin Jiahang

Classifications

• G01K13/00

  Thermometers specially adapted for specific purposes · CPC title

• G01K7/427 Primary

  Temperature calculation based on spatial modeling, e.g. spatial inter- or extrapolation · CPC title

• H01L29/7393

  Electricity · mapped topic

• H10D12/411

  Insulated-gate bipolar transistors [IGBT] · CPC title