Method and system for determining junction temperature of power semiconductor

Patent metadata

Field	Value
Publication number	US-12480823-B2
Application number	US-202118276800-A
Country	US
Kind code	B2
Filing date	Sep 14, 2021
Priority date	Mar 9, 2021
Publication date	Nov 25, 2025
Grant date	Nov 25, 2025

Abstract

The present invention concerns a method for determining the junction temperature of a power semiconductor using a temperature sensitive electrical parameter of a thermal sensitive electrical device in a system comprising the thermal sensitive electrical device, an external electrical circuit, a compensation module and a measurement module. The compensation module is composed at least of a first and a second switches. The invention: —puts the first switch in a closing state and puts the second switch in an opening state during a first period of time in order to measure a first set of voltages, —changes the state of the first switch and/or the state of the second switch or the state of at least one another switch during at least one another period of time in order to measure at least one another voltage, —determines a value of the temperature sensitive parameter using the measured voltages.

First claim

The invention claimed is:

1 . A method for determining a junction temperature of a power semiconductor using a temperature sensitive electrical parameter of a thermal sensitive electrical device in a system comprising the thermal sensitive electrical device, an external electrical circuit, a compensation module and a measurement module, characterized in that the compensation module is composed at least of a first and a second switches, a first terminal of the first switch is connected to a first terminal of the thermal sensitive electrical device, a second terminal of the first switch is connected to a first terminal of the second switch, to a first terminal of a signal source and to a first output of the compensation module, a second terminal of the second switch is connected to a second terminal of the signal source and to a second output of the compensation module, wherein the method comprises:
putting the first switch in a closing state and putting the second switch in an opening state during a first period of time in order to measure a first set of voltages,
changing the state of the first switch and/or the state of the second switch or the state of at least one another switch during at least one another period of time in order to measure at least one another voltage, and
determining a value of the temperature sensitive parameter using the measured voltages, and wherein:
the state of the second switch is changed during the at least one another period of time named second period of time in order to measure the at least one another voltage, and the at least one another voltage is a voltage that is representative of an offset voltage generated by parasitic resistors of the compensation module and by an internal offset of the measurement module or;
the state of the first and the second switches are changed during the at least one another period of time named third period of time, and the at least another switch is a third switch the state of which is set to closing state, the at least another voltage is a second set of voltages that are representative of the signal source and the external electrical circuit and a first terminal of the third switch is connected to the second terminal of the first switch, a second terminal of the third switch is connected to a first terminal of a first capacitor and a second terminal of the first capacitor is connected to a second terminal of the thermal sensitive electrical device and to a second terminal of the external electrical circuit or;
the state of the first switch is changed during the at least one another period of time named fourth period of time, and the at least another switch is a fourth switch the state of which is set to closing state, the at least another voltage is a set of voltages that are representative of the functioning of the second switch and a first terminal of the fourth switch is connected to the second terminal of the second switch, a second terminal of the fourth switch is connected to a first terminal of a second capacitor and a second terminal of the second capacitor is connected to the first terminal of the second switch or;
the at least another switch is a fifth switch the state of which is set to closing state during the at least one another period of time named fifth period of time, the at least another voltage is a voltage that is representative of the signal source and a first terminal of the fifth switch is connected to the second terminal of the second switch, a second terminal of the fifth switch is connected to a first terminal of a resistor and a second terminal of the resistor is connected to the first terminal of the second switch.

2 . The method according to claim 1 , characterized in that the thermal sensitive electrical parameter is an internal gate resistance in series with an input capacitance of a power semiconductor device.

3 . The method according to claim 2 , characterized in that the external circuit is a voltage source in series with a resistor or a short circuit or a resistor or a capacitor or an inductor or a switch.

4 . The method according to claim 1 , characterized in that the signal source is a current source.

5 . The method according to claim 1 , characterized in that the thermal sensitive electrical device is a PN junction implanted on a power semiconductor device or implanted close to the power semiconductor device.

6 . The method according to claim 1 , characterized in that the thermal sensitive electrical device is a resistance dependent on the temperature implanted on the power semiconductor device or implanted close to a power semiconductor.

7 . The method according to claim 1 , characterized in that the at least one other voltage is compared to a reference voltage and a notification is generated if the at least one other voltage is out of the range of the reference voltage.

8 . A system for determining a junction temperature of a power semiconductor using a temperature sensitive electrical parameter of a thermal sensitive electrical device, the system comprising the thermal sensitive electrical device, an external electrical circuit, a compensation module and a measurement module, characterized in that the compensation module is composed at least of a first and a second switches, a first terminal of the first switch is connected to a first terminal of the thermal sensitive electrical device, a second terminal of the first switch is connected to a first terminal of the second switch, to a first terminal of a signal source and to a first output of the compensation module, a second terminal of the second switch is connected to a second terminal of the signal source and to a second output of the compensation module, wherein the system comprises circuitry configured to:
put the first switch in a closing state and putting the second switch in an opening state during a first period of time in order to measure a first set of voltages, change the state of the first switch and/or the state of the second switch or the state of at least one another switch during at least one another period of time in order to measure at least one another voltage, and determine a value of the temperature sensitive parameter using the measured voltages and wherein: the state of the second switch is changed during the at least one another period of time named second period of time in order to measure the at least one another voltage, and the at least one another voltage is a voltage that is representative of an offset voltage generated by parasitic resistors of the compensation module and by an internal offset of the measurement module or; the state of the first and the second switches are changed during the at least one another period of time named third period of time, and the at least another switch is a third switch the state of which is set to closing state, the at least another voltage is a second set of voltages that are representative of the signal source and the external electrical circuit and a first terminal of the third switch is connected to the second terminal of the first switch, a second terminal of the third switch is connected to a first terminal of a first capacitor and a second terminal of the first capacitor is connected to a second terminal of the thermal sensitive electrical device and to a second terminal of the external electrical circuit or; the state of the first switch is changed during the at least one another period of time named fourth period of time, and the at least another switch is a fourth switch the state of which is set to closing state, the at least another voltage is a set of voltages that are representative of the functioning of the second switch and a first terminal of the fourth switch is connected to the second terminal of the second sw

Assignees

• Mitsubishi Electric Corp

Inventors

• Brandelero Julio
• Lefevre Guillaume

Classifications

• G01K7/24

  in a specially-adapted circuit, e.g. bridge circuit · CPC title

• G01K2215/00

  Details concerning sensor power supply · CPC title

• G01K7/16

  using resistive elements · CPC title

• G01K2217/00

  Temperature measurement using electric or magnetic components already present in the system to be measured · CPC title

• G01K7/01 Primary

  using semiconducting elements having PN junctions (G01K7/02, G01K7/16, G01K7/30 take precedence) · CPC title