Systems and methods for monitoring junction temperature of a semiconductor switch

A semiconductor switch device, comprising:

• a gate driver configured to turn-on and turn-off the semiconductor switch device;
• and
• a junction temperature monitoring system electrically coupled to the semiconductor switch device and configured to a monitor junction temperature of the semiconductor switch device, wherein the junction temperature monitoring system comprises:
• a sensing resistor electrically coupled to a source terminal of the semiconductor switch device in a gate loop of the semiconductor switch device;
• a detection circuit electrically coupled to the gate loop of the semiconductor switch device and configured to measure a voltage difference across the sensing resistor;
• and
• an electronic control unit electrically coupled to the gate loop and the detection circuit, wherein the electronic control unit is configured to:
• determine a first gate current peak driven by a gate driver during a switching process of the semiconductor switch device, wherein the first gate current peak is determined based on the voltage detected by the detection circuit;
• and
• determine the junction temperature based on the first gate current peak.

A method of online monitoring a junction temperature of a semiconductor switch, comprising:

• initiating at least one switching cycle of the semiconductor switch;
• logging gate voltage of the semiconductor switch during the at least one switching cycle;
• receiving an electrical signal from a detection circuit that is electrically coupled to a gate loop of the semiconductor switch, wherein the electrical signal is indicative of a voltage measured across a sensing resistor of the gate loop and is electrically coupled to a source terminal of the semiconductor switch;
• determining a first gate current peak based on the electrical signal;
• and
• determining the junction temperature based on the first gate current peak.