Introduction

The junction temperature of power devices is a vital intimate state of any power electronic converter, and very hard to measure in operation. The invention relates to a method and a system for real-time estimating the devices’ temperature in power electronic converters. The invention applies to multiple semiconductor technologies like IGBT, Silicon and Silicon-Carbide (SiC) MOSFETs.

Technical features

State of the art power converters use a thermistor placed just outside or inside the power module for protection from overheating, and do not estimate the intimate operating temperature of the semiconductors. Such “blind” operation imposes design margins and limited reliability in critical operating conditions. The invention relates to a method and a system for characterizing the devices’ temperature footprint and for estimating the temperature during the operation. The solution comes at low additional cost in front of a high precision estimate, and it is valid for various types of switching converter. Moreover, it covers different semiconductors technologies like IGBT and Silicon or Silicon-Carbide MOSFETs. The direct temperature estimate increases the peak current of the converter and its reliability at the same time. Moreover, aging of components becomes predictable allowing for advanced prognostics.

Possible Applications

• Applications with frequent overloads like automotive and servo-drives;
• Safety critical applications like medical and aerospace;
• Applications were the downtime is costly (industrial processes, oil & gas);
• Extreme power density applications;
• Harsh ambient temperature conditions.

Advantages

• Individual temperature map calibration for each device of the converter;
• Temperature detection is precise;
• Does not affect the operation of the converter;
• Has a fast dynamic response;
• No complex computation required;
• Hardware modifications are minor and low cost.