Kevin Muñoz Barón

Abstract

This paper presents a robust and easy-to-implement approach to measure junction temperature of SiC power devices using quasi-threshold voltage as temperature sensitive electrical parameter with adjustable temperature sensitivity. Static and dynamic measurements were performed and compared on a commercially available 1.2 kV/120 A SiC power module. The voltage drop across the parasitic inductor is used as the trigger for the data acquisition circuit. A robust approach by using a D-flip-flop for latching in data acquisition circuit while keeping fast turn-on behavior and low noise susceptibility in consideration with the option of variable sensitivity has been successfully implemented and presented.

Abstract

This paper presents a robust and easy-to-implement approach to measure the junction temperature of SiC power devices using quasi-threshold voltage as temperature sensitive electrical parameter with adjustable temperature sensitivity. The voltage drop across the parasitic inductance between Kelvin and power source is used to trigger the data acquisition circuit. The novelty of the proposed method lies in the concept of variable temperature sensitivity where the robustness decreases with the increase in the sensitivity. This concept proposes a trade-off between temperature sensitivity and robustness. A D flip-flop is used to make the acquisition circuit more robust to prevent false triggering while keeping fast switching speed and low noise susceptibility. Basic simulations, static and dynamic measurements are performed successfully on a commercially available 1.2 kV/120 A power module in a buck converter topology. The effect of DC-link voltage and load current invariance is also verified in this paper.

Abstract

In order to determine the reliability of power semiconductor devices, power cycling tests are applied. Most commonly the necessary heat is generated by conduction losses in the die. As this does not reflect the loss generation in the application, this paper presents a new approach. The heat is generated by a combination of switching and conduction losses exactly as in the application. The inputs and outputs of two three-phase inverters are coupled in order to achieve circular energy flow and therefore high efficiency of the power cycling test. Furthermore, a novel 3D-printed aluminum module heat sink is designed and utilized to achieve the highest possible temperature dynamic.

Abstract

In many power electronic applications, it is important to monitor the junction temperature of the power semiconductor devices. This enables for example an abnormal temperature protection, lifetime monitoring or junction temperature control. This paper proposes an online junction temperature measurement based on the internal gate resistance as a temperature sensitive electrical parameter. A direct measurement of this resistance is not possible. Therefore, a high frequency signal is injected into the gate circuit to measure the gate circuit's impedance, which includes the temperature sensitive internal gate resistance. This paper focuses on a simple realization of this method.