Calorimetric measurement methodology for comprehensive soft and hard switching loss characterisation

Accurate measurement of soft and hard switching losses is challenging. Electrical methods are prone to errors and calorimetric measurements most often cannot separate turn-on and turn-off energies. We present a calorimetric test setup capable of measuring and separating turn-on and turn-off energies in soft and hard switching regimes. The resulting loss map can be used to accurately predict power semiconductor losses, even when the converter is not fully in the soft-switching regime

Compensated Power Sensor for Semiconductor Switching Loss Measurement

Quantifying switching losses is crucial for designing high efficiency power converters. However, switching energy data is limited, partially due to limitations of a standard double-pulsetest (DPT). This paper presents a simple calorimetric fixture operating on the principle of heat flux balance, capable of separating turn-on and turn-off energies at various junction temperatures. It requires minimal calibration and is significantly faster than conventional calorimetric methods. Contrary to DPT-based data, a complete loss map of a transistor can be extracted, including hard- and soft-switching regimes. The method does not modify the commutation loop and can be operated in situ in the designed converter, measuring switching energies that include effects of actual circuit parasitics and component parameters