Comparison of calorimetric and electrical loss measurement methods in a frequency converter research and development application

New applications of frequency converters such as solar energy have growing need to determine the efficiency of a converter with good precision. The component level losses are not easy to measure as the input and output of converter components are not sinusoidal. The calorimetric method gives an approach for measuring the losses directly rather than using the difference of the electrically measured quantities. This paper compares the feasibility of the described methods in an active rectifier input filter power loss measurement. The calorimetric method is superior in accuracy, but the measurement time is multiple compared to the electrical method. Electrical measurement instrument calibration by comparison with calorimetric method could have significant practical applications resulting in a combined system with high accuracy and short measurement duration.