Real Operating Loss Measurement of Low-Loss Inductors

This technical article presents a detailed methodology for measuring the operating loss of low-loss inductors using a high-precision wideband power analyzer and current sensor. The study focuses on inductors used in electric and hybrid vehicles, emphasizing the importance of accurately measuring inductor loss to enhance overall system efficiency. The measurement system comprises a Power Analyzer PW8001 and an AC/DC Current Sensor CT6904, which are capable of low phase error even at high frequencies. The article outlines the experimental setup, including the excitation device and measurement methods employed. It compares the results obtained from the Power Analyzer with those from a measurement system developed by the Shimizu Lab at Tokyo Metropolitan University and values calculated using extended Steinmetz equations. The findings demonstrate that the measurement systems yield results that agree within approximately ±5%, indicating their precision in measuring inductor loss under operational conditions.