In recent years, development of high-efficiency inverters using power semiconductors such as SiC and GaN has progressed, enabling high-speed switching. However, in variable-frequency drive systems, only the fundamental wave power is actually input to the motor and directly generates rotational torque; all other high-frequency components are lost as ineffective energy (heat, sound, and vibration). Therefore, reducing high-frequency power loss is a key focus in developing efficient variable-frequency motor systems, requiring precise power measurement data to analyze relevant factors.

This case study introduces the differences between the harmonic analysis function of ordinary power analyzers and the Power Spectrum Analysis (PSA) function of the PW8001 High-Precision Power Analyzer, as well as a method for estimating inverter motor loss coefficients using power spectrum analysis.