This paper addresses the topic of a model-free system identification of highly nonlinear power electronics systems from the data either through a time-domain simulation or a hardware measurement. This system identification method based on the black-box approach using the data generated from well-known design tools such as PSpice and MATLAB is generally simpler and independent of type of converter. As an application of identifying an unknown plant in power electronics systems, a constructive black-box approach is presented which aims at generating discrete-time small-signal linear equivalent models for a general class of converters, which includes resonant converters, pulsewidth modulation (PWM) converters and zero-voltage-switched (ZVS) PWM converters. The resulting small-signal model describes the converter as a linear time-invariant system, and the knowledge of the identified linear system can be applied to the switching converters for constructing feedback controllers. The identification results are compared with the analytical model and experimental data

The resolver is mainly used to obtain position information when driving the permanent magnet synchronous motor (PMSM). A resolver generates periodic position errors owing to the transformer ratio difference and excitation signal distortion. When the vector control is done with the position information that includes position error, torque ripple is periodically generated. An algorithm is proposed that reduces torque ripple components by applying a simple torque ripple compensation method to the current controller.