Reducing the Effect of Iron Losses on the Quality of Self-Sensing Control Based on Current Oversampling

Parasitic effects lead to a distorted current response to an injected test signal. This paper investigates how this distortion affects the quality of a self-sensing control (SSC) with current oversampling (OS) and square-wave injection (SWI). Furthermore, a grey box model (GM) filter is designed to eliminate this effect in order to improve the quality of the SSC. This GM filter is based on the difference between the basic permanent magnet synchronous machine (PMSM) model and a PMSM model considering an iron path. The two filter parameters are obtained using a two-step numerical optimisation. The filter is validated with a simulation and with an experimental investigation.