Machine-Parameter-Independent Reduction of Harmonic Errors in Self-Sensing Control of PMSM

For anisotropy-based self-sensing control of PMSM at standstill and low speeds a minimal difference between the differential d-axis and q-axis inductances is necessary. The machine geometry, saturation and inverter nonlinearities can cause rotor-position-dependent machine parameters, leading to harmonic position errors in closed loop self-sensing control. This can deteriorate the overall control performance, the stability and the acoustics of the self-sensing drive system. In this work a novel method for machine parameter free adaptive compensation of harmonic position errors is proposed and validated by experimental results.