An Improved IDIM Technique for Sensorless Control of Single-Phase Electromagnetic Drives

Sensorless control algorithms for single-phase electromagnetic actuators are nowadays a favorable solution for drive applications where the usage of position sensors is undesired. This work proposes an improved version of the “Integrator-Based Direct Inductance Measurement” (IDIM) technique for the sensorless control of such actuators, which is able to perform online identification of the position-dependent actuator inductance and resistance by evaluating the current ripple which is caused by a PWM-driven switching electronics. The improved technique does not require oversampling nor high computational effort. This work describes the technique thoroughly and uses it exemplary for the position control of an electromagnetic levitation setup. Experimental results proving the accuracy and the stability of the approach are shown and discussed.