A Position Estimation Method for Single-Phase Electrical Machines Without Injecting Extra Test Pulses

Sensorless position estimation algorithms for electromagnetic actuators are becoming increasingly significant in the field of control and condition monitoring since they allow the estimation of the actuator position without any mechanical sensor. Such algorithms typically exploit the position dependency of the actuator inductance. This work presents a new technique capable of identifying the inductance of a single-phase electromagnetic actuator in operation without having to add test pulses, achieving high accuracy and with little signal processing effort. Using this technique, the inductance behavior of an industrial solenoid is characterized. In a further step, the obtained characteristic is modeled by means of different curve fitting approaches and inverted for position estimation. The resulting position estimation technique is implemented and validated experimentally on the Investigated solenoid.