Torque and Rotational Speed Estimation with Parameter Identification of Line-Start Induction Motor for Motor-Operated Valves

Abstract

This paper presents a method for estimating the torque and rotational speed of line-start induction motors for motor-operated valves. Routine inspections of the valves are carried out because motor-operated valves are used in momentous plants such as power plants where securing, the reliability of the valves are very important. Movement environments in these plants are characterized by high temperature and humidity and therefore, it is difficult to position sensors near motors. In such a case, we must troubleshoot the system without using torque or speed sensors. The proposed method can estimate the torque and speed of an induction motor by using currents and voltages near the switchboard. Furthermore, we propose the parameter identification of mutual inductance by comparing the scalar and vector products between currents and voltages. The proposed method is validated by experimental results.