A sensorless torque and speed monitoring system for electrical machines

In general, the torque and speed monitoring system used in industrial process or electrical machine testing requires dedicated torque and speed sensors, which are expensive and difficult to install. To overcome these problems, a sensorless torque and speed monitoring system is developed and presented in this paper. The proposed system detects the input voltage and current of the induction motor, and uses them to calculate the torque and speed by a digital signal processor instead of using the torque and speed sensors. The effects of the core loss and mechanical loss are also compensated to improve the accuracy of the calculated torque and speed.