A Microprocessor-Based Load Angle Measurement System

This paper describes a transient load angle measurement system using a 6800 microprocessor. A photodetector senses the rotor position and its output is compared with a reference signal from the terminal voltage. The phase difference representing load angle is fed to the microprocessor for storage and display. The system also provides a feedback signal for control purposes. The technique used makes the system suitable for variable frequency inverter driven synchronous machines. The system is novel and the response is fast. It has been successfully employed for an inverter-driven reluctance motor. Experimental results are presented along with the description of the system.