Determination of the Torque-Speed Characteristic of Induction Motor in Electric Machinery Education

The paper describes the measuring method for determination of the torque-speed characteristic of an induction machine used in electric machinery classes performed at the Polytechnic of Zagreb. The torque-speed characteristic is determined by recording and differentiating speed signal during the starting. Data is gathered using a measuring system based on a simple digital acquisition card, and processed in custom software, built with LabVIEW, on a personal computer. Advantages and shortages of this sort of measurement compared with other measuring methods are given, and measuring equipment deployment and software development are described.