An energy-saving automatic system for the measurement of the characteristics of asynchronous machine

This paper presents an energy-saving system to measure the characteristics of the induction machine automatically. This system includes control unit, data acquisition unit(DAS20, SSH4), voltage,current, power, speed and torque sensing unit(power meter 2533E32, speed-torque sensor) and energy feedback unit (DC motor, DC generator and asynchronous machine). A new method is introduced here to generate pulse-width tunable trigger signal to control single-phase AC/DC converter which supplies power to DC motor excitation winding in the energy feedback unit. Therefore the load of the asynchronous machine under test becomes changeable and the energy is saved during the measurement process. In the system PC is utilized to increase the measurement efficiency. C language is utilized to create the measurement menu. The drive for the data acquisition board DAS20 is programmed using assembly language. The drive program is mixed in the C language environment. Therefore the menu programmed by C language can fulfill the data acquisition. Furthermore I/O signals can trigger the switch to supply or cut the power to induction machine under test. The whole measurement is controlled by PC. The operator only needs to press the button in the keyboard, the measurement procedure will be finished. The measured data and related curves will be presented on the screen of the PC.