Test-bench for motor-converter efficiency measurement. A preliminary study

摘要

This work is to support first information for the project 'Realization of a motor-test-bench'. This project itself is a part of an energy advising project. Purpose of the test-bench is to provide measured performance data of the variable speed drive components induction motor and frequency converter. A database with the efficiency values of numerous motors and converters at different operation points is to be generated. Based on this report and further studies, decisions for the configuration of the test-bench can be made. In this paper the different test methods are presented. At the beginning these test methods for motors and converters are viewed isolated and with a special eye on standards. Three test methods for motors are considered to be relevant possibilities for our purpose. These are namely two IEC Standard 34-2 tests, one with separated loss measurement and the other with calorimetric loss measurement, and the IEEE Standard 112 Method B test with mechanical output measurement. Accuracy of the different test methods is investigated roughly and no cost estimation is made by now. Two ideas how the effects of non-sinusoidal motor supply can be treated are presented. Efficiency interpolation for not measured operating points is analyzed and a method with recalculation of the different types of losses in the motor is shown. For time-variable load-function, only the effect of machine temperature and speed variation have been investigated. At the end of this report there is a listing of unsolved problems. (EG) (57 refs.)