The purpose of this diploma thesis is calibration of the torque signal at measuring stations for measuring electrical characteristics of permanent magnet synchronous electric motors in slovenian company Elaphe. Currently, when calculating uncertainty of torque measurement, only uncertainty of the torque transducer is taken into account. Behind the torque measurement on the user interface there is a chain of components, that bring additional uncertainty to torque measurement. Because of this, a procedure and it's execution for calibrating torque measuring chain and implementation of measurement correction in the current program for automatic measurement, with the purpose of reducing systematic error, are needed. Firstly, the measuring station MS3, that is used for end-of-line testing of in-wheel motors is introduced. Program for calibration consists of three main sub-programs, that are used for the aproximation of systematic error versus torque, evaluation of aproximation and measurement correction. In the following chapter, the calibration procedure is thoroughly explained. The test results had shown, that when measuring higher torque values (in clock-wise direction) relatively high systematic error appears. This doesn't apply for the counter-clock-wise direction of torque. With the implementation of correction, we succesfully corrected measured values at most of the working points and reduced the systematic error in average by 62 percents. In the conclusion, there are results of calculated uncertainty of torque measurement, propositions of improvements for the calibration program and summary of diploma thesis contents.
|
