Quick Test Theory And Methods For Mechanical Charateristics Of Brushless DC Motor

The brushless DC motor was widely used in the automobile,communications equipment, office supplies, industrial control, aerospace industryand other fields for its advantages of high reliability and efficiency, also because ithas larger output torque, more wide speed range and less steady state speed error, ect.Meanwhile brushless DC motor production industry has a rapid development. In theproduction process of motor, the performance test is effective measure to assure thequality of motor. Therefore, the fast measurement technology for brushless DCmotor becomes the focus. Based on mordern signal analysis technology, thedissertation presents a mechanical characteristic testing method of brushless DCmotor. The method is realized by using virtual instrument technology according tothe basic motor theory. The feasibility of test method is proved through theoreticalanalysis and experiment verification. The dissertation also discusses the practicalapplication about technology of rapid test method.First of all, the dissertation studied the structure and work principle of brushlessDC motor in details, and builded its mathematical model. To establish the model ofmotor and simulinking, the stating process and stable operation of motor is analysedby matlab/simulink software. The change process of main electrical paramnters aresimulinked by the model, such as change of the stating current, the relationshipbetween current and commutation frequency, torque ripper and the effect of rotorposition sensor during motor reversing,ect. Based on all of these analysises, thedissertation puts forword a characteristic testing method based on MSSA, andcompares it with another testing method based on MCSA.Then, the dissertation makes a signal processing algorithm study of quick testtheory and methods for mechanical characteristics. During brushless DC motorno-load starting process, the signals are usually non-stationarity, for examplearmature current and the signal of rotor position, so that the signal denoisingalgorithm and the transient feature extraction algorthm is the important work.Finally, the dissertation designs an experiment to verify the quick test theoryand methods for mechanical characteristics of blushless DC motor. The completed work is to build the test construction and making the current collecting circuit. UsingLabview software, the user-interface operation was developed. It can realize signaldata acquisition, read and save. Duing the experiment, the mechanical characteristiccurve is getted by speed-torque sensor. It was regarded as the reference value, with itto verify the quick test theory and method proposed by the dissertation, and analysethe error, preliminary build up test system met the actual needs of production.To explore the actual application value of testing theory and method, thedissertation also studies the motor from aspects of inertia on-line test, design oftesting system based on labview and testing performance evaluation.