Performance Calculation Of Permanent Maget Brushless DC Motor And Control System

With the dramatic development of power electronics, permanent- magnet materials, micro-processor, modern control theory, electrical machinery theory and other relational science and technology, the brushless DC motors (BLDCM) has made great development, and has been applied in all kinds of driven and servo-control system. The successful application in the drive system of capital ship in foreign countries has proved the feasibility of the high-power BLDCM. In domestic, the medium or low power BLDCM is manufactured on a large scale, while the development effort on the high-power BLDCM drive is still preliminary. In this subject, one 2.2kW brushless DCmotor is developed for the research and development of the high-power BLDCM. The modeling and design analysis of the samples are presented in this paper.Firstly, three methods of designing BLDCM are summarized and compared with each other, and a field-circuit coupled method is applied. By using this method and Combining considering economic performance and operating performance, the 2.2kW brushless DC motor was designed and produced. At the same time, Operation rule of brushless DC motor was analyzed, topological circuit and equivalent circuit equation in six operation intervals under single-flow and inversion mode were discussed in detail.Transient electromagnetic field of a 2.2kW eight-poles PM BLDC motor was calculated and analyzed by time-step FEM coupling field, and circuit, and calculation methods of some important parameters also were researched. Meanwhile, the effect of magnetic steel dimension on back electromotive force, and the torque were analyzed under rated loads. The leakage flux was analyzed too.At last, experiment platform was given and the method of motor test and measurement was introduced in detail. By comparing simulated result and test result, the validity of the field-circuit coupled method is proved.