| Compared with the traditional electrically excited synchronous motor, the permanent magnet synchronous motor (PMSM) has significant advantages. It not only own a higher power density and efficiency, but also has a variety of structures, which makes it can take the place of the traditional AC motor in most situations. Currently, due to its wide power range, PMSM has been used deeply in all of the national industry with a sharply increased production. So the electrical machine industry and colleges of the world have regarded the development of PMSM as a research hotspot.This thesis pay close attention to the Adjust-Speed PMSM (also called Sinusoidal PMSM). And several main aspects of this type of motor has been further studied, such as electromagnetic design, the optimization of air-gap magnetic field, control system simulation and how to increase electrical power density. The thesis is divided into the following parts:Part â… reviewed the development status of the PMSM and the Variable Frequency Control Technology, and summarizes the research background. The control technology of PMSM can be divided into two types with distinctive characters, one is open-loop control, and the other is vector control. When PMSM drives are used for applications like pumps and fans, where high dynamic performance is not a demand, a simple open-loop control strategy can be used. However, for high-performance motion control applications, like servo applications, the vector control with field orientation should be incorporated with those machines to achieve high dynamic performance in position, speed, and torque control. Consequently, it is quite necessary to carry on research in PMSM and its control system.Part â…¡ introduced the classification of PMSM and analyzed the advantages and disadvantages of different rotor structures of interior PMSM. Based on the electromagnetic equation and phasor graph, this part has also studied the steady state performance of the PMSM. Then two kinds of the most common control theory have been discussed, so called open-loop V/F control and id=0 control. This part has laid a theoretical foundation for the following parts.Part â…¢ studied about electromagnetic design and performance optimization of Adjust-Speed PMSM. The main task of electromagnetic design of a motor is based on the performance requirements given by the client, choosing the reasonable motor structure, ensure the materials, calculating the corresponding electromagnetic loading, so that the main dimension of the motor can be confirmed. In order to study its load characteristics, this part required a combination of commercial software to establish a two-dimensional finite element analysis model of PMSM. Next, by changing the shape of permanent magnet, the wave of air-gap flux has been optimized to improve the performance of the interior PMSM.Part â…£ used Simplorer and Maxwell 2D to combine PMSM and its control system. Then some simulation has been done by using open-loop v/f control strategy and id=0 control strategy to achieve the dynamic performance of PMSM. The co-simulation method used in this part will have practical significance because it has solved some problems occurs in Adjust-Speed PMSM simulation.Part V did some researches about the dual-rotor PMSM. The dual-rotor PMSM consists of inner rotor, outer rotor and a stator in the middle. The initial electromagnetic design of a dual-rotor PMSM can be divided in two parts-an inner rotor PM motor and an outer rotor PM motor. In this part, an equivalent magnetic-circuit method has been given to design dual-rotor PMSM. And a prototype was fabricated and tested in order to prove the validity of the method and indicate the superiority of this kind of machine. |
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