Radial Magnetic Field Of Dual-rotor Permanent Magnet Motor

High efficiency and high torque density are two basic features for an electric machine. Rare earth permanent magnet machine has high efficiency and high torque density because of the use of rare earth permanent magnet. However, the cost of the machine is raised . So it has very important sense to design a ferrite permanent magnet machine with high force index and low cost. The thesis makes a primary research of an electric machine which can satisfy the advantages above. Generally speaking, the research of the thesis mainly includes the following points:In the first part, the structure and principle of the machine are discussed. Then the thesis gives the analytical method and sums up the advantages of the machine compared to the traditional ones.The second part gives the calculation of the inductance. First of all, this part establishes the magnetic circuit model of the machine by which the inductance is calculated. The inductance formula is given. In order to check the formula, the thesis also calculates the inductance using electromagnetic software. Then this part gives the contrast of the two kinds of results, giving the characteristics of each result.The third part analyzes the cogging torque in detail. First of all, this part gives some methods for reducing the torque fluctuation of the machine. The methods includes slot opening shifting, varying slot opening angular width, varying PM angular width, varying the middle line of the PM. In order to check the methods, the thesis gives the formula of cogging torque first, and then proves the methods using the formula. The thesis also calculates the cogging torque using electromagnetic software, giving the curve of the cogging torque. Through the two different ways, the methods are proved to be practical. At last, this part gives the infection to average torque of the methods.The fourth part discusses the design thought, bringing forward the...