Study On Rare Earth Permanent Magnet Generator In Vehicle Application And Voltage Regulate Technic Based On PWM

In this paper the structure, magnetic field, thermal field and voltage regulate technique of the rare-earth-permanent-magnet generator( REPM generator) in vehicle application are analysed and studied detailedly. Utilizing the finite element method(FEM), the generator's magnetic field and thermal field are analysed to be basic theory for optimizing the design in future. In this paper a circuitry controlled by PWM is put forward, and some experiments is given, and a high-accuracy effect in the first step could be achieved.First of all, the paper analyzed the structure of the REPM generator. The rotor of REPM generator uses Nd-F-B permanent magnet material, and this material's magnetic has some excellences such as high Br,Hc,(B·H)_max, the curve of demagnetization is nearly rectilineal etc.Secondly, the finite element method(FEM) is used to analyse the generator's magnetic field of REPM generator .In paper ANSYS10.0 which is a large and general purpose FEM software is used to establish the generator's model, and based on the model the 2-D static magnetic field is analysed. The powerful capability of ANSYS10.0 in dealing with graph and numerical value could make the design of PM generator accurate and intuitional.Thirdly, according to the excellence which the magnetism of Nd-F-B permanent magnet material would get down when the generator's temperature rose speedily. The paper used ANSYS10.0 to analyse the generator's thermal field in order to make sure the permanent magnet can work safely.At last, this paper analyzed existing voltage regulator methods of REPM, and a voltage regulator which controlled by PWM is developed. The voltage regulator had some merits such as high precision, simple structure, stable performance, economy and so on. Using the high-frequency and full-wave control mode, the problem brought by Thyristor can be solved.The problem is that when used a Thyristor in a half wave controlled rectifier ,the precision would not be high. The results of test achieves designer's purpose, this constated that the method is practical.