Design And Research Of Hybrid Excitation Permanent Magnet Synchronous Generator

The hybrid excitation permanent magnet synchronous generator (HEPMSG) has many advantages, such as simple structure and high reliability. It can realize the adjustment of exciting magnetic flux and expand the application domain of permanent magnet electrical machines. The research of the paper is carried out around the development of HEPMSG, five parts are included as following:First of all, based on analysis with 3D finite element on HEPMSG, the magnetic circuit is simplified and the calculation model of air-gap magnetic density for permanent magnet and iron poles magnetic circuits are concluded, the model is valid by finite element calculation.Second, based on research and calculation method of inductance parameters for permanent magnet electrical machine, the finite element calculation and testing method of HEPMSG are presented.In this paper, the voltage characteristic and inherent voltage regulation are deeply analyzed and the mathematical model of relation of inherent voltage regulation and performance parameters is presented on the basis of double-reaction theory. The influence of the performance and the structure parameters on the voltage characteristic is quantitatively analyzed.Some important coefficients including leakage coefficient, air-gap coefficient and waveform factor of armature reaction are studied and validated by electromagnetic software ANSOFT. The selecting principle of main configuration dimensions such as stator, permanent magnet and the slot for locating the dc exciting winding and electromagnetic design principle is presented. Based on above studies, the program for electromagnetic design of HEPMSG is developed.On the basis of research on voltage harmonic distortion of permanent magnet electrical machines, a method for predicting and calculating the harmonics of no-load is derived by the finite element and FFT. The low voltage harmonic distortion is achieved by optimizing the shape of permanent magnet.At last, based on above theories a prototype of HEPMSG with rated power 7.5kW and four poles is manufactured. Experiment results and theory analysis is almost same and output voltage of generator is effectively adjusted by regulating the DC excitation current, which shows the theory of HEPMSG is feasible.