The Electromagnetic Field Analysis Of Permanent Magnet Synchronous Generator

Permanent Magnet Synchronous Generator (PMSG) is widely used in industry and agriculture production, aerospace and spaceflight ,national defense, daily life and so on and has attracted extensive interest from many scholars because of its excellence such as high efficiency and energy conservation. The main fields of the research involve the design, the accurate performance analysis and the control of permanent magnet synchronous generator.As part of National Natural Sciences Foundation Project "harmonic hybrid excitation permanent magnet generator without brush and exciter", this project mainly studies the calculation of no-load and on-load electromagnet field of PMSG and the waveform and voltage regulation are obtained, which lays solid foundation for hybrid excitation permanent magnet generator with two part rotor. The prime work is as follows:First of all, the fundamental principle of PMSG is introduced including the structural styles and performance characteristics of PMSG .The computational method of voltage regulation and the calculation model of external characteristics are given by the traditional analytic method. Then the prototype of PMSG is simulated by Finite Element Method ANSYS software. Vector magnetic potential AZ, magnetic field intensity H, magnetic induction intensity B etc. can be obtained through defining and assigning material ,meshing, exerting boundary condition and loads, solving and so on ,which can intuitively know the distribution of the electromagnet field in interior generator.Second, the tooth flux method is used to deal with the calculation result of the electromagnetic field. This method calculates the magnetic field of different position within one tooth pith and takes the tooth of the stator as the smallest analysis unit. According to the relationship between the windings and teeth, the change of flux linkage along with time can be calculated and the values and waveforms of winding voltage for PMSG in no-load and on-load condition can be further obtained. The validity of this method is verified by the comparison of the calculation results and the experiment results, which provides the powerful tool for calculating various Performance characteristics of PMSGIn the end, the external characteristic of PMSG has been deeply studied based on tooth flux method and the influence of the structure parameters on the external characteristic is quantitatively analyzed. The efficient method of reducing the voltage regulation is put forward like increasing the air-gap length and properly enhancing the length of permanent magnet. Moreover, reducing series winding number N per phase as far as possible and increasing the cross-sectional area of windings are desirable to minish impedance parameter. By changing the structure parameter, the change rule of voltage regulation for PMSG is obtained through calculating the electromagnet field, which makes good preparation for adding electricity excitation to hybrid excitation permanent magnet generator and achieves the purpose of steadying the output voltage.