Stator Design And Loss Calculation For High Speed PM Generator

The high speed permanent magnet (PM) machine has been widely investigated since it has high speed, small size, high efficiency and power density. The application areas for this machine include compressor, energy storage flywheel, distributed power generation and so on. Distributed power generation takes pressure off electric transmission infrastructure and has benefits, such as low emissions, fuel flexibility and high efficiency.In this paper, the structure design characteristics of high speed PM machine are analyzed. Due to the high rotor speed and high frequency of the stator flux variation, it is quite different from designing a conventional machine in high speed machine design and loss calculation and thermal analysis. There are many problems need to be researched on stator, rotor and bearing. For a high speed PM machine, this paper will pay attention to study the stator key problems such as the design of stator core and stator winding, choice of polar, calculation of loss and temperature.A comparative study on the influence of different stator structures on machine performance for a same PM rotor is carried out based on the magnetic field analysis. The influence of different winding modes and different polar numbers on machine performance is also studied respectively, and their advantages and disadvantages are compared.The magnetic field analytical method of PM generator based on ANSYS is studied. For generator, a circuit-field coupled finite element method need be used. In this paper, the current iteration method is used to analyze the dynamic operation of high speed PM generator based on ANSYS programs, and the results will be processed by MATLAB.Because of the influence of the high frequency, the iron loss calculation method of traditional machine is not appropriate for high speed machine, and the material parameters have changed. Three single phase transformers which have different modes have been manufactured. The BH curve and loss coefficient in 400Hz are measured by experiment.The influence of anisotropic material is also studied.An important problem is to ensure that the rotor never reaches a temperature, which would demagnetize the magnets. The high speed generator which has 6 slots and uses ring type winding is manufactured, and for the generator, the preparatory temperature of stator is calculated.