Fluid Field Analysis And Temperature Calculation Of HSPM Machine

The work in this thesis is supported by the National Nature Science Foundation of China. The project name is "The distributed high speed generator driven by micro-turbine and its energy conversion system". The high speed permanent magnet (HSPM) machine has been widely investigated since it has small size, high speed and power density. Although the HSPM machine has much merit, some new problems appear in high speed condition. Loss and temperature calculation for high speed machine is a key issue for the machine design. In this thesis, the calculation method of air friction loss based on fluid field analysis, the method of temperature field analysis based on coupling with fluid field and temperature field, the experiment for loss and temperature of the 24-slot high speed machine were researched in particularly in the thesis.Firstly, the air friction loss on the rotor surface can take a large part of the total losses for motors and generators with high rotating speed. So the air friction loss should be calculated accurately, however, it is difficult to be determined theoretically or experimentally. In this thesis, a calculation method of air friction loss for high speed machine based on fluid field analysis was introduced. The influences of rotor speed, axial airflow velocity, air gap structure and roughness of the rotor surface on the air friction loss were discussed.Then, it is a key issue to calculate and analyze the temperature distribution for the high speed machine accurately. In this thesis, the CFD software was adopted to analyze the temperature field of high speed machine. The method which was coupled by fluid field and temperature field was used in this software. The method only needs axial airflow velocity which is forced at the inlet of vent, material attribute and heat source and then the temperature distribution was calculated. In the thesis, the 3D model of 24-slot high speed machine was built and the temperature field was analyzed. Comparative research on with ventilation and without ventilation was carried on.Finally, the experiment of loss and temperature for the 24-slot high speed machine is carried on under no load condition. During the experiment, the temperature sensor and anemometer was used to measure winding, the axis end, and airflow temperature and airflow velocity in the vent outlet among 24000r/min to 60000r/min. These experimental data was analyzed to calculate the total losses of the machine. The method of loss separation was researched preliminary about the iron loss and air friction loss.