The Research Of Flow Field In Air-gap And Whole Temperature Field In Global Of Permanent Magnet Wind Turbine

By eliminating the permanent magnet generator brushes, slip rings, and fieldwinding, therefore with a compact structure, easy maintenance, no excitation loss, powerfactor and high efficiency large. In recent years has been widely used in small windpower systems. However, due to the complete closure of the structural characteristics,during the running process the temperature rise is not easy to lose in time, causing hightemperature permanent magnet demagnetization, output current is not stable, lowefficiency and a series of adverse consequences. Therefore, in order to improve theefficiency of the whole machine for the purpose, Research on permanent magnet windturbine temperature field with the change of structure and optimum temperaturedistribution corresponding structure is of great significance. This study is to reveal thelaw of temperature rising and its impact factors of various components.According todifferent conditions between the stator and rotor generator air gap flow field and differentstructure temperature field was carried out by research.First of all, based on test data generator steady-state temperature field, adopted CFXsoftware for numerical analysis using its set, the air gap between the rotor flow field.Calculated by simulating different speed and load along the radial distribution of air gapin the fluid velocity, Combined with the same temperature field distribution of the rotormagnet steel under the condition of surface, Choose the best running load; Combinedwith the empirical formula to get fixed, the optimum rotor surface convective heattransfer coefficient, Provide an effective parameter for the whole temperature fieldnumerical calculation.Then，the generator internal flow field numerical calculated convective heat transfercoefficient for the optional boundary conditions，choosing the ANSYS finite elementmethod simulation of its Thermal Field. Analysis found that the generator stator slot typeand the air gap length overall have great effect on temperature rise, In order to solve thisproblem, this study further analyzes the different air gap length0.025cm to0.065cmcorresponding pear-shaped, fan, inclined shoulder round bottom three kinds of thetemperature field distribution of tooth structure. The results show that increasing the gaplength, optimized stator structure can significantly improve the internal temperaturedistribution; And overall efficiency, temperature rise and thermal considerations, the corresponding gap length is0.055cm pear-shaped groove structure is the optimalstructure.Eventually, in order to heat a small, heat intensity of the subject, combined with theoptimal structure, To identify the optimal operating conditions, Providing the reliablemeasures to control the generator temperature problem effectively, And providing atheoretical basis for the design of off-grid wind power system dedicated permanentmagnet generator.