Design And Research On High Power Density Permanent Magnet Stater/Generator For Aviation

ISG(Integrated Starter/Generator)is the core of aviation Starter/Generator System.For the aviation ISG,the starting torque and starting power of the turbine engine should be satisfied during the electric operation,and power generation should meet the load at both ends of the output power and output voltage,at the same time the motor also needs to achieve small size,light weight,good heat dissipation to meet the actual load requirements of the aircraft and aviation environmental temperature requirements.Permanent magnet synchronous motor,with its advantages of high power density,high torque output,small size,simple structure,light weight and high efficiency,is very suitable for the application in the aviation field,and it has a good prospect in aviation HVDC power system.In this thesis,the study on the design and optimization of high power density aviation permanent magnet Integrated Starter/Generator are completed,and the specific work content is as follows:Firstly,according to the design requirements of the subject,the prototype design of high power density airborne permanent magnet ISG is completed: selection of motor materials to meet aviation environmental conditions;winding and groove design optimize the motor groove full rate;the performance of the motor with different polar slots is compared and the integer slot distributed winding structure is finally determined.Comparing different rotor structures,the rotor "radial" type structure is finally established,which improves the output capacity of the motor.In view of the large cogging torque of the integer slot motor,two kinds of optimization schemes are proposed,and finally the segmented skew pole rotor scheme is selected to optimize the cogging torque and back-EMF(electric magnet force)of the motor.Secondly,the electromagnetic performance of permanent magnet ISG under electric and power generation conditions is simulated and verified by finite element method.Under the condition of power generation,a associated simulation combined with the circuit of finite element motor model of motor and uncontrollable rectifier load is built.The harmonic analysis of permanent magnet ISG at different generating speeds and different generating powers is carried out and the influence of three-phase bridge uncontrollable rectifier load on permanent magnet ISG is studied.Finally,the copper loss of winding,stator core loss and PM eddy current loss underdifferent working conditions are analyzed,the loss ratios under different working conditions are summarized.In addition,the effect of filter capacitance on harmonic and loss in rectifier load circuit is analyzed,and the specific measures to restrain eddy current loss of permanent magnet are put forward,the motor loss is also optimized,as a result of the motor efficiency is improved.