Design And Analysis Of PM Machines With Combined Stator Blocks

Fractional slot concentrated winding permanent magnet(FSCW PM)machines have attracted more and more attention and research due to their unique advantages such as small size,high torque density,and high operating efficiency.The combination of the block stator structure and the FSCW has the advantages of easy installation and transportation,short production cycle,simple and convenient maintenance,and strong fault tolerance.It is of great significance for improving energy efficiency and further developing clean energy.In this thesis,the traditional stator structure is modified by removing part of the stator yoke or inserting the stator gap in the FSCW PM machine.The electromagnetic performance of the PM machine with different stator structures is compared and studied.First,the basic theory of FSCW and stator block type PM machine is introduced in detail,and different block ways of stator block type PM machine are discussed,including T-block and E-block.Selection of slot pole matching of stator block type PM machine,calculation of winding factor under slot electromotive force star diagram,generation mechanism of cogging torque and machine efficiency;Secondly,it is determined that the research object is a 70 k W FSCW PM machine for a 12-slot,10-pole electric vehicle.The full-tooth winding with T-shaped block or U-shaped block and isolated tooth winding with E-shaped block or U-shaped block are compared with traditional integrated PM motor.Design the main dimensions of the motor,the block stator structure,the rotor structure,and the built-in "V" type magnetic poles,etc.,and use the finite element simulation software Ansoft to model and simulate to obtain the final machine design plan;Finally,analyze the advantages of the stator block type PM and compare it with traditional integrated PM machine,then analyze the performance characteristics of the machine when the same U-shaped stator block is used with different windings.The effects of the stator structure on the air gap magnetic flux density,magnetic flux,back EMF and torque characteristics were studied.The changes under different stator structure design schemes are compared in detail,which provides a basis for the design of stator block type PM machines.