Analysis And Design Research Of Using Random-Wound Windings In The Stator Of High Voltage Line Start Permanent Magnet Motor

The advantages of high-voltage asynchronous induction motors and permanent magnet synchronous motors are combined on high-voltage line start permanent magnet synchronous motors,which have line start ability,high efficiency and power factor at wide load rates,as well as high torque density and low operating current.However,formed windings are usually used in high-voltage line start permanent magnet synchronous motors,and open slots are required for matching,which leads to a series of problems such as increased motor cost,increased air gap magnetic field harmonic content,and increased cogging torque.In order to solve the above-mentioned problems,a novel high-voltage line start permanent magnet synchronous motor with random-wound copper wire windings in the stator is proposed in this paper,namely,High-Voltage Random-Wound Line Start Permanent Magnet Synchronous Motor,referred to as HVRW-LS-PMSM.Taking a prototype as an example,the structure,insulation,characteristics and other design issues of HVRW-LS-PMSM are studied to provide a reference for the design of HVRW-LS-PMSM.For HVRW-LS-PMSM,the insulation problem is the key to the design,therefore,the insulation problem of the prototype is analyzed and optimized.The finite element method is used to analyze the reliability of the insulation structure of HVRW-LS-PMSM with scattered winding,the insulation conditions of the turn-to-turn insulation,the main insulation,the interlayer insulation and the end insulation,and the electric field distribution when the main insulation is scratched by the burrs of the punching sheet are respectively analyzed.According to the analysis results,the insulation in the motor slot is optimized.The insulation reliability of the prototype is verified,which provides a basis for the electromagnetic design of HVRW-LS-PMSM.The electromagnetic design method of HVRW-LS-PMSM is studied.The selection principles and methods of main dimensions,pole slot combination,slot combination of stator and rotor are studied.The design method of rotor magnetic circuit structure,rotor punching sheet and starting cage is studied.The design method of stator punching sheet and high-voltage scattered winding is studied.The finite element method is used to analyze the performance of HVRW-LS-PMSM,and a prototype is manufactured and tested.The starting performance of HVRW-LS-PMSM is analyzed,including load starting and load starting under reduced voltage conditions,as well as the no-load and load steady-state running performance of the prototype.Based on the design scheme and finite element analysis,a prototype is manufactured and withstand voltage test to ground is carried out,which verifies that it is feasible to use random-wound winding on the stator of line-start permanent magnet synchronous motors to a certain extent.