Magnetic Circuit Optimization And Performance Analysis Of Coil-assisted Reluctance Type BLDCM

As a new type of reluctance motor,the coil-assisted reluctance type BLDCM uses an auxiliary excitation coil to replace the permanent magnet material.On the one hand,the risk of permanent magnet demagnetization is avoided.On the other hand,the magnetic field generated by the auxiliary coil can be controlled by controlling the current of the auxiliary coil.,To assist in adjusting the main magnetic field.At the same time,it has the advantages of traditional reluctance motors,namely,simple structure,low manufacturing cost,high operating reliability,wide speed range,and many controllable parameters.Because the coil-assisted reluctance BLDCM is a new structure of double-salient pole motor,there is little research on the electromagnetic design of the motor body.This paper takes the special topology of the motor as the research object to carry out the electromagnetic design of the motor body and analyze the magnetic circuit of the motor.Because the coil-assisted reluctance type BLDCM magnetic circuit has nonlinear characteristics,and the magnetic circuit of the motor contains both axial and radial directions,only three-dimensional simulation can be used when using finite element analysis,so the simulation takes a long time and requires a lot of work.To solve this problem,this paper uses the magnetic circuit method to build a nonlinear model of this kind of motor.The nonlinear model has high accuracy and fast calculation speed for solving the steady-state performance of the motor.Finally,the nonlinear model is combined with genetic algorithm for the motor The structure is optimized,the specific process is as follows:First,by analyzing the current status of the research on bi-salient pole motors at home and abroad,especially reluctance motors,starting from the magnetic flux path and structural characteristics of the motor,the working principle of the coil-assisted reluctance type BLDCM and the differences from other reluctance motors are analyzed,Push the electrical machine mathematical model.Then,referring to the design methods of reluctance motors at home and abroad,combined with the special structure of the motor in this paper,design a motor,use the three-dimensional finite element method to study the performance of the motor,analyze the rationality of the design plan,analyze the static and steady-state performance of the motor,Prepare for follow-up research.Third,the analytical method is used to calculate the magnetization curves of the four key positions of the motor.Based on the magnetization curve,the Ψ(θ,i)data sheet of the electrical machine is pushed out,and then the motor voltage balance equation and the analytical calculation results are used to push the electrical machine to be stable.State current waveform and electromagnetic torque waveform,and compare the final result with the finite element result to analyze its rationality.Finally,a nonlinear model combined with genetic algorithm is used to optimize the structural parameters of the motor.