Design And Optimization Of Sinusoidal Interior Permanent Magnet Synchronous Motors

With the advantages of high power density, high efficiency, adjustability of power factor,Permanent Magnet Synchronous Motor (PMSM) was received extensive attention. InteriorPermanent Magnet Synchronous Motor (IPMSM) is one of them. Compared to other types ofPermanent Magnet Motor (PMM), IPMSM is more compaction, easier to control thecoefficient of pole-arc and can provide more magnetic flux of each pole for the case ofembedded the permanent magnet to the rotor steel. The common characteristic of machinery,equipment and processing industry is that they all need high performance of servo controlsystem and high performance motor. This paper looks IPMSM which used in machinery,equipment and processing industry as a subject investigated, represents the course ofelectromagnetic calculation, motor designing and optimal designing of IPMSM overall.First of all, it gives an improved equivalent magnetic circuit which considered theinfluence of the slots of stator and rotor and considered the internal leakage flux of motor. Theaccurate estimation of air gap flux density and the rationality of the designing of motor'selectromagnetic parameters are the basic to the optimal designing of motor. There exists twoimprovements of the equivalent magnetic circuit, first is considering the effect of slotted instator and rotor, second is detailing the leakage flux of the end of permanent magnet andamong the poles caused by the different location which lay out the permanent magnet intorotor steel. To program for the electromagnetic calculation based on the improved equivalentmagnetic circuit and running it, result is then obtained. Compared to the result of FiniteElement Analysis (FEA), it can provide the veracity of the equivalent magnetic circuit whichis the basic of the optimal designing of motor for obtaining the electromagnetic parameters.Secondly, it presents the Taguchi method for optimize the parameters of motor whichused to heighten the quality of products and which is a method for robust designing. Taguchimethod is an optimal designing method for local optimization. Compared to other traditionalmethod for local optimization, it can realize the optimization for several objectives and canobtain the optimal combination of several parameters. It builds the orthogonal array for experiment first, then solves the array by FEA, and obtains the optimal combination of severalparameters for single objective or several objectives. The prototype of20kW IPMSM whichused for a spinner is then manufacturing which to obtain the basic electromagnetic parametersby the equivalent magnetic circuit and to choose the minimum of the cogging torque and themaximum of the average torque for optimal objective. The prototype test shows the validity ofthe Taguchi method.It a development trend of applying the global optimization for motor designing. GeneticAlgorithm (GA) is widely used in optimal designing of motor with the advantage of parallelsearch and easier to program. This details the course of realization and improvements of GA,chooses the Improved Adaptive GA (IAGA) and Niche GA (NGA) for optimize IPMSM,analyzes the acquisition of the argument objective function and obtain the fitness value byprogram solving.GA can approach the optimum value for using the improved GA which can be out oflocal optimum value, but it increases the calculated times and iterating gap. The advantage ofTaguchi method is that it can obtain the parameters optimum combination by analysis ofsignal to noise ratio using the minimum times of experiment. This paper presents a newhybrid GA which embedded the Taguchi method into GA after crossover operator, which canguarantee GA be out of local optimize and then decrease the times for optimizing anditerating gap, then the prototype of30kW IPMSM using for dieing machine is manufacturingwhich selecting the efficiency as the optimization target. The prototype test shows the validityof the Taguchi method.