Interior permanent magnet (IPM) synchronous machines have experienced a surge of growing popularity during the past decade that began with the introduction of the Toyota Prius powertrain in 1997. However, IPM machines themselves have a much longer history that can be traced back many more years to the first half of the twentieth century. It is an instructive exercise to review some of the key milestones in this history in order to understand the intermingled impacts of the available magnet technology and the additional external factors that encouraged the early development of IPM machine technology.
Although IPM machine were limited to a relatively small number of specialized applications for many years, this presentation will highlight three separate factors that combined to spur the accelerated development and much-widened applications of today’s IPM machines. This factors include: 1) the development of high-strength NdFeB magnets made available at reduced prices; 2) advances in the theory and design of IPM machines; and 3) the development of advanced power electronics marked by major improvements in performance, size, and cost.
The discussion will conclude with a review of current factors, both positive and negative, that are influencing the current status of IPM machine technology and its future directions.

In the works

This presentation will introduce the development history of the drive motor for hybrid vehicle developed by TOYOTA.
Development examples for reducing motor and system losses for the new Prius released in 2009 will also be introduced to illustrate our technology used to improve the fuel efficiency of hybrid vehicles.

Novel designs of interior permanent magnet motors with distributed and concentrated windings are developed by the electromagnetic field analysis in order to reduce the core and magnet eddy current losses.
First, the losses in the motors are investigated by the 3-D nonlinear time-stepping finite element method that considers the rotor movement and carrier of the inverters. From the results, the main loss factors and the loss generation mechanisms are clarified. Next, automatic shape optimizations of the motor cores and magnets are carried out in order to reduce the losses. Finally, the validity of the optimizations is confirmed by the experiments with the prototype motors.

AcuSolve is a robust, fast and accurate, general purpose finite-element flow solver, developed by ACUSIM Software, a leading provider of powerful Computational Fluid Dynamics (CFD) solutions.
AcuSolve is used globally in a wide variety of industries such as electronic cooling, automotive, chemical, bio-medical, consumer products, energy, government labs and more. In this session, we give a brief introduction to AcuSolve, and present some relevant flow solutions to JMAG user, and introduce an interface between JMAG and AcuSolve to perform full 3D steady and transient thermal flow solution using heat sources simulated by JMAG.

Virtual motors to use as a model base for the development and evaluation of controllers without an actual motor are raising expectations for the schedule and efficiency of development as motors are more widely used for a variety of applications.
This presentation introduces the hardware for a virtual motor that can be connected to an inverter and supports nonlinear response.

The motors are widely used in our daily life and vibration or noise reduction is demanded.
The origin of the vibration or noise is the electromagnetic excitation forces, and we investigate the theory and experimental study considering inevitable manufacturing tolerances and waveform of the current.
We also examine the mechanical system and show the example about the development of low-noise motors.

An outline of recent rare-earth magnet developments and forecasts of magnet’s market.
We then explain about comparison results between magnet’s characteristics and field analysis especially focusing on thermal demagnetization of the Grain Boundary Diffusion magnet which is applied distributional coercivities, and confirmed correlativities of their behaviors.

Induction heater is a machine heating metals up to a certain temperature
Quickly. We are designing, manufacturing and selling them heating various metals from billets over 200mm in diameter to plates about under 1mm in thickness at customer’s request. At this conference we shall introduce how to utilize Jmag with examples.

It is necessary that the product to high efficiency and high performance is developed. In this product development, not only to shorten the development period but also to obtain more accurate behavior, a highly accurate simulation technology is required. For the purpose, a linked analysis between the control and the magnetic field (motor) is executed recently.
In this report, we describe the examination of the motor torque estimation method by the simulation that uses JMAG-RT. First, the difference of JMAG-RT model (Simple spatial harmonics model▪spatial harmonics model) and the validity of JMAG-RT model by the comparison between JMAG-RT model and FEM model are described. Next, by the simulation that uses JMAG-RT model, the effectiveness of the torque estimation method which we propose is confirmed.
In addition, the effectiveness of the proposed method is verified by the experiment.

The induction heat treatment of crankshaft process was optimized by computer simulation of JMAG Designer.
Comparisons were made between the actual induction heat treatment and the simulation results.

“Good model permits Good control”, it is unwritten law for control engineers. Unfortunately, as recent high-performance motors can not be expressed well by a conventional mathematical model, various new models for the motors have discussed.
On the other hand, electromagnetic field analysis becomes popular with its accuracy improvement. As the results, almost all of the new developed motors mostly have accurate results of electromagnetic field analysis.
In this lecture, we discuss the method that electromagnetic field analysis utilizes a motor control directly and designate a control method using a behavior model generated by JMAG-RT.

The temperature-dependent relative magnetic permeability depends on the magnetic characteristic of the particular metal parts. This is given a definite value in the current computer simulation of induction heating and is set by the past empirical results. In order to further improve the analytical accuracy of temperature distribution in induction heating simulations, it is necessary to create continual change in the relative magnetic permeability by altering temperature and magnetic field strength.
In this study, a computer simulation using the measured data of the B-H curve was applied to the induction heating test of ring specimens. Additionally, the experimental and simulated results were compared in order to examine the validity of this method.

Packaging is a big factor to install HEV unit into the small car’s under-food space. Moreover, It is required to work out high power density, high efficiency and low cost on a level simultaneously. On this presentation, we introduce the development case of small car HEV motor.
More specifically, we explain the problem, countermeasure and effect on designing the optimumized motor for small car from magnetic field analysis perspective.
In addition, we worked on co-simulation of motor and inverter using JMAG-RT and compared the current waveform obtained by simulation with the measured one.
Moreover, we compared the motor characteristics obtained by co-simulation with measured value.

A contactless inductive power supply (IPS) system has been developed and tested as a charger for electric-driven vehicles. By using the developed system, charging can be carried out safely, easily, and in a short period. Optimizing the track and pick up of IPS achieved significant improvements in efficiency.

A hybrid stepping motor is a motor that has axial flux and generates field using small teeth facing the gap. One advantage of these types of motors is the ability to achieve high-synchronous stability without any feedback devices because of multiple poles (normally 100 poles). However, the iron losses get larger as the frequency increases. Examples of magnetic field analyses for hybrid stepping motors are extremely rare because the three-dimensional magnetic pathways and narrow gap widths (less than 0.1 mm) are difficult to analyze. Estimating the motor constants from the geometry is also difficult.
This presentation will outline the characteristics of stepping motors, compare the results from examples of a 3D magnetic field analysis with the results from actual stepping motors, define the difficulties when performing analyses, and describe the requirements to perform highly accurate analyses.

Power Reactor consists of Iron Loss and Copper Loss mainly. Iron Loss increases to be affected by Skin Effect, Proximity Effect and the fringing flux from air gap, besides the resistance loss in the winding. The influence appears more and more conspicuously, so that the high frequency shows a tendency for miniaturization of the machinery particularly in late years.
These influences bring about complicated current-distribution in the winding. Therefore it is desirable to analyze it with CAE to calculate correct copper loss. We have been able to calculate Copper Loss visually and quantitatively in analyzing the current-distribution that we used JMAG.
In this lecture, we describe our observations about Joule Loss in the winding for Power Reactor, and present some analysis examples by JMAG.

It is necessary to use the wind power from a viewpoint of environmental protection of the earth. However a large wind power generation system has limitations on the location, and a small wind power system is required for wide use of wind power.
This paper describes a new approach to simulate the small wind power generating systems using PMSG. The dynamic transient of the generating system by finite element method taking into account the motion equation of the wind turbine is analyzed. The influence of cogging torque on the generating performance is investigated.

CCFL inverters used for backlighting devices such as LCD TV operate via the series resonance of the leakage inductance of the transformers and the parasitic capacitance of the lamps. The frequency of the series resonance is important factors because it affects the efficiency of the circuits and the operating characteristics of the lamps. This presentation will describe how to obtain the necessary leakage inductance by evaluating the coupling coefficient using JMAG before designing the transformer while also investigating the relationship between the coil construction and the coupling coefficient.

We have been developing so-called High Temperature Superconductor Induction/Synchronous Machine (HTS-ISM). Although basic structure of the HTS-ISM is the same as that of the conventional squirrel-cage type induction machine, we could shown for the first time in the world that the wonderful performance can be realized by replacing the secondary windings with the HTS wires, i.e., (1) co-existence of synchronous and slip rotation modes, (2) high efficiency thanks to the steady state synchronous rotation, (3) realization of higher torque density and/or higher power density, (4) robustness against the overload condition, (5) availability of continuous operation from non-superconductivity state to the superconductivity state, etc.
In order to realize the industrial applications of the HTS-ISM, we have to show that such machine possesses the merits compared to the conventional machines, when the motor is operated at the variable speed that is depending upon the target applications. Then, we have to model the nonlinear current transport properties of the HTS windings, perform the characteristic analysis by using such modeled expressions, and realize the optimal drive technology. The current status of the aforementioned study will be reported.

At Mitsubishi Electric Corporation, Human Resources Development Center is doing the project and the execution of the corporate class education. In this presentation, it briefly introduces our corporation and product. And the outline of the electric engineering courses that we are executing at Human Resources Development Center is mentioned. Moreover, JMAG is especially used about the course in the electromagnetic field that we are executing for the student to a middle level. The contents and the environment in this course will be also mentioned, because students will obtain the analytical result by using JMAG in a short time.

We have examined the modeling and analytical technique of a permanent magnet synchronous machine by JMAG using Harumi-1(IPMSM) that we designed and manufactured.
This time we’ll report the iron loss and vibration estimation technique and compare with measured results.
[Iron Loss] Iron losses can be estimated by the coupling analysis between JMAG(JMAG-RT) and control simulator. The iron losses at various operating conditions (phase angle, carrier frequency, modulation factor..) are calculated by the coupling analysis system and compared with measured losses.
[Vibration] We introduce the modeling method for a vibration analysis in order to estimate the electromagnetic vibration of a stator case due to the resonance phenomenon between the natural frequency and the electromagnetic force.