A flux reversal motor (FRM) is a type of double salient pole motor. It has almost same as the double salient permanent magnet motor (DSPMM) in that both coil and permanent magnets are located on the stator side. However, in the DSPMM, the permanent magnets are located on the stator yoke, so the change in the winding flux is unipolar, while in the FRM, the permanent magnets are located at the stator pole tips, so the change in the winding flux makes FRM can be drive as bi-polar motor. As a result, FRM are expected to have the same power density as conventional permanent magnet synchronous motor (PMSM). In addition, since no magnets are arranged in the rotor, FRM have advantages in terms of mechanical strength and manufacturability, and they have small inertia and excellent high-speed response. On the other hand, however, the armature flux flows into the magnets attached to the tips of the stator poles, resulting in large magnet eddy current losses.
In this study, we propose a new FRM structure in which the armature magnetic flux does not flow directly into the magnet by making the stator poles cross-shaped (cross pole), and we report the calculation of various properties of the proposed FRM by using the finite element method (FEM).

A traction motor of an electric vehicle must be highly efficient both at low and high speeds. Normally used inner permanent magnet synchronous motors (IPMSMs) are highly efficient at low speeds. However, their efficiency decreases at high speeds. To solve this problem, I added a pull-out mechanism to an IPMSM to change the facing area between the rotor and stator by drawing out the stator, adjusting the flux of the coils to achieve a high-efficiency drive over a wide range of speeds. In this study, I propose a mechanism that achieves a high-efficiency operation in both low- and high-speed ranges by dividing the rotor in the axial direction and combining cores with different torque constants to increase the variable magnetic flux effect by drawing out the stator. I created models of the rotor without and with axial splitting, and compared the characteristics in terms of a variable magnetic flux and efficiency. I found that the combination of the rotor cores with different torque constants improves both the variable magnetic flux amount and efficiency.

A new sensorless vector control method applicable to a 12/10 switched reluctance motor is proposed by using a mathematical model applying the extended induced voltage method. In order to evaluate the validity of the analytical results, a coupled analysis of JMAG and Matlab Simulink was conducted.

Measured values and JMAG analysis values were compared for the receiving coil used in the running wireless power transfer experiment under three different conditions: with an empty core, with ferrite, and with ferrite and aluminum plate.

We investigated the influence of the air region size around a DC motor and the mesh size of the motor for the FEM analysis result of electromotive force in this report.

Electric aircraft requires a lightweight motor capable of a high power
density. We have proposed a magnetic resonance coupling motor (MRCM) based on induction motors and magnetic resonance coupling (MRC). The MRC allows a motor to produce a power without an iron core. However, a large leak age flux of stator and rotor windings makes little contribute to the output power. The leakage flux is suppressed by attaching a magnetic ring to the MRCM. We present the characteristics of the MRCM with magnetic rings and the influence of the number of poles.

This paper presents design study on a compact and lightweight quasi-coreless surface permanent magnet synchronous motor (SPMSM) employing Carbon Fiber Reinforced Plastics (CFRP) as the stator body to make it lighter. Stator body is composed of CFRP, a little soft magnetic composites (SMC) core and aluminum winding for high power density. The design procedure for lightening the coreless SPMSM and experimental drive performance evaluation results are reported. Finally, some issue which has been founded are discussed.

Electric vehicles require high efficiency motor that can operate at over the wide range of speed and output.
Therefore, We have proposed a hybrid IPM motor combined at with permanent magnets with a different coercive force and a field winding to vary the magnetic flux linkage.
The changing the magnetic polarity of the permanent magnet due to the field winding yields a high efficiency over a wide speed range.
This paper describes motor characteristics of operating over a wide speed range using JMAG-Designer.

With the technological development of power semiconductors and power electronics devices, high-frequency inverters have become inexpensive, and induction heating devices using high-frequency methods have become popular. As a result, many design sites are incorporating induction heating analysis in the design stage of induction heating devices. The Finite Element Method (FEM) is widely used as one of the leading methods for induction heating analysis because of its versatility and high accuracy. However, when the FEM is applied to high-frequency induction heating where the skin depth of the conductor becomes extremely small, the elements are divided according to the small skin depth, resulting in a vast matrix and, thus, enormous computational time. As a solution to this problem, Model Order Reduction (MOR), which approximates a system described by a large matrix with a small number of elements, is being actively studied by research institutes worldwide. Among them, we have focused on the CLN method. The CLN method is an approximate method that replaces the Maxwell equation for eddy current fields with a Cauer-type equivalent circuit to speed up electromagnetic field analysis. We propose that the CLN method could be applied not only to the Maxwell equation but also to the heat conduction equations. In this presentation, we compare the results of induction heating analysis using the CLN method with JMAG and show that it is fast and produces nearly identical results.

In accelerator systems, the current value of the accelerator magnets is adjusted after installation to compensate errors from the design. However, the current adjustment does not consider the effect of magnetic hysteresis, and the magnets are initialized (demagnetized) each time the current value is modified. If a real-time magnetic field analysis could be performed during beam commissioning that considers the effect of magnetic hysteresis, this initialization would be unnecessary. Therefore, we have proposed a reduced play model as one of the MORs. In this study, we performed a magnetic field analysis incorporating the play model using JMAG and re-identified the shape functions from the obtained current and magnetic field characteristics. The reduced play model constructed using these shape functions is expected to enable real-time magnetic field analysis with dc hysteresis. This reduced play model will be verified with actual measurements in the future.

Identifying the induction motor parameters is important to investigate the performance of the motor.
The magnetizing inductance and iron-loss resistance can be identified through no-load test analysis.
This research presents the analysis results of copper and iron losses under different simulation settings at no-load condition by finite element analyze in JMAG-Designer.
In the analysis, the influence of settings of resolution and time convergence with respect to copper and iron losses in wide range of rotational speeds are investigated.
The analysis results show that high resolution and time convergence in the simulation are required for induction motor at high speed.

With the technological development of power semiconductors and power electronics devices, high-frequency inverters have become inexpensive, and induction heating devices using high-frequency methods have become popular. As a result, many design sites are incorporating finite element analysis in the design stage of induction heating devices. The design of induction heating involves optimization of the induction heating coil shapes and induction heating waveforms. We use the target field method for heating coil shape optimization. The target field method is a method to obtain the winding pattern of the coils on a user-defined current evaluation surface from the desired magnetic field distribution on a magnetic field evaluation point, we are studying printing the optimized coil shape on metal 3D printers. For heating waveforms, the CLN method is being applied to study speeding up transient analysis. The CLN method was initially proposed for eddy current problems, but we have shown that it can also be applied to heat conduction problems, and we are also considering speeding up the method for induction heating problems. We also use JMAG to validate these proposed methods. In this presentation, we will report the results of the analysis of high-frequency induction heating using the zooming method in JMAG and compare them with the measured results.

Bearingless motors, which use electromagnetic force to support rotating parts in a non-contact manner, are expected to find applications in ventricular assist devices and ultrapure water pumps because of their features such as low loss, long life, and maintenance-free operation. Single-axis active control type bearingless motors, in which only the direction of the axis of rotation is controlled by a sensor, require fewer sensors and inverters than other bearingless motors such as 5-axis active control type motors and are less expensive, but tend to have lower torque density due to lower reliability.
Repulsive passive magnetic bearings are often the element responsible for the reliability of single-axis active control types, and research is needed to strengthen them.
This presentation reports the results of a comparative study of the validity of two different methods of parameter definition in RPMBs by analysis using JMAG-Designer.