Magnetic gears offer advantages such as low vibration, low noise, high efficiency, and maintenance-free operation. However, magnetic gears have problems known as "pole slipping" under conditions of rapid acceleration or the application of high loads, synchronization between the input and output rotors may be lost, resulting in a failure to transmit torque. In this study, a load angle control method is proposed to enhance the controllability of magnetic gears by preventing pole slip through feedback control based on the load angle.

Large EVs are required to obtain more regenerative energy to extend a driving range. However, a pitch motion which is a change in vehicle attitude during braking occurs. Therefore, this study aims to obtain more regenerative energy and suppress the pitching simultaneously. In this study, two types of pitching suppression methods are proposed; steady and transient state pitching controls. Moreover a reducion gear ratio optimization method for obtaining more regenerative energy is also proposed that is compatible with the pitching suppression method. As a result of simulation, pitch RMS acceleration is suppressed by 14 % in JE05 mode, and the reducion ratio optimization method curbs energy efficiency deterioration which is caused by the pitching suppression.

Solid state transformer (SST) is attracting significant attention as a novel alternative to conventional pole-mounted transformers. Thus, it is crucial to explore magnetic materials that can enable both miniaturization and low loss in SST. In this paper, the properties of various candidate magnetic materials are measured, and a proposed model for the actual SST device is developed. Based on these specifications, the device is designed, and finite element analysis is employed to calculate the volume and losses associated with each material. By evaluating the trade-offs between volume and losses, magnetic materials suitable for SST cores are identified. Furthermore, a prototype transformer is designed and assessed using the selected magnetic materials.

This paper proposes an improved position sensor fault detection based on back-electromotive force (back-EMF) estimation in an interior permanent magnet synchronous motor (IPMSM). The threshold value in order to detect the position sensor fault of rotor is one of the most important things in IPMSM drive system. This threshold value should be designed by a higher value than the maximum overshoot of estimated angle error caused by acceleration or deceleration of motor as well as steady state error. In this paper, the fast fault detection method using adaptive threshold design is determined and proposed method is verified in transient state such as acceleration and deceleration by simulation and experimental results.

Magnetic gears achieve the system with maintenance-free, low noise and low vibration characteristics by contact-less power transformation. However, conventional magnetic gears are not suitable system for high speed motors because the mechanical strength is weak due to permanent magnets of the high speed rotor. This paper presents a novel flux switching magnetic gear for the super high speed motor. The high speed rotor of the proposed magnetic gear is constructed by only iron core. Therefore, the structure is very simple and robust and it is possible to rotate in the high speed region. Moreover, the flux switching magnetic gear realizes the high torque density by utilizing the magnetomotive force of stationary field magnets. In this paper, the performances of the proposed magnetic gear including torque density, mechanical strength, loss and efficiency are evaluated.

This paper proposes an improved PLL-type estimator for self-sensing control based on back-electromotive force (back-EMF)estimation in an interior permanent magnet synchronous motor (IPMSM). Although the position and speed of rotor are accurately estimated by PLL-type estimator in steady state, the estimated information in transient state may be unstable. To analyze the transient performance of rotor position estimators, the structure design and proposed methods of estimator are introduced. And, the effect of proposed method has been figured out that the estimated speed error and torque ripple are decreased in transient state. The feasibility of the introduced estimator effect are verified through simulation results.

This paper proposes a cross-coupling decoupling PI controller based on a complex vector notation for the harmonic current control system of Interior Permanent Magnet Synchronous Machines. The proposed method could achieve decoupling control in synchronous reference frame rotated with the harmonic order, and could improve a performance of harmonic current control system, e.g. transient response. In addition, the proposed current controller is designed by using only controller bandwidth and fundamental parameters such as armature resistance and d-q axis inductances, therefore the proposed method is not effected by identification errors of spatial harmonics and has low parameter sensitivity. Effectiveness of the proposed method is revealed by simulation results and experimental results.

This paper presents a high performance torque control of Permanent Magnet Synchronous Motors using a real time simulator with a Finite Element Analysis (FEA) based motor model. This model can simulate some behaviors of the actual motor includes nonlinear characteristics such as spatial harmonics and magnet saturations. Therefore, a model based control developed with FEA based motor model takes some advantages for motor control. This research aims to achieve advanced motor control and drive techniques. In this paper, the high performance torque control techniques of PMSM are proposed. Proposed torque control is constructed based on direct torque control with torque prediction. This proposed method can achieve both fast response and smooth torque. The effectiveness is verified by performing some simulations and experiments.