Sari Maekawa

Study of the Magnetization Method Suitable for Fractional-Slot Concentrated-Winding Variable Magnetomotive-Force Memory Motor

This paper describes a variable magnetomotive-force memory motor with a fractional-slot concentrated winding. We propose a method for optimal control of magnetization suitable for a fractional-slot concentrated winding. Our result shows that variable magnetized magnets are more highly magnetized when a fractional-slot concentrated winding is used than those using the conventional method.

EMI prediction method for SiC inverter by the modeling of structure and the accurate model of power device

In recent years, the switching speed is increased accelerately. And, the increase of EMI by high dv/dt is a problem. In this paper, the Tri-phase 400 Vrms inverter for system interconnections which used SiC-JFET is analyzed. And, it is shown that noise terminal voltage is analyzable with an error of ±15 dB by highly precise modeling.

The proposal of low speed sensorless drives by symmetrical carrier PWM

The rotor position sensor is required to control Permanent Magnet Synchronous Motor (PMSM). However, the rotor position sensor, for example, Resolvers or Pulse Generator (PG) have some disadvantages which are an increase of total volume of the motor, fault of power supply lines and signal lines of these sensors, and maintenance. To overcome these difficulties, sensorless control methods have been developed. From standstill, sensorless drive method for saliency PMSMs has been already proposed [1]-[5]. However, audible noise occurs by supply. In this paper, we achieve sensorless drive for PMSM using the PWM generation method which used three symmetrical carriers. We verify that proposed method has low audible noise and a high response.

Study of low speed sensorless drives for SPMSM by controlling elliptical inductance

The rotor position sensor is required to control Permanent Magnet Synchronous Motor (PMSM). However, the rotor position sensor, for example, Resolvers or Pulse Generator (PG) have some disadvantages which are an increase of total volume of the motor, fault of power supply lines and signal lines of these sensors, and maintenance. To overcome these difficulties, sensorless control methods have been developed [1-10]. From standstill, Sensorless drive method for saliency PMSMs has been already proposed. However, applying these conventional techniques is not adequate to Surface Permanent Magnet Synchronous Motor (SPMSM) because of a few saliency of SPMSM. This paper proposes a low speed sensorless drive method for SPMSM which has small salient magnets. The low speed range is zero to 2-3% of rated speed. The study proposes the principle of anisotropy of the inductance of SPMSM generated by the d-axis current and magnetic saturation by the magnet flux.

A proposal for a single stage isolated AC-DC converter with zero voltage switching

In this paper, we propose new isolated AC-DC converters which have only one conversion stage; in addition it can operate zero voltage switching in all switching devices. Moreover, we propose control strategy for these converters, and also confirmed it by experimentation or simulation using 100W prototype.