Akihiko Maemura

A wide speed range high efficiency EV drive system using winding changeover technique and SiC devices

The Silicon Carbide (SiC) based devices will become the mainstream in the motor drive technology in the near future. These next generation power devices give benefits of lower losses, higher voltage, and high temperature operation in the power conversion system, realizing its downsizing and high power density. The winding change over technique, on the other hand, is useful to extend the speed control range with high efficiency of ac motors. This paper describes the effects of using high power SiC MOSFET and SiC SBD, together with the electronic winding changeover technique in the EV motor drives.

Saliency-based Sensorless Drive of Adequate Designed 1PM Motor for Robot Vehicle Application

Technology fusion between motor design and control can produce new applications. This paper introduces a saliency-based sensorless drive of adequate designed IPM motor for a specific application in a robot vehicle. The motor is designed considering both configuration so as to fit to the application and the electromagnetic feature to be better adapted to saliency-based sensorless control. The speed and position synchronous control for each wheel-motor in entire speed ranges including zero speed is realized by a single motion controller and drive-amps for individual motors. Finally, two types of robot vehicle, one being a two-wheel deferential drive and the other being an omni direction drive, are developed to transport objects and human. The paper mainly focuses on the concept of motor design and its control. Some analysis and test data are shown in this paper.