A great deal of research and development work has been done on electric vehicles (EVs) and hybrid electric vehicles (HEVs) in recent years. As a result, EVs and HEVs have been greatly evolved for latest 30 years. Their performance has been improved to 3 or 4 times. Why do they have got such a good performance? A look at the course of research over the years shows that the reason is significant progress in power electronics technologies. In order to spread EVs and HEVs, the technologies will become more important in the future.
Photovoltaic power generation technology (PV) is expected as a promising means to keep the national energy security and solve the various ecological and environmental issues in the future. In this situation, power electronics technologies may have a chance of great contribution for cost reduction and improving performances of PV system to 21st Century, because PV system is composed only from full solid state technologies.
People with slight disabilities on motion capability can be active in daily life using properly designed motion-assisting devices. Using these devices in various cases would help them as rehabilitation in a broad sense. We developed a robotic orthosis capable of helping human motion by forearm. This orthosis was carefully designed such that mechanical safety for human beings could be ensured. A control scheme for power assistance and motion guide is proposed. The performance of the control scheme is examined by several experiments.