Tokyo Institute of Technology

About: Tokyo Institute of Technology is a education organization based out in Tokyo, Tôkyô, Japan. It is known for research contribution in the topics: Thin film & Catalysis. The organization has 46775 authors who have published 101656 publications receiving 2357893 citations. The organization is also known as: Tokyo Tech & Tokodai.

State-of-Charge (SOC)-Balancing Control of a Battery Energy Storage System Based on a Cascade PWM Converter

Abstract: Renewable energy sources such as wind turbine generators and photovoltaics produce fluctuating electric power. The fluctuating power can be compensated by installing an energy storage system in the vicinity of these sources. This paper describes a 6.6-kV battery energy storage system based on a cascade pulsewidth-modulation (PWM) converter with focus on a control method for state-of-charge (SOC) balancing of the battery units. A 200-V, 10-kW, 3.6-kWh (13-MJ) laboratory system combining a cascade PWM converter with nine nickel metal hydride (NiMH) battery units is designed, constructed, and tested to verify the validity and effectiveness of the proposed balancing control.

Photocontrollable liquid-crystalline actuators.

Abstract: The history of human civilization is accompanied by the development of novel materials, from the period of natural stone, the bronze and iron age, to the modern times of synthetic materials and promising advanced materials. Liquid crystals (LCs) are one of such kind of materials that greatly infl uence our daily life, and which are not limited to displays such as TVs and personal computers. Being an intermediate phase of matter, LCs show characteristics of both controllable mobility of an isotropic liquid and ordered regularity of a crystalline solid. Combined with their photoresponsive properties, photocontrollable LC actuators have enabled a variety of applications in various fi elds, which include fl at panel displays, photonics, photo-driven devices, and more recently nanotechnology. The LC’s unique features provide soft materials in a liquid-crystalline state with interesting properties such as 1) selfassembly, 2) fl uidity with long-range order, 3) molecular and supramolecular cooperative motion (MCM and SMCM), 4) large birefringence and anisotropy in various physical properties (optical, mechanical, electrical and magnetic), 5) alignment change induced by external fi elds at surfaces and interfaces, and 6) deformation of LC elastomers (LCEs) in response to stimuli. [ 1–4 ]