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Okada A.,Power Systems Company | Nishioka A.,Hitachi Ltd. | Omori T.,Information and Control Systems Company | Yasaka Y.,Hitachi Ltd.
Hitachi Review | Year: 2011

Hitachi, Ltd., Japan, established its new Transmission & Distribution Systems Division in April 2011 to meet the demands for electric power transmission and distribution technologies that delivered new value. Electric power transmission and distribution technologies delivered new value, such as long-distance cross-border transmission system and power system stabilizing solutions that supported the wider adoption of renewable energy. These technologies delivered new value by strengthening coordination with other power system equipment and solutions within the company that helped in maintaining a reliable supply of electric power and delivering these in a way that suited the needs of different communities. The company adopted such a strategy to contribute to creating a sustainable society by responding to the growing global demand for power transmission and distribution technologies.


Yoshikawa Y.,Hitachi Ltd. | Tada K.,Information and Telecommunication Systems Company | Furuya S.,Yokohama Research Laboratory | Koda K.,Information and Control Systems Company | Geerli,Global Business Promotion Center
Hitachi Review | Year: 2011

Overview: Successfully combining protection of the global environment with prosperous urban lifestyles that are secure and convenient is an important factor in ensuring the sustainability of cities. The social infrastructure that supports such a city is required not only to establish robust safety and security, it also needs to satisfy criteria such as enhancing urban value by overall optimization and reduction of total cost. To achieve this, parts of the social infrastructure like power, transport, and water which have been optimized independently in the past need to be comprehensively redesigned based on considerations such as environmental performance, customer service level, and operation and maintenance costs. This is one of the prerequisites for achieving what Hitachi calls "next-generation smart cities.".


Watanabe M.,Hitachi Ltd. | Onishi T.,Information and Control Systems Company | Omori T.,Information and Control Systems Company | Terada H.,Yokohama Research Laboratory | Inagaki K.,Hitachi Ltd.
Hitachi Review | Year: 2011

OVERVIEW: How to maintain the quality of electric power on the grid in terms of voltage and other parameters and ensure that equipment operates efficiently will be important considerations if large quantities of solar power generation are to be connected. In response, Hitachi is working on technology development with the aims of introducing equipment such as section switches with built-in sensors and advanced metering infrastructure, developing control equipment, and enhancing monitoring and control. In particular, research and development of SCADA system technologies and voltage control equipment that help maintain power quality on the grid are helping to speed up preliminary investigations into how to maintain power quality and minimize the cost of adapting the grid to cope when large amounts of photovoltaic and other distributed power resources are introduced, thereby helping achieve reductions in CO2 emissions.


Nagura O.,Adjustable Speed Pumped Storage System Development Center | Higuchi M.,Information and Control Systems Company | Oyake T.,Information and Control Systems Company
Hitachi Review | Year: 2010

OVERVIEW: To help prevent global warming, it is anticipated that renewable sources of electric power will provide an increasing proportion of energy needs. Because energy sources such as wind and solar power are dependent on weather conditions, their output can vary widely. Usually, balancing supply and demand for power has been performed by adjusting the generation output in response to varying load, but there is a need to improve the supply and demand balancing functions of existing generation systems to allow the addition of generation capacity produced from renewable energy sources. Hitachi has developed a world-first adjustable-speed pumped-storage generation system that incorporates active-power-based control to provide a power supply and demand balancing function that can operate on time scales from the order of seconds to the order of hours, something that is not possible with conventional systems. It is anticipated that the addition of a large number of adjustable-speed pumped-storage generation systems to the electricity grid will help prevent global warming.


Komatsu C.,Information and Control Systems Company | Noro J.,Information and Control Systems Company | Kido M.,Information and Control Systems Company | Yoshida S.,Information and Control Systems Company | And 2 more authors.
Hitachi Review | Year: 2011

Protection and control equipment are used to ensure a reliable supply of electric power by detecting abnormal voltage or current levels when lightning strikes or other incidents occur and by signaling circuit breakers to trip, thereby disconnecting the section of the grid containing the fault. In addition to the higher reliability requirement, in view of next generation of technologies, Hitachi developed new generation of digital relays featured with real-time network functions suitable for mission critical protection application, and distributed system configuration applicable for new applications such as wide area protection for maintaining power system stability. Also this new digital relays support unit replacement to prolong the life time of total equipment that is currently in demand from the market.

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