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Medium-voltage (MV) switchgears are used in an extensive range of applications from power generation through power transmission to power receiving. To meet the needs of this broad spectrum of users, the problems associated with MV switchgears have changed in accordance with the timely needs for diversification and sophistication, calling for high-reliability to assure stable power supply, protective control system, miniaturization to meet the needs for more effective land use and economic efficiency, improved ease of operation and predictive maintenance to facilitate maintenance and inspection, enhanced safety of housings to protect operator personnel from electric shock and high-temperature and high-pressure gases that are generated in equipment during breakdown, disaster prevention measures in accidents due to equipment breakdown or arc formation and enhanced weather resistance to exclude the adverse influences of ambient conditions. In recent years, the need for recycling and for the prevention of global warming as well as the need for environmental compatibility have been added as new problem areas based on a life-cycle assessment that the entire life of equipment into consideration, from the extraction of the material resources to the disposal of the products at the end of their life cycle.
The general practice in the past was to install individual units such as breakers in grounded panels. In response to the above problem areas, however, complex equipment has been developed through the integrating and compounding of individual units.
The main technical issues for the development of next-generation medium-voltage switchgear call for fundamental technology development in a range of technical fields, including primarily technical advances in insulation techniques using vacuum, air, solid, or liquid insulation with a view to miniaturization, the development of elemental units with complex functions and the development of technology to reduce heat generation in an effort to prevent global warming.
Against this backdrop, this Report investigates and scrutinizes in a systematic manner the technology improvement and the new technology development efforts required in terms of MV switchgear equipment configuration, insulation and circuit breaking performance. |
