New network concepts using electronic hybrid circuit breakers

The electrical power industry forecasts a significant increase in demand of electrical power around the world during the next years. Old distribution and transmission systems are not designed for the load that will be expected only a few years from now. As utilities have a long view on equipment (designed is at least for 30-40 years of normal use), they are starting to request from switchgear manufacturers a viable long term solution. Fault current limiters are now requested by power utilities due to re- regulations in the US and elsewhere. Unfortunately, designs for new FCLs are still in its infancy, but many manufacturers are working on it. Plain electronic FCLs are less sophisticated that fast FCLs hybrid circuit breakers called electronic circuit breakers or e-CB. The DOE awarded a contract to EPRI to develop a 69 kV class Solid State Current Limiter. This program is planned to be completed in 2009. EPRI is subcontracting a prototype of the electronic FCL at 69 kV based on the new SGTO developed by a Pennsylvania company at 3000 A. The prototype is called a SSCL. The ultimate objective is to manufacture an e-CB at 145 kV for world wide applications. The description of the e-CB below shows that private applications on existing substations are already multiple at 15 kV and solutions from the private industry are entertained in the switchgear industry.