Construction
	
	Operation & Maintenance
	
Substation 
	TEPCO have 1577 substations in 2005. We have built a variety of substations
	  depending on their purpose, supplying voltage, installing cost, and its supplying
	  area. 500kV large-scale underground type substation has been built for stable
	  and efficient supply for Tokyo metropolitan area. 
	  Even though we operate a variety of substations and machineries, We have
	  achieved very low annual average electricity interrupting time. For stable
	  supply, we have introduced many up-to-date techniques. And we have organized
	  quality management system for substation design and construction (e.g. Guidelines
	  for installation of SF6 Gas Insulated Switchgears.). And we have developed
	  effective diagnostic/maintenance techniques for every machinery (e.g. dissolved
	  gas analysis and circuit breaker operation monitoring are employed).
	  We can offer the best solutions for substation construction/operation from
	  our technical experience.
	
	Fault Restoration System
	
	Control system can isolate internal and external faults of distribution substations,
	  and restore power supply automatically as much as possible.
	

	Expected Effects
	
	  - Quickness - Power system can be restored automatically.
 
	  - Reliability - Automatic control system can perform restoration certainly.
 
	  - Labor Saving - Fault restoration can be conducted without human operations.