The solution makes it possible – for the first time – to build compact extra-high voltage AIS substations and load hubs close to large cities and urban areas where high land prices and space restrictions usually prohibit the construction of large air-insulated substations.
A typical 500 kV air-insulated substation requires a site of around 60,000 square meters, which is equivalent to six soccer pitches. With the new ABB concept, the size of the AIS substation is reduced by more than half.
Similarly large reductions in installation and construction costs and visual impact add to the strength of the concept.
The concept is based on ABB’s award-winning HPL Combined Disconnecting Circuit Breaker technology, which integrates the disconnecting function into the circuit breaker and eliminates the need for two separate free-standing disconnectors.
ABB has already delivered more than 700 disconnecting circuit breakers at rated voltages of between 72.5 and 420 kV and is the first company to develop the technology for the 500 kV voltage level.
ABB is also in the process of reducing AIS substation footprint and installation costs even more by replacing large current transformers with optical sensors that are so small they can easily be integrated with the breaker in the same circuit.
Fiber-optic current sensors measure current with a fiber-optic loop around the conductor, replacing large electromagnetic current transformers.
Known as fiber-optic current sensors (FOCS), this second award-winning ABB innovation has already revolutionized current measurement in the metals industry.
In substation applications FOCS will measure the current with a fiber-optic loop placed around the conductor instead of with large electromagnetic current transformers.
This reduces the footprint and eliminates long stretches of cabling. FOCS can also transfer all measured values digitally and interface with digital substation automation systems, making it compatible in the future with the new IEC 61850-9-2 (LE) standard for integrated substation automation systems.