New model of smart underground transformation center, adapted to smart cities and climate change

Abstract

Smart grids face the challenge of having an intelligent node that allows the
management of distribution network. This one can not be other than transformer
stations, as an energetic node where high voltage grid get to, and where distribution
grid come out in low voltage for consumers, and as a node in the communications
architecture, necessary for the intelligent control of the network.
It should be noted that it is important that these energy and communication nodes
achieve greater reliability, security and a better continuity of supply in case of
catastrophes (floods, fires, earthquakes,...). It can not be forgotten that in these
emergency situations, getting the distribution grid working is essential to be able to supply critical services, such as communications, hospitals, pumping systems, ...
helping to create what is called "resilient cities".
It is also important to consider that the location of new transformer stations in
consolidated urban centres is increasingly difficult. This effect will be accentuated even
more if the incorporation of the electric vehicle as a usual means of urban mobility is
taken into account, since this will mean an increase in the installed power of the
distribution grid.
A new model of underground smart transformer station is proposed, which, with an
innovative design, is capable of solving these problems. The proposed model has a
cylindrical metallic envelope, giving it a greater resistance to external forces while
keeping its watertightness against floods and forces characteristic of seismic
movements. Within the inside, all the switchgear is available, with motorized drives. It
will have protection relays and sensors to control parameters. All the system is
managed by a control unit which is located in a tight and resistant exterior box. From
this control unit, all the elements can be managed, checking the connection status of
each one and knowing the operating parameters of the equipment. Also, the control
unit will enable to store a data history of performed operations and granted accesses
by big data and Cloud Computing technologies. The system will also allow the
possibility of a remote management from a control station or through an APP
(application) system for mobile devices, allowing the incorporation of this equipment in
another intelligent integrated one or smart grids. In addition, it will allow a better
maintenance management and a more efficient operation of the network.
With the purpose of solving the heat evacuation of the transformer tank, the
conventional fin design of the tank is modified by a new design based on installing
exchangers on the outside and by means of collectors in the tank that will allow the
refrigerant oil to circulate with a pump. In order to make the station invisible, this
exchanger will be installed replacing part of the curb on the sidewalk. In this way, the
station is totally sealed and resistant to any type of flood or tsunami. In addition, this
cooling system, more efficient, and an envelope without openings, will increase
durability of components and their useful life.
It is hereby concluded that the use of this innovative transformer station model will
make electrical infrastructures of cities more resistant and operational, enabling them
to face the great challenges of the future brought by the digital revolution, electric
vehicles and climate change.