These are low-voltage systems that do not belong to power equipment. Most of them are critical and fully redundant.

The low-voltage supply uses two direct current systems with batteries to provide energy in case of main power failures and is backed up by generators.

• Control

  The control systems implement functionalities for all equipment. From the electrical drive for operating circuit breakers or transformer tap changers to the programming of automatic systems (PLCs) that monitor alarms and the state of other equipment, including those that send this information to control centres.

• Protection

  Protection systems constantly monitor the transmission grid to detect irregular situations and quickly isolate faulted areas. Their main mission is to disconnect the minimum number of elements possible to ensure system safety and stability.

• Communications

  Communication systems are considered to be as critical as the services they provide. Examples of essential services include the protection of both ends of a line, sub-station control systems, real-time monitoring for equipment maintenance, and the transmission of orders from operators (located in control centres) to switching equipment (circuit breakers or disconnectors).