Coexistence Between The Metro System And Power Lines In The Urban Area Of Lisbon

Abstract

Within an urban environment due to lack of space more often infrastructure systems are bundled. In the case of electrical systems such as a high-voltage line and a Metro system this can lead to compatibility problems; therefore a careful analysis may be necessary. In the case of Metropolitano de Lisboa a 220 kV high-voltage line is running in parallel and crossing over a new extension (on a viaduct) of the Yellow Line of the Lisbon Metro system. Also the station Senhor Roubado and Odivelas are located in the near vicinity. As the possibility exists that the EM-fields generated by the high-voltage line can influence the safety critical signalling and telecommunication installations used by the Metro system, as well as human beings, both measurements in a wide frequency band as well as simulations have been performed. As a precautionary measure, a metal covering primarily intended as a guard against vandalism has been designed to act as a Faraday Cage. The reinforcement present in the civil structure supporting the Metro System has been earthed properly. The measurements and simulations are in good agreement and lead to the conclusion that a sufficient safety margin exists over the complete frequency bandwidth, therefore Electro Magnetic Compatibility can be guaranteed. For human beings a safe situation has been created, EM fields are lower than the limits as imposed by the World Health Organisation (ICNIRP). It can be concluded that bundling of infrastructure systems in an urban area is possible, but the designs have to be adapted meticulously, and care should be given to the analysis of the coexistence of all systems concerned.