Equipotentiality
Equipotentiality management system in high voltage railway installations (PNAC ).
Constant supervision of the operation of the elements and connections of the system to ensure that the equipotentiality carried out has been produced.
A self-supervised voltage sensor (6) measures the catenary voltage twice and if the readings coincide, it transmits it to the control unit so that if it receives a closing order through the communications bus (24) (from a remote control) the disconnector performs equipotentiality and earthing of the catenary and guard cable.
The voltage sensor receives the voltage from the voltage converter (7) and from galvanic isolation, made up of two connected modules. The first one (7a) receives the supply voltage (25) and is also connected to the negative rail.
The voltage sensor is also connected to the disconnector (1) establishing a loop through which current flows continuously. If the current should stop flowing, the voltage sensor turns off, providing a value of 0 to the control unit, generating a fault signal.
ENSURE the equipotentiality of the facilities once they are without power and their earthing has been carried out.
ENSURE that the connection of the catenary and guard cable with the negative rail has been made correctly.
The invention verifies by two means that the disconnector is in the closed position, ensuring equipotentiality as long as the current loop is closed.
- End-of-stroke control on the motor that generates and sends a signal with the position to the control unit.
- An optical angle sensor (2) informs the control unit of the position of the disconnector blades (18), through a receiver / transmitter (11) powered by a third voltage converter (13).
The invention responds to standards related to railway safety, such as for example in electrified tunnels according to different regulations, among others, by the Technical Specifications for Interoperability ("ETI") on safety in tunnels in conventional and high-speed trans-European railway systems (European Commission decision of 20 December 2007).
The installation of sockets is required to make equipotentiality between the catenary and the rail, at the access points to the tunnel and near the separation points between sections.