Electric fields around catenary wires, and an evaluation of relevant legislation

Electric fields around catenary wires, and an evaluation of relevant legislation

#Electric fields, #Catenary wires, #Comsol Multiphysics, #EU legislation

Challenge

An operator for public electric railways was faced with an issue of cleaning front wind shields on their running equipment. Due to EU regulations, there is a limit of how large electric field the service technician can be exposed to during cleaning; hence the catenary wires had to be shut off, causing traffic delay during rush hours.

The service provider wanted to explore the actual field strengths to which the service providers were exposed to, and investigate if cleaning could take place while keeping catenary wires live.

Upvious contribution

Electric fields around complex geometries are easily calculated using numerical tools like the FEM software Comsol Multiphysics. Upvious retrieved relevant geometries of catenary wires, platform and relative positions of the railway, and established 3D geometries of the different locomotives in question.

Secondly, the EU legislations (2013/35/EU Electromagnetic fields) and the Danish interpretation (BEK nr. 472) was reviewed, to understand the exact requirements and threshold for safe working under the exposure of electric fields at grid frequency.

Different combinations of cleaning operation, platform and rail geometry, and support structures for the catenary wires was considered, and the electric fields were calculated.

Results

The results were indeed very positive. The different configurations all demonstrated that the electric field through a service technicians body (Elow) as well as the Electric Field through the service technician’s head (Ehigh) were substantial lower than the thresholds defined by the legislation, such that the procedures for washing wind shields could be maintained even when keeping the catenary wires energized.

The customer received a thorough report documenting the process and results, and Upvious also presented the output for the maintenance team, and those locomotive drivers who had an interest in getting the full picture.