Application of smart wayside object controllers to railway signalling systems for decarbonisation

In railway signalling systems, trackside equipment and signalling devices are controlled by wayside object controllers (OC). With the application of radio communication to wirelessly transmit command control and signals, the cost of cabling and installation has been significantly reduced. However, for non-electrified regional lines in rural areas, dedicated cables are still installed along the track to drive the wayside object controllers, which increases both capital and operational costs. With the development of renewable energy sources (RES) and wayside energy storage systems (ESS), a concept of smart wayside object controllers (SWOC) is proposed, which are autonomous, off-grid and powered by local renewable energy sources to reduce the related costs. To assist future system development, this work develops methods to not only calculate power and energy demand for system configuration but also estimate the life cycle cost in long-term operation. A case study based on a railway test site in Sweden is performed. This study shows that it is sufficient to use 100% local renewable energy sources to power the SWOC, trackside equipment and signalling devices. Compared with the existing system, the SWOC shows a significant cost saving in long-term operation by removing cabling and installation, reducing trackside maintenance and replacing the power supply with renewable energy power sources for decarbonisation. Therefore, the SWOC shows its significant benefits over the existing system from both economical and environmental aspects. In the end, some suggestions for future development and implementation of SWOC are given.