Onboard energy storage systems for resilient operations during electrified railway power supply failures

Onboard Energy Storage Systems (OESS) have multiple applications in electrified railways. One such application is in discontinuous electrification where an electric train travels across a route that has some electrified and some non electrified sections. Where this is intentional, the OESS can be optimised for the specific design requirement. However, when a normally electrified route experiences a power failure in the Traction Power Supply System (TPSS) this would stop all electric only trains running. A method of using OESS to reduce delays and cancellations associated with TPSS failures is presented and a case study performed using a model developed for discontinuous electrification. A moderately sized 50kWh OESS can be used to allow resilient operation over failed sections approximately 6km in length, when simulated to have 55% of the route in a failed state. A small delay is incurred compared to the normal timetable when using the OESS however this can be compensated through changes to driver behaviour. The results presented here show utilisation of a small energy store greatly enhances resilience of electric railways when failures occur.