This document specifies the requirements and test methods for a stationary energy storage system to be introduced as a trackside installation and used in a power supply network of a DC electrified railway. This system can take electrical energy from the DC power supply network, store the energy, and supply the energy back to the DC power supply network when necessary. This document does not apply to onboard energy storage systems.

This document applies to systems which are installed to achieve one or more of the following objectives.

• Absorption of regenerative energy:

  • effective use of regenerative energy (saving energy);

  • reduction of rolling stock maintenance (reduction of brake shoe/pad wear, etc.);

  • avoidance of adverse effects of heat generated during braking (e.g. in tunnels, etc.).

• Power compensation:

  • compensation of line voltage;

  • reduction of peak power;

  • reduction in the requirement of the rectifier ratings.

If this system is combined with one or more of the following functions, this document may be used as a guideline:

• reverse transmission of regenerated power to the upstream power supply network (e.g. inverting or reversible substations);

• use of the regenerated energy for purposes other than the running of trains, such as for station facilities, etc.;

• resistive consumption of regenerated power.

Although it is assumed that the system uses the following typical energy storage technologies, this document also applies to other existing or future technologies:

• batteries (lithium-ion, nickel metal hydride, etc.);

• capacitors (electric double layer capacitors, lithium-ion capacitors, etc.);

• flywheels.