2. Dynamic brake

2.1 Operating principles

The dynamic brake uses the train's inertia (i.e. its motion) to generate braking effort, possibly by providing "excitation" energy to initiate braking.

The dynamic brake is, by its very nature, wear-free, making it a highly cost-effective brake. What's more, in some versions, the train's kinetic energy can be partially recovered to power other on-board devices, or more frequently to be fed back into the power supply line for other trains running on the same line, or even to the power supply network if substations allow.

It is particularly interesting at high speeds, where friction brakes show their limits (very high speeds), but also when frequent braking is required (urban operation).