Mechanical energy storage of trolley circuit breaker

Can a stationary supercapacitor save energy in a trolleybus traction network?

The aim is to determine potential energy savings in the power supply system of the trolleybus traction network. The use of a stationary supercapacitor energy storage device and the reconfiguration of the power system was compared.

How much power does a trolleybus have?

Even so the selected cell type (see Tab. 2.1) allows a maximum discharge power of only 120 kW while the rated power of the trolleybus is 250 kW. For independent traction without power limitation, the battery would have to be rated at twice the capacity, which would be unused (range of independent drive needlessly long).

How much braking energy is wasted in trolleybus braking resistors?

These routes were chosen by DPMB as representative ones. It can be deduced from the performed calculation (4.5) that the average percentage of braking energy being wasted in the braking resistors of the trolleybuses is about 24% from the total energy delivered to these trolleybuses from the trolley.

Should braking energy be stored in a trolley or ultracapacitor?

It is clearly more favorable to return the braking energy into trolley than into energy storage tank (ultracapacitor, LiFePO4 battery) in economic point of view. Most of the braking energy is consumed by another vehicles connected into the same trolley section in macroscopic point of view.

Can a full recuperation energy balance be applied to a trolleybus traction?

Research on the analysis of the full recuperation energy balance are relatively rare, e.g. a riveting research paper is presented in , but it concerns the underground power system and its resultscannot be applied to the trolleybus traction.

How much braking energy does a trolleybus return?

Approximately 50 % of the trolleybuses allow returning of braking energy back to the trolley, while the ratio of returned energy to withdrawn energy is 20 % – similar result as in our study (see Chap. 4.2.4). The first trolleybuses of the type Solaris Trollino 12 with independent driving capability were put into service in 2009.