| Electric urban Public Transport in Craiova Municipality |
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Craiova (Romania)
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| RAT Craiova, is the URTP demonstrator in RECODRIVE project with European financing. This project is applying measures to reduce fuel consumption in its bus fleet and is concerned with energy savings within its Public Transport system by trams.
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Background & ObjectivesThe transport on the main axis of Craiova city, from east to west, is assured by 26 second hand trams.
The electric supply system and the tracks for these trams are quite old at 85 years. This is the major reason for which the electric Public Transport system in Craiova, both trams and infrastructure, needs major improvements. Another reason is to reduce the exploitation costs, in parallel with increasing passengers safety and comfort. The final goal is to reduce the energy invoice for the whole electric Public Transport system.
ImplementationIn order to observe the same tendency of improving the quality of local Public Transport services assured by different operators from the European Union, RAT Craiova has taken into consideration environmental requirements, the energy consumptions reduction and planning of its services according to passenger flow.
RAT Craiova, is endowed with old trams which have not been used for some time, as such, they have an old fashion driving system and a high power input/consumption. This system can be replaced by a system with chopper driving system, 9 trams being able again to be used with a low power consumption.
Due to the chopper’s electric circuit, currents of hundred amperes are appearing in tram driving system, for short intervals (few μs). These currents may disturb different electric systems existing in the proximity of the chopper. These disturbances can be avoided by using a radiofrequency filter, in series with the input filter and the smoothing coils from the chopper’s power circuit. Simulations of the filtering circuits have shown their influence over the operation of a trams electric energy supplying system. Using a program dedicated to the electric circuit analysis (like SPICE), the variations of the voltage when the radiofrequency filter is present or absent can be illustrated. |
Experimental determinations were performed on a tram, subject to modernization, with respect to the driving system chopper. The voltage at chopper’s output and the current absorbed from the electric supplying network were recorded. The recordings were achieved for various current steps of acceleration and respectively for the braking regime on a tram that uses chopper. The different steps for current at acceleration and braking were observed. In the same time the numerical records emphasize the choppers’ efficiency, including the processes for the electric energy regeneration. The efficiency of the input filter was noticed, thanks to the capacitor of this filter discharging. The energy transmitted through resistive couplings toward network and inductive couplings had no influence over the supplying line, the braking regeneration regime being normal.
ConclusionsTaking into account the project’s progress, the results are:
- Improving passengers comfort by eliminating the start-up and braking shocks
- Reducing power by about 35%
AuthorURTP Bucuresti and RAT Craiova teams -
Contact URTP Bucuresti and RAT Craiova teams -
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Beyond eco-driving - fuel savings multiply when fleet management meets eco-driving for all kinds of fleets