Parameters of capacitor devices used for storing energy from recuperative braking and the profitability of their application in tram traction
Ładowanie...
Data
2009
Autorzy
Tytuł czasopisma
ISSN czasopisma
Tytuł tomu
Wydawca
Gdansk University of Technology
Abstrakt
Simulation results have been used for producing estimates of economic profitability of
replacing braking systems with recuperation of energy directly into the traction network by
systems which store braking energy in devices installed in vehicles. The estimates have
indicated that, with the current price relations of energy and supercapacitors, using energy
storage devices is not justified from the economic point of view. However, it must be noted
that these estimates were based on the assumption that the storage device capacity is
0.9 kWh, which makes it nearly always possible to store all of the braking energy. Similar
calculations performed for the storage device with a capacity reduced to 0.6 kWh, which
results in a decrease in energy savings by approximately 12%, but reduces the cost of a
storage device by one-third, indicate that such a solution, is on the verge of profitability. It
could be expected that in the future, with the decreasing prices of supercapacitors and improvements
in their parameters, and, on the other hand, with the increasing energy prices,
using energy storage devices in the rolling stock will be fully justified economically.
In addition, using braking systems equipped with energy storage devices is justified by
certain benefits of this solution, e.g. off-induction of relatively high voltage surges in traction
network (in systems with recuperation of energy directly into the network, voltage
could surge as high as ca. 800 V). In addition, a tram equipped with a storage device becomes,
to some extent, an autonomous vehicle, e.g. it can leave a crossroads on its own in
the event of voltage loss in the traction network.
The cost of installing storage devices at substations is recovered relatively soon, but a
fundamental question arises about the longevity of such devices installed at substations.
The frequency of charge cycles of storage devices installed at substations is several times
higher than that of storage devices installed in vehicles. On the other hand, as it could be
seen from the histograms in Fig. 6.8, 6.10 and 6.11, full charge cycles of storage devices
occur rather rarely. Most often, storage devices are charged until 1/3 of their capacitance.
One can expect that, as a result, their longevity, expressed in a number of charge cycles,
will increase substantially. Unfortunately, a valid answer to the question how often the
storage devices will need to be replaced can be obtained only from operational tests.
Opis
Słowa kluczowe
tram traction, storing energy, recuperative braking, trakcja tramwajowa, magazynowanie energii, hamowanie rekuperacyjne
Cytowanie
Solarek T., Parameters of capacitor devices used for storing energy from recuperative braking and the profitability of their application in tram traction. W: Modern electric traction : power supply, Karwowski K. (red.), Szeląg A. (red.), Gdańsk University of Technology, Gdańsk 2009, s. 59-70, ISBN 83-911669-7-X.