Electric Power Systems Research 112 (2014) 1–11 Contents lists available at ScienceDirect Electric Power Systems Research j o ur na l ho mepage: www.elsevier.com/locate/epsr Energy recovery effectiveness in trolleybus transport ˇ Stefan Hamacek a,∗ , Mikołaj Bartłomiejczyk b,1 , Roman Hrbᡠc a,2 , Stanislav Miˇ sák c,3 , Vítˇ ezslav St ´ yskala a,4 a V ˇ SB-Technical University of Ostrava, Faculty of Electrical Engineering and Computer Science, Department of Electrical Engineering (420), 17. listopadu 15/2172, 708 33 Ostrava, Poruba, Czech Republic b Gdansk University of Technology, Faculty of Electrical and Control Engineering, Department of Electrical Transport, ul. J. Sobieskiego 7, 80-216 Gda´ nsk, Poland c V ˇ SB-Technical University of Ostrava, Faculty of Electrical Engineering and Computer Science, Department of Electrical Power Engineering (410), 17. listopadu 15/2172, 708 33 Ostrava, Poruba, Czech Republic a r t i c l e i n f o Article history: Received 26 March 2013 Received in revised form 28 February 2014 Accepted 2 March 2014 Keywords: Supercapacitor Energy recuperation Electric traction Monte Carlo simulation Traction substation a b s t r a c t Nowadays the issue of electric energy saving in public transport is becoming a key area of interest which is connected both with a growth in environmental awareness of the society and an increase in the prices of fuel and electricity. One of the possibilities to reduce energy consumption in urban public transport is to increase the extent of regenerative braking energy utilization. This can be achieved by its accumulation in the supercapacitors or a change in the topology of the power supply system in order to facilitate its flow. The article presents an analysis of applying these two options for increasing recovery energy usage on the example of the trolleybus network in the Polish city of Gdynia. For the purpose of the analysis there was used a simulation model of trolleybus traction power system based on the Monte Carlo simulation method. The research results and findings can be applied in other similar trolley or tram networks. © 2014 Published by Elsevier B.V. 1. Introduction One of the distinctive features of electrical vehicles is their capacity to return electricity to the traction network, which is called energy recuperation. Recuperation reduces energy consump- tion in transport through energy re-use. In recent years, the issues related to increasing the efficiency of regenerative braking have been assuming growing importance. This is caused by the increased number of vehicles equipped with the recuperation module and the necessity of curbing electricity consumption due to environmen- tal and financial factors. Energy storage devices, which allow the storage of recovered energy, are increasingly used. They include supercapacitors and flywheels. Today, a vast number of such storage devices are already applied in undergrounds, trams, and trolleybuses. As a result, the optimization of recuperation energy storage devices is growing in significance [1–6]. ∗ Corresponding author. Tel.: +420 597 329 309; mobile: +420 776 749 582. E-mail addresses: stefan.hamacek@seznam.cz ( ˇ S. Hamacek), mbartlom@ely.pg.gda.pl (M. Bartłomiejczyk), roman.hrbac@vsb.cz (R. Hrbᡠc), stanislav.misak@vsb.cz (S. Miˇ sák), vitezslav.styskala@vsb.cz (V. St ´ yskala). 1 Tel.: +48 58 347 28 57. 2 Tel.: +420 597 321 503. 3 Tel.: +420 597 329 308. 4 Tel.: +420 597 321 511. Energy storage devices can be divided into two groups: the on- board devices placed in vehicles and off-board devices installed in traction substations or other power supply system units. There are two main lines of research related to increasing the energy efficiency of urban traction systems which can be found in the lit- erature: vehicle storage devices for light electrical vehicles (LEV) [7–9] and lowering energy consumption in heavy electrical vehicles (HEV) such as railway, suburban railway, and underground [10–13]. There is a clear shortage of publications on stationary energy stor- age devices or on energy consumption reduction in light electrical vehicles (LEV) and urban transport systems. In Europe, tram and trolleybus transportation is still developing. Over the last decade, many new tram and trolleybus systems have been launched. This creates a need for research on increasing the efficiency of urban traction power supply systems, which could be possible by e.g. using stationary energy storage devices. Moreover, attention should be paid to another deficiency in the current areas of research: the issues of design, construction, and control of energy storage devices. Although they are often the sub- ject of studies [5,8,9,14,15], these studies are usually limited to the accumulation of electricity in the storage devices alone. There is no literature on the methods of increasing the scale of recuper- ation energy re-use from the global perspective, i.e. with regard to re-using such energy by auxiliaries and other electrical vehicles. Research on the analysis of the full recuperation energy balance are http://dx.doi.org/10.1016/j.epsr.2014.03.001 0378-7796/© 2014 Published by Elsevier B.V.