Application of Traction Supply System for Charging Electric Cars

Abstract

The development of electromobility involves the development of electric cars charging infrastructure. The increase of the number of chargers poses new demands for the AC power grid, especially in regard to its capacity of delivering high peak power. As an alternative for the public AC power grid, urban electrified transportation systems (trams, trolleybuses, and metro) can be used for supplying electric cars chargers. The article discusses four options of integrating electric cars chargers with a traction power supply system. The option of connecting the charger to the traction overhead supply line has been selected due to the spatial availability of the power source and possibility to use regenerative braking energy for charging. A set of criteria has been developed for analysing the capability of the traction supply system to feed electric cars chargers. An exemplary feasibility analysis was carried out for trolleybus traction supply system in Gdynia, Poland. The impact of installing the charging station on specific traction supply parameters has been predicted using present-state recordings of electrical parameters and assumed charging station power. The study shows that every supply section of the considered trolleybus traction system has the capability of installing a fast-charging station, which provides opportunities of expanding the charging stations network in Gdynia.

A New Approach to Use of Traction Power Network in Poland for Charging Electric Vehicles

“…The use of railway power infrastructure to charge electric vehicles is not a frequently used solution. However, there are several technical solutions regarding charging, power supply and the intercorrelation of electric vehicles with electric traction networks (mainly with urban traction networks powering trams, metro and trolleybuses) [1,[12][13][14][18][19][20][21][22][23][24][25][26].…”

“…A very interesting solution was proposed in the article by the researchers of [18] where connection to an overhead traction line would allow the use of energy from regenerative braking. A feasibility analysis was carried out for a trolleybus traction power supply system in the Polish city of Gdynia, which confirmed the validity and advantages of such a solution.…”

“…There are no implemented solutions that directly use RPI for EV charging, but after familiarizing ourselves with the structure of RPI and the proposals presented in the literature [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26], it can be concluded that it is technically possible to use RPI for the development of electromobility.…”

Opportunity Charging of Electric Buses Directly from a DC Metro Catenary and Without Storage

“…In particular, the integration of smart loads such as electric vehicles (EV) chargers into transport networks can both increase the braking energy recuperation and provide a base load for the integrated renewable energy sources. Both are phenomena that can reduce the dependency on costly, inefficient, and complex storage systems [20,21,26,27]. Indeed, an EV charger connected to the DC side (directly to the catenary/third rail) of a traction grid can recuperate some of the otherwise-wasted braking energy.…”

A Review of the Key Technical and Non-Technical Challenges for Sustainable Transportation Electrification: A Case for Urban Catenary Buses

“…Trolleybuses are destined to (re)become a key player, after decades of expansion and contraction that saw many of their networks going out of commission [8,9]. Their electrical grids are becoming increasingly more sophisticated with the inclusion of smart grid technologies [10], renewable energy sources (RES) [11][12][13][14][15][16][17][18][19][20], on-board and/or off-board storage [21][22][23][24][25], electric-vehicle (EV) chargers [15,[26][27][28], and In-Motion-Charging (IMC) buses [8,29,30].…”