Proceedings of 7th Transport Research Arena TRA 2018, April 16-19, 2018, Vienna, Austria Ground-level feeding systems

Philippe Veyrunesa, Patrick Dupratb, Jean-Luc Hourtanéc

aSRS Solution Manager, , 48 rue Albert Dhalenne, Saint-Ouen 93400, b ERS Program Manager, Alstom, 48 rue Albert Dhalenne, Saint-Ouen 93400, France cAPS-SRS Engineering Manager, Alstom, 27 bd Europe, Vitrolles, France

Abstract

As a promoter of sustainable mobility and a pioneer in ground-based feeding solutions for urban rail transport, Alstom extends the use of its APS technology to road transport, accompanying the shift from petrol/diesel- powered vehicles to electrically-powered vehicles. Originally a dynamic feeding solution for catenaryless tramways, APS supplies electricity to vehicles at ground level by means of a segmented conductive rail installed on the road surface. Service proven in 7 tramway networks, the technology has undergone further developments to comply with other applications: the static recharge of autonomous and buses, as well as the dynamic feeding of road vehicles. APS is currently being tested for powering trucks on highways, as part of the ERS project included in a programme by the Swedish Energy Agency.

Keywords: Electromobility; power supply; electrification; infrastructure; charging; static; dynamic; feeding.

1 Philippe Veyrunes, Patrick Duprat, Jean-Luc Hourtané / TRA2018, Vienna, Austria, April 16-19, 2018

1. SRS: Ground-based static charging for electric buses

1.1. Introduction

Today, cities seek sustainable public transport with low emissions, and turn towards electrically-powered buses. Deemed too obtrusive, trolley buses powered by overhead contact lines are now being supplanted by autonomous vehicles equipped with on-board energy storage, which have to be recharged at the depot or the along the route. This trend gives rise to two main categories of solutions, based on the charging mode: bus charging at depot and bus charging in the city.

- Depot charging is achieved by plugging the bus into a charger installed at the depot, during several hours. In addition to impacting the availability of the vehicles, this brings operating constraints, as actions are required from drivers or other operator’s staff. Moreover, buses resorting to this charging mode carry large battery banks on board, increasing their weight, and thereby limiting passenger capacity. Depot charging is also generally ill-adapted to high-mileage or steep-slope lines, and restricts the usage of HVAC. - The second charging mode, city charging (i.e. automatic recharge along the route) offers more benefits: it enables fast and opportunistic charging, allows for lighter vehicles with optimised on-board energy storage systems, has no impact on vehicle availability, passenger capacity, or HVAC usage, and is compatible with high-mileage or steep-slope lines.

Alstom developed SRS, as an innovative ground-based static charging solution designed to recharge electric vehicles equipped with on-board energy storage, especially well adapted to city charging. SRS was derived from Alstom’s APS, the market’s very first dynamic feeding system for catenary-free tramway lines, which consists in supplying power to the vehicle through a segmented conductive rail embedded in the track, between the running rails. Conductive segments are switched off-on-off as the vehicle progresses, ensuring total safety for all road users (pedestrians, cyclists, other vehicles, etc.). The electricity transmitted by the segmented rail is picked up by current-collector shoes located under the vehicle. APS is a solution which helps preserve the aesthetics of city centres/urban environments and allows to reduce LRT systems’ footprint, by eliminating overhead contact lines and masts. Since the first implementation of APS in (France) in 2003, more than 350 trams and 144 kilometres of tracks equipped with this system have been sold, totaling over 25 million kilometers run. Other service-proven APS references include , , Orléans, (France), Dubai () and Rio (). In the world today, five catenaryless tramway projects are being built with APS: Cuenca (Ecuador), Lusail (), Sydney (Australia), another phase of Rio (Brazil) and a new line in Bordeaux (France).

Fig. 1 Dubai Al-Sufouh: World’s first fully catenary-free tramway line, powered with APS

2 Philippe Veyrunes, Patrick Duprat, Jean-Luc Hourtané / TRA2018, Vienna, Austria, April 16-19, 2018

1.2. Solution composition

Based on its extensive return of experience with APS, Alstom launched SRS. Also compatible with tramway/light rail applications, SRS is a response to the need for the recharge of electric buses along the route, offering the following benefits:

- SRS allows for fast charging (at stations during normal dwell time or in terminus within a few minutes) without power limitation. - With SRS, the recharge process is automatic, with no additional constraint on operation. - Being compact, it allows for easy urban insertion. - Being a street-level electrification system, SRS is compatible with a wide range of vehicle dimensions (regardless of length, height or manufacturer). - The SRS solution allows for optimised power and weight of on-board batteries. - SRS is an all-in-one system with control of vehicle positioning and power supply integrated within the same equipment. - Being a fixed infrastructure solution, it allows for facilitated maintenance and higher availability of the charging spot.

Fig. 2 Overview of SRS for electric buses

1.3. Operation of the system

SRS is based on the same functional and safety principles as APS, which was validated by several renowned certification bodies, including Lloyd’s and CERTIFER. A coded radio signal is continuously emitted by the power pads installed on the road, at a stop or a terminus. As the vehicle approaches, it detects the signal and positions itself to stop over the power pads. Then, a coded signal is sent by the bus and recognized by the infrastructure to initiate the recharge. When recharge is complete, the charging current is interrupted and the vehicle stops emitting the signal. Pads are then unpowered and the contact shoe is raised before the bus drives off. The power delivered by SRS depends on the on-board storage characteristics and/or operational constraints: - An on-board to charge in less than 20 seconds at passenger stops (up to 1.2 MW). - An on-board battery to charge in several minutes at each terminus of a bus line (from 150 kW).

3 Philippe Veyrunes, Patrick Duprat, Jean-Luc Hourtané / TRA2018, Vienna, Austria, April 16-19, 2018

Fig. 3 Electrical architecture of the SRS charger

1.4. Commercial highlights

SRS is among the e-bus fast charging solutions recognized by the UITP, and is the only solution combining all the benefits from both conductive charging (as opposed to inductive) and ground-based charging (versus overhead charging). Alstom is also part of the UITP working group supporting CENELEC for the implementation of a standardization norm for electric vehicle’s charging systems.

Alstom officially launched SRS at the UITP World Congress & Exhibition in June 2015, in Milan (Italy). In 2014, it achieved its first commercial success with its tramway application ordered for the Nice tramway Lines 2 & 3 project (France).

2. APS for road: Ground-based dynamic charging for electric vehicles

2.1. Introduction

The electric vehicle (EV) is a promising solution to improve sustainability in road transport. There is a major challenge to meet the demands placed on a new vehicle such as regarding cost, efficiency, range, and functionality. Great resources are spent to increase the EV range by increasing the vehicle efficiencies and the battery capabilities. Despite this, the energy storage capacity of the batteries is not enough for long-distance transport of EVs and even output power could be a limiting factor. Larger batteries are not necessarily the solution since they require a longer time to recharge or access to charging stations with extreme charge capabilities.

Moreover, the battery is a substantial part of the total cost and weight of the EV, which reduces the cargo load capacity, and thereby also the monetary gain for the otherwise less energy-demanding vehicle. To make the EV less dependent on the battery, especially for long distance heavy transport, and at the same time reduce the vehicle cost, a possible solution could be to transfer power to the vehicle from the roadway.

Electric Road Systems (ERS) can be defined as roads supporting dynamic power transfer to the vehicles from the roads they are driving on. An ERS could connect cities and allow the bulk distance to be driven on external electric power instead of using fossil fuels. The propulsion of the short remaining distance outside the ERS network could either be based on internal combustion engine (ICE), or on energy stored in small, on-board batteries optimized for city routes. With this solution, both the costs and the weight of the batteries can be kept small. In addition, there is no need to stop and recharge since this is possible while driving.

The APS for road solution is based on Alstom’s APS solution for tramways, i.e., a continuous energy transfer by contact from under the vehicles.

2.2. First APS for road demonstrator

Alstom’s first experience of APS for Road comes from a Strategic Vehicle Research and Innovation program

4 Philippe Veyrunes, Patrick Duprat, Jean-Luc Hourtané / TRA2018, Vienna, Austria, April 16-19, 2018

Alstom’s first experience of APS for Road comes from a Strategic Vehicle Research and Innovation program launched by the Swedish Energy Agency (SEA) in 2011.

This project aims to improve the knowledge and experience of the power transfer from the road to a vehicle, especially on energy efficiencies, installation costs, maintenance costs and safety.

The basic principle is to power an electric engine within the vehicle from an external power source that is built into the road infrastructure. The electrical power is transmitted while the vehicle is in motion, through a pick-up assembled to the vehicle in a similar way as for a trolley bus. The roads would be accessible for both vehicles with ERS-propulsion as well as conventional fossil fuelled vehicles. Further on, the ERS-vehicles would be equipped with a small battery and a potentially smaller internal combustion engine (ICE), which allows the vehicles to drive also on conventional roads outside the ERS network.

Fig. 4 Principal design of an Electric Road System (ERS)

The APS technology (or principle) has been adapted to the ERS needs: - Addition of a second rail to manage the return current (back to the power substations) - New switching device adapted to road traffic (vehicles up to every few seconds instead of every few minutes for tramway application) - Pick-up shoe ( device) with automatic and accurate lateral positioning - New safety rules adapted to the length and the speed of the vehicle.

The project has been carried out in two phases: During Phase 1, a Test Track was built in Hällered (in Volvo testing centre in Sweden) based of APS component coming from tramway application according to the following power architecture:

Fig. 5 Power architecture of the ERS test track

5 Philippe Veyrunes, Patrick Duprat, Jean-Luc Hourtané / TRA2018, Vienna, Austria, April 16-19, 2018

The ERS equipment was installed in 2012:

Fig. 6 Installation of ERS test track Phase 1

The main objectives of Phase 2 were to develop or improve the equipment to be better adapted to ERS needs: - New rails for better integration into the road - New switching box (static switching instead of electro-mechanic) - New pick-up shoe (more robust and with improved accuracy in lateral positioning) - Use of radio communication from ground to vehicle in order to lower and raise the pick-up shoe - Use of new metallic conductive bars to improve adhesion The test track was extended in 2014 to include the above changes.

Fig. 7 Installation of ERS test track Phase 2

Test campaigns were carried out after Phase 1 and Phase 2 with the following results:

Current collection tests Result

126kWatts 180Amps 690VDC transfer ✓ Truck speed over 80 km/h ✓ 20 km of continuous power transfer ✓ Rainy conditions ✓ Short circuit tests ✓

Track adherence tests ✓

Table 1. Test results

6 Philippe Veyrunes, Patrick Duprat, Jean-Luc Hourtané / TRA2018, Vienna, Austria, April 16-19, 2018

2.3. Next APS for road projects

Following the proof of concept validated during this demonstrator in Sweden and also after analysis of the others ERS solutions, we are now developing a new solution that should be offering the best compromise between: safety, power efficiency, field of application (Trucks, buses, cars), robustness, costs and aesthetic. This safe, sustainable and reliable solution will be available for the following applications: - Electric corridors on highways - Harbor - Dynamic charging for buses - Mining application Our ground-based dynamic charging will be available for a large range of EV (by priority): - Long Haul Trucks - Heavy trucks - Buses - Light Vehicles

Fig. 8 Highway equipped with APS

3. References slide_in_conductive_project_report_phase_1.pdf

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