Pending prohibitions for diesel vehicles have compelled cities and municipalities to take action: suppliers of electric buses can hardly meet the enormous market demand at the moment. When it comes to fast, safe and reliable recharging of batteries, the innovative current transmission solutions of Schunk Bahn- und Industrietechnik GmbH, located in Heuchelheim, in the German state of Hesse, is the market leader. Product Manager Timo Staubach explains where electrical mobility stands today and what can be expected in the near future.
Mr. Staubach, your company has been supplying perfected charging technologies for electrical buses since the year 2014. The industry is currently working with two different charging concepts: opportunity charging along the bus route or depot-based fleet charging. How do these two methods differ?
Staubach: Opportunity charging, as it is called in the industry, takes place at strategically selected bus stop. To accomplish this, the pantograph, which is mounted on the roof of the vehicle, makes contact with a docking station installed at the bus stop. The advantage is that a comparatively smaller vehicle battery can be used because only a relatively small amount of energy need be stored – just enough until the next stop. This method is particularly well suited for cities with bus lines extensive operating ranges. Overnight charging, or depot charging, on the other hand, takes place after operating hours, in the vehicle depot. The significantly larger batteries with their correspondingly higher charging capacities require more space and can easily add a few tons of additional weight to the vehicle, depending on the operating range requirements. This also means less space on the bus for passengers. For smaller municipalities with less extensive operating ranges, this can, however, be a practicable solution.
Schunk offers current collectors for both concepts. What advantages do they have when compared to the conventional plug-in solution?
Staubach: Our pantographs are well suited for recharging both at the bus stop and for overnight recharging in the depot; here the contact connection is simply located in the vehicle depot hall. Transit companies with large fleets naturally do not want to individually plug in each bus every evening. That’s why were convinced that the manual plug-in solution has no long-term future. Whether opportunity charging or depot charging is the more efficient solution, depends on the respective charging strategy, the number of vehicles to be recharged, the characteristics of the bus routes and their particular requirements. The main thing here is to take into account and analyze the individual needs of the customer.
When the buses are in operation, adhering to the bus schedule has the highest priority. What technical challenges do you have to overcome to ensure this is the case?
Staubach: When parking the bus at the charging station, the tolerance range has to be chosen to be as large as possible. In their day-today work, we cannot expect bus drivers to be able to park with millimeter precision. The pantographs developed by Schunk provide a very large tolerance range. A visual orientation aid is sufficient for bringing the vehicle into the proper position. In addition, the current collector automatically connects with the charging infrastructure in just five seconds and with 800 amps allows an extremely high current transfer. Because of this, our systems are some of the leading and best engineered recharging solutions currently in use in public local transport with battery-powered electrical buses. The so-called kneeling effect, the sideways tilting of the bus at the bus stop, is compensated by the rocking suspension design of the pantograph so that no interruption of current flow occurs. Our products, by the way, can be found in many cities around the world, such as Amsterdam in the Netherlands where 100 buses are already serially driven in this configuration and deployment of even more buses is being planned in the country.
Time for a forecast: What do you expect for the year 2019 with respect to electrical mobility?
Staubach: I expect that we will have approved a common standard for uniform plugs and interfaces by the end of 2019. Schunk is already working on this together with other suppliers on various standardization committees. And I would like to see the cities, municipalities and transit authorities altogether in Germany become a little more daring. German cities could learn quite a bit from our European neighbors. As a supplier, we have years of experience and have long since progressed beyond the stage of experimenting and designing prototypes and moved on to serial operation. It is certain that significantly more electrical buses will also be used in Germany in the year 2019. And the reasons are more than just the reduction of CO2 emissions; e-buses also generate less odor and noise in inner cities. The future surely belongs to the electrical drive!
Interested? Find mor information here: www.schunk-smartcharging.com Visit us at ElekBu 2019 in Berlin!
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When it comes to fast, safe and reliable recharging of batteries, the innovative current transmission solutions of Schunk Bahn- und Industrietechnik GmbH, located in Heuchelheim, in the German state of Hesse, is the market leader. Product Manager Timo Staubach explains where electrical mobility stands today and what can be expected in the near future. When it comes to fast, safe and reliable recharging of batteries, the innovative current transmission solutions of Schunk Bahn- und Industrietechnik GmbH, located in Heuchelheim, in the German state of Hesse, is the market leader. Product Manager Timo Staubach explains where electrical mobility stands today and what can be expected in the near future.
