Equipped with Voith’s parallel DIWA hybrid system and packed to the gills with Maxwell’s ultracapacitors, the Solaris Urbino 18 hybrid city bus is peoplemoving technology taken to the next level. With 51 seats and room for 161 passengers, the Urbino 18 hauls one heck of a load, while its articulating mid-section makes navigating tight corners a breeze.
The Solaris Urbino 18 features a 150 kW electric motor paired with a downsized diesel engine. Energy recaptured during braking is stored in a massive supercapacitor that weighs in at 904 pounds and boasts a total storage capacity of 0.5 kWh.
Voith describes the functionality of the Urbino 18’s unique hybrid system like this:
In the DIWA hybrid system, an asynchronous electric motor supports the diesel engine when pulling away from stops and accelerating. During braking, the asynchronous motor acts as a generator and primary retarder, complementing the DIWA secondary retarder. This allows electric energy to be recuperated, reducing the use of the driving brake, minimizing brake wear and tear and lowering resulting particulate emission.
The DIWA hybrid setup puts out up to 389 horsepower and 1,180 pound-feet of torque, while its 150 kW electric motor substantially reduces the load on the bus’ 6.7-liter diesel engine. Surprisingly, the Urbino 18 tips the scales at just 1,323 pounds more than its diesel-only counterpart. The new hybrid city bus is set to launch in mid-2011.
[Source: Voith Turbo]
The new Solaris Urbino 18 DIWAhybrid articulated city bus uses a Voith parallel hybrid system. A 150 kW electric motor supports the diesel engine. Energy is stored in supercapacitors, resulting in reduced fuel consumption and lower wear and tear. Field testing by Bochum-Gelsenkirchener Straßenbahnen AG is under way.
Reliable, economic and eco-friendly – the new Solaris Urbino 18 with Voith DIWAhybrid system is a trendsetting choice for state-of-the-art public transport. It was designed in cooperation between established partners, using well-proven components. Thousands of Solaris Urbino 18 low-floor city buses already show their credentials throughout Europe. Its new Voith Turbo hybrid drive is based on the seasoned quality of DIWA automatic gearboxes, which are used around the world, and Voith´s long-standing experience in developing electric drive systems.
“Together with our partner of many years, Voith Turbo, we now take another important step towards sustainable electric mobility. In choosing the Urbino 18 DIWAhybrid, our customers benefit from a parallel hybrid bus that makes no compromises in economy or reliability,” explains Solaris CEO Solange Olszewska.
Dr Volker Zimmermann, Managing Director Voith Turbo, adds: “Technologies that further reduce costs for transport operators and make buses even more environmentally-friendly have long been our focus. Developing electric drives for the specific operating profiles of city buses is a top priority for us. For our parallel hybrid drive, the Urbino 18 DIWAhybrid is the reference application in Germany and Europe.”
DIWAhybrid: Parallel Hybrid System with Supercapacitor Storage
The new Urbino 18 DIWAhybrid seamlessly fits into existing bus fleets and is straightforward in everyday operation. At the heart of this new bus is the DIWAhybrid parallel hybrid system developed by Voith Turbo.
In the DIWAhybrid system, an asynchronous electric motor supports the diesel engine when pulling away from stops and accelerating. During braking, the asynchronous motor acts as a generator and primary retarder, perfectly complementing the DIWA secondary retarder. This allows electric energy to be recuperated, reducing the use of the driving brake, minimising brake wear and tear and lowering resulting particulate emission.
Energy recaptured during braking is stored in a supercapacitor unit weighing only 410 kg. Its five 125 V modules have a total storage capacity of 0.5 kWh. Supercapacitors as well as the Voith inverter are roof-mounted, eliminating passenger saloon intrusion. Elegant exterior roof panels point to the Urbino 18 DIWAhybrid´s trendsetting technology.
The DIWAhybrid system is designed for up to 290 kW power input and a maximum input torque of 1 600 Nm. At 150 kW electric traction power, the DIWAhybrid system reduces the load of the diesel engine enough for the latter to be substantially smaller than on conventional diesel buses. The Urbino 18 DIWAhybrid uses a 6.7-litre, 181 kW (246 PS) Cummins ISB6.7EV 250H diesel engine meeting the demanding EEV emissions standard.
Thanks to the use of a smaller diesel engine, the weight of the entire bus is just 600 kg above that of a diesel-powered Urbino 18. The passenger saloon layout is identical to the conventional version, with passenger capacity only marginally affected. The Urbino 18 DIWAhybrid has 51 comfortable seats and a room for 161 passengers total.
BOGESTRA AG Chooses Electric Mobility
The Urbino 18 DIWAhybrid was developed with support from the German Federal Ministry of Transport, Building and Urban Development and NOW GmbH National Organisation Hydrogen and Fuel Cell Technology. As part of the Rhein-Ruhr Electric Mobility Model Region, a pre-production vehicle entered service with Bochum-Gelsenkirchener Straßenbahnen AG
(BOGESTRA AG) in mid-February 2011. After six months of field testing, the first production vehicles for BOGESTRA AG and other German operators will follow in summer 2011.
BOGESTRA AG has successfully used climate-friendly drive technology since early 2008, when it took delivery of the first hybrid bus in North Rhine-Westphalia. Three more followed in 2010 and when the new Urbino 18 DIWAhybrid arrive in mid-2011, the company´s fleet will increase to 15 hybrid buses.
