Cummins engines for over 2,000 hybrid buses in Europe
Cummins is very active on the front of traditional hybrids. Right now, more than 2,000 hybrid buses are operating in Europe equipped with the H B4.5 (with 157 kW of power and a torque of 850 Nm) and the B6.7 Euro VI series (with 224 kW of power and maximum torque of 1200 Nm) of the North American producer.
The most important numbers were made in the UK, with Alexander Dennis Enviro400H and Wrightbus New Routemaster, all powered by the B4.5-H and the articulated interurban Van Hool Belfast Glider with the B6.7- H.
Also other producers, such as VDL, Solaris, Vectia and Irizar, use the H series hybrids.
The electric motor is able to turn off the engine during stops, keeping the auxiliaries running up to 30 times in one hour (compared to a normal usage average estimated at 16) with a restart time of less than 0.5 seconds.
But there is more…
In addition to this, the electric engine intervenes to support the engine during accelerations, reducing the duration of transients where diesel is less efficient.
On the other hand, the control system ensures that the batteries are recharged when the thermal engine operates at maximum efficiency.
Depending on the objectives of the bus manufacturer and the intended use, it is possible to choose to operate in series or parallel.
The goal is a reduction in emissions and consumption of 12%. Also taking into account the reduction in average noise emissions ensured by the periods when the engine remains off, a particularly interesting condition for urban areas.
In the presence of a hybrid engine, all the accessories and auxiliaries (in a bus 60 kW can be easily reached) become electrically operated, with the advantage of further reducing the periods of operation of the internal combustion engine, otherwise normally forced to run for many hours at low-speed.