London launches a hybrid propulsion system in their buses

Passengers on buses in the London Borough of East London (East London) are the first of the United Kingdom enjoy a hybrid propulsion system, incorporated in four new buses Optare Tempos.

Buses, equipped with the hybrid system and^P, developed by General Motors and Allison, just put into circulation. In parallel, which has been patented, dual hybrid technology combines the injection of energy directly through a diesel engine electronically controlled with the electrical power that is obtained through a system of energy storage. Thus the system allows a significant savings of fuel, produces fewer emissions of gaseous pollutants, and has increased the performance of the fleets of buses of more than 115 cities around the world.

The Organization Transport for London (TfL) is proving to those buses as part of an important and in principle long study on the performance offered by different hybrid systems and the various components susceptible to be specified when requesting a vehicle such as the checksthe batteries and the gearboxes. In this study, 5 buses equipped with the system belong to the East London Bus Group company, which covers the route 276 Newham General Hospital and Store Newington. For its part, the company Metroline will be circulated another 5 to cover the route E8 between Ealing Broadway and Bretford.

The introduction of these 10 new buses equipped with the new technology will contribute to the goal that the Mayor of London has been proposed by the year 2025: reduce by 60% the emission of gaseous pollutants in London.

Also, Londoners will appreciate that hybrid buses are also considerably quieter than the diesel buses, which will be to make more pleasant bus routes and reduce noise pollution affecting residents of the areas where a greater concentration of routes run.

The complete system and^p40/50 GM-Allison consists of a module that acts as a transmission of the vehicle; a module of inverter of dual propulsion, a system of energy storage, which is based on Nickel Metal hydride (NIMH) batteries; two electronic control modules, and the electronic interface of the driver, which incorporates a screen.

This hybrid architecture combines the low consumption obtained thanks to a direct mechanical connection between the motor and chain kinematics of the hybrid system in parallel, with the advantages it brings to the management of the engine a hybrid design in series.

The real novelty is the module and^(V) Drive, whose design includes a concentric arrangement of transmission - sets of planetary changes - and two electric motors. This module integrates (combination of pairs) the power of the electric motor and the diesel engine. Thanks to this original electromechanical combination module already not experiencing fixed gear ratios, as is often the case with the traditional gearboxes. Its transmission, speed and torque ratios vary from form continuous and infinite.

The key factor for consumer savings that allow hybrid systems lies in their system of regenerative braking, i.e. in the recovery of the energy usually lost during braking. When the driver stops to reduce the speed of the vehicle, the kinetic energy that normally goes away in the brakes heat becomes again reusable electricity thanks to an electric motor that acts in reversemaking it a generator to recharge the battery. It is estimated that 40% of the energy used to speed up a bus equipped with the GM-Allison dual hybrid system comes from the energy that is recovered during regenerative braking.