Measuring energy consumption of hybrid vehicles
In a hybrid vehicle, the energy for the electric motor is stored in a battery. That motor can act as a generator to charge the batteries, as well as draw energy from them. In contrast, the petrol or diesel in the fuel tank can only power the fossil fuel engine. The aim of the SUVA project was to develop a marketable and cost-effective hybrid 'powertrain', including the engine, transmission and drive axle. Quantifying the state of charge of the battery, together with the fuel consumption, is an essential feature in ensuring the drivability of such a hybrid vehicle. The project tested vehicles, and made simulations and measurements to determine the energy consumption of a hybrid vehicle design where external recharging of the battery was not possible. The team developed a procedure that measures the state of battery charge regression. The procedure indicates the fuel consumption based on a comparative measure against a situation where the battery charge is the same at the beginning and end of the driving time. The test procedure has been verified in simulation and on test benches.
