One of the usual measures to increase the energy efficiency in automotive vehicles has been the adoption of generators with variable voltage systems, commanded by the vehicle control unit.
Thus, the vehicle system voltage no longer remains constant during operation of the engine, but becomes variable as needed to charge the vehicle electrical system and better use of available engine torque.
A study using the Design for Six Sigma (DFSS) methodology was performed in order to understand the influence of the supply voltage and of the fuel conductivity in the lifetime of fuel pump commutation system by brushes. Durability tests were conducted in bench test, where parameters of temperature, current draw, voltage and fuel conductivity were monitored, correlating them with the results of wear in the pump commutation system.
The conclusion of the study shows how the fuel pump life varies according to the supply voltage and the conductivity of the fuel used, given that the conductivity can be affected not only by the fuel composition, but also for its quality.