Riassunto analitico
Vehicles are developing day by day. The goal of the newest vehicles is to increase their efficiency and at the same time to reduce the pollutant emissions. In order to reach these targets, it is common to introduce electric motors so as to provide assistance to the internal combustion engine; in this way, it is possible to install a smaller ICE. The electric machine also operates as starter of the ICE when its cranking is requested. The presence of this element means an electrification of the vehicle, with the consequence of the introduction of a High Voltage Battery (HVB) pack and all related components.
Beside this development, in order to improve comfort and safety of users, modern vehicles include a large variety of new functionalities, which are provided by different consumers. The price to be paid is an increasing of current consumption; this high demand of current is entirely supported by the HVB. If these functionalities are improperly used when both ICE and electric motors are not operative, so the vehicle cannot be started due to an excessive battery drain.
The aim of the study is to develop a new architecture focused on the reduction of battery drain through the inhibition of some functionalities which are not of main importance for the cranking of the vehicle. The research comprises the estimation of the most absorbing loads, followed by the evaluation of the best solution to disable them; at the beginning, an investigation of possible approaches of other carmakers’ is computed; after, an initial working principle is proposed. The inhibition of consumers is actuated through the integration of relays and the transmission of CAN signals. For this purpose, a comparison between Electromechanical Relay (EMR) and Solid State Relay (SSR) is made. In addition, since to propose an innovative solution, high-side switches are taken into account. The choice of the best component is computed also from costs, weight and installation space viewpoint. Successively, the transmission of messages on CAN bus is exploited by node involved in the power saving; furthermore, the different indications exploited to inform the user of the inhibited functionalities are illustrated.
At the end of the research, final results are shown together with the advantages and drawbacks of the designed technique.
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