VS - Electrical Systems From Stop-Start to Hybridization

Secure the cranking capacity and stabilize the board net voltage A very basic requirement for a Stop-Start system is to secure that the next engine start will happen whatever the conditions. Battery and alternator performances are key to cranking capacity and the so called load balance is the very first parameter to secure. The load balance In order to be able to operate normally, a vehicle must be able to produce at least as much electric energy as it consumes, it is admitted nevertheless that at a given moment the balance can show a deficit - it is then the battery to provide the remainder. To establish this balance during the electrical system conception phase, mission profiles are used with operating scenarios based on: ●● alternator speeds

Stabilize the board net voltage In Stop-Start system, regular cranking phases have forced designers to develop complementary electrical circuit that secures the on-board voltage level to avoid any side effects related to ECU’s undesirable reset. On-board voltage stabilization circuits depend on car manufacturers and on Stop-Start system generation, they can either be: complementary batteries, super- capacitors or DC converters. Whatever the circuit, it is controlled by complex strategies mixing hardware and software.

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●● operating time when idling ●● global electric consumption

The load balance is at the heart of any automotive charging system, it is nevertheless not sufficient in Stop-Start vehicles where the battery remaining capacity and health prediction are now mandatory.

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