摘要 |
A vehicle includes an engine, a controller for turning off the engine when the vehicle is idle, a motor/generator for starting the engine, an inverter for converting a DC auxiliary voltage from a battery into an AC voltage for powering the motor/generator, and a device for isolating a DC voltage from the DC auxiliary voltage to prevent voltage sag in a vehicle system during engine starting. The device includes a transformer, a rectifier/regulator, and an isolator. A mechanical relay opens, or an FET is activated, to isolate the DC voltage during engine start. A method for preventing voltage sag in an auxiliary vehicle system includes detecting a commanded engine start, comparing a measured auxiliary voltage to a threshold, isolating a predetermined DC voltage from a DC auxiliary voltage when the measured auxiliary voltage is less than the threshold, and powering the auxiliary vehicle system using the isolated DC voltage.
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