Motor vehicle electrical system having an active bridge rectifier and overvoltage protection during a load dump, rectifier system, associated operating method and means for its implementation
First Claim
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1. A vehicle electrical system, comprising:
- an active bridge rectifier connected to a generator via multiple phase terminals, the active bridge rectifier having terminals on a direct voltage side;
a load shedding recognition unit which recognizes load shedding at the active bridge rectifier in response to a voltage between the terminals of the bridge rectifier on the direct voltage side rising above a first predetermined voltage threshold, and short-circuits the phase terminals during the load shedding in a clocked manner so that the active bridge rectifier provides a pulsed current including an on phase during a rectifying operation and an off phase during the load shedding;
at least one vehicle electrical system capacitor connected to the direct voltage side of the active bridge rectifier to receive a portion of the pulsed current during the rectifying operation and provide a current to the vehicle electrical system during the load shedding; and
a voltage limiter which clips the voltage between the terminals of the bridge rectifier on the direct voltage side in response to the voltage between the terminals of the bridge rectifier on the direct voltage side rising above a second predetermined voltage threshold during transitions between the rectifying operation and the load shedding, the second predetermined voltage threshold being greater than the first predetermined voltage threshold.
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Abstract
A vehicle electrical system includes: an active bridge rectifier which is connected to a generator via multiple phase terminals, and having terminals on the direct voltage side; a unit for recognizing load shedding at the active bridge rectifier and short-circuiting the phase terminals in a clocked manner, as the result of which a pulsed current is fed to the vehicle electrical system; a vehicle electrical system capacitor configured for smoothing the pulsed current; and a voltage limiting unit configured for clipping a voltage between the terminals of the bridge rectifier on the direct voltage side to a predefined maximum voltage.
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Citations
17 Claims
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1. A vehicle electrical system, comprising:
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an active bridge rectifier connected to a generator via multiple phase terminals, the active bridge rectifier having terminals on a direct voltage side; a load shedding recognition unit which recognizes load shedding at the active bridge rectifier in response to a voltage between the terminals of the bridge rectifier on the direct voltage side rising above a first predetermined voltage threshold, and short-circuits the phase terminals during the load shedding in a clocked manner so that the active bridge rectifier provides a pulsed current including an on phase during a rectifying operation and an off phase during the load shedding; at least one vehicle electrical system capacitor connected to the direct voltage side of the active bridge rectifier to receive a portion of the pulsed current during the rectifying operation and provide a current to the vehicle electrical system during the load shedding; and a voltage limiter which clips the voltage between the terminals of the bridge rectifier on the direct voltage side in response to the voltage between the terminals of the bridge rectifier on the direct voltage side rising above a second predetermined voltage threshold during transitions between the rectifying operation and the load shedding, the second predetermined voltage threshold being greater than the first predetermined voltage threshold. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method for operating a vehicle electrical system that includes an active bridge rectifier connected to a generator via multiple phase terminals and having terminals on a direct voltage side, a load shedding recognition unit, at least one vehicle electrical system capacitor, and a voltage limiter, the method comprising:
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ascertaining, by the load shedding recognition unit, an occurrence of load shedding at the active bridge rectifier in response to a voltage between the terminals of the bridge rectifier on the direct voltage side rising above a first predetermined voltage threshold; upon ascertaining the occurrence of load shedding at the active bridge rectifier, short-circuiting the phase terminals by the load shedding recognition unit during the load shedding in a clocked manner so that the active bridge rectifier provides a pulsed current including an on phase during a rectifying operation and an off phase during the load shedding; receiving by the at least one vehicle electrical system capacitor a portion of the pulsed current during the rectifying operation, and providing by the at least one vehicle electrical system capacitor a current to the vehicle electrical system during the load shedding; and clipping, using the voltage limiter, the voltage which is present between the terminals of the bridge rectifier on the direct voltage side in response to the voltage between the terminals of the bridge rectifier on the direct voltage side rising above a second predetermined voltage threshold during transitions between the rectifying operation and the load shedding, the second predetermined voltage threshold being greater than the first predetermined voltage threshold. - View Dependent Claims (11, 12, 13)
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14. A non-transitory machine-readable storage medium having program instructions, which when executed by a processor perform a method for operating a vehicle electrical system, the vehicle electrical system including an active bridge rectifier connected to a generator via multiple phase terminals and having terminals on a direct voltage side, a load shedding recognition unit, at least one vehicle electrical system capacitor, and a voltage limiter, the method comprising:
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ascertaining, by the load shedding recognition unit, an occurrence of load shedding at the active bridge rectifier in response to a voltage between the terminals of the bridge rectifier on the direct voltage side rising above a first predetermined voltage threshold; upon ascertaining an occurrence of load shedding at the active bridge rectifier, short-circuiting the phase terminals by the load shedding recognition unit during the load shedding in a clocked manner so that the active bridge rectifier provides a pulsed current including an on phase during a rectifying operation and an off phase during the load shedding; receiving by the at least one vehicle electrical system capacitor a portion of the pulsed current during the rectifying operation, and providing by the at least one vehicle electrical system capacitor a current to the vehicle electrical system during the load shedding; and clipping, using the voltage limiter, the voltage which is present between the terminals of the bridge rectifier on the direct voltage side in response to the voltage between the terminals of the bridge rectifier on the direct voltage side rising above a second predetermined voltage threshold during transitions between the rectifying operation and the load shedding, the second predetermined voltage threshold being greater than the first predetermined voltage threshold. - View Dependent Claims (15, 16, 17)
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Specification