Engine cranking system and method
First Claim
1. A vehicle comprising:
- an engine;
a motor connected to the engine, the motor being operable for selectively cranking and starting the engine;
an energy storage system (ESS) having a first voltage level;
a DC-DC converter configured to boost the first voltage level;
a supercapacitor module having a second voltage level;
a first electrical switch configured to close immediately upon detection of a commanded cranking and starting of the engine, wherein closing of the first electrical switch connects the supercapacitor module to the motor and thereby delivers the second voltage level to the motor;
a second electrical switch connected in electrical parallel with the DC-DC converter, and configured to selectively close when the second voltage level drops below a threshold during the cranking and starting of the engine, thereby placing the ESS in electrical parallel with the supercapacitor module, and thereby providing the first voltage level and the second voltage level to the motor; and
wherein the supercapacitor module is chargeable to the second voltage level by the ESS when the engine is running.
12 Assignments
0 Petitions
Accused Products
Abstract
A vehicle has an engine, a starter motor, an energy storage system (ESS) for powering an auxiliary system, and a supercapacitor module for powering the starter motor during engine cranking and starting. The supercapacitor module disconnects from the starter motor to recharge. A DC-DC booster converter increases the level of voltage supplied from the ESS so as to charge the supercapacitor module to a relatively higher voltage level, such as approximately 125 to 140 percent of the voltage level supplied by the ESS. A method for preventing voltage sag in an auxiliary system of the vehicle includes disconnecting the supercapacitor module from the starter motor when the engine is running, and then charging the supercapacitor module using the ESS until a cranking support voltage equals a stored target voltage. A detected commanded cranking and starting of the engine causes the connection of the supercapacitor module to the starter motor.
22 Citations
13 Claims
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1. A vehicle comprising:
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an engine; a motor connected to the engine, the motor being operable for selectively cranking and starting the engine; an energy storage system (ESS) having a first voltage level; a DC-DC converter configured to boost the first voltage level; a supercapacitor module having a second voltage level; a first electrical switch configured to close immediately upon detection of a commanded cranking and starting of the engine, wherein closing of the first electrical switch connects the supercapacitor module to the motor and thereby delivers the second voltage level to the motor; a second electrical switch connected in electrical parallel with the DC-DC converter, and configured to selectively close when the second voltage level drops below a threshold during the cranking and starting of the engine, thereby placing the ESS in electrical parallel with the supercapacitor module, and thereby providing the first voltage level and the second voltage level to the motor; and wherein the supercapacitor module is chargeable to the second voltage level by the ESS when the engine is running. - View Dependent Claims (2, 3, 4)
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5. An apparatus for preventing voltage sag during engine cranking and starting in a vehicle having an engine, a DC starter motor, a battery having a first voltage level, and a DC-DC converter, the apparatus comprising:
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a first and a second switch, wherein the first switch is connected in series between the DC-DC converter and the starter motor, and the second switch is connected in parallel with the DC-DC converter; a supercapacitor module which is electrically connected to the battery and adapted for providing a second voltage level for exclusively powering a cranking and starting of the engine immediately upon detection of a commanded cranking and starting of the engine; and a controller having an algorithm for selectively opening and closing the first and the second switches; wherein closing the first switch connects the supercapacitor module to the starter motor to thereby allow the supercapacitor module to deliver the second voltage level to the starter motor, thereby cranking and starting the engine exclusively using the second voltage level without delaying the cranking and starting; and wherein closing the second switch connects the battery to the starter motor when the second voltage level drops below a threshold during the cranking and starting of the engine, thereby placing the battery in electrical parallel with the supercapacitor module, thereby cranking and starting the engine using at least the first voltage level. - View Dependent Claims (6, 7, 8)
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9. A method for preventing voltage sag in an auxiliary system of a vehicle having an engine, a starter motor, a DC-DC converter, an energy storage system (ESS) having a first voltage, and a supercapacitor module electrically connectable to the ESS, the method comprising:
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disconnecting the supercapacitor module from the starter motor when the engine is running by opening a first switch in series between the DC-DC converter and the starter motor; charging the supercapacitor module by opening a second switch in electrical parallel with the DC-DC converter, such that a second voltage stored by the supercapacitor module approaches a stored target voltage; detecting a commanded cranking and starting of the engine; and immediately connecting the supercapacitor module to the starter motor by closing the first switch when the commanded cranking and starting of the engine is detected, thereby delivering the second voltage to the starter motor to power the cranking and starting of the engine. - View Dependent Claims (10, 11, 12, 13)
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Specification