Alternator rectifier
View Patent ↗An alternator for a motor vehicle includes a current generation device and a rectifier. The current generation device has multiple phase stator windings in which AC currents are generated. The rectifier is connected to the windings of the current generation device. The rectifier includes multiple sets of first and second diodes for the multiple phase windings. At least one of the first and second diodes of each set is a Schottky diode. A voltage clamping device is connected to the rectifier to protect the Schottky diodes from surge reverse voltage.
1. An alternator for a motor vehicle, the alternator comprising:
a current generation device having multiple stator phase windings in which AC currents are generated;
a rectifier connected to the windings of the current generation device; the rectifier including multiple sets of first and second diodes for each phase of the multiple phase windings, at least one of the first and second diodes of each set being a Schottky diode; and
a voltage clamping device connected in parallel to the entire rectifier.
2. The alternator of claim 1 , wherein the voltage clamping device is not connected directly to the multiple phase windings of the current generation device.
3. The alternator of claim 1 , wherein the voltage clamping device is a MOV.
4. The alternator of claim 1 , wherein the voltage clamping device is a voltage regulation diode.
5. The alternator of claim 1 , wherein the voltage clamping device has a rated clamping voltage that is less than the maximum allowable reverse voltage of each Schottky diode.
6. The alternator of claim 1 , wherein the rated clamping voltage of the voltage clamping device is in the range of 18 to 30 volts, and wherein the maximum allowable reverse voltage of each Schottky diode is in the range of 30 to 45 volts.
7. The alternator of claim 1 , wherein each Schottky diode does not have a voltage clamping device formed therein.
8. The alternator of claim 1 , the alternator being electrically connected to a power source line having a battery, and wherein the voltage clamping device is connected between the power source line and the ground.
9. The alternator of claim 1 , wherein the first and second diodes of each set are both Schottky diodes.
10. The alternator of claim 9 , wherein the first diodes have a lower forward voltage drop than the second diodes, and wherein the second diodes have a lower reverse leakage current capability than the first diodes.
11. The alternator of claim 10 , wherein the second diodes are fabricated using GaN or GaS as a base material.
12. The alternator of claim 1 , wherein each of the first diodes are connected to the high potential side of the battery, and each of the second diodes are connected to the low potential side of the battery, and wherein the first diodes of each set are Schottky diodes.
13. The alternator of claim 11 , wherein the second diodes of each set are P/N junction diodes.
14. The alternator of claim 1 , wherein the voltage regulation device comprises a first voltage regulation diode and a second voltage regulation diode, the first and second voltage regulation diodes forming a portion of the rectifier by forming one set of first and second diodes, the first and second voltage regulation diodes connected to the high potential side and low potential side of the battery, respectively, of less than all the phases of the multiple phase windings, the remaining sets of first and second diodes of the rectifier being connected to the remaining phases of the multiple phase windings.
15. The alternator of claim 1 , wherein the alternator contains a claw-pole rotor.
16. A rectifier for an alternator of a motor vehicle, the alternator including a current generation device having multiple phase stator windings in which AC currents are generated, the rectifier comprising:
multiple sets of first and second diodes for each phase of the multiple phase stator windings, each set of first and second diodes being connected to an output terminal of the stator windings of the current generation device;
at least one of the first and second diodes of each set being a Schottky diode; and
a voltage clamping device connected in parallel to each set of first and second diodes.
17. The rectifier of claim 16 , wherein the voltage clamping device has a rated clamping voltage that is less than or equal to the maximum allowable reverse voltage of each Schottky diode.
18. The rectifier of claim 16 , wherein each Schottky diode does not have a voltage regulation diode formed therein.
19. The rectifier of claim 16 , the alternator being electrically connected to a power source line and a battery, the voltage clamping device being connected between the power source line and the ground.
20. The rectifier of claim 16 , wherein the first and second diodes of each set are both Schottky diodes.
21. The rectifier of claim 16 , wherein each of the first diodes are connected to the high potential side of the battery, and each of the second diodes are connected to the ground, and wherein the second diodes of each set are not Schottky diodes.
22. The rectifier of claim 16 , further comprising a second voltage regulation diode, the first and second voltage regulation diodes forming a portion of the rectifier by forming one set of first and second diodes, the first and second voltage regulation diodes connected to the high potential side and low potential side, respectively, of less than all the phases of the multiple phase windings, the remaining sets of first and second diodes of the rectifier being connected to the remaining phases of the multiple phase windings.
23. The rectifier of claim 16 , wherein, the voltage clamping device is a voltage regulation diode.
24. The rectifier of claim 16 , wherein, the voltage clamping device is not connected directly to the multiple phase windings of the current generation device.