Generating apparatus for providing different rated output voltages to a plurality of electric loads

• US 5,719,486 A
• Filed: 04/17/1996
• Issued: 02/17/1998
• Est. Priority Date: 04/24/1995
• Status: Expired due to Term

• Current Assignee: Nippondenso Co., Ltd. (DENSO Corporation)
• Original Assignee: Nippondenso Co., Ltd. (DENSO Corporation)
• Inventors: Umeda, Atsushi, Kusase, Shin, Taniguchi, Makoto
• Primary Examiner(s): Dougherty, Thomas M.
• Assistant Examiner(s): Ponomarenko, Nicholas
• Application Number:
  US08/634,033
• Time in Patent Office: 671 Days
• Field of Search: 322/25, 322/26, 322/27, 322/28
• US Class Current: 322/28
• CPC Class Codes: H02J 7/1438 in combination with power supplies for loads other than batteries

Abstract

A generating apparatus includes a generator, a first and a second rectifiers, and a voltage regulator. The generator has three-phase star-connected armature windings which generate three-phase high-output voltage at phase-terminals and low-output voltage at a neutral point. The first rectifier is a three-phase full-wave rectifier connected between the phase-winding and a high-voltage load, and the second rectifier is a diode connected between the neutral point and a low-voltage load with a battery. The regulator regulates the high output voltage to energize the high-voltage load and, at the same time, the low-output voltage to become an optimum voltage level for charging battery. MOSFETs may be used for the first rectifier to short-circuit the armature windings thereby supplying them with leading currents which are respectively ahead of the high-output voltages, so as to increase the generator output power.

Claims

1. A generating apparatus for supplying a high-voltage load with a high-voltage electric power and a low-voltage load with low-voltage electric power, said apparatus comprising:

a multi-phase AC generator having star-connected armature windings, said armature windings having respective phase-terminals and a common neutral point and generating high-output-voltages at said phase-terminals and a low-output-voltage at said neutral point;

a first rectifier, connected between said respective phase-terminals and said high-voltage load, for full-wave-rectifying said high-output-voltage to be supplied to said high-voltage load, and

a second rectifier, connected between said neutral point of said armature windings and said low-voltage load, for rectifying said low-output voltage to be supplied to said low-voltage load separately from said first rectifier, and at the same time as when said first rectifier rectifies said high-output voltage.

2. A generating apparatus according to claim 1 further comprising a field coil disposed in said generator and means for regulating said high-output voltage, wherein

said voltage regulating means controls field current in said field coil so that said low-output voltage becomes a first low-value when said high-voltage load is not energized and said high-output voltage becomes a set high value when said high-voltage load is energized.

3. A generating apparatus according to claim 2 further comprising a switch for selectively connecting said first rectifier to one of said high-voltage load and said low-voltage load, wherein said voltage regulating means controls said field current to regulate said high-output voltage to a second low value when said switch connects said first rectifier to said low-voltage load, and controls said field current to regulate said high-output voltage to said set high-value when said switch connects said first rectifier to said high-voltage load.

4. A generating apparatus according to claim 1, wherein said second rectifier comprises a diode which has an anode connected to said neutral point and a cathode connected to said low-voltage load.

5. A generating apparatus according to claim 1, wherein said second means comprises a semiconductor switching element, and

said voltage regulating means makes said semiconductor switching element conductive when said neutral point becomes higher than a set voltage.

6. A generating apparatus according to claim 1 further comprising a voltage-setting diode which has an anode connected to a ground terminal of said first means and a cathode connected to said neutral point.

7. A generating apparatus according to claim 1 further comprising a voltage-setting diode which has an anode connected to said neutral point and a cathode connected to an output terminal of said first means.

8. A generating apparatus according to claim 1 further comprising means for on-off controlling output current of said first rectifier to regulate said high-output voltage to a set high value when said high-voltage load is energized.

9. A generating apparatus according to claim 5, wherein at least one group of said semiconductor switching elements are made of one of a group of materials including Si and SiC.

10. A generating apparatus according to claim 8, wherein said generator comprises a permanent magnet rotor.

11. A generating apparatus for supplying a high-voltage load with a high-voltage electric power and a low-voltage load with low-voltage electric power, said apparatus comprising:

a multi-phase AC generator including star-connected armature windings, said armature windings having respective phase-terminals and a common neutral point and generating high-output-voltages at said phase terminals and a low-output-voltage at said neutral point;

a first rectifying unit, connected between said respective phase terminals and said high-voltage load, for full-wave-rectifying said high-output-voltage to be supplied to said high-voltage load,

a second rectifying unit, connected between said neutral point and said low-voltage load, for rectifying said low-output voltage to be supplied to said low-voltage load separately from said first rectifying unit and at the same time as when said first rectifying unit rectifies said high-output voltage, and

means for supplying leading current, which has phase ahead of a corresponding one of said high-output voltages, to a corresponding one of said armature windings, wherein

said first rectifying unit comprises first semiconductor elements connected between said respective phase-terminals and one terminal of said high-voltage load and second semiconductor elements connected between said respective phase terminals and another terminal of said high-voltage load,

at least one group of said first and second semiconductor elements includes two-way-switching elements, and

said leading current supplying means controls said two-way switching elements to supply corresponding armature windings with said leading current respectively.

12. A generating apparatus according to claim 11 further comprising a field coil disposed in said generator and voltage regulating means for controlling field current supplied to said field coil to control said high-output voltages, wherein

said voltage regulating means regulates said high-output voltages to a set low level when said high-voltage load is not energized, and regulates said high-output voltage to a set high level higher than said set low level when said high-voltage load is energized.

13. A generating apparatus according to claim 11, wherein said leading current supplying means supplies said leading current to at least one of said armature windings by short-circuiting one of said semiconductor switching elements when said high-voltage load is energized.

14. A generating apparatus according to claim 12, wherein said leading current is not supplied when said high-voltage load is not energized and said field current does not exceed a set value.

15. A generating apparatus according to claim 12, wherein said leading current is supplied when said high-voltage load is not energized and said field current exceeds a set value.

16. A generating apparatus according to claim 12, further comprising a switch for selectively connecting said first rectifying unit to one of said high-voltage load and said low-voltage load, wherein said voltage regulating means and said means for supplying leading current control one of said field current and said leading current to regulate said high-output voltage to said set low level when said switch is connected to said low-voltage load, and control one of said field current and said leading current to regulate said high-output voltage to said set high level and control output voltage of said second rectifying unit to said set low voltage when said switch is connected to said high-voltage load.

17. A generating apparatus according to claim 12 further comprising a battery connected to said second rectifying unit, wherein said voltage regulating means regulates said high-output voltage so that voltage of said neutral point becomes said set low-voltage when said high-voltage load is energized.

18. A generating apparatus according to claim 12, wherein said voltage regulating means regulates said high-output voltage to said set high-level when said high-voltage load is energized.

19. A generating apparatus according to claim 17, wherein said voltage regulating means regulates said high-output voltage so that voltage of said neutral point becomes said set low-level when a voltage of said battery deviates from a predetermined range.

20. A generating apparatus according to claim 11, wherein said second means comprises a diode which has an anode connected to said neutral point and a cathode connected to a terminal of said low-voltage load.

21. A generating apparatus according to claim 11 further comprising means for on-off controlling output current of said first rectifying unit to regulate said high-output voltage to said set high level when said high-voltage load is energized.

22. A generating apparatus according to claim 21, wherein said generator comprises a permanent magnet rotor.

23. A generating apparatus according to claim 11, wherein at least one group of said semiconductor elements are made of one of a group of materials including Si and SiC.