Aircraft providing variable and constant electric power

• US 4,587,436 A
• Filed: 07/28/1980
• Issued: 05/06/1986
• Est. Priority Date: 07/28/1980
• Status: Expired due to Term

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Corporation (Martin Marietta Corporation)
• Inventors: Cronin, Michael J.
• Primary Examiner(s): Dwyer, James L.
• Application Number:
  US06/173,111
• Time in Patent Office: 2,108 Days
• Field of Search: 307/9, 307/10 R, 307/84, 307/25, 307/26, 307/27, 307/28, 307/18, 307/21, 322/7, 322/8, 219/202
• US Class Current: 307/21
• CPC Class Codes: H02P 2101/30 for aircraft
• CPC Class Codes: H02P 9/307 more than one voltage output

Abstract

The invention is a two-level power system for electrically powered aircraft sub-systems. An aircraft engine (2) drives a three phase generator (30) at a variable speed. The output of generator (30) is primary variable-voltage/variable-frequency (VV-VF) power which is utilized by various aircraft subsystems. A portion of the primary VV-VF power is converted to constant voltage-constant frequency (CV-CF) power by an inverter (31) which includes front end rectification. The CV-CF power is then available to selected aircraft subsystems while portions of the CV-CF power are converted by rectifier (32) and transformer-rectifier (33) into 270 vdc and 28 vdc power, respectively, which power is also then available to aircraft sub-systems.

Claims

1. In an aircraft having at least one variable speed engine first electricity driven subsystems and devices including fuel pumps, electrohydraulic pumps, electric-galley, de-icing, and environmental control subsystems, and second electrically driven subsystems and devices including solenoids, control valves, shut-off valves, indicators, lamps and instruments, the improvement comprising:

generator means associated with and adapted to be driven by said at least one aircraft engine continuously and at variable speeds, said generator means being further adapted for generating primary variable-voltage/variable-frequency power to said first electrically driven subsystems and devices; and

means associated with said primary power generating means for converting a minor portion of said primary variable-voltage/variable-frequency power to conditioned secondary power for said second electrically driven subsystems and devices.

2. An aircraft in claim 1 wherein said generating means comprises a three phase generator.

3. An aircraft as in claim 1 wherein said means associated with said primary power generating means converts at least a portion of said primary variable-frequency/variable-voltage power to constant-voltage/constant-frequency power.

4. An aircraft as in claim 3 wherein said means for converting to constant-voltage/constant-frequency power comprises an inverter with front end voltage control circuitry.

5. An aircraft as in claim 3 including means for converting at least a portion of said constant-voltage/constant-frequency power to a constant level of 270 volt dc power.

6. An aircraft as in claim 5 wherein said means for converting to 270 volt dc power includes a three phase bridge rectifier.

7. An aircraft as in claim 3 wherein said means associated with said primary power generating means converts at least a portion of said primary variable-frequency/variable-voltage power to a constant level of 270 volt dc power.

8. An aircraft as in claim 7 wherein said means for converting to said constant level of 270 volt dc power includes a three phase rectifier bridge, said rectifier bridge including voltage-control means connected to the variable-voltage/variable frequency power.

9. An aircraft as in claims 3, or 26 including means for converting at least a portion of said constant-voltage/constant-frequency power to 28 volt dc power.

10. An aircraft as in claim 9 wherein said means for converting to 28 volt dc power includes a transformer-rectifier device.

11. An aircraft as in any of claims 1, 3, or 5 wherein said means for generating primary variable-frequency/variable-voltage power comprises a permanent magnet rotor generator.

12. An aircraft as in claim 11 wherein said generator includes a high energy permanent magnet rotor.

13. An aircraft as in claim 12 wherein said high energy permanent magnet rotor comprises a samarium cobalt rotor.