Low input harmonic induced multiple use AC synchronous generator starter converter

• US 5,406,189 A
• Filed: 12/08/1992
• Issued: 04/11/1995
• Est. Priority Date: 12/08/1992
• Status: Expired due to Term

• Current Assignee: Alliedsignal Inc.
• Original Assignee: Alliedsignal Inc.
• Inventors: Wohlberg, Al, Murugan, Muthu K., Eckenfelder, Robert C.
• Primary Examiner(s): KINCAID, KRISTINE LYNN
• Application Number:
  US07/987,524
• Time in Patent Office: 854 Days
• Field of Search: 322/10, 322/59, 290/38, 290/38 R, 290/46
• US Class Current: 322/10
• CPC Class Codes: H02M 1/007 Plural converter units in cascade push-pull DC/DC converters with pre-regulator H02M3/3374; DC-AC converters following a DC-DC stage including a high frequency transformer H02M7/4807; DC-AC converters following a DC-DC conversion stage generating periodically varying voltages H02M7/4826
• CPC Class Codes: H02M 1/4216 operating from a three-phase input voltage H02M1/4233 takes precedence
• CPC Class Codes: H02M 3/28 using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
• CPC Class Codes: H02P 2101/30 for aircraft
• CPC Class Codes: H02P 9/08 Control of generator circuit during starting or stopping of driving means, e.g. for initiating excitation
• CPC Class Codes: H02P 9/30 using semiconductor devices
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Abstract

A synchronous generator start converter offers power conversion for performing multiple functions such as starting AC generators as a motor, charging batteries and also providing regulated DC output without degradation of input power quality. The converter utilizes common magnetic components and common semiconductor rectifiers within its three subcircuits. The three subcircuits include flyback converters, a square wave inverter and a field excitation controller.

Claims

1. A low input harmonic induced multiple use AC synchronous generator starter converter comprising:

flyback converter means for receiving input power of either AC or DC;

output power means connected to said flyback converter means for providing converted output power of either AC or DC without degradation of said input power;

wherein said output power means comprises;

square wave inverter means connected between said flyback converter means and said synchronous generator;

field excitation controller means for providing single phase excitation to exciter stator of said synchronous generator;

timing logic means for controlling said square wave inverter means;

PWM controller means for controlling said flyback converter means; and

,

control power supply means for receiving said input power of either AC or DC and for providing control power to said field excitation controller means, said timing logic means and said PWM controller means.

2. A low input harmonic induced multiple use AC synchronous generator starter converter as claimed in claim 1 wherein said square wave inverter means comprises:

bus capacitor means connected across said flyback converter means; and

,

transistor/diode means connected across said bus capacitor means.

3. A low input harmonic induced multiple use AC synchronous generator starter converter as claimed in claim 2 wherein said transistor/diode means comprises:

three pairs of transistors.

4. A low input harmonic induced multiple use AC synchronous generator starter converter as claimed in claim 1 wherein said square wave inverter means comprises:

a plurality of steps.

5. A low input harmonic induced multiple use AC synchronous generator starter converter as claimed in claim 1 wherein said timing logic comprises:

EMF sensing means for monitoring output of said square wave inverter means; and

,

resolver means for providing a rotor position signal.

6. A low input harmonic induced multiple use AC synchronous generator starter converter as claimed in claim 5 wherein:

drive signals of said square wave inverter means are locked to said rotor position signal.

7. A low input harmonic induced multiple use AC synchronous generator starter converter as claimed in claim 1 wherein:

output of said square wave inverter means is a variable voltage, variable frequency, square wave AC output.

8. A low input harmonic induced multiple use AC synchronous generator starter converter comprising:

flyback converter means for receiving input power of either AC or DC; and

,

output power means connected to said flyback converter means for providing converted output power of either AC or DC without degradation of said input power;

wherein;

magnetic components as well as several semiconductor rectifiers perform multi-functions.

9. A low input harmonic induced multiple use AC synchronous generator starter converter as claimed in claim 8 wherein:

said converted output power is capable of starting AC generators as a motor, charging batteries or providing regulated DC outputs.

10. A low input harmonic induced multiple use AC synchronous generator starter converter as claimed in claim 8 wherein said flyback converter means comprises:

a plurality of flyback converters;

rectifier bridge means connected between said input power and each of said plurality of flyback converters; and

,

summing diode means, connected between each of said plurality of flyback converters and said output power means.

11. A low input harmonic induced multiple use AC synchronous generator starter converter as claimed in claim 8 wherein said input power comprises:

three phase alternating current.

12. A low input harmonic induced multiple use AC synchronous generator starter converter as claimed in claim 8 wherein said input power comprises:

direct current.

13. A low input harmonic induced multiple use AC synchronous generator starter converter as claimed in claim 8 wherein:

said flyback converter means provides input/output isolation.

14. A low input harmonic induced multiple use AC synchronous generator starter converter as claimed in claim 8 wherein:

said flyback converter means operates in discontinuous conduction mode at a maximum (50%) duty cycle during AC start or DC start.

15. A low input harmonic induced multiple use AC synchronous generator starter converter as claimed in claim 8 wherein:

output voltage of said flyback converter means increases as load decreases.

16. A low input harmonic induced multiple use AC synchronous generator starter converter as claimed in claim 8 wherein said flyback converter means comprises:

three flyback converters;

rectifier bridge means connected between said input power and each of said three flyback converters; and

,

summing diode means, connected between each of said three flyback converters and said output power means.

17. A low input harmonic induced multiple use AC synchronous generator starter converter as claimed in claim 16 wherein each of said three flyback converters comprises:

transistor means connected to said rectifier bridge means; and

,

transformer means connected between said transistor means and said summing diode means.

18. A low input harmonic induced multiple use AC synchronous generator starter converter as claimed in claim 16 wherein said rectifier bridge means comprises:

low pass filter means for receiving and filtering said input power;

rectifier means connected to said low pass filter means;

capacitor means connected across said rectifier means for removing high frequency voltage spikes.