SYSTEMS AND METHODS INVOLVING STARTING VARIABLE SPEED GENERATORS

• US 20090251109A1
• Filed: 04/04/2008
• Published: 10/08/2009
• Est. Priority Date: 04/04/2008
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Larsen, Einar Vaughn
• Granted Patent: US 7,977,925 B2
• Time in Patent Office: Days
• US Class Current: 322/10
• CPC Class Codes: H02P 9/08 Control of generator circuit during starting or stopping of driving means, e.g. for initiating excitation

Abstract

An exemplary method for starting a generator, the method comprising, starting a rotor with an AC voltage across the rotor. Starting a stator. Increasing a speed of the rotor.

Claims

1. A method for starting a generator, the method comprising:

starting a rotor with an AC voltage across the rotor;

starting a stator; and

increasing a speed of the rotor.

2. The method of claim 1, further comprising increasing a current in the rotor until the generator reaches a rated full flux.

3. The method of claim 1, further comprising increasing a current in the stator to achieve a desired stator torque responsive to starting the stator.

4. The method of claim 1, wherein the rotor is started with a first phase sequence.

5. The method of claim 4, further comprising reversing the first phase sequence of a rotor converter responsive to a stator voltage reaching a rated stator voltage limit, wherein the reversing of the phase sequence of the rotor converter lowers the stator voltage.

6. The method of claim 1, further comprising increasing a speed of the generator until a stator voltage reaches a rated stator voltage limit.

7. The method of claim 1, further comprising increasing a frequency of the current in the rotor and a speed of the rotor and a frequency of the current in the stator and the speed of the generator until a first speed of the generator is reached.

8. The method of claim 1, further comprising increasing a frequency of the current in the rotor and a speed of the rotor and a frequency of the current in the stator and the speed of the generator until a starting speed of a prime mover of the generator is reached.

9. A method for starting a generator, the method comprising:

starting a rotor;

starting a stator having a first phase sequence;

increasing a speed of the rotor; and

applying a second phase sequence to the rotor.

10. The method of claim 9, wherein the second phase sequence is opposite to the first phase sequence.

11. The method of claim 9, further comprising increasing a current in the rotor until the generator reaches a rated full flux.

12. The method of claim 9, further comprising increasing a current in the stator to achieve a desired stator torque responsive to starting the stator.

13. The method of claim 9, further comprising increasing a speed of the generator until a stator voltage reaches a rated stator voltage limit.

14. The method of claim 9, further comprising increasing a frequency of the current in the rotor and a speed of the rotor and a frequency of the current in the stator and the speed of the generator until a first speed of the generator is reached.

15. The method of claim 9, further comprising increasing a frequency of the current in the rotor and a speed of the rotor and a frequency of the current in the stator and the speed of the generator until a starting speed of a prime mover of the generator is reached.

16. An electrical generation system comprising:

a generator, wherein the generator includes;

a stator;

a rotor; and

a speed controller with a first logic operative to control the speed of the generator;

a variable frequency generator (VFG) exciter, wherein the VFG exciter includes;

a first converter operative to supply AC power to the stator; and

a second converter operative to supply AC power to the rotor;

a VFG exciter controller with a second logic operative to control the operation of the VFG exciter, the second logic being further operative to;

start a second converter operative to start the rotor with an AC voltage across the rotor;

start a first converter operative to start the stator; and

increase a speed of the rotor.

17. The system of claim 16, wherein the second logic is further operative to increase a current in the rotor until the generator reaches the rated full flux.