Systems and methods involving starting variable speed generators

• US 7,977,925 B2
• Filed: 04/04/2008
• Issued: 07/12/2011
• Est. Priority Date: 04/04/2008
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Larsen, Einar Vaughn
• Primary Examiner(s): Cuevas; Pedro J
• Application Number:
  US12/098,134
• Publication Number:
  US 20090251109A1
• Time in Patent Office: 1,194 Days
• Field of Search: 322/36, 290/52
• US Class Current: 322/36
• 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, the AC voltage supplied by an AC voltage source connected to 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. 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 connected to the rotor 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.

10. The system of claim 9, wherein the second logic is further operative to increase a current in the rotor until the generator reaches the rated full flux.