Doubly-Fed, Variable-Speed, Dual-Voltage AC Generation and Distribution Systems

• US 20160079898A1
• Filed: 09/16/2015
• Published: 03/17/2016
• Est. Priority Date: 09/17/2014
• Status: Active Grant

• Current Assignee: ABB Schweiz AG (ABB Limited)
• Original Assignee: ABB Technology AG (ABB Limited)
• Inventors: Liang, Jiaqi, Pan, Zhiguo, Qi, Li, Kondabathini, Anil
• Granted Patent: US 9,742,331 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H02P 9/007 Control circuits for doubly fed generators

Abstract

A generation and distribution system comprises an adjustable-speed prime mover and a doubly-fed asynchronous alternating-current (AC) generator driven by the prime mover and having a first poly-phase circuit, e.g., a stator, and a second poly-phase circuit, e.g., a rotor. The system further includes a first AC bus electrically coupled to the first poly-phase circuit and configured to deliver AC power at a first AC voltage to multiple loads, and a second AC bus configured to deliver AC power at a second AC voltage to another group of loads, the second AC voltage being lower than the first. Finally, the system includes a poly-phase transformer having first windings electrically coupled to the first poly-phase circuit and the first AC bus and having second windings electrically coupled to the second AC bus, and a poly-phase AC-to-AC electronic converter circuit electrically coupled between the second poly-phase circuit and the second AC bus.

Claims

1. An electric generation and distribution system, comprising:

a prime mover configured for adjustable speed operation;

a doubly-fed asynchronous alternating-current (AC) generator driven by the prime mover and having a first poly-phase circuit and a second poly-phase circuit;

a first AC distribution bus electrically coupled to the first poly-phase circuit and configured to deliver AC power at a first AC voltage to a first plurality of loads;

a second AC distribution bus configured to deliver AC power at a second AC voltage to a second plurality of loads, the second AC voltage being lower than the first AC voltage;

a poly-phase transformer having first windings electrically coupled to the first poly-phase circuit and the first AC distribution bus and having second windings electrically coupled to the second AC distribution bus; and

a poly-phase AC-to-AC electronic converter circuit electrically coupled between the second poly-phase circuit and the second AC distribution bus.

2. The electric generation and distribution system of claim 1, wherein the doubly-fed asynchronous AC generator is one of the following:

a wound-rotor induction generator with slip rings; and

a wound-rotor induction generator with brushless excitation.

3. The electric generation and distribution system of claim 1, wherein the AC-to-AC electronic converter circuit is an indirect converter comprising a poly-phase AC-to-DC converter, a poly-phase DC-to-AC converter, and a DC link between the poly-phase AC-to-DC converter and the poly-phase DC-to-AC converter.

4. The electric generation and distribution system of claim 1, wherein the AC-to-AC electronic converter circuit is configured to convert AC power between a variable-voltage, variable-frequency, AC voltage at the second poly-phase circuit and a substantially fixed frequency AC voltage at the second AC distribution bus.

5. The electric generation and distribution system of claim 1, further comprising:

a second prime mover configured for adjustable speed operation;

a second doubly-fed asynchronous alternating-current (AC) generator driven by the second prime mover and having a third poly-phase circuit electrically coupled to the first AC distribution bus and a fourth poly-phase circuit; and

a second poly-phase AC-to-AC converter circuit electrically coupled between the fourth poly-phase circuit and the second AC distribution bus.

6. A method of configuring an electric generation and distribution system, the method comprising:

configuring a prime mover for driving a doubly-fed asynchronous alternating current (AC) generator, the doubly-fed asynchronous AC generator having a first poly-phase circuit and a second poly-phase circuit;

electrically coupling a first AC distribution bus to the first poly-phase circuit and to a first plurality of loads, so as to deliver AC power at a first AC voltage to the first plurality of loads;

electrically coupling a second AC distribution bus to a second plurality of loads, so as to deliver AC power at a second AC voltage to the second plurality of loads;

electrically coupling first windings of a poly-phase transformer to the first poly-phase circuit and to the first AC distribution bus and electrically coupling second windings of the poly-phase transformer to the second AC distribution bus, so as to deliver AC power at a second AC voltage to the second AC distribution bus, the second AC voltage being lower than the first AC voltage; and

electrically coupling a poly-phase AC-to-AC electronic converter circuit between the second poly-phase circuit and the second AC distribution bus.

7. The method of claim 6, wherein the doubly-fed asynchronous AC generator is one of the following:

a wound-rotor induction generator with slip rings; and

a wound-rotor induction generator with brushless excitation.

8. The method of claim 6, wherein the AC-to-AC electronic converter circuit is an indirect converter comprising a poly-phase AC-to-DC converter, a poly-phase DC-to-AC converter, and a DC link between the poly-phase AC-to-DC converter and the poly-phase DC-to-AC converter.

9. The method of claim 6, wherein the AC-to-AC electronic converter circuit is configured to convert AC power between a variable-voltage, variable-frequency, AC voltage at the second poly-phase circuit and a substantially fixed frequency AC voltage at the second AC distribution bus.

10. The method of claim 6, further comprising:

configuring a second prime mover for driving a second doubly-fed asynchronous alternating current (AC) generator, the second doubly-fed asynchronous AC generator having a third poly-phase circuit and a fourth poly-phase circuit;

electrically coupling the third poly-phase circuit to the first AC distribution bus; and

electrically coupling a second poly-phase AC-to-AC converter circuit between the fourth poly-phase circuit and the second AC distribution bus.

11. A method of operating an electric generation and distribution system, the method comprising:

driving a doubly-fed asynchronous alternating current (AC) generator with a prime mover, the doubly-fed asynchronous AC generator having a first poly-phase circuit and a second poly-phase circuit;

coupling AC power from the first poly-phase circuit to a first AC distribution bus, without voltage conversion, and from the first AC distribution bus to a first plurality of loads, so as to deliver AC power at a first AC voltage to the first plurality of loads;

converting AC power from the second poly-phase circuit to a second AC voltage, using a poly-phase AC-to-AC electronic converter circuit, and coupling the converted AC power to a second AC distribution bus, wherein the second AC voltage is lower than the first AC voltage;

transforming AC power from the first poly-phase circuit to the second AC voltage, using a poly-phase transformer having first windings electrically coupled to the first poly-phase circuit and the first AC distribution bus and second windings electrically coupled to the second AC distribution bus; and

delivering power at the second AC voltage to a second plurality of loads, using the second AC distribution bus.

12. The method of claim 11, wherein the doubly-fed asynchronous AC generator is one of the following:

a wound-rotor induction generator with slip rings; and

a wound-rotor induction generator with brushless excitation.

13. The method of claim 11, wherein the AC-to-AC electronic converter circuit is an indirect converter comprising a poly-phase AC-to-DC converter, a poly-phase DC-to-AC converter, and a DC link between the poly-phase AC-to-DC converter and the poly-phase DC-to-AC converter.

14. The method of claim 11, wherein the AC-to-AC electronic converter circuit is configured to convert AC power between a variable-voltage, variable-frequency, AC voltage at the second poly-phase circuit to a substantially fixed frequency AC voltage at the second AC distribution bus.

15. The method of claim 11, further comprising:

driving a second doubly-fed asynchronous alternating current (AC) generator with a second prime mover, the second doubly-fed asynchronous AC generator having a third poly-phase circuit and a fourth poly-phase circuit;

coupling AC power from the third poly-phase circuit to the first AC distribution bus, without voltage conversion;

converting AC power from the fourth poly-phase circuit to the second AC voltage, using a second poly-phase AC-to-AC electronic converter circuit, and coupling the converted AC power to the second AC distribution bus.