LOW COST CURRENT SOURCE CONVERTERS FOR POWER GENERATION APPLICATION

• US 20110310642A1
• Filed: 06/21/2010
• Published: 12/22/2011
• Est. Priority Date: 06/21/2010
• Status: Active Grant

• Current Assignee: Rockwell Automation Technologies Incorporated (Allen-Bradley Co., Inc.)
• Original Assignee: Rockwell Automation Technologies Incorporated (Allen-Bradley Co., Inc.)
• Inventors: Dai, Jingya, Zargari, Navid R., Wu, Bin, Xu, David Dewei, Wang, Jiacheng
• Granted Patent: US 8,698,335 B2
• Time in Patent Office: Days
• US Class Current: 363/37
• CPC Class Codes: H02J 2300/28 The renewable source being wind energy wind motors F03D
• CPC Class Codes: H02J 3/381 Dispersed generators
• CPC Class Codes: H02J 3/48 Controlling the sharing of the in-phase component
• CPC Class Codes: H02J 3/50 Controlling the sharing of the out-of-phase component
• CPC Class Codes: H02M 1/126 using passive filters
• CPC Class Codes: H02M 5/458 using semiconductor devices only
• CPC Class Codes: H02M 7/06 using discharge tubes without control electrode or semiconductor devices without control electrode
• CPC Class Codes: H02M 7/1626 with automatic control of the output voltage or current
• CPC Class Codes: Y02E 10/72 Wind turbines with rotation axis in wind direction
• CPC Class Codes: Y02E 10/76 Power conversion electric or electronic aspects

Abstract

A system comprising low cost topology for power converter systems is provided. The system takes advantage of the voltage-boost characteristic of a current source inverter (CSI) and utilizes a PWM CSI as a grid-side converter for power generation systems. Moreover, the generator-side converter employs low-cost devices, such as, but not limited to diode bridge, thyristor bridge, and/or a combination of diodes and thyristors, and accordingly simplifies generator-side converter and control. Further, the system provides a wider range of operation than traditional voltage source converter based topologies that utilize a voltage source inverter (VSI) as the grid-side convertor along with a diode rectifier as the generator-side converter.

Claims

1. A system for power conversion that facilitates delivery of electric energy to a utility grid, comprising:

a generator-side converter, comprising a circuit that includes at least one of a diode bridge or a phase-controlled thyristor bridge, that generates a direct current (DC) current; and

a grid-side converter comprising a current source inverter that converts the DC current into a three-phase alternating current (AC) current.

2. The system of claim 1, further comprising a gating current employed to switch on a thyristor in the thyristor bridge.

3. The system of claim 1, further comprising, a DC-link that connects the generator-side converter with the grid-side converter and provides a forward current path between the generator-side converter and the grid-side converter.

4. The system of claim 3, wherein, the DC-link includes an inductor.

5. The system of claim 1, further comprising at least one of a wind or hydro turbine that facilitates power conversion.

6. The system of claim 5, further comprising a generator connected to the at least one of the wind or hydro turbine that converts kinetic energy to electric energy, the electric energy provided to the generator-side converter.

7. The system of claim 6, wherein the generator is at least one of a permanent magnet synchronous generator (PMSG) or an electrical excited synchronous generator (EESG).

8. The system of claim 1, wherein the three-phase AC current is delivered to the utility grid.

9. The system of claim 1, further comprising a three phase capacitor connected to an output of the grid-side converter, that at least one of assists current commutation or filters harmonics, prior to delivering the three-phase AC current to the utility grid.

10. The system of claim 1, further comprising, a disparate generator-side converter, comprising a disparate circuit that includes at least one of a disparate diode bridge or a disparate thyristor bridge, wherein output of the generator-side converter and the disparate generator-side converter is connected in series.

11. The system of claim 10, wherein inputs of the generator-side converter and the disparate generator-side converter are connected to a single generator.

12. The system of claim 9, wherein inputs of the generator-side converter and the disparate generator-side converter are connected to disparate generators.

13. The system of claim 1, wherein the generator-side converter and the grid-side converter are connected by a long cable that includes at least part of an inductance of a DC-link, which connects the generator-side converter and the grid-side converter.

14. A low cost method for power generation, comprising:

converting at least one of a variable frequency or a variable voltage input to a direct current (DC) current by employing at least one of a diode rectifier or a thyristor rectifier;

passing the DC current through an inductor; and

generating a three-phase alternating current (AC) current with at least one of a fixed frequency or a fixed voltage by employing a pulse width modulated (PWM) current source inverter (CSI).

15. The method of claim 14, further comprising, delivering the three-phase AC current to a utility grid.

16. The method of claim 14, further comprising, controlling at least one of active or reactive power at the output of the PWM CSI by changing a delay angle of at least one thyristor within the thyristor rectifier.

17. A power generation system for applications, comprising:

a first circuit adapted to receive at least one of a variable frequency or a variable voltage as input and generate a direct current (DC) current by employing at least one of a diode rectifier or a thyristor bridge; and

a second circuit adapted to receive the DC current and generate a corresponding alternating current (AC) current with at least one of a fixed frequency or fixed voltage by employing a current source inverter (CSI) comprising a set of reverse-blocking active power devices.

18. The power generation system of claim 17, further comprising, a third circuit adapted to connect the first circuit to the second circuit, the third circuit includes an inductor.

19. The power generation system of claim 17, wherein the CSI is a pulse width modulated (PWM) CSI.

20. The power generation system of claim 17, further comprising at least one of a permanent magnet synchronous generator (PMSG) or an electrical excited synchronous generator (EESG) that generates the at least one of the variable frequency or the variable voltage input.