Wind-power generation system with over-speed protection and method of operating the same

• US 8,552,577 B2
• Filed: 05/08/2012
• Issued: 10/08/2013
• Est. Priority Date: 09/07/2011
• Status: Active Grant

• Current Assignee: Delta Electronics Company Limited (Delta Electronics Incorporated)
• Original Assignee: Delta Electronics Company Limited (Delta Electronics Incorporated)
• Inventors: Lu, Yan-Song, Chen, Jun, Luo, Xue-Xiao
• Primary Examiner(s): Cuevas, Pedro J
• Application Number:
  US13/466,493
• Publication Number:
  US 20130056985A1
• Time in Patent Office: 518 Days
• Field of Search: 290/44, 290/55
• US Class Current: 290/44
• CPC Class Codes: F03D 7/0248 by mechanical means acting on the power train
• CPC Class Codes: F03D 7/0272 by measures acting on the electrical generator
• CPC Class Codes: F03D 9/255 connected to electrical distribution networks; Arrangements therefor
• CPC Class Codes: H02H 7/067 on occurrence of a load dump control on sudden change of load H02P9/10
• CPC Class Codes: Y02E 10/72 Wind turbines with rotation axis in wind direction

Abstract

A wind-power generation system with an over-speed protection is disclosed. The system is provided to convert wind energy into mechanical energy by a wind turbine, and mechanical energy is converted into electric energy by the wind turbine driving a generator. Also, electric energy is delivered to a power grid. The wind-power generation system mainly includes an AC crowbar, a fuse, and a DC chopper. The AC crowbar or the DC chopper is provided to consume superfluous energy outputted from the generator, thus providing an over-load operation to brake the wind turbine when the wind turbine operates under a first stage over-speed operation. Finally, the generator is isolated from the generator-side converter by disconnecting the fuse when the wind turbine operates under a second stage over-speed operation.

Claims

1. A wind-power generation system with an over-speed protection providing a wind turbine to convert wind energy into mechanical energy, the wind turbine driving a generator to convert the mechanical energy into electric energy, the electric energy delivered to a power grid to provide a grid connection between the wind-power generation system and the power grid;

the wind-power generation system comprising;

an AC crowbar electrically connected to the generator;

a fuse electrically connected to the AC crowbar and the generator;

a generator-side converter electrically connected to the fuse to provide an AC-to-DC conversion of electric energy;

a DC chopper electrically connected to the generator-side converter;

a grid-side converter electrically connected to the DC chopper to provide a DC-to-AC conversion of electric energy;

a grid-connected filter electrically connected to the grid-side converter to filter electric energy; and

a transformer electrically connected to the grid-connected filter and the power grid to convert a voltage level of the electric energy of the grid connection between the wind-power generation system and the power grid;

wherein the AC crowbar or the DC chopper is provided to consume superfluous energy outputted from the generator, thus providing an over-load operation to brake the wind turbine when the wind turbine operates under a first stage over-speed operation;

the generator is isolated from the generator-side converter by disconnecting the fuse when the wind turbine operates under a second stage over-speed operation.

2. The wind-power generation system of claim 1, wherein the fuse is disconnected by turning on switches of an upper-bridge arm and switches of a lower-bridge arm of the generator-side converter.

3. The wind-power generation system of claim 1, wherein the wind-power generation system further comprises a controllable rectification circuit, the controllable rectification circuit is electrically connected to the fuse and the generator-side converter.

4. The wind-power generation system of claim 3, wherein the fuse is disconnected by shorting the three-phase controllable rectification circuit out.

5. The wind-power generation system of claim 1, wherein the wind-power generation system further comprises a three-phase short-circuit contactor, the three-phase short-circuit contactor is electrically connected to the fuse and the generator-side converter.

6. The wind-power generation system of claim 5, wherein the fuse is disconnected by shorting the three-phase short-circuit contactor.

7. A method of operating the wind-power generation system with an over-speed protection of claim 1, steps of operating the wind-power generation system comprising:

(a) providing the AC crowbar or the DC chopper to consume superfluous energy outputted from the generator, thus providing an over-load operation to brake the wind turbine when the wind turbine operates under a first stage over-speed operation; and

(b) isolating the generator from the generator-side converter by disconnecting the fuse when the wind turbine operates under a second stage over-speed operation.