Protection for redundancy of isolated inverter blocks

• US 10,103,665 B2
• Filed: 01/06/2017
• Issued: 10/16/2018
• Est. Priority Date: 01/06/2017
• Status: Active Grant

• Current Assignee: GE Infrastructure Technology, LLC (General Electric Company)
• Original Assignee: General Electric Company
• Inventors: Wagoner, Robert Gregory, Ganireddy, Govardhan, Shukla, Saurabh, Raju, Ravisekhar Nadimpalli, Schnetzka, Harold Robert
• Primary Examiner(s): Laxton, Gary L
• Application Number:
  US15/399,824
• Publication Number:
  US 20180198393A1
• Time in Patent Office: 648 Days
• CPC Class Codes: F03D 7/042 by means of an electrical or electronic controller
• CPC Class Codes: H02H 7/1225 responsive to internal faults, e.g. shoot-through avoiding shoot-through H02M1/38
• CPC Class Codes: H02K 11/33 Drive circuits, e.g. power electronics H02K11/38 takes precedence
• CPC Class Codes: H02K 7/183 wherein the turbine is a wind turbine adaptation of a wind turbine to an electric generator F03D9/25
• CPC Class Codes: H02M 1/0077 Plural converter units whose outputs are connected in series
• CPC Class Codes: H02M 1/32 Means for protecting converters other than automatic disconnection
• CPC Class Codes: H02M 1/325 with means for allowing continuous operation despite a fault, i.e. fault tolerant converters
• CPC Class Codes: H02M 7/4807 having a high frequency intermediate AC stage
• CPC Class Codes: H02P 27/08 with pulse width modulation
• CPC Class Codes: H02P 9/00 Arrangements for controlling electric generators for the purpose of obtaining a desired output
• CPC Class Codes: H02P 9/007 Control circuits for doubly fed generators
• CPC Class Codes: H02P 9/10 Control effected upon generator excitation circuit to reduce harmful effects of overloads or transients, e.g. sudden application of load, sudden removal of load, sudden change of load
• 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

Systems and methods for protecting the redundancy of inverter blocks are provided. In one example implementation, a system can include a plurality of inverter blocks. Each inverter block can include a first conversion entity configured to convert DC power to AC power, a second conversion entity configured to convert AC power to DC power, and a third conversion entity configured to convert DC power to AC power. An isolation transformer can be coupled between the first conversion entity and the second conversion entity. The system includes an inverter block switching element coupled to an output of each inverter block. A protection element is disposed in each inverter block. The system includes one or more control devices configured to isolate at least one of the plurality of inverter blocks based at least in part on a status of the protection element disposed in the inverter block.

Claims

1. A power converter system, the power converter, comprising:

a plurality of inverter blocks, each inverter block comprising a plurality of conversion entities, each conversion entity having a plurality of bridge circuits, each bridge circuit comprising a plurality of semiconductor switching elements coupled in series, wherein the plurality of conversion entities comprise a first conversion entity configured to convert DC power to AC power, a second conversion entity configured to convert AC power to DC power, and a third conversion entity configured to convert DC power to AC power, wherein an isolation transformer is coupled between the first conversion entity and the second conversion entity;

an inverter block switching element coupled to an output of each inverter block;

at least one protection element disposed in each inverter block;

one or more control devices configured to isolate at least one of the plurality of inverter blocks based at least in part on a status of the at least one protection element disposed in the inverter block.

2. The power converter system of claim 1, wherein the one or more control devices are configured to isolate at least one of the plurality of inverter blocks by opening the inverter block switching element coupled to the output of the at least one inverter block.

3. The power converter system of claim 1, wherein each inverter block comprises a first protection element coupled in series with a first DC bus input to the inverter block and a second protection element coupled in series with a second DC bus input from the inverter block.

4. The power converter system of claim 3, wherein the one or more control devices are configured to isolate at least one of the plurality of inverter blocks using the inverter block switching element associated with the at least one inverter block based at least in part on a status of the first protection element or the status of the second protection element disposed in the inverter block.

5. The power converter system of claim 3, wherein each inverter block comprises a third protection element coupled in series with a first AC output of the inverter block and a fourth protection element coupled in series with a second AC output of the inverter block.

6. The power converter system of claim 5, wherein the one or more control devices are configured to isolate at least one of the plurality of inverter blocks using the inverter block switching element associated with the at least one inverter block based at least in part on a status of the first protection element, the status of the second protection element, the status of the third protection element, or the status of the fourth protection element disposed in the inverter block.

7. The power converter system of claim 1, wherein each the plurality of semiconductor switching elements in each bridge circuit comprises a silicon carbide MOSFET.

8. The power converter system of claim 1, wherein each the plurality of semiconductor switching elements in each bridge circuit comprises an insulated gate bipolar transistor.

9. The power converter system of claim 1, wherein the inverter block switch comprises a relay.

10. The power converter system of claim 1, wherein the inverter block switch comprises a power semiconductor switch.

11. The power converter system of claim 1, wherein the at least on protection element comprises a fuse.

12. The power converter system of claim 1, wherein the plurality of inverter blocks are part of a line converter of a two-stage power converter used in a wind driven doubly-fed induction generator system.

13. The power converter system of claim 1, wherein the isolation transformer comprises a plurality of secondary windings, wherein each inverter block comprises a pair of second conversion entities, each second conversion entity coupled to one of the plurality of secondary windings.

14. The power converter system of claim 1, wherein each inverter block further comprises an input conversion entity, the input conversion entity having a plurality of bridge circuits, each bridge circuit comprising a plurality of semiconductor switching elements coupled in series, the input conversion entity configured to convert AC power to DC power, wherein the at least one protection element is coupled in series with an AC input to the input conversion entity.

15. The power converter system of claim 1, wherein DC inputs to the plurality of inverter blocks are coupled in parallel.

16. A method for isolating an inverter block in a power converter system, the power converter system comprising a plurality of inverter blocks, each inverter block comprising a plurality of conversion entities, each conversion entity having a plurality of bridge circuits, each bridge circuit comprising a plurality of silicon carbide MOSFET switching elements coupled in series, wherein the plurality of conversion entities comprise a first conversion entity configured to convert DC power to AC power, a second conversion entity configured to convert AC power to DC power, and a third conversion entity configured to convert DC power to AC power, wherein an isolation transformer is coupled between the first conversion entity and the second conversion entity, the method comprising:

obtaining, by one or more control devices, a signal from a one or more sensors associated with a protection element disposed in the inverter block;

determining, by the one or more control devices, a status of the protection element based at least in part on the signal from the one or more sensors;

controlling an inverter block switching element to isolate one of the plurality of inverter blocks based at least in part on the status of the protection element.

17. The method of claim 16, wherein when the status of the protection element is determined to be open, controlling an inverter block switching element comprises opening the inverter block switching element.

18. The method of claim 16, wherein the inverter block switching element is normally closed.

19. The method of claim 16, wherein DC inputs to the plurality of inversion blocks are coupled in parallel.

20. A wind driven generator system, the system comprising:

a wind driven generator;

a power converter comprising;

a plurality of inverter blocks, each inverter block comprising a plurality of conversion entities, each conversion entity having a plurality of bridge circuits, each bridge circuit comprising a plurality of semiconductor switching elements coupled in series, wherein the plurality of conversion entities comprise a first conversion entity configured to convert DC power to AC power, a second conversion entity configured to convert AC power to DC power, and a third conversion entity configured to convert DC power to AC power, wherein an isolation transformer is coupled between the first conversion entity and the second conversion entity;

an inverter block switching element coupled to an output of each inverter block;

at least one fuse disposed in each inverter block;

one or more control devices configured to isolate at least one of the plurality of inverter blocks using the inverter block switching element associated with the at least one inverter block based at least in part on a status of the at least one fuse disposed in the inverter block.