Automatic modularity control for multi power stack air cooled inverter

Patent metadata

Field	Value
Publication number	US-10243511-B1
Application number	US-201816007721-A
Country	US
Kind code	B1
Filing date	Jun 13, 2018
Priority date	Jun 13, 2018
Publication date	Mar 26, 2019
Grant date	Mar 26, 2019

Abstract

Provided is a method for performing automatic modularity control of an inverter and an inverter that includes DC power sources configured to supply DC power, a plurality of converters to convert direct current power to alternating current power to be supplied to a load, and a controller. The controller performs automatic modularity control of the plurality of converters, by separately controlling the plurality of converters and detecting an operation status thereof and performs fault detection at the plurality of converters at an early stage and isolates a respective converter of the plurality of converters, while continuously supplying power to the load via remaining converters of the plurality of converters. The automatic modularity control further includes early fault detection based continuous monitoring of the current produced by each converter and semiconductor switching feedback and cyclic starting of the inverter to normalize the lifecycle of the circuit breaker.

First claim

What is claimed is:

1. An inverter comprising:
a plurality of DC power sources configured to supply DC power,
a plurality of converters to convert direct current power to alternating current power to be supplied to a load or a utility grid, and
a controller configured to:
(i) perform automatic modularity control of the plurality of converters, by separately controlling the plurality of converters and detecting an operation status thereof; and
(ii) perform fault detection at the plurality of converters and isolate a respective converter of the plurality of converters, while continuously supplying power to the load via remaining healthy converters of the plurality of converters.

2. The inverter of claim 1 , wherein the plurality of DC power sources comprise a plurality of photovoltaic arrays.

3. The inverter of claim 1 , further comprising:
a plurality of direct current circuit breakers each connected between a respective DC power source and an input of a converter of the plurality of converters, and
a plurality of alternating current circuit breakers each connected between a respective DC power source and an output of a converter of the plurality of converters along with inter bridge contactors and fuses.

4. The inverter of claim 3 , further comprising a line filter connected between each converter of the plurality of converters and a respective alternating current circuit breaker, and configured to remove harmonics from the alternating current power at the output of the converter.

5. The inverter of claim 1 , wherein each converter of the plurality of converters comprises:
a semiconductor device configured to perform a switching operation;
a plurality of resistors and a plurality of capacitors formed in series, and connected in parallel with the semiconductor device.

6. The inverter of claim 4 , further comprising a plurality of voltage/current sensors disposed at the input and output of each converter of the plurality of converters and configured to monitor the voltage/current at the input and output of each converter of the plurality of converters.

7. The inverter of claim 6 , further comprising a main alternating current system circuit breaker connected with the plurality of alternating circuit breakers and configured to supply the alternating current power directly to the load or the utility grid.

8. The inverter of claim 7 , further comprising a plurality of power interface boards, each corresponding to a respective converter of the plurality of converters, and connected together to interface between the plurality of converters and the controller for controlling operation and monitoring the status of each converter, the plurality of power interface boards, each configured to supply control signals from the controller to plurality of converters.

9. The inverter of claim 8 , wherein the controller comprises:
a programmable pulse generator configured to generate a pulse to control operation of each converter of the plurality of converters,
a dual core central processing unit configured to perform control operations of the plurality of converters,
a plurality of control modules, each configured to perform line current and voltage measurements, wherein the plurality of control modules are connected to the plurality of current/voltage sensors via power interface boards and then through ports of the controller using power interface board communication.

10. The inverter of claim 9 , wherein the controller is further configured to:
(i) continuously monitor the operation status of the plurality of converters, the DC power sources, and the power interface boards, for fault detection,
(ii) perform the automatic modularity control by monitoring, tracking and storing faults detected.

11. The inverter of claim 10 , wherein when a fault is detected, the controller is configured to:
switch off the plurality of converters to isolate a faulty converter of the plurality of converters and reconfigure a power rating of the inverter and restart the inverter with power from remaining converters of the plurality of converters.

12. The inverter of claim 10 , wherein when a fault is detected, the controller is configured to:
isolate a faulty converter of the plurality of converters while simultaneously continuously supplying power to the inverter via remaining converters of the plurality of inverters.

13. The inverter of claim 10 , wherein the controller is further configured to store the faults detected prior to automatically isolating the faulty converter of the plurality of converters.

14. The inverter of claim 10 , wherein when a fault is detected, the controller is further configured to open the main alternating current circuit breaker, the direct current circuit breakers and the alternating current circuit breakers and disable a pulse release from the programmable pulse generator, to thereby isolate the faulty converter of the plurality of converters.

15. The inverter of claim 10 , wherein the controller is further configured to issue a warning notification if one of the plurality of converters is operating outside of specified limit, by comparing actual current from the plurality of converters with an estimated current to be produced by an individual converter.

16. The inverter of claim 15 , wherein the controller is further configured to monitor an operation status of the semiconductor device of each converter, the plurality of DC sources, and the power interface boards, and issue a warning notification if malfunction thereof is detected.

17. The inverter of claim 16 , wherein the controller is further configured to perform a cyclic start operation of the plurality of converters comprising:
(i) operating a specific converter of the plurality of converters at an initial startup operation of the inverter and when sufficient energy is available at a respective DC source,
(ii) switching the plurality of converters off and restarting the inverter with a total of the plurality of converters.

18. The inverter of claim 17 , wherein the controller is further configured to selectively vary the specific converter of the plurality of converters to be operated at the initial startup operation.

19. A method of performing automatic modularity control of an inverter having a plurality of converters and a controller, the method comprising:
supplying DC power from a plurality of DC power sources to the plurality of converters to convert direct current power to alternating current power to be supplied to a load, and
performing, via the controller, the automatic modularity control of the plurality of converters, by separately controlling the plurality of converters and detecting an operation status thereof; and
performing, via the controller, fault detection at the plurality of converters and isolating a respective converter of the plurality of converters, while continuously supplying power to the load via remaining healthy converters of the plurality of converters.

20. The method of claim 19 , further comprising:
connecting a plurality of direct current circuit breakers between a respective DC power source and an input of a converter of the plurality of converters, and connecting a plurality of alternating current circuit breakers between a respective DC power source along with inter bridge contactors, fuses, and an output of a converter of the plurality of converters, and
connecting a main alternating current circuit breaker with the plurality of alternating circuit breakers and supplying the alternating current power dir

Assignees

• Ge Energy Power Conversion Technology Ltd

Inventors

• Gollapudi Datatreya Reddy
• Arputhanathan Britto
• Mathurai Venkateswaran

Classifications

• H02M7/003 Primary

  Constructional details, e.g. physical layout, assembly, wiring or busbar connections · CPC title

• G05F1/67

  to the maximum power available from a generator, e.g. from solar cell · CPC title

• H02H7/1225

  responsive to internal faults, e.g. shoot-through (avoiding shoot-through H02M1/38) · CPC title

• H02M7/5387

  in a bridge configuration · CPC title

• H02S40/345

  with cooling means associated with the electrical connection means, e.g. cooling means associated with or applied to the junction box (cooling means for PV cells H10F77/63, for PV modules H02S40/42) · CPC title