Inverter, in particular as part of a power generation network, and method

Patent metadata

Field	Value
Publication number	US-10355491-B2
Application number	US-201615213439-A
Country	US
Kind code	B2
Filing date	Jul 19, 2016
Priority date	Jan 22, 2014
Publication date	Jul 16, 2019
Grant date	Jul 16, 2019

Abstract

An inverter for converting DC power of a generator into grid-conforming AC power includes an inverter bridge circuit and a scanning circuit configured to trace at least one part of a characteristic curve of the generator to determine an MPP power value (PMPP). The scanning circuit is configured, in the case of a derating to a derated power (Pred), to trigger a tracing of the characteristic curve with provision of a first power profile deviating from the derated power (Pred) if an enable signal is present at the inverter, and to indicate a start and an end of the tracing by outputting a start signal and an end signal, respectively. The scanning circuit is further configured to provide a second power profile as AC power upon receiving a start signal, wherein the first power profile has a deviation from the derated power (Pred) with a sign that is opposite to a sign of a deviation of the second power profile from the derated power (Pred).

First claim

The invention claimed is:

1. An inverter for converting DC power of a generator into grid-conforming AC power, comprising:
an inverter bridge circuit; and
a scanning circuit configured to trace at least one part of a characteristic curve of the generator to determine an MPP power value (P MPP ),
wherein the scanning circuit is configured, in the case of a derating to a derated power (P red ), to trigger a tracing of the characteristic curve with provision of a first power profile deviating from the derated power (P red ) if an enable signal is present at the inverter, and to indicate a start and an end of the tracing by outputting a start signal and an end signal, respectively, and
wherein the scanning circuit is configured to provide a second power profile as AC power upon receiving a start signal, and
wherein the first power profile has a deviation from the derated power (P red ) with a sign that is opposite to a sign of a deviation of the second power profile from the derated power (P red ).

2. The inverter as claimed in claim 1 , wherein the inverter is configured to provide the MPP power value (P MPP ) after tracing the characteristic curve via a communication interface.

3. The inverter as claimed in claim 1 , wherein the first power profile has increased power values in comparison with the derated power (P red ).

4. The inverter as claimed in claim 1 , wherein the inverter is configured to connect to the Internet for the purpose of transmitting the enable signal, the start signal and the end signal.

5. The inverter as claimed in claim 1 , wherein the derated power (P red ) comprises a predefined percentage of the MPP power value (P MPP ).

6. The inverter as claimed in claim 1 , wherein the derated power comprises a value that is reduced by a predefined percentage of a rated power of the inverter or of the generator in comparison with the MPP power value (P MPP ).

7. A power generation network, comprising:
a first inverter and a second inverter, wherein the first inverter and the second inverter each comprise:
an inverter bridge circuit; and
a scanning circuit configured to trace at least one part of a characteristic curve of the generator to determine an MPP power value (P MPP ),
wherein the scanning circuit is configured, in the case of a derating to a derated power (P red ), to trigger a tracing of the characteristic curve with provision of a first power profile deviating from the derated power (P red ) if an enable signal is present at the inverter, and to indicate a start and an end of the tracing by outputting a start signal and an end signal, respectively, and
wherein the scanning circuit is configured to provide a second power profile as AC power upon receiving a start signal, and
wherein the first power profile has a deviation from the derated power (P red ) with a sign that is opposite to a sign of a deviation of the second power profile from the derated power (P red ), and

wherein the first inverter and the second inverter are connected to one another and are configured to exchange the enable signal, the start signal and the end signal with one another.

8. The power generation network as claimed in claim 7 , further comprising a control device configured to generate the enable signal, wherein the control device is connected to the first inverter and the second inverter.

9. The power generation network as claimed in claim 7 , wherein the power generation network is configured to alternately trigger the tracing of the characteristic curves within the power generation network via a token.

10. The power generation network as claimed in claim 7 , wherein the first inverter is configured to adapt its derated power (P red ) depending on the MPP power value (P MPP ) of the second inverter.

11. The power generation network as claimed in claim 7 , wherein the first inverter is connected to a generator with an adjustable orientation, and wherein the first inverter is configured to provide the first power profile by adjusting the generator orientation.

12. The power generation network as claimed in claim 7 , wherein the first inverter comprises a group having a plurality of inverters configured to trace their characteristic curve successively in a temporally overlapping manner.

13. A method for converting DC power of a generator into grid-conforming AC power by an inverter comprising a scanning circuit that is configured to trace at least one part of a characteristic curve of the generator for determining an MPP power value (P MPP ) if the inverter is in a state reduced to a derated power (P red ), comprising:
tracing the characteristic curve with provision of a first power profile deviating from the derated power (P red ), under a precondition that an enable signal is present at the inverter,
transmitting a start signal at a beginning of the tracing and transmitting an end signal at an end of the tracing of the characteristic curve, and
providing a second power profile as AC power upon receiving the start signal, wherein the first power profile has a deviation from the derated power (P red ) with a sign that is opposite to a sign of a deviation of the second power profile from the derated power (P red ).

14. The method as claimed in claim 13 , wherein the inverter comprises a group having a plurality of individual inverters, and wherein tracing the characteristic curve is performed by the individual inverters of the group tracing an individual characteristic curve assigned to the individual inverters successively in a temporally overlapping manner.

15. The method as claimed in claim 13 , carried out on a first inverter and a second inverter, wherein tracing the first characteristic curve is performed by a step by step increase of a setpoint value of the power for the first inverter, and wherein tracing the second characteristic curve is performed by a step by step decrease—compensating for the increase—of a setpoint value of the power for the second inverter.

16. The method as claimed in claim 15 , further comprising tracing the first characteristic curve by a step by step increase of a setpoint value of the power for the second inverter and tracing the second characteristic curve by a step by step decrease of a setpoint value of the power for the first inverter, the decrease compensating for the increase of the setpoint value of the second inverter.

Assignees

• Sma Solar Technology Ag

Inventors

• Mende Denis
• Premm Daniel
• Sander Stephan

Classifications

• H02J2101/25

  involving maximum power point tracking control for photovoltaic sources · CPC title

• H02J2101/24

  Photovoltaics · CPC title

• H02M7/44

  by static converters · CPC title

• Y02E10/563

  Cross-Sectional Technologies · mapped topic

• G05F1/67 Primary

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