Regulating method for a decentralized energy generating system, and decentralized energy generating system

Patent metadata

Field	Value
Publication number	US-11677247-B2
Application number	US-202217567373-A
Country	US
Kind code	B2
Filing date	Jan 3, 2022
Priority date	Mar 1, 2018
Publication date	Jun 13, 2023
Grant date	Jun 13, 2023

Abstract

A method for regulating a decentralized energy generating system with a plurality of inverters (IN) is disclosed. The method includes receiving at the PPC a detected active power, reactive power and voltage amplitude at a grid connection point (PCC) of the energy generating system; and regulating, in a normal operating mode of the energy generating system, the reactive power and the active power to target values stipulated by a grid operator by virtue of the central control unit (PPC) dividing the stipulated target values into individual target stipulations for the plurality of inverters (IN) and communicating individual target stipulations to the inverters (IN). The method further includes selectively changing to a special operating mode of the energy generating system if particular criteria are present at the grid connection point (PCC) in a stipulated time interval. In the special operating mode, the central control unit (PPC) effects a reduction of the active power provided at the grid connection point (PCC) compared to the stipulated target values.

First claim

The invention claimed is:

1. A method for regulating a decentralized energy generating system with a plurality of inverters (IN), wherein a infeed of energy into a grid is determined by a central control unit (PPC), the method comprising:
receiving at the PPC a detected active power, reactive power and voltage amplitude at a grid connection point (PCC) of the decentralized energy generating system; and
regulating, in a normal operating mode of the decentralized energy generating system, the reactive power and the detective active power to target values; and
reducing, in a special operating mode of the decentralized energy generating system, an active power at the PCC when the following three criteria are satisfied at the PCC in a predetermined time interval:
a decrease in the voltage amplitude by more than a predetermined first threshold value;
an active power increase by more than a predetermined second threshold value; and
a reactive power change which does not exceed a predetermined third threshold value.

2. The method as claimed in claim 1 , further comprising changing, by the PPC in the special operating mode, the reactive power provided at the PCC.

3. The method as claimed in claim 1 , wherein ascertaining the decrease in the voltage amplitude or the active power increase is carried out at the PPC by comparing differences between actual values at a beginning and at an end of the predetermined time interval to the respective threshold values.

4. The method as claimed in claim 1 , wherein the central control unit (PPC) effects a reduction of the active power provided at the grid connection point (PCC) and/or a change in the reactive power provided at the grid connection point (PCC) in a direction of an overexcitation of the reactive power by communicating to the inverters (IN) individual special target stipulations that are correspondingly changed compared to individual target stipulations.

5. The method as claimed in claim 1 , further comprising signaling a change to the special operating mode of the decentralized energy generating system is to a grid operator.

6. The method as claimed in claim 1 , further comprising returning to the normal operating mode by a control signal being communicated to the central control unit (PPC).

7. A decentralized energy generating system with a plurality of inverters (IN) and a central control unit (PPC) configured to drive the plurality of inverters (IN), wherein the driving comprises, in a normal operating mode, communicating target stipulations to the plurality of inverters (IN) for an infeed of active power and reactive power into a grid via a grid connection point (PCC) of the decentralized energy generating system, wherein the central control unit (PPC) is configured to effect a change to a special operating mode of the decentralized energy generating system by effecting a reduction of the active power provided at the grid connection point (PCC) when the following three criteria are satisfied at the grid connection point (PCC) in a predetermined time interval:
a decrease in a voltage amplitude by a predetermined first threshold value;
an active power increase by a predetermined second threshold value; and
a reactive power change which does not exceed a predetermined third threshold value.

8. The decentralized energy generating system as claimed in claim 7 , wherein a maximum possible active power output of the energy generating system is greater than a maximum permissible active power uptake capacity of the grid connected to the grid connection point (PCC) taking account of a power exchange of other grid participants connected to the grid.

9. The decentralized energy generating system as claimed in claim 7 , wherein the criteria that the reactive power change does not exceed the predetermined third threshold value occurs in a direction of an underexcitation of the reactive power.

10. The method as claimed in claim 1 , wherein the criteria that the reactive power change does not exceed the predetermined third threshold value occurs in a direction of an underexcitation of the reactive power.

Assignees

• Sma Solar Technology Ag

Inventors

• Premm Daniel
• Fuetterer Cornelius
• Glitza Oliver

Classifications

• H02J3/381 Primary

  Dispersed generators · CPC title

• H02J3/46

  Controlling the sharing of generated power between the generators, sources or networks · CPC title

• H02J3/16

  by adjustment of reactive power · CPC title

• H02J2101/24

  Photovoltaics · CPC title

• H02J2101/20

  Dispersed power generation using renewable energy sources · CPC title