Method and device for determining the power output by a photovoltaic installation

Patent metadata

Field	Value
Publication number	US-9618546-B2
Application number	US-201214114201-A
Country	US
Kind code	B2
Filing date	Apr 25, 2012
Priority date	Apr 28, 2011
Publication date	Apr 11, 2017
Grant date	Apr 11, 2017

Abstract

A method for improving the usability of photovoltaic installations (PV installations) by taking account of shading information of adjacent PV installations for forecasting the power output by a relevant PV installation is provided. In particular, cloud movements and cloud shapes are taken into account. This improves the accuracy of the forecast. Here, it is advantageous that short-term forecasts in relation to e.g. the next 15 minutes are possible and a substitute energy source can be activated accordingly, in good time, prior to a dip in the power output by the PV installation. The invention can be used e.g. in the field of renewable energies, PV installations or smart grids.

First claim

The invention claimed is:

1. A method for determining a power output by a respective one photovoltaic installation of a plurality of photovoltaic installations, the method comprising:
providing to a processor unit associated with the respective one photovoltaic installation shading information by at least one adjacent photovoltaic installation being adjacent to the respective one photovoltaic installation,
establishing by the processor unit a temporal and spatial forecast in relation to an imminent shading on the basis of the shading information from the at least one adjacent photovoltaic installation,
determining by the processor unit the expected power output by the respective one photovoltaic installation on the basis of the imminent shading in relation to cloud drift,
wherein a speed of a shading, in particular of the cloud drift, is established by maximizing a cross-correlation R ab

R
ab

=

1
T

·

∫

-
T

/
2

T
/
2

⁢

P
a

⁡

(
t
)

·

P
b

⁡

(

t
+
τ

)

⁢

⁢

ⅆ
t

,

⁢
with

τ
=

d
ab

v
Cloud

,

where
a, b denote two photovoltaic installations,
T denotes a considered time interval,
P denotes a feed-in power,
d ab denotes a distance between the photovoltaic installations a and b,
ν Cloud denotes an estimated speed of the cloud drift, and
activating a substitute energy source depending on the expected power output by the respective one photovoltaic installation.

2. The method according to claim 1 , wherein the shading information comprises an item of information based on a reduced brightness and, in particular, based on a shading caused by cloud movement.

3. The method according to claim 1 , wherein the substitute energy source comprises at least one of a controllable load, an energy store, and an energy producer.

4. The method according to claim 1 , wherein the at least one adjacent photovoltaic installation comprises several adjacent photovoltaic installations arranged spatially surround the respective one photovoltaic installation at least in part.

5. The method according to claim 1 , wherein, on the basis of the shading information, the temporal and spatial forecast in relation to the imminent shading is established using a forecasting model.

6. The method according to claim 1 , wherein a direction of the shading, based on the cloud drift, is established on the basis of a comparison of the cross-correlations of spatially differently aligned photovoltaic installations.

7. The method as according to claim 1 , further comprising:
determining a direction of an airflow,
determining a variance of the cross-correlation of photovoltaic installations at different distances apart, and
establishing a change in the shading, based on a change in a shape of the cloud drift, on the basis of the direction of the airflow and the variance.

8. The method according to claim 7 , wherein the expected power output by the respective one photovoltaic installation is determined on the basis of the established change in the shading.

9. The method according to claim 8 , wherein the power output is determined on the basis of a hybrid model wherein the hybrid model comprises an error correction neural network.

10. A device for setting a respective one photovoltaic installation, comprising:
a processing unit, configured to determine a power output by the respective one photovoltaic installation on the basis of shading information from at least one adjacent photovoltaic installation, wherein the processing unit to
receive the shading information provided by the at least one adjacent photovoltaic installation,
establish a temporal and spatial forecast in relation to an imminent shading on the basis of the shading information,
determine an expected power output by the respective one photovoltaic installation on the basis of the imminent shading in relation to cloud drift,
establish a speed of a shading, based on the cloud drift, by maximizing a cross-correlation R ab

R
ab

=

1
T

·

∫

-
T

/
2

T
/
2

⁢

P
a

⁡

(
t
)

·

P
b

⁡

Assignees

• Bamberger Joachim
• Grothmann Ralph
• Heesche Kai
• Hoffmann Clemens
• Metzger Michael
• Siemens Ag

Inventors

• Bamberger Joachim
• Grothmann Ralph
• Heesche Kai
• Hoffmann Clemens
• Metzger Michael

Classifications

• H02J3/004 Primary

  Generation forecast, e.g. methods or systems for forecasting future energy generation · CPC title

• H02J3/381

  Dispersed generators · CPC title

• H02S50/10

  Testing of PV devices, e.g. of PV modules or single PV cells (testing of semiconductor devices during manufacturing {H10P74/00}) · CPC title

• H02J2101/24

  Photovoltaics · CPC title

• G01R21/133 Primary

  by using digital technique · CPC title