Method for Controlling PV Installations in an Electrical Grid

• US 20130200702A1
• Filed: 06/15/2011
• Published: 08/08/2013
• Est. Priority Date: 07/06/2010
• Status: Abandoned Application

• Current Assignee: Phoenix Contact GmbH & Company KG
• Original Assignee: Phoenix Contact GmbH & Company KG
• Inventors: Schppner, Helmut
• Application Number:
  US13/805,450
• Publication Number:
  US 20130200702A1
• Time in Patent Office: Days
• US Class Current: 307/24
• CPC Class Codes: G06Q 50/06 Energy or water supply
• CPC Class Codes: H01L 31/02021 for solar cells electrical connection means, e.g. junction boxes, specially adapted for structural association with photovoltaic modules H02S40/34
• CPC Class Codes: H02J 1/10 Parallel operation of dc sources
• CPC Class Codes: H02J 2300/24 of photovoltaic origin
• CPC Class Codes: H02J 3/381 Dispersed generators
• CPC Class Codes: H02J 3/46 Controlling of the sharing of output between the generators, converters, or transformers
• CPC Class Codes: Y02E 10/56 Power conversion systems, e.g. maximum power point trackers

Abstract

In a public electric grid (30) of an energy provider, the feed-in power of photovoltaic systems (10) are controlled depending on feed-in requirements, the feed-in power of the photovoltaic systems (10) being reduced to a non-zero fraction factor (B) of the maximum possible feed-in power. The photovoltaic systems (10) each comprise a photovoltaic inverter (20) and a feed-in electricity meter (50) on the AC side (20b) of the photovoltaic inverter (20), wherein the AC side feed-in electricity meter (50) continuously measures the power actually fed into the public electric grid (30) and transmits the respective measured power data. Then, the maximum possible feed-in power of the photovoltaic systems (10) is calculated based on the fraction factor (B) and the continuously measured power data time-correlated therewith, and the feed-in remuneration for the respective photovoltaic system (10) is determined based on the thus calculated maximum possible feed-in power.

Claims

1. A method for controlling photovoltaic solar systems (10) connected to a public electric grid (30) of an energy provider, wherein

a plurality of photovoltaic solar systems (10) feed electric energy into the public electric grid (30),

the feed-in power of the photovoltaic systems (10) is controlled by the energy provider depending on feed-in requirements, wherein the feed-in power of the photovoltaic systems (10) is reduced (10) to a non-zero fraction factor (B) of the maximum possible feed-in power,

the photovoltaic systems (10) each comprise a photovoltaic inverter (20) and a feed-in electricity meter (50) on the AC side (20b) of said photovoltaic inverter (20), wherein said AC side feed-in electricity meter (50) continuously measures the power actually fed into the public electric grid (30), and the respective measured power data are periodically transmitted over a data connection (72) between the photovoltaic systems (10) and a portal (82) to a computing device (80) of the portal (82) to be stored therein, and

the maximum possible feed-in power of the photovoltaic systems (10) is calculated using the fraction factor (B) and the continuously measured power data time-correlated therewith, and the feed-in remuneration for the respective photovoltaic system (10) is determined based on the thus calculated maximum possible feed-in power.

2. The method as claimed in claim 1, wherein the reduction of the feed-in power of each of the photovoltaic systems (10) is effected by controlling the photovoltaic inverter (20) of the photovoltaic system (10).

3. The method as claimed in claim 2, wherein each photovoltaic system comprises a data logger (41), and the photovoltaic inverters (20) are controlled by the data logger of the respective photovoltaic system to effect the reduction of feed-in power.

4. The method as claimed in any of the preceding claims, wherein upon an interruption of the data connection (72) between one of the photovoltaic systems (10) and the portal (82), this photovoltaic system (10) automatically stores the measured power data in a data memory (32) of this photovoltaic system (10) and upon restoration of the data connection (72) subsequently automatically transfers the stored power data to the portal (82), and the subsequently transferred power data are stored by the portal (82).

5. The method as claimed in any of the preceding claims, wherein current measurements (61-65) are performed for each string on the DC side (20a) of the photovoltaic inverter (20) of each photovoltaic system (10), and the respective measured direct current data are periodically transmitted over the data connection (72) between the photovoltaic systems (10) and the portal (82) from the photovoltaic systems (10) to the central computing device (80) of the portal (82) to be stored therein.

6. The method as claimed in claim 5, wherein upon an interruption of the data connection (72) between one of the photovoltaic systems (10) and the portal (82), this photovoltaic system (10) automatically stores the measured direct current data in the data memory (32) of this photovoltaic system (10) and upon restoration of the data connection (72) subsequently automatically transfers the stored direct current data to the portal (82), and the subsequently transferred direct current data are stored by the portal (82).

7. The method as claimed in any of the preceding claims, wherein each of the photovoltaic systems (10) comprises a ripple control receiver (90), and wherein the fractional reduction of feed-in power of the photovoltaic systems (10) is triggered by a ripple control signal (92) received by said ripple control receiver (90).

8. The method as claimed in any of the preceding claims, wherein the fraction factors (B) of the photovoltaic systems (10) are each time-stamped and transmitted over the data connection (72) between the photovoltaic systems (10) and the portal (82) to the portal (82) and centrally stored therein.

9. An electric grid (30) for supplying a plurality of consumers with electric energy, comprising a plurality of power plants feeding into the electric grid (30), a plurality of photovoltaic solar systems (10) feeding into the electric grid (30), a plurality of consumers which are supplied with electric energy from the electric grid (30), and a central portal (82),

wherein each of the photovoltaic solar systems (10) comprises:

at least one photovoltaic inverter (20) for converting the DC voltage (18) generated by the photovoltaic modules (16) into grid-compatible alternating voltage;

a data transmission device (74, 76, 77) for establishing a data connection (72) with the portal (82);

a feed-in electricity meter (50) on the AC side (20b) of the photovoltaic inverter (20), adapted for continuously measuring the power actually fed into the public electric grid (30) and for periodically transmitting the respective measured power data over the data connection (72) to a central processing device (80) of the portal (82);

an internal control unit (40) for controlling the power of the respective photovoltaic system (10);

wherein the energy provider is connected to the photovoltaic systems (10) by a data connection (92) and transmits a feed-in requirement depending non-zero fraction factor (B) to the internal control units (40) of the photovoltaic systems;

wherein the internal control units (40) reduce the feed-in power of the respective photovoltaic system (10) to the non-zero fraction factor (B); and

wherein the maximum possible feed-in power of each of the photovoltaic systems (10) is calculated using the fraction factor (B) and the continuously measured power data time-correlated therewith and transmitted to the computing device (80) of the portal (82), and wherein the feed-in remuneration for the respective photovoltaic system (10) is determined based on the thus calculated maximum possible feed-in power.

10. A photovoltaic solar system (10) for connection to a public electric grid (30) of an energy provider, comprising:

one or more strings (11-15) each comprising a plurality of solar modules (16);

at least one power-controllable photovoltaic inverter (20) for converting the DC voltage (18) generated by the solar modules (16) into grid-compatible AC voltage;

a data transmission device (74, 76, 77) for establishing a data connection (72) with a portal (82);

an internal control unit (40) adapted for controlling the power of the photovoltaic inverter (20) to a non-zero fraction factor (B) received from the energy provider;

a feed-in electricity meter (50) on the AC side (20b) of the photovoltaic inverter (20) adapted for continuously measuring the power actually fed into the public electric grid (30) and for periodically transmitting the respective measured power data over the data connection (72) to a central processing device (80) of the portal (82).