Monitoring of distributed power harvesting systems using DC power sources

• US 8,903,681 B2
• Filed: 05/24/2013
• Issued: 12/02/2014
• Est. Priority Date: 12/06/2006
• Status: Active Grant

• Current Assignee: Solaredge Technologies Incorporated
• Original Assignee: Solaredge Technologies Incorporated
• Inventors: Adest, Meir, Handelsman, Lior, Galin, Yoav, Fishelov, Amir, Sella, Guy
• Primary Examiner(s): Moffat, Jonathan C Teixeira
• Assistant Examiner(s): VO, HIEN XUAN
• Application Number:
  US13/901,890
• Publication Number:
  US 20130332093A1
• Time in Patent Office: 557 Days
• Field of Search: None
• US Class Current: 702/182
• CPC Class Codes: G01D 2204/125 Utility meter reading systems specially adapted for determining the environmental impact of user behaviour
• CPC Class Codes: G01D 2204/14 Displaying of utility usage with respect to time, e.g. for monitoring evolution of usage or with respect to weather conditions
• CPC Class Codes: G01D 2204/30 Remote utility meter reading systems specially adapted for metering the generated energy or power
• CPC Class Codes: G01D 2204/35 Monitoring the performance of renewable electricity generating systems, e.g. of solar panels
• CPC Class Codes: G01D 4/004 Remote reading of utility meters to a fixed location
• CPC Class Codes: G01R 21/133 by using digital technique
• CPC Class Codes: G01R 22/063 related to remote communication
• CPC Class Codes: H02J 13/00 Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network
• CPC Class Codes: H02J 13/00002 characterised by monitoring
• CPC Class Codes: H02J 13/00009 using pulsed signals
• CPC Class Codes: H02J 13/00016 using a wired telecommunication network or a data transmission bus
• CPC Class Codes: H02J 13/00022 using wireless data transmission
• CPC Class Codes: H02J 13/00026 involving a local wireless network, e.g. Wi-Fi, ZigBee or Bluetooth
• CPC Class Codes: H02J 2300/26 involving maximum power point tracking control for photovoltaic sources
• CPC Class Codes: H02J 3/38 Arrangements for parallely feeding a single network by two or more generators, converters or transformers
• CPC Class Codes: H02J 3/381 Dispersed generators
• CPC Class Codes: Y02B 10/10 Photovoltaic [PV]
• CPC Class Codes: Y02B 70/30 Systems integrating technologies related to power network operation and communication or information technologies for improving the carbon footprint of the management of residential or tertiary loads, i.e. smart grids as climate change mitigation technology in the buildings sector, including also the last stages of power distribution and the control, monitoring or operating management systems at local level
• CPC Class Codes: Y02B 70/34 Smart metering supporting the carbon neutral operation of end-user applications in buildings
• CPC Class Codes: Y02B 90/20 Smart grids as enabling technology in buildings sector smart grids supporting the management or operation of end-user stationary applications in general, or like technologies with no associated climate change mitigation effect Y04S20/00
• CPC Class Codes: Y02E 10/50 : Photovoltaic [PV] energy
• CPC Class Codes: Y02E 10/56 : Power conversion systems, e.g. maximum power point trackers
• CPC Class Codes: Y02E 40/70 : Smart grids as climate change mitigation technology in the energy generation sector
• CPC Class Codes: Y02E 60/00 : Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
• CPC Class Codes: Y04S 10/123 : the energy generation units being or involving renewable energy sources
• CPC Class Codes: Y04S 10/30 : State monitoring, e.g. fault, temperature monitoring, insulator monitoring, corona discharge
• CPC Class Codes: Y04S 20/30 : Smart metering, e.g. specially adapted for remote reading
• CPC Class Codes: Y04S 40/121 : using the power network as support for the transmission
• CPC Class Codes: Y04S 40/124 : using wired telecommunication networks or data transmission busses
• CPC Class Codes: Y04S 40/126 : using wireless data transmission

Abstract

A monitoring system and method for monitoring performance of individual powers sources in a distributed power source system. A monitoring module is coupled to each of the power sources, or to each string of serially connected power sources, to monitor and collect data regarding current, voltage, temperature and other environmental factors at the power source. The collected data is transmitted over a power line to a central analysis station for analysis. Data collected from each source indicates malfunction or degradation at the source. Comparison of data collected from adjacent sources filters for environmental factors impacting neighboring sources such as cloudy days for a solar panel. Comparison of data collected from the same source at different times indicates soiling or degradation of the source with time or periodic events such as a moving shade from an adjacent building.

Claims

1. A monitoring system for distributed DC power installation, comprising:

a plurality of power sources, each of the power sources connected to a shared power line;

a plurality of monitoring modules, each monitoring module associated with one of the power sources and collecting performance data of the associated power source and each monitoring module comprises a timer;

a plurality of transmitters, each transmitter associated with one of the monitoring modules and transmitting the performance data of the associated monitoring module over the shared power line; and

a plurality of controllers, each associated with one of the transmitters, initializing the timer of the associated monitoring module whenever the associated power source starts to generate power, and controlling the associated transmitter to transmit the performance data when elapsed time from initialization of the timer reaches a transmission time of the associated transmitter.

2. The monitoring system of claim 1, wherein each of the monitoring modules comprises:

a current measurement module for collecting current data of the associated power source; and

a voltage measurement module for collecting voltage data of the associated power source.

3. The monitoring system of claim 1, wherein each of the monitoring modules further comprises a temperature sensor module for sensing temperature data at the associated power source.

4. The monitoring system of claim 1, wherein each of the monitoring modules further comprises an arc detection module for detecting arcing at the power source.

5. The monitoring system of claim 1, wherein each of the monitoring modules further comprises a randomizer for including random time increments in the transmission times of the power source.

6. The monitoring system of claim 1 further comprising a memory storing the performance data accumulated since timer initialization.

7. The monitoring system of claim 6, further comprising:

a central analysis station; and

a communication translator for receiving the performance data from the monitoring modules and transmitting the performance data to the central analysis station.

8. The monitoring system of claim 7, wherein the central analysis station analyzes fault detection.

9. The monitoring system of claim 7, wherein the central analysis station compares measured power to expected power determined based on external data.

10. The monitoring system of claim 7, wherein each of the power sources comprises a solar panel.

11. The monitoring system of claim 7, wherein each of the power sources comprises a string of serially connected solar panels.

12. The monitoring system of claim 11, wherein each of the monitoring modules comprises a current measurement module for collecting current data.

13. The monitoring system of claim 12, further comprising:

a connection box for parallel coupling all of the string of serially connected solar panels; and

,

a voltage measuring module measuring the voltage of the parallel coupling.

14. The monitoring system of claim 12, further comprising:

a connection box for parallel coupling all of the string of serially connected solar panels; and

,

total current measuring module measuring the total current of the parallel coupling.

15. The monitoring system of claim 14, wherein the monitoring system detects current leakage by comparing output of the total current measuring module to a sum of the current measuring modules of each of the monitoring modules.

16. The system of claim 1, wherein the transmission time comprises a periodic time period component and a random time increment determined by the randomizer.

17. A method for monitoring distributed power harvesting systems including DC power sources, the method comprising:

individually monitoring power generation at each of the DC power sources;

when power generation passes a threshold at a first DC power source of the DC power sources,

initializing a timer for the power source and

collecting performance data for the first DC power source;

monitoring elapsed time of the timer from initialization of the timer; and

when the elapsed time reaches a transmission time associated with the first DC power source, transmitting the collected performance data at least over a power line shared with other DC power sources to a central analysis station.

18. The method of claim 17, wherein collecting performance data further comprises storing the performance data in memory, and wherein transmitting the collected performance data comprises transmitting the collected performance data accumulated since initialization of the timer.

19. The method of claim 18, wherein collecting performance data comprises measuring at least one of output voltage and output current.

20. The method of claim 17, further comprising:

determining the transmission time by adding a random time increment from a randomizer to a periodic transmission time period of the first DC power source.