METHOD OF DIAGNOSING DEFECTIVE ELEMENTS IN A STANDALONE SYSTEM, POWERED BY AN INTERMITTENT POWER SOURCE

• US 20100085063A1
• Filed: 05/07/2008
• Published: 04/08/2010
• Est. Priority Date: 05/11/2007
• Status: Active Grant

• Current Assignee: Commissariat a L'Energie Atomique (French Alternative Energies and Atomic Energy Commission)
• Original Assignee: Commissariat a L'Energie Atomique (French Alternative Energies and Atomic Energy Commission)
• Inventors: Genies, Sylvie, Lebrunie, Antoine
• Granted Patent: US 8,476,870 B2
• Time in Patent Office: Days
• US Class Current: 324/537
• CPC Class Codes: G01R 31/382 Arrangements for monitoring battery or accumulator variables, e.g. SoC
• CPC Class Codes: H02J 7/0029 with safety or protection devices or circuits
• CPC Class Codes: H02J 7/35 with light sensitive cells
• CPC Class Codes: H02S 50/10 Testing of PV devices, e.g. of PV modules or single PV cells testing of semiconductor devices during manufacturing H01L22/00
• CPC Class Codes: Y02E 10/50 Photovoltaic [PV] energy

Abstract

The diagnostic method applies to a standalone system including a generator, a power regulator and a power storage element. The method includes comparison of the effective charging power or current of the power storage element respectively with a predefined power or current threshold. If the effective charging power or current is lower than said threshold, the power storage element is disconnected. An abnormal behavior is then detected either by comparing the effective charging power with the smaller of the values representative of the theoretical charging power of the power storage element and of the maximum power able to be delivered by the generator and comparing the effective and theoretical charging voltages, or by comparing the effective and theoretical charging currents.

Claims

1-18. -18. (canceled)

19. A method for diagnosing defective elements in a standalone system powered by an intermittent power source, said standalone system comprising in series a generator, a power regulator, a power storage element, and a converter arranged between the generator and the power storage element, method comprising

measuring an effective charging current and an effective charging voltage of the storage element, determining an effective charging power according to said measurements, and comparing said effective charging power with a predefined power threshold,

disconnecting the power storage element if the charging power is lower than the power threshold,

while the power storage element is disconnected, measuring a maximum instantaneous deliverable power by the generator, and determining a state of charge of the disconnected power storage element, a corresponding theoretical charging voltage, and a corresponding theoretical charging power,

determining a behavior of the system among a normal behavior, a malfunctioning of the generator and a malfunctioning of the power storage element according to the comparison between the effective charging power of the storage element and the smaller of the theoretical charging power of the storage element and of the maximum power deliverable by the generator, and according to the comparison between the effective charging voltage and the theoretical charging voltage of the power storage element.

20. The method according to claim 19, comprising measurement of input and output voltages of the power regulator and detection of a fault in the power regulator according to said measurements.

21. The method according to claim 20, wherein the power regulator is considered to be defective if its output voltage is zero.

22. The method according to claim 19, wherein if the effective charging power of the power storage element is lower than the theoretical charging power and lower than the maximum power able to be delivered by the generator and if the theoretical charging voltage is equal to the effective charging voltage, the power storage element is considered to be degraded.

23. The method according to claim 22, wherein if the power storage element is considered to be degraded, indication of defectiveness is performed.

24. The method according to claim 19, wherein if the effective charging power of the power storage element is lower than the maximum power able to be delivered by the generator and lower than the theoretical charging power and if the theoretical charging voltage is greater than the effective charging voltage, the generator is considered to be degraded.

25. The method according to claim 24, wherein that if the generator is considered to be degraded, a charging algorithm is reinitialized.

26. The method according to claim 24, wherein if the generator is considered to be degraded, a search algorithm of the maximum power point of the regulator is reinitialized.

27. The method according to claim 25, comprising indication of defectiveness of the generator after a predefined number of successive reinitializations of at least one algorithm.

35. The method according to claim 19, wherein the generator is a photovoltaic panel.

36. The method according to claim 19, wherein the generator is a wind power generator.

28. A method for diagnosing defective elements in a standalone system powered by an intermittent power source, said standalone system comprising a generator connected directly by means of switches to a power storage element, method comprising:

measuring an effective charging current and an effective charging voltage, comparing the effective charging current with a predefined current threshold,

disconnecting the power storage element if said effective charging current is lower than the current threshold,

while the power storage element is disconnected, measuring a maximum instantaneous current and a maximum instantaneous voltage deliverable by the generator, determining a state of charge of the disconnected power storage element, and determining a theoretical charging current and a theoretical charging voltage,

determining a behavior of the system among a normal behavior and a malfunctioning of the standalone system according to comparison of the effective charging current with the theoretical charging current.

29. The method according to claim 28, wherein the effective charging current being lower than the theoretical charging current, if the effective charging voltage of the power storage element is lower than the theoretical charging voltage, the generator is considered to be degraded.

30. The method according to claim 29, wherein if the generator is considered to be degraded, indication of defectiveness is performed.

31. The method according to claim 28, wherein the effective charging current being lower than the theoretical charging current if the effective charging voltage of the power storage element is greater than the theoretical charging voltage, the power storage element is considered to be degraded.

32. The method according to claim 31, wherein if the power storage element is considered to be degraded, indication of defectiveness is performed.

33. The method according to claim 28, wherein the effective charging current being lower than the theoretical charging current, if the effective charging voltage of the power storage element is equal to the theoretical charging voltage the standalone system is considered to be degraded due to an indeterminate cause.

34. The method according to claim 33, wherein if the standalone system is considered to be degraded, indication of defectiveness is performed.