Title: Diagnosis method and diagnosis apparatus of photovoltaic power system
Abstract: A reference output characteristic of a photovoltaic power system at the time of normal operation is obtained in accordance with an installation condition (topography of installation site, meteorological condition, configuration of the system itself, or the like) of the photovoltaic power system, an output characteristic in the photovoltaic power system during operation is actually measured, the obtained reference output characteristic and the measured output characteristic are compared and, based on the comparison result, the normality/abnormality of the output is diagnosed and, at the same time, the cause is diagnosed in the case of abnormality. The reference output characteristic at the time of normal operation can also be obtained based on the measured value of the past output characteristic.
Patent Number: 6,892,165 Issued on 05/10/2005 to Yagi, et al.
| Inventors:
|
Yagi; Yasuhiro (Yawata, JP);
Ninomiya; Kunimoto (Hirakata, JP)
|
| Assignee:
|
Sanyo Electric Co., Ltd. (Moriguchi, JP)
|
| Appl. No.:
|
800515 |
| Filed:
|
March 8, 2001 |
Foreign Application Priority Data
| Feb 08, 1991[JP] | 2001-032310 |
| Mar 10, 2000[JP] | 2000-067635 |
| Current U.S. Class: |
702/183; 136/290; 320/101; 702/59; 702/63 |
| Intern'l Class: |
G06F 011/30; G21C017/00 |
| Field of Search: |
702/57- 61,63-65,108,182-185,187
320/101,136
324/522
136/240
186/290
|
References Cited [Referenced By]
U.S. Patent Documents
| 4571532 | Feb., 1986 | Jaster.
| |
| 4636931 | Jan., 1987 | Takahashi et al.
| |
| 4649334 | Mar., 1987 | Nakajima.
| |
| 4755942 | Jul., 1988 | Gardner et al.
| |
| 5302902 | Apr., 1994 | Groehl.
| |
| 5594313 | Jan., 1997 | Takeda.
| |
| 5669987 | Sep., 1997 | Takehara et al.
| |
| 6119047 | Sep., 2000 | Eryurek et al.
| |
| 6278052 | Aug., 2001 | Takehara et al.
| |
| 6512458 | Jan., 2003 | Kobayashi et al.
| |
| Foreign Patent Documents |
| 2439392 | Jun., 1980 | FR.
| |
| 2445955 | Sep., 1980 | FR.
| |
| 62100819 | May., 1987 | JP.
| |
| 01135078 | May., 1989 | JP.
| |
| 10091259 | Apr., 1998 | JP.
| |
| 2000022192 | Jan., 2000 | JP.
| |
| 2000040838 | Feb., 2000 | JP.
| |
Other References
English Translation of JP 2000022192 A cited above.*
English Translation of JP 2000022192 A cited above.*
Begovic, M. et al., Monitoring and data Acquisition for a large Roof-Mounted
Photovoltaic Array, Apr. 12-14, 1997, IEEE, Proceedings IEEE Southeastcon '97.
‘Engineering the New Century’ pp. 298-300.*
English Translation of JP 2000022192 A cited above.*
Begovic, M. et al., Monitoring and data Acquisition for a large Roof-Mounted
Photovoltaic Array, Apr. 12-14, 1997, IEEE, Proceedings IEEE Southeastcon '97.
‘Engineering the New Century’ pp. 298-300.
|
Primary Examiner: Assouad; Patrick
Assistant Examiner: Barbee; Manuel L
Attorney, Agent or Firm: Armstrong, Kratz, Quintos, Hanson & Brooks, LLP
Claims
1. A method for diagnosing the normality/abnormality of an output of an installed
photovoltaic power system, comprising the steps of:
comparing a reference output characteristic obtained chronologically in accordance
with an installation condition of said photovoltaic power system with a measured
output characteristic in said photovoltaic power system obtained during operation
of the photovoltaic power system itself, said installation condition includes a
topography of an installation site, meteorological conditions and configuration
of the photovoltaic power system, and
diagnosing the normality/abnormality of the output of said photovoltaic power
system based on the comparison result,
wherein said photovoltaic power system in diagnosed as normal only if said measured
output characteristic is greater than a first predetermined value and less than
a second predetermined value, said first and second predetermined values being
based on said reference output characteristic,
wherein comparisons of the reference output characteristic and the measured output
characteristic are performed at different time points of a day,
wherein said photovoltaic power system is diagnosed as normal if the following
condition is satisfied, a base value (b) times a correction factor (v) times a
lower limit diagnosis factor (r) is less than an actual measured value which is
less than the base value (b) times the correction factor (v) times an upper limit
diagnosis factor (s).
2. The diagnosis method according to claim 1, wherein
the installation condition of said photovoltaic power system includes, at least,
one of the following installation site, installation direction, installation angle
and configuration.
3. The diagnosis method according to claim 1, further comprising the step of:
diagnosing the cause, in the case that the output of said photovoltaic power
system is abnormal, based on the comparison result.
4. The diagnosis method according to claim 1, wherein
the reference output characteristic and the output characteristic include, at
least, one of the following: direct current voltage, alternating current voltage,
direct current electric energy and alternating current electric energy.
5. The diagnosis method according to claim 1, wherein
said reference output characteristic vary in accordance with actually measured
output characteristic.
6. A method for diagnosing the normality/abnormality of an output of an installed
photovoltaic power system, comprising the steps of:
calculating a reference output characteristic chronologically at the time of
normal operation of the photovoltaic power system itself in accordance with an
installation condition of said photovoltaic power system;
measuring an output characteristic chronologically in said photovoltaic power
system obtained during operation of the photovoltaic power system itself;
comparing the calculated reference output characteristic chronologically with
the measured output characteristic; and
diagnosing the normality/abnormality of the output of said photovoltaic power
system based on the comparison result,
wherein comparisons of the reference output characteristic and the measured output
characteristic are performed at different time points of a day,
wherein said photovoltaic power system is diagnosed as normal if the following
condition is satisfied, a base value (b) times a correction factor (v) times a
lower limit diagnosis factor (r) is less than an actual measured value which is
less than the base value (b) times the correction factor (v) times an upper limit
diagnosis factor (s).
7. The diagnosis method according to claim 6, wherein
the installation condition of said photovoltaic power system includes, at least,
one of the following: installation site, installation direction, installation angle
and configuration.
8. The diagnosis method according to claim 6, further comprising the step of:
diagnosing the cause, in the case that the output of said photovoltaic power
system is abnormal, based on the comparison result.
9. The diagnosis method according to claim 6, wherein
the reference output characteristic and the output characteristic include, at
least, one of the following: direct current voltage, alternating current voltage,
direct current electric energy and alternating current electric energy.
10. A method for diagnosing the normality/abnormality of an output of a photovoltaic
power system, comprising the step of:
diagnosing the normality/abnormality of the output of said photovoltaic power
system during operation based on the past measurement result of an output characteristic
chronologically of said photovoltaic power system itself,
wherein comparisons of the reference output characteristic and the measured output
characteristic are performed at different time points of a day,
wherein said photovoltaic power system is diagnosed as normal if the following
condition is satisfied, a base value (b) times a correction factor (v) times a
lower limit diagnosis factor (r) is less than an actual measured value which is
less than the base value (b) times the correction factor (v) times an upper limit
diagnosis factor (s).
11. The diagnosis method according to claim 10, wherein
said reference output characteristic vary in accordance with actually measured
output characteristic.
12. A method for diagnosing the normality/abnormality of an output of a photovoltaic
power system, comprising the steps of:
obtaining a reference output characteristic chronologically at the time of normal
operation of the photovoltaic power system itself in accordance with past measurement
result of an output characteristic of said photovoltaic power system;
measuring an output characteristic chronologically in said photovoltaic power
system during operation of the photovoltaic power system itself;
comparing the obtained reference output characteristic chronologically with the
measured output characteristic; and
diagnosing the normality/abnormality of the output of said photovoltaic power
system based on the comparison result,
wherein comparisons of the reference output characteristic and the measured output
characteristic are performed at different time points of a day,
wherein said photovoltaic power system is diagnosed as normal if the following
condition is satisfied, a base value (b) times a correction factor (v) times a
lower limit diagnosis factor (r) is less than an actual measured value which is
less than the base value (b) times the correction factor (v) times an upper limit
diagnosis factor (s).
13. The diagnosis method according to claim 12, wherein
the reference output characteristic is obtained differently for each period of
time among the plurality of periods of time gained by dividing a year.
14. The diagnosis method according to claim 12, wherein
in the case that the output of said photovoltaic power system is diagnosed as
being abnormal the output characteristic at that time is not reflected in the subsequent
reference output characteristic, the output characteristic at that time output
of said photovoltaic power system is diagnosed as being normal the output characteristic
at that time is reflected in the subsequent reference output characteristic.
15. The diagnosis method according to claim 12, further comprising the step of:
diagnosing the cause, in the case that the output of said photovoltaic power
system is abnormal, based on the comparison result.
16. The diagnosis method according to claim 12, wherein
the reference output characteristic and the output characteristic include, at
least, one of the following: direct current voltage, alternating current voltage,
direct current electric energy and alternating current electric energy.
17. A method for diagnosing the normality/abnormality of an output of a photovoltaic
power system, comprising the steps of:
obtaining a reference output characteristic at the time of normal operation of
a first photovoltaic power system to be diagnosed in accordance with a measurement
result of output characteristic of a second photovoltaic power system, said first
and second photovoltaic power system being installed at different sites;
measuring an output characteristic in said first photovoltaic power system during
operation;
comparing the obtained reference output characteristic with the measured output
characteristic; and
diagnosing the normality/abnormality of the output of said first photovoltaic
power system based on the comparison result,
wherein comparisons of the reference output characteristic and the measured output
characteristic are performed at different time points of a day.
18. An apparatus for carrying out a diagnosis of the normality/abnormality of
an output of an installed photovoltaic power system and/or a diagnosis of the cause
whenever the output of said photovoltaic power system is abnormal, comprising:
a storage unit for storing a reference output characteristic chronologically
at a time of normal operation of the photovoltaic power system itself in accordance
with an installation condition of said photovoltaic power system;
a measurement unit for measuring an output characteristic chronologically in
said photovoltaic power system during operation of the photovoltaic power system
itself; and
a comparison unit for comparing the reference output characteristic chronologically
stored in said storage unit with the measured the output characteristic obtained
by said measurement unit,
wherein said photovoltaic power system is diagnosed as normal only if said measured
output characteristic is greater than a first predetermined value and less than
a second predetermined value, said first and second predetermined values being
based on said reference output characteristic,
wherein comparisons of the reference output characteristic and the measured output
characteristic are performed at different time points of a day,
wherein said photovoltaic power system is diagnosed as normal if the following
condition is satisfied, a base value (b) times a correction factor (v) times a
lower limit diagnosis factor (r) is less than an actual measured value which is
less than the base value (b) times the correction factor (v) times an upper limit
diagnosis factor (s).
19. The diagnosis apparatus according to claim 18, further comprising:
a storage unit for storing the output characteristic measured by said measurement
unit.
20. The diagnosis apparatus according to claim 18, further comprising:
a solar radiation amount measurement unit for measuring an amount of solar radiation
in said photovoltaic power system.
21. An apparatus for carrying out a diagnosis of the normality/abnormality of
an output of an installed photovoltaic power system and/or a diagnosis of the cause
in the case that the output of said photovoltaic power system is abnormal, comprising:
an input unit for accepting an input of an installation condition of said photovoltaic
power system; and that the and
a calculation unit for calculating a reference output characteristic chronologically
of said photovoltaic power system itself, in accordance with the installation condition
inputted to said input unit;
a measurement unit for measuring an output characteristic chronologically in
said photovoltaic power system during operation of the photovoltaic power system
itself; and
a comparison unit for comparing the reference output characteristic chronologically
calculated by said calculation unit with the measured output characteristic obtained
by said measurement unit,
wherein comparisons of the reference output characteristic and the measured output
characteristic are performed at different time points of a day,
wherein said photovoltaic power system is diagnosed as normal if the following
condition is satisfied, a base value (b) times a correction factor (v) times a
lower limit diagnosis factor (r) is less than an actual measured value which is
less than the base value (b) times the correction factor (v) times an upper limit
diagnosis factor (s).
22. The diagnosis apparatus according to claim 21, further comprising:
a storage unit for storing output the characteristic measured by said measurement
unit.
23. The diagnosis apparatus according to claim 21, further comprising:
a solar radiation amount measurement unit for measuring an amount of solar radiation
in said photovoltaic power system.
24. An apparatus for carrying out a diagnosis of the normality/abnormality of
an output of a photovoltaic power system, comprising:
a storage unit for storing a past measurement result of an output characteristic
chronologically of said photovoltaic power system itself; and
a diagnosis unit for diagnosing the normality/abnormality of the output of said
photovoltaic power system based on the measurement result of the photovoltaic power
system itself stored in said storage unit,
wherein comparisons of the reference output characteristic and the measured output
characteristic are performed at different time points of a day,
wherein said photovoltaic power system is diagnosed as normal if the following
condition is satisfied, a base value (b) times a correction factor (v) times a
lower limit diagnosis factor (r) is less than an actual measured value which is
less than the base value (b) times the correction factor (v) times an upper limit
diagnosis factor (s).
25. The diagnosis apparatus according to claim 24, further comprising:
a determination unit for determining the cause of the abnormality in the case
the output of said photovoltaic power system is diagnosed, by said diagnosis unit,
as being abnormal.
26. The diagnosis apparatus according to claim 24, further comprising:
a solar radiation amount measurement unit for measuring an amount of solar radiation
in said photovoltaic power system.
27. A method for diagnosing the normality/abnormality of an output of an installed
photovoltaic power system, comprising the steps of:
comparing a reference output characteristic chronologically obtained in accordance
with an installation condition of said photovoltaic power system with a measured
output characteristic in said photovoltaic power system obtained during operation
of the photovoltaic power system itself; and
diagnosing the normality/abnormality of the output of said photovoltaic power
system based on the comparison result,
wherein said photovoltaic power system is diagnosed as normal only if said measured
output characteristic is greater than a first predetermined value and less than
a second predetermined value, said first and second predetermined values being
based on said reference output characteristic,
wherein comparisons of the reference output characteristic and the measured output
characteristic are performed at different time points of a day,
wherein said photovoltaic power system is diagnosed as normal if the following
condition is satisfied, a base value (b) times a correction factor (v) times a
lower limit diagnosis factor (r) is less than an actual measured value which is
less than the base value (b) times the correction factor (v) times an upper limit
diagnosis factor (s).
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method and an apparatus for diagnosing a photovoltaic
power system provided in a house, or the like and, in particular to a diagnosis
method and a diagnosis apparatus of a photovoltaic power system which diagnoses
the normality/abnormality of the output and which, if necessary, diagnoses the
cause of the abnormality.
2. Description of the Related Art
Conventionally, photovoltaic power, which has very little effect
on the earth's environment and which generates electricity through the use of solar
energy has been considered the most promising clean energy for the future, unlike
thermal power generation in which fossil fuels undergo combustion and in which
large amounts of carbon dioxide are discharged leading to global warming, hydroelectric
power generation which has the difficulty of securing installation sites or atomic
power generation which has the problem of the disposal of waste, or the like. In
recent years, the spread to residential houses of the photovoltaic power system
has expanded in accordance with the introduction of financial assistance from public organizations.
Such a photovoltaic power system comprises a solar battery panel, having a plurality
of solar battery cells electrically connected in series, which is mounted on a
roof, or the like; an inverter, which converts the direct current output from the
solar battery panel to an alternating current output; and wires, which make connections
between the solar battery panel and the inverter as well as between the inverter
and the loads. Then, when the solar rays irradiate the solar battery panel, a photovoltaic
conversion is carried out in each solar battery cell and these conversion outputs
are collected so as to generate direct current power and, then, this direct current
power is converted to alternating current power by the inverter so as to be supplied
to the loads.
In order to stably gain a desired electric energy to be supplied to the loads,
it is necessary to monitor whether or not the photovoltaic power system operates
normally so as to take measures after quickly discovering the cause in the case
that it is found that the output is abnormal. However, a system wherein the diagnosis,
of whether or not the operation of the photovoltaic power system is normal, is
carried out simply and with a high precision has not yet been constructed. Though
a variety of methods for detecting abnormalities of each component of a solar power
system have been conventionally known, there is a problem that, in the case that
the output of the photovoltaic power system is abnormal, the work of the discovery
of the cause by inspecting each component using such methods takes a long period
of time. In addition, there is a problem in that the work of the discovery of the
cause cannot be carried out in the case that the output of the system becomes abnormal
in spite of the fact that each component operates normally.
SUMMARY OF THE INVENTION
One object of the present invention is to provide a diagnosis method and a diagnosis
apparatus of photovoltaic power system which can easily and precisely diagnose
the normality/abnormality of the output of the photovoltaic power system.
Another object of the present invention is to provide a diagnosis method
and a diagnosis apparatus of photovoltaic power system which can not only diagnose
the normality/abnormality of the output but can also quickly diagnose the cause
of the abnormality.
Still another object of the present invention is to provide a diagnosis method
and a diagnosis apparatus of photovoltaic power system which can easily diagnose
a cause other than the abnormality of the components.
In a diagnosis method and apparatus according to the first aspect of the invention,
a reference output characteristic at the time of normal operation that is obtained
in accordance with the installation condition and an output characteristic obtained
during actual operation are compared and the comparison result is evaluated to
diagnose the normality/abnormality of the output of the photovoltaic power system.
Therefore, a precise diagnosis result can be quickly obtained.
In a diagnosis method and apparatus according to a second aspect of the invention,
the reference output characteristic at the time of normal operation is calculated
in accordance with the installation condition and the calculated reference output
characteristic and the output characteristic which has actually been measured are
compared and the comparison result is evaluated in order to diagnose the normality/abnormality
of the output of the photovoltaic power system. Accordingly, the reference output
characteristic is calculated in accordance with the installation condition and,
therefore, it is not necessary to store, in a memory, a large number of reference
output characteristics in accordance with a variety of installation conditions
so as to be able to correspond to all installation conditions.
According to a third aspect of the invention, as for the installation condition
of the photovoltaic power system according to the first or the second aspect of
the invention, site (longitude, latitude, topography, meteorological condition,
or the like), direction (16 directions), angle (inclination angle with respect
to the ground), configuration (types of solar batteries, number of cells in series,
total area of cells (panel area)) are used. Accordingly, precise data of the reference
output characteristic can be obtained and, together with that, the diagnosis result
becomes precise.
According to a fourth aspect of the present invention, the output characteristic
measured in the first or second aspect of the invention is stored in a memory.
Accordingly, a diagnosis process can be carried out at an arbitrary point of time.
In a diagnosis method and apparatus according to a fifth aspect of the invention,
a past output characteristic is preserved and this output characteristic is taken
into consideration in diagnosing the normality/abnormality of the photovoltaic
power system. Accordingly, a precise diagnosis result can be quickly obtained by
taking into consideration the effect of the characteristic particular to the photovoltaic
power system to be diagnosed.
In a diagnosis method and apparatus according to a sixth aspect of the invention,
the reference output characteristic at the time of normal operation is obtained
in accordance with the past output characteristic and the obtained reference output
characteristic and the output characteristic which has actually been measured are
compared so that the comparison result is taken into consideration so as to diagnose
the normality/abnormality of the output of the photovoltaic power system. Accordingly,
the reference output characteristic is obtained in accordance with the actual output
characteristic of the past and, therefore, the optimal reference output characteristic
suitable for each photovoltaic power system can be easily obtained so as to quickly
obtain a precise diagnosis result.
According to a seventh aspect of the invention, the reference output characteristic
is made to be different for each of a plurality of time periods, gained by dividing
up a year in the sixth aspect of the invention. The output characteristic in a
photovoltaic power system is easily influenced by seasonal changes in the meteorological
condition (air temperature, solar radiation time, sun altitude, or the like). Therefore,
a standard output characteristic suitable for the meteorological condition is set
for each of a plurality of time periods (monthly unit, seasonal unit, or the like)
in a year. Accordingly, the reference output characteristic which is always optimal
throughout the year can be obtained so as to quickly obtain a precise diagnosis result.
In an eighth aspect of the invention, only the output characteristic at the time
of the normal case, as a result of a diagnosis in the sixth or the seventh aspect
of the invention, is reflected in the reference output characteristic for the next
time. Accordingly, the output characteristic of the abnormal case is not reflected
in the reference output characteristic for the next time and, therefore, a reference
output characteristic with a high precision can always be obtained.
In a diagnosis method and apparatus according to a ninth aspect of the invention,
the reference output characteristic used for the diagnosis of the normality/abnormality
of the first photovoltaic power system of to be diagnosed is obtained in accordance
with the output characteristic of the second photovoltaic power system. Accordingly,
even in the first photovoltaic power system which is newly set, the reference output
characteristic thereof is obtained by considering the output characteristic of
the second photovoltaic power system during actual operation which has a similar
installation condition and system characteristic and, therefore, a precise reference
output characteristic can easily be obtained.
In a diagnosis method and apparatus according to a tenth aspect of the invention,
the comparison result of comparing the reference output characteristic at the time
of normal operation with the output characteristic during actual operation, in
the first to the ninth aspects of the invention, is considered so as to diagnose
the cause of the case where the output is abnormal. Accordingly, the cause of the
abnormality can be quickly discovered so as to take immediate measures.
In a diagnosis method and apparatus according to an eleventh aspect of the invention,
as for the reference output characteristic and the output characteristic in the
first to the tenth aspects of the invention, a direct current voltage, an alternating
current voltage, a direct current electric energy, an alternating current electric
energy, or the like, are used. Accordingly, a diagnosis can be carried out from
multiple points of view and not only the cause resulting from the abnormality of
a component but also other causes can be diagnosed.
In a diagnosis method and apparatus according to a twelfth aspect of the invention,
the actual amount of solar radiation during the operation of the photovoltaic power
system is measured. Accordingly, data of the amount of solar radiation can be acquired
as the data for diagnosis so as to carry out a diagnosis from a greater number
of multiple points of view.
The above and further objects and features of the invention will more fully be
apparent from the following detailed description with accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram showing a first embodiment of the present invention
in which a diagnosis of a photovoltaic power system is carried out by using a diagnosis
apparatus of photovoltaic power system;
FIG. 2 is a flow chart showing an operation procedure of the diagnosis apparatus
of photovoltaic power system according to the first embodiment;
FIG. 3 is a schematic diagram showing a second embodiment of the present invention
in which a diagnosis of a photovoltaic power system is carried out by using a diagnosis
apparatus of photovoltaic power system;
FIG. 4 is a flow chart showing an operation procedure of the diagnosis apparatus
of photovoltaic power system according to the second embodiment;
FIG. 5 is a schematic view showing a third embodiment of the present invention
in which a diagnosis of a photovoltaic power system is carried out by using a diagnosis
apparatus of photovoltaic power system;
FIG. 6 is a flow chart showing an operation procedure of the diagnosis apparatus
of photovoltaic power system according to the third embodiment;
FIG. 7 is a flow chart showing a procedure of a diagnosis process according
to the present invention;
FIG. 8 is a flow chart showing a procedure of a diagnosis process according
to the present invention;
FIG. 9 is a graph showing the relationship between the reference output characteristic
(direct current voltage) at the time of normal operation and the actually measured
output characteristic (direct current voltage);
FIG. 10 is a graph showing the relationship between the reference output characteristic
(direct current voltage) at the time of abnormal operation and the actually measured
output characteristic (direct current voltage);
FIG. 11 is a graph showing the relationship between the reference output characteristic
(electric energy) at the time of normal operation and the actually measured output
characteristic (electric energy); and
FIG. 12 is a graph showing the relationship between the reference output characteristic
(electric energy) at the time of abnormal operation and the actually measured output
characteristic (electric energy).
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE PRESENT INVENTION
In the following, the present invention is described based on the drawing showing
the preferred embodiments.
First Embodiment
FIG. 1 is a schematic diagram showing the first embodiment in which a diagnosis
of a photovoltaic power system is carried out by using a diagnosis apparatus of
photovoltaic power system according to the present invention.
A solar battery panel 21 which has a plurality of solar battery cells 20
electrically connected in series is attached to the roof 31 of a house 30
at a predetermined angle with respect to the ground surface. A wire 22 for
taking out the output of the solar battery panel 21 is connected to a power
adjuster 24 which has an inverter 23 for converting a direct current
output to an alternating current output. In addition, a wire 25 for the
output from the power adjuster 24 is connected to a load 26, comprising
a variety of electric appliances.
When solar rays irradiate the solar battery panel 21, photovoltaic conversion
is carried out in each of the solar battery cells 20 and these conversion
outputs are collected so as to generate a direct current power which is converted
into an alternating current power by an inverter 23 so that the converted
alternating current power is supplied to the load 26.
The diagnosis apparatus of photovoltaic power system according to the first embodiment
has a measurement unit 1, a diagnosis unit 2, a diagnosis reference
value storage unit 3, a diagnosis factor storage unit 4, a program
storage unit 5, a measurement data memory unit 6, an output unit
7 and a pyrheliometer 8.
The measurement unit 1 measures the value of the output characteristic
of the photovoltaic power system during operation. More specifically, the measurement
unit 1 chronographically measures the value of the output characteristic
(direct current voltage, direct current) before the conversion by the inverter
23 and the output characteristic (alternating current voltage, alternating
current, electric power, electric energy) after the conversion. In addition, the
measurement unit 1 measures the amount of solar radiation detected by the
pyrheliometer 8 installed on the roof 31. Those measured values are
stored in the measurement data memory unit 6. Here, each of these measured
values is averaged during one segment of one hour so as to be stored in the measurement
data memory unit 6. In addition, an abnormal signal of the inverter outputted
from the inverter 23 whenever an abnormality occurs in the inverter 23
is also stored in the measurement data memory unit 6.
The diagnosis reference value storage unit 3 stores diagnosis reference
values as a plurality of reference output characteristics obtained in advance in
accordance with a variety of installation conditions of the photovoltaic power
system. Parameters for these reference output characteristics are the same types
of parameters of the characteristic measured in the measurement unit 1 which
are stored in the measurement data memory unit 6. In addition, as for the
installation condition of the photovoltaic power system at this time, the installation
site (longitude, latitude, topography, meteorological condition, or the like),
the installation direction (16 directions), the installation angle (inclination
angle with respect to the ground surface), the configuration (types of solar batteries,
number of cells in series, total area of cells (panel area)), and the like, are used.
The diagnosis factor storage unit 4 stores a diagnosis factor used at
the time of diagnosis of the normality/abnormality and diagnosis of the cause of
the abnormality in the photovoltaic power system. The program storage unit 5
stores an operation program for carrying out these diagnosis processes.
The diagnosis unit 2 reads out the actual characteristic (measured value)
gained by the measurement unit 1 from the measurement data memory unit 6
in accordance with the operation program stored in the program storage unit 5
and, at the same time, reads out the diagnosis reference value and the diagnosis
factor, respectively, from the diagnosis reference value storage unit 3
and the diagnosis factor storage unit 4 so as to compare the actual measured
value which has been read out with the result of multiplication of the diagnostic
reference value by the diagnosis factor and, then, diagnoses the normality/abnormality
of the output of the photovoltaic power system based on that comparison result
and, at the same time, diagnoses the cause of the abnormal case. The output unit
7 outputs and displays the diagnosis result by the diagnosis unit 2.
Here, for example, in the case that the above measurement unit 1 and
the diagnosis unit 2 are configured by a CPU, the diagnosis reference value
storage unit 3, the diagnosis factor storage unit 4, the program
storage unit 5 and the measurement data memory unit 6 are configured
of a hard disc device and the output unit 7 is configured of a liquid crystal
display, the diagnosis apparatus of photovoltaic power system according to the
first embodiment can be configured by one personal computer for all of the function
parts, except for the pyrheliometer 8. Or, the above CPU and the hard disc
device may be provided within the power adjuster 24 and the output unit
7 alone may be provided within the house.
Next, the operation of the diagnosis apparatus of photovoltaic power system
according to the first embodiment having the above configuration is described in
reference to the flow chart of FIG. 2 which shows the procedure thereof.
The values of the characteristic (direct current voltage, direct current, alternating
current voltage, alternating current, electric power, electric energy, amount of
solar radiation, or the like) of the photovoltaic power system during operation
is measured by the measurement unit 1 (Step S1). Then, these measured
values are averaged with a unit of one hour and the averaged measured value is
stored in the measurement data memory unit 6 (Step S2).
The actual characteristic (measured value) gained by the measurement unit 1
is read out from the measurement data memory unit 6 and, at the same time,
the diagnosis reference value and the diagnosis factor are read out from the diagnosis
reference value storage unit 3 and the diagnosis factor storage unit 4
(Step S3). Based on these pieces of information which have been read out,
the normality/abnormality of the output of the photovoltaic power system is diagnosed
and, at the same time, the cause is also diagnosed in the abnormal case (Step S4).
Here, in this diagnosis process, in the case that the lower limit diagnosis factor
and the upper limit diagnosis factor are, respectively, denoted as r and s, the
diagnosis has a result of normal when the condition of the following (1) is satisfied,
of which the diagnosis process is described later in detail. The gained diagnosis
result is outputted and displayed in the output unit 7 (Step S5).
Second Embodiment
FIG. 3 is a schematic diagram showing the second embodiment in which a diagnosis
of a photovoltaic power system is carried out by using a diagnosis apparatus of
photovoltaic power system according to the present invention. Here, in FIG. 3,
the same or similar elements as in FIG. 1 are denoted as the same numerals, of
which the descriptions are omitted.
The diagnosis apparatus of photovoltaic power system according to the second
embodiment has a measurement unit 1, a diagnosis unit 2, a diagnosis
reference value calculation unit 11, a diagnosis factor storage unit 4,
a program storage unit 5, a measurement data memory unit 6, an output
unit 7, a pyrheliometer 8 and an input unit 12.
The input unit 12 accepts an external inputs of the installation condition
of the photovoltaic power system. The installation condition of the photovoltaic
power system at this time includes the installation site (longitude, latitude,
topography, meteorological condition, or the like), the installation direction
(16 directions), the installation angle (inclination angle with respect
to the ground surface), the configuration (types of solar batteries, number of
cells in series, total area of cells (panel area)), or the like.
The diagnosis reference value calculation unit 11 calculates the diagnosis
reference value as the reference output characteristic at the time of normal operation
in accordance with the installation condition of the photovoltaic power system
accepted by the input unit 12. These calculated parameters of the reference
output characteristic are the same types of parameters of the output characteristic
measured by the measurement unit 1 which are stored in the measurement data
memory unit 6.
The diagnosis unit 2 reads out the actual characteristic (measured value)
gained by the measurement unit 1 from the measurement data memory unit 6
in accordance with the operation program stored in the program storage unit 5
and, at the same time, reads out the diagnosis factor from the diagnosis factor
storage unit 4 so as to compare the actual measured value which has been
read out with the result of multiplication of the diagnosis reference value calculated
by the diagnosis reference value calculation unit 11 by the read out diagnosis
factor, and then diagnoses the normality/abnormality of the output of the photovoltaic
power system based on that comparison result and, at the same time, diagnoses the
cause of the abnormal case.
Here, for example, in the case that the above measurement unit 1, the
diagnosis unit 2 and the diagnosis reference value calculation unit 11
are configured by a CPU, the diagnosis factor storage unit 4, the program
storage unit 5 and the measurement data memory unit 6 are configured
of a hard disk device, the output unit 7 is configured by a liquid crystal
display and the input unit 12 is configured by a keyboard, the diagnosis
apparatus of photovoltaic power system according to the second embodiment can be
configured by one personal computer for all of the function parts, except for the
pyrheliometer 8. Alternatively, the above CPU and the hard disc device may
be provided within the power adjuster 24 and the output unit 7 alone
may be provided within the house.
Next, the operation of the diagnosis apparatus of photovoltaic power system
according to the second embodiment that has such a configuration is described in
reference to the flow chart of FIG. 4 which shows the procedure thereof.
The values of the characteristic (direct current voltage, direct current, alternating
current voltage, alternating current, electric power, electric energy, amount of
solar radiation, and the like) of the photovoltaic power system during operation
are measured by the measurement unit 1 (Step S11). Then, these measured
values are averaged with a unit of one hour so that the averaged measured value
is stored in the measurement data memory unit 6 (Step S12).
The installation condition of the photovoltaic power system is inputted via the
input unit 12 (Step S13). The diagnosis reference value as the reference
output characteristic at the time of normal operation is calculated by the diagnosis
reference value calculation unit 11 in accordance with the inputted installation
condition (Step S14).
The actual characteristic (measured value) gained by the measurement unit 1
is read out from the measurement data memory unit 6 and, at the same time,
the diagnosis factor is read out from the diagnosis factor storage unit 4
(Step S15). Based on these pieces of information which have been read out
and the calculated diagnosis reference value, the normality/abnormality of the
output of the photovoltaic power system is diagnosed and at the same time, in the
abnormal case, the cause thereof is also diagnosed (Step S16). Here, the
diagnosis has a result of normal when the condition of the above (1) is satisfied
and this diagnosis process is later described in detail. The gained diagnosis result
is outputted and displayed in the output unit 7 (Step S17).
Third Embodiment
FIG. 5 is a schematic diagram showing the third embodiment in which a diagnosis
of a photovoltaic power system is carried out by using a diagnosis apparatus of
photovoltaic power system according to the present invention. Here, in FIG. 5,
the same or similar elements as in FIG. 1 or FIG. 3 are denoted by the same numerals,
of which the descriptions are omitted.
The diagnosis apparatus of photovoltaic power system according to the third embodiment
has a measurement unit 1, a diagnosis unit 2, a diagnosis factor
storage unit 4, a program storage unit 5, a measurement data memory
unit 6, an output unit 7, a pyrheliometer 8, a base value
storage part 13 and a correction factor storage unit 14.
The base value storage unit 13 stores twelve types of base values (B)
for respective months which become bases for obtaining the diagnosis reference
values for respective months as the reference output characteristic. These base
values are obtained in advance by taking into the consideration a variety of installation
conditions of a photovoltaic power system as described above, in particular the
meteorological condition for each month. The correction factor storage part 14
stores the correction factor (v) for correcting the base value in accordance with
the value of the actual output characteristic due to the operation of the photovoltaic
power system for many years. This correction factor is rewritten by the diagnosis
unit 2 in accordance with the value of the output characteristic in the
case that the photovoltaic power system has gained a normal output. Here, at the
initial year, the correction factor v=1 is stored. In addition, in the course of
operation of the photovoltaic power system for years, the diagnosis factors (r,
s) stored in the diagnosis factor storage unit 4 are also rewritten by the
diagnosis unit 2. Here, at the initial year, for example, the diagnosis
factors r=0.7, s=1.3 are stored.
The diagnosis unit 2, in accordance with the operation program stored
in the program storage unit 5, obtains the diagnosis reference value by
multiplying the base value read out from the base value storage unit 13
by the correction factor read out from the correction factor storage unit 14
and compares the actual measured value at present which has been read out from
the measurement data memory unit 6 with the result of multiplication of
that obtained diagnosis reference value by the diagnosis factor read out from the
diagnosis factor storage unit 4, and then diagnoses the normality/abnormality
of the output of the photovoltaic power system based on that comparison result
and, at the same time, diagnoses the cause of the abnormal case.
Here, for example, in the case that the above measurement unit 1 and
the diagnosis unit 2 are configured by a CPU, the diagnosis factor storage
unit 4, the program storage unit 5, the measurement data memory unit
6, the base value storage unit 13 and the correction factor storage
unit 14 are configured by a hard disk device and the output unit 7
is configured by a liquid crystal display, the diagnosis apparatus of photovoltaic
power system according to the third embodiment can be configured by one personal
computer for all of the function parts, except for the pyrheliometer 8.
Alternatively, the above CPU and the hard disc device may be provided within the
power adjuster 24 and the output unit 7 alone may be provided within
the house.
Next, the operation of the diagnosis apparatus of photovoltaic power system
according to the third embodiment that has such a configuration is described in
reference to the flow chart of FIG. 6 which shows the procedure thereof.
The values of the characteristic (direct current voltage, direct current, alternating
current voltage, alternating current, electric power, electric energy, amount of
solar radiation, and the like) of the photovoltaic power system during operation
are measured by the measurement unit 1 (Step S21). Then, these measured
values are averaged with a unit of one hour so that the averaged measured value
is stored in the measurement data memory unit 6 (Step S22).
The base value and the correction factor are respectively read out from the base
value storage unit 13 and the correction factor storage unit 14 (Step
S23) and they are multiplied with each other so as to obtain a diagnosis
reference value as the reference output characteristic (Step S24). The actual
measured value gained by the measurement unit 1 is read out from the measured
data memory unit 6 and, at the same time, the diagnosis factor is read out
from the diagnosis factor storage unit 4 (Step S25). Based on these
pieces of information which have read out and the obtained diagnosis reference
value, the normality/abnormality of the output of the photovoltaic power system
is diagnosed and, at the same time, in the abnormal case, the cause thereof is
diagnosed (Step S26). At this time, the diagnosis has a result of normal
when the condition of the above (1) is satisfied while the diagnosis has a result
of abnormal in other cases. Here, the diagnosis process of the cause is later described
in detail.
Whether or not the diagnosis result is normal is determined (Step S27)
and, in the abnormal case (S27: NO), the output unit 7 outputs and
makes a display to that effect (Step S31) so as to complete the process
as it is.
On the other hand, in the normal case (S27: YES), after the output unit
7 outputs and makes a display to that effect (Step S28), the correction
factor is changed in accordance with the actual measured value at that time so
that the new correction factor is written into the correction factor storage unit
14 (Step S29) and, at the same time, the diagnosis factor is also
changed and the new diagnosis factor is written into the diagnosis factor storage
unit 4 (Step S30).
In the following, an example of this diagnosis process in the third embodiment
is described. Here, the output characteristic which becomes the diagnosis reference
is assumed to be electric energy, the diagnosis process in January of every year
(for three years) is described.
<First Year>
The base value B=100 kWh is stored in the base value storage unit 13,
the correction factor v=1 is stored in the correction factor storage unit 14,
the lower limit diagnosis factor r=0.7 and the upper limit diagnosis factor s=1.3
are stored in the diagnosis factor storage unit 4, respectively, as initial
values. By multiplying this base value B=100 kWh by the correction factor v=1,
the diagnosis reference value 100 kWh is obtained (S24). The actual measured
value is assumed to be 120 kWh. In this case, the condition of the above (1) is
satisfied as shown in (2) below and, therefore, the electric energy is diagnosed
as normal (S26).
Because the diagnosis has the result of normal (S27: YES), "normal"
is outputted and displayed in the output unit 7 (S28). In addition,
the correction factor v of the correction factor storage unit 14 is changed
(S29). More specifically, the average value 1.1 between actual measured
value (120)÷base value (100)=1.2 and present v=1 is written
into the correction factor storage unit 14 as a new correction factor v.
In addition, the diagnosis factors r, s of the diagnosis factor storage unit 4
are changed (S30). More specifically, because the actual measured value
is reflected for the correction factor, the diagnosis factors r, s are both made
closer to 1 by 0.01 so as to be r=0.71, s=1.29, which are written into the diagnosis
factor storage unit 4.
<Second Year>
At this point in time, the base value B=100 kWh is stored in the base value storage
unit 13, the correction factor v=1.1 is stored in the correction factor
storage unit 14, the lower limit diagnosis factor r=0.71 and the upper limit
diagnosis factor s=1.29 are stored in the diagnosis factor storage unit 4,
respectively. By multiplying this base value B=100 kWh by the correction factor
v=1.1, the diagnosis reference value 110 kWh is obtained (S24). The actual
measured value is assumed to be 77 kWh. In this case, the condition of the above
(1) is not satisfied as the following (3) and, therefore, the electric energy is
diagnosed as abnormal (S26).
Because the diagnosis has the result of abnormal (S27: NO), "abnormal"
is outputted and displayed in the output unit 7 (S31). Here, because
the abnormality is obtained, the correction factor and the diagnosis factor are
not changed.
<Third Year>
At this point in time, in the same manner as in the second year, the base value
B=100 kWh is stored in the base value storage unit 13, the correction factor
v=1.1 is stored in the correction factor storage unit 14, the lower limit
diagnosis factor r=0.71 and the upper diagnosis factor s=1.29 are stored in the
diagnosis factor storage unit 4, respectively. By multiplying this base
value B=100 kWh by the correction factor v=1.1, the diagnosis reference value 110
kWh is obtained (S24). The actual measured value is assumed to be 130 kWh.
In this case, the condition of the above (1) is satisfied as in the following (4)
and, therefore, the electric energy is diagnosed as normal (S26).
Because the diagnosis has the result of normal (S27: YES), "normal"
is outputted and displayed in the output unit 7 (S28). In addition,
the correction factor v of the correction factor storage unit 14 is changed
(S29). More specifically, the average value 1.2 between actual measured
value (130)÷base value (100)=1.3 and present v=1.1 is written
into the correction factor storage unit 14 as a new correction factor v.
In addition, the diagnosis factors r, s of the diagnosis factor storage unit 4
are changed (S30). More concretely, since the actual measured value is reflected
for the correction factor, the diagnosis factors r, s are both further made closer
to 1 by 0.01 so as to be r=0.72, s=1.28, which are written into the diagnosis factor
storage unit 4.
Here, though in this third embodiment the base value stored in the base value
storage unit 13 is assumed not to change, it is preferable to change the
base value to correspond to changes in the surrounding environment in the case
that those changes are large, such as the construction of a large building in the
neighborhood. At this time, as for the changed base value, a simulation result
which is obtained again after taking respective conditions into consideration in
the same manner as in the case of the initial value may be adopted or the actual
measured value after the change of the environment may be adopted. In addition,
though in the specific example of the third embodiment the base value, the diagnosis
reference value, or the like, are made to be different for every month, that period
may be a
