JP3450697B2 - Method and apparatus for measuring ground state of solar cell module - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for measuring the ground state of a solar cell module in a solar power generation system.

[0002]

2. Description of the Related Art In recent years, there has been great expectation for a solar power generation system, which is a clean energy source, due to an increase in awareness of environmental problems and energy problems that develop on a global scale. As the installation form of the solar cells used in such a system, a ground-installed type installed on the field,
There is a roof-mounted type installed on the roof of a house, but a large installation area is required to install a solar cell, and therefore the roof-mounted type that effectively uses the roof of the house is mainstream. Also, in the form of roof installation type, there are mainly a pedestal installation type and a roof material integrated type, but a roof material that has a function as a roof material by stacking solar cells on a steel plate for roof and modularizing them. The number of integrated solar cell modules is increasing.

When constructing a solar power generation system,
By grasping the characteristics of the solar cell module and determining the number of series-parallel solar cell modules so that a desired output can be obtained, a solar cell array is configured.

Generally, the above-mentioned solar cell module is
In order to prevent electric shock due to accidents, breakdowns, etc., or leakage fire, it is desirable to connect the outer metal part (steel plate for roof) of all solar cell modules to the ground electrode, especially to connect to the power supply system without insulation. When using a transformerless inverter, grounding is highly necessary.

[0005]

In performing the grounding work of the solar cell module, it is necessary to accurately confirm whether or not each solar cell module is grounded. Usually, the surface of the solar cell module is a polymer resin,
It is covered with a non-conductive surface protective material such as plastic or glass. Therefore, it is difficult to measure the ground resistance value from the surface of the solar cell module, and it is necessary to measure the ground resistance value from the back surface of the solar cell module.

However, after laying the solar cell module, the outer metal part on the back surface of the solar cell module is hidden, and it is difficult to measure the ground resistance. Therefore,
Every time the solar cell modules are laid one by one, it is necessary to interrupt the solar cell module laying work and measure the ground resistance. Therefore, the workability is poor, the installation period of the solar cell module is extended, and the construction cost is increased.

Therefore, an object of the present invention is to provide a solar cell module.
It is an object of the present invention to provide a measuring method and a measuring device capable of measuring the grounded state of a tool with good workability.

[0008]

In order to achieve this object, the solar cell module grounding state measuring method of the present invention has a surface covered with a non-conductive surface protective material.
And a metal part to be grounded to the ground electrode is provided on the back
A method for measuring a grounding state of a positive battery module, comprising a conductor on the surface of the positive battery module facing the metal part.
The plate was placed, by detecting the current flowing by applying an AC voltage between the conductor plate and the ground electrode, wherein the benzalkonium measuring the grounding condition of the metal part.

The surface of the solar cell module grounded state measuring device of the present invention is covered with a non-conductive surface protective material.
Overturned, provided the metal parts to be grounded to a ground electrode on the back surface
A solar cell module ground condition measuring device,
A conductive plate that is <br/> arranged the metal portion and opposed to the surface of serial solar cell module, by detecting a current flowing by applying an AC voltage between the conductor plate and the ground electrode,
And a measuring unit for measuring a grounding state of the metal portion.

In this structure, if the metal portion of the solar cell module to be grounded is securely connected to the grounding electrode, the current flowing by the application of the AC voltage can be detected, and the solar cell module can be grounded. Can be measured. According to this, since it is not necessary to directly use the metal part to be grounded, the electrode can be arranged on the surface side of the solar cell module after installation, and the grounded state can be measured with good workability.

[0011]

In a preferred embodiment of the present invention, the ground state is measured by measuring the voltage value and frequency of an AC voltage applied between the electrode and the ground electrode, and thereby measuring the electrode and the ground electrode. The relationship is established among the current value of the current flowing between the two, the capacitance value, and the wiring resistance value.

The target solar cell module is, for example, a building material-integrated solar cell module, the surface of which is covered with a non-conductive surface protective material such as glass, polymer resin, plastic, etc. It has a conductor plate. Also, the electrodes are planar and covered with an insulator.

When measuring the grounded state, the flowing current may be detected a plurality of times while changing the frequency of the AC voltage applied between the electrode and the ground electrode. According to this, the grounding state of the solar cell module can be measured even when the electrostatic capacitance between the electrode and the metal portion is unknown.

Further, the measurement result of the grounded state can be notified to the measurer by a buzzer or the like or displayed on a liquid crystal display or the like, so that the measurer can easily and accurately confirm the grounded state of the solar cell module. You may allow it.

[0015]

[Embodiment 1] FIG. 1 is a schematic view showing a solar cell module grounding state measuring method and device according to a first embodiment of the present invention, and FIG. 3 is a schematic block diagram of this device. As shown in these figures, this device forms a capacitance between the roof steel plate 11 to be grounded and the roof steel plate 11 on the solar cell module 10 connected to the ground electrode 50 by the ground wire 51. A conductor plate 20 as an electrode arranged as appropriate, an AC standard voltage generator 30 for applying an AC voltage between the conductor plate 20 and the ground electrode 50, and a high-frequency ammeter 40 for detecting a current flowing thereby. Prepare Figure 3
In the figure, 61 is an operation control means for measuring the ground state based on the voltage value and frequency of the AC voltage applied by the AC standard voltage generator 30 and the current value measured by the AC standard voltage generator 30, and 62 is the It is a display means for displaying the measurement result.

FIG. 2 is a detailed sectional view of the building material integrated solar cell module 10 (Canon made amorphous silicon solar cell module SR-02) whose grounding state is measured. As shown in FIG. 2, the solar cell module 10 has a back surface reflection layer 14, an amorphous silicon semiconductor layer 15, and a transparent conductive layer 16 which are sequentially laminated on a solar cell substrate 13 (here, a stainless steel substrate). Is laminated on a steel plate 11 for a roof with an insulating layer 12 interposed therebetween, and is covered with a surface protective material 17 to form a module. As shown in FIG. 1, the roof steel plate 11 is connected to a ground electrode 50 using a conductor wire (earth wire) 51.

The grounded state of the solar cell module 10 was measured as follows. First, as shown in FIG. 1, a 10 cm × 10 cm conductor plate 20 was used as an electrode and placed on the surface portion of the solar cell module 10 where there was no cell. By placing the conductor plate 20 on the solar cell module 10, the roof steel plate 11 on the back surface of the solar cell module 11
And the conductor plate 20 function as a capacitor having an electrostatic capacity C [F].

Next, the AC standard voltage generator 30 is used to apply a voltage of 10 [V] and a frequency of 1 between the ground electrode 50 and the conductor plate 20.
An AC voltage of 00 [kHz] was applied, and an AC current flowing between the ground electrode 50 and the conductor plate 20 was measured by the high frequency ammeter 40. The applied AC voltage is dangerous if the voltage and the frequency are too high, and a large power supply device is required. Therefore, the voltage is 500 [V] or less and the frequency is 1 [MHz] or less. Is desirable.
The measured current value was 2.51 × 10 ^-1 [A].

Next, the capacitance C between the roof steel plate 11 and the conductor plate 20 at a frequency of 100 [kHz] was measured by a capacitance measuring device. The measured capacitance C was 40 [PF].

Next, based on the above-mentioned applied voltage value, frequency, measured current value, and capacitance, the solar cell module 1
A wiring resistance value R _L between 0 and the ground electrode 50 was obtained. The obtained wiring resistance value R _L [Ω] was 1.6 [Ω]. From this result, it can be seen that the solar cell module 10 is reliably connected to the ground electrode. The wiring resistance value R _L [Ω] can be calculated by the following equation. This equation can be easily derived from Ohm's law.

[0021]

[Equation 1] For comparison, the solar cell module 10 and the ground electrode 5
The conducting wire 51 connected between 0 was removed and the same measurement was performed. As a result, since no current flows between the ground electrode 50 and the conductor plate 20, it is confirmed from the above equation that the ground resistance value R _L = ∞ and the solar cell module 10 is not connected to the ground electrode 50.

Further, by displaying the above-mentioned measurement result on the display means 62 such as a liquid crystal display, the measurer can accurately measure the grounding state of the solar cell module. Further, an alarming means such as a buzzer emits a normal sound when the solar cell module 10 is reliably connected to the ground electrode 50, and an abnormal sound when the solar cell module 10 is not connected, so that the workability can be further measured. it can.

As described above, the conductor plate 20 is placed on the solar cell module 10, an AC voltage is applied from the AC voltage source 30 between the ground electrode 50 and the conductor plate 20, and the current flowing at that time is measured by the ammeter 40. Thereby, the grounded state of the solar cell module 10 can be measured from the surface of the solar cell module 10.

Although the amorphous silicon solar cell manufactured by Canon was used in this embodiment, it is needless to say that the present invention is not limited to this and can be applied to a solar cell module such as a single crystal or a polycrystal. . In addition, in this embodiment, the solar cell module 10 using the conductor plate 20 as an electrode.
Although it was placed on the surface part of the cell where there is no cell, the measurement can be performed on the part with the cell.

[Embodiment 2] Next, a second embodiment of the present invention (a measurement example of a solar cell array on a roof) will be described. In this embodiment, 120 building material-integrated solar cell modules 10 (Canon amorphous silicon solar cell module SR-02) used in Embodiment 1 are used.

First, the solar cell module 10
The solar cell array of 3 kW was constructed by laying on the roof so as to be in series and 6 in parallel. Of this solar array,
Each solar cell module 10 for 5 parallels was connected to the ground electrode 50 using the ground wire 51, and the remaining solar cell modules 10 for 1 parallel were not connected to the ground electrode 50. At this time, each solar cell module 1 connected to the ground electrode 50
The ground resistance value of 0 was 30 [Ω].

Next, regarding the solar cell module 10 connected to the ground electrode 50, first, the conductor plate 20 of 10 cm × 10 cm is placed as an electrode on the cell-free surface portion of the solar cell module 10, and the AC standard voltage generator 30 is used. , An AC voltage having a voltage of 10 [V] and a frequency of 100 [kHz] is applied between the ground electrode 50 and the conductor plate 20, and the ground electrode 5
AC current flowing between 0 and the conductor plate 20
It was measured by 0. The measured current value is 2.51 x 1
It was 0 ^-1 [A].

Next, the capacitance C between the roof steel plate 11 and the conductor plate 20 on the back surface of the solar cell module 10 at a frequency of 100 [kHz] was measured by a capacitance measuring device. The electrostatic capacity C was 40 [PF].

The wiring resistance value R _L [Ω] between the solar cell module and the ground electrode was determined from the above voltage value, frequency, current value, and electrostatic capacity. Wiring resistance value R _L [Ω] is 1.6
It was [Ω]. This shows that the solar cell module 10 is reliably connected to the ground electrode 50. In addition,
The wiring resistance value R _L can be obtained by the equation 1 as in the first embodiment.

Further, when the solar cell module 10 not connected to the ground electrode 50 is similarly measured, no current flows between the ground electrode 50 and the conductor plate 20, so that the wiring resistance value R _L = ∞ and the solar It was confirmed that the battery module 10 was not connected to the ground electrode 50.

As described above, according to the method of the present invention, it is possible to measure the grounding state of the solar cell module similarly in the solar cell module laid on the roof. Normally, when a solar cell module whose surface is covered with a non-conductive surface protective material is laid on the roof,
Since the outer metal part on the back surface of the solar cell module is hidden, it is extremely difficult to confirm the grounded state of the solar cell module. However, according to the present invention, the grounded state of the solar cell module can be confirmed from the surface of the solar cell module even after installation, which is very convenient.

[Embodiment 3] Next, a third embodiment of the present invention will be described. The present embodiment is a grounding state when it is impossible to measure the capacitance C between the roof steel plate 11 and the conductor plate 20 on the back surface of the solar cell module in advance, such as after several years from the installation of the solar cell module. Regarding confirmation. In this embodiment, a solar cell array similar to that of the second embodiment is constructed on the roof, and each solar cell module is connected to a ground electrode by a ground wire.

FIG. 4 shows an outline of the method for measuring the grounding state of the solar cell module according to this embodiment. 10c as shown in FIG.
An m × 10 cm conductor plate 20 is placed on a portion of a cell of the solar cell module 10, and an AC standard voltage generator 30 is used to apply a voltage of 10 [V] between the ground electrode 50 and the conductor plate 20.
An alternating voltage having a frequency of 80 [kHz] was applied, and the alternating current flowing between the ground electrode 50 and the conductor plate 20 was measured by the high frequency ammeter 40. The measured current value is 3.01
It was × 10 ^-1 [A]. Next, the ground electrode 50 and the conductor plate 2
The frequency of the AC voltage applied between 0 and 100 [kH
The current value was 3.76 × 10 ^-1 [A] when the current value was measured again after changing to z]. Based on the above results, the wiring resistance value R _L [Ω] of the solar cell module and the roof steel plate 11 and the conductor plate 2 on the back surface of the solar cell module
When the electrostatic capacitance C between 0 was obtained, the wiring resistance value R _L =
1.8 [Ω] and capacitance C = 60 [PF] were obtained.

In this way, different voltages are applied between the roof steel plate 11 and the conductor plate 20 on the back surface of the solar cell module,
By performing the measurement a plurality of times, the grounded state of the solar cell module 10 can be confirmed even when the electrostatic capacitance between the solar cell module 10 and the conductor plate 20 is not known in advance. Furthermore, since the capacitance between the solar cell module 10 and the conductor plate 20 can be measured, the state of the surface of the solar cell module 10 such as peeling of the surface protective material can be checked from the change in the capacitance C, It is possible to prevent danger such as electric shock. In this embodiment, the conductor plate 2 is provided on the portion of the solar cell module 10 where the cells are located.
Although 0 is arranged, it goes without saying that it is possible to arrange it on a portion where there is no cell.

[Fourth Embodiment] Next, a fourth embodiment of the present invention will be described. In this embodiment, an LCR meter (HI
OKI3520LCR HiTester) was used. This measuring instrument is very convenient because it can measure capacitance, wiring resistance, etc. necessary for implementing the present invention. Actually, when the same measurement was performed by the LCR meter using the solar cell module 10 and the conductor plate 20 similar to those in Example 1, when the solar cell module 10 was grounded, at a frequency of 100 [kHz], The wiring resistance value R _L = 1.8 [Ω] and the electrostatic capacitance C = 40 [PF], and values substantially similar to those in Example 1 were obtained. When the solar cell module 10 is not grounded, the wiring resistance value R _L = ∞ and the solar cell module 10 is connected to the ground electrode 5
It was confirmed that it was not connected to 0. Even if only the LCR meter is used as the measuring device and the power source as in the present embodiment, the grounded state of the solar cell module 10 can be easily and accurately confirmed.

As described above, in each embodiment, the non-conducting surface protection material 17 of the solar cell module 10, the outer metal part 11 of the solar cell module 10 and the conductor plate 20 are configured to have an electrostatic capacity. The greatest feature is that the ground state can be measured from the surface of the solar cell module 10 even in the solar cell module 10 whose surface is covered with the non-conductive surface protective material 17 by applying an AC voltage thereto and measuring the impedance. Has become.
A wide variety of embodiments are possible for the measuring device, the power supply, and the like described in each example.

[0037]

As described above, according to the present invention, it is not necessary to measure the ground resistance value every time the solar cell modules are laid one by one as in the conventional case, and after laying all the solar cell modules, The grounded state can be measured from the surface of the solar cell module. Therefore, the workability can be significantly improved, the installation period of the solar cell module can be shortened, and the construction cost can be reduced. Further, the work time can be further shortened by displaying the measurement result or giving an alarm. Furthermore, while changing the frequency of the AC voltage applied between the conductor plate arranged on the solar cell module and the ground electrode,
By performing multiple measurements, even after several years from the laying of the solar cell module can measure the grounding condition without peeling the solar cell module of the roof, and the electrostatic between the conductor plate and the solar cell module Capacity can also be measured. Therefore, the solar cell module and the
Etc. change in capacitance between the conductive plate, a surface protective material can also be found abnormality of the solar cell module surface, such as peeling. As described above, by using the present invention when measuring the grounding state of the solar cell module, remarkable effects can be obtained.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a ground state measuring method and device for a solar cell module according to a first embodiment of the present invention.

2 is a cross-sectional view showing the configuration of a solar cell module measured by the method and apparatus of FIG.

3 is a schematic block diagram of the apparatus of FIG.

FIG. 4 is a configuration diagram showing a grounding state measuring method for a solar cell module according to a third embodiment of the present invention.

[Explanation of symbols]

10: solar cell module, 11: steel plate for roof, 12:
Insulating layer, 13: stainless steel substrate, 14: backside reflecting layer, 1
5: amorphous silicon semiconductor layer, 16: transparent conductive layer, 17: surface protective material, 20: conductor plate, 30: AC voltage source, 40: ammeter, 50: ground electrode, 51: ground wire, 6
0: measuring device, 61: arithmetic control means, 62: display device.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Naoki Manabe 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (56) Reference JP-A-5-167095 (JP, A) −49263 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) G01R 31/02

Claims (12)

(57) [Claims] 1. A surface thereof is covered with a non-conductive surface protective material.
Overturned, provided the metal parts to be grounded to a ground electrode on the back surface
And a grounded measuring method of the solar cell module, wherein the metal part facing the surface of the solar cell module
The conductive plate is arranged Te, by detecting a current flowing by applying an AC voltage between the conductor plate and the ground electrode, the solar cell, wherein the benzalkonium measuring the grounding condition of the metal part Module grounding state measurement method. 2. The ground state is measured by measuring the voltage value and frequency of an AC voltage applied between the conductor plate and the ground electrode, and thus the current value of the current flowing between the conductor plate and the ground electrode. 2. The solar cell module ground state measurement according to claim 1, wherein the measurement is performed using a relationship that holds between a value of capacitance between the metal portion and the conductor plate and a wiring resistance value. Method. Wherein the solar cell module is the solar cell module ground state measuring method according to claim 1 or 2, characterized in that it has a plate-like conductive member as the metal part on the back surface. Wherein said conductive plate is a solar cell module ground state measuring method according to any one of claims 1-3, characterized in that it is covered with an insulator. While changing the frequency of the AC voltage applied between the 5. Before SL conductor plate and the ground electrode, the current flowing by detecting a plurality of times, claims, characterized in that to measure the grounding condition The solar cell module grounding state measuring method according to any one of claims 1 to 4 . 6. The solar cell module ground state measuring method according to any one of claims 1 to 5, characterized in that it has an alarm step of informing to the subject a measurement result of the ground state. 7. The solar cell module ground state measuring method according to any one of claims 1 to 6, characterized in that a display step of displaying the measurement result of the ground state. 8. The surface of the conductor plate without the solar cells
Put it on the surface part Measuring the grounding condition of metal parts
The sun according to any one of claims 1 to 7,
Battery module ground condition measurement method. 9. The surface thereof is covered with a non-conductive surface protective material.
Overturned, provided the metal parts to be grounded to a ground electrode on the back surface
And a grounded measuring apparatus of the solar cell module, wherein the metal part facing the surface of the solar cell module
A conductor plate disposed Te, to detect a current flowing by applying an AC voltage between the conductor plate and the ground electrode
And a measuring means for measuring the grounding state of the metal part. 10. The solar cell module ground state measuring device according to claim 9 , wherein the conductor plate is covered with an insulator. 11. Moreover claim 9 characterized in that it has an alarm means for notifying to the subject a measurement result of the ground state
Is a solar cell module grounding state measuring device according to 10. 12. The solar cell module ground state measuring device according to any one of claims 9-1 1, characterized in that a display means for displaying the measurement result of the ground state.