JP7006025B2 - Solar cell module diagnostic system and solar cell module diagnostic method - Google Patents

Description

The present invention relates to a solar cell module diagnostic system for diagnosing an abnormality in a solar cell module used in a photovoltaic power generation system and a solar cell module diagnostic method.

In recent years, the introduction of feed interriffs, which set the purchase price (tariff) of energy by law, is progressing worldwide. Along with this, photovoltaic power generation systems have begun to be introduced not only in companies but also in ordinary households. In particular, mega solar systems with a large number of solar cell modules spread over a vast site are beginning to spread. In this mega solar system, it is expected that the photovoltaic power generation system, which was an auxiliary role, will play a role in the core power generation and supply the electricity in the region.

In a solar cell module constituting a photovoltaic power generation system, if the module surface is contaminated by bird dung or the like, or if the module surface is damaged by a collision of flying objects or the like, the power generation output is reduced. As a method for detecting such an abnormality of the solar cell module, for example, a visual inspection, an inspection of heat generation by a thermometer, an inspection of electrical characteristics by a tester, and the like are performed.

On the other hand, the solar cell module is composed of a series circuit of solar cell cells. In addition, it is divided into a plurality of blocks for the purpose of suppressing the influence of partial shadows and defects in the module. A bypass diode is incorporated in each of these blocks to prevent current interruption. By the action of this bypass diode, the influence of a partial failure of the solar cell module or the like is absorbed. As a result, a stable power generation output is ensured from the solar cell module.

However, when a part of the solar cell module is contaminated or damaged, if the output reduction factors such as shadows and scattering of trees overlap, multiple bypass diodes operate and the power generation output suddenly occurs. May occur. In order to prevent the occurrence of such a situation, it is preferable to detect the partially defective solar cell module at an early stage and perform maintenance.

In view of such circumstances, the applicant is provided with a light-shielding mechanism that blocks incident light in units of substrings of the solar cell module, and determines an abnormality in the solar cell module based on the measurement result of the string current change before and after the light-shielding. A solar cell module diagnostic system has been proposed (see, for example, Patent Document 1). In this solar module diagnostic system, the abnormality of the solar cell module can be determined in the substring unit, and the labor and cost required for the diagnostic work can be reduced as compared with the case of determining the abnormality of the solar cell module in the cell unit. Further, since the change in the string current before and after the adjustment of the incident light in the substring unit is measured, it is possible to detect the solar cell module having a partial defect in the actual usage environment without removing the bypass diode.

Japanese Unexamined Patent Publication No. 2016-20491

By the way, in the solar cell module diagnostic system as described above, it is required to further reduce the labor and cost required for the diagnostic work. Realizing such abnormalities in the solar cell module with low labor and low cost is an important technical issue for the sound operation of the photovoltaic power generation system including the mega solar system.

The present invention has been made in view of such circumstances, and is a solar cell module capable of easily detecting a partially defective solar cell module while suppressing an increase in labor and cost required for work. It is an object of the present invention to provide a diagnostic system and a method for diagnosing a solar cell module.

In the solar cell module diagnostic system according to the present invention, the solar cell module has a light-shielding member capable of blocking light incident on the solar cell module in units of substrings included in the solar cell module in the arrangement direction of a plurality of units of the substrings. The light-shielding means driven along the line, the detection means for detecting the waveform pattern of the string current that changes with the driving of the light-shielding member, and the waveform pattern of the string current included in the detection result by the detection means are held in advance. A determination means for determining an abnormality in a specific substring unit included in the solar cell module according to a location of a mismatch between the standard string current waveform pattern obtained and the standard string current waveform pattern obtained by comparison. The standard string current waveform pattern is characterized by being comb-shaped .

In the method for diagnosing a solar cell module according to the present invention, a light-shielding member that shields light incident on the solar cell module in units of substrings contained in the solar cell module is attached to the solar cell module in the arrangement direction of a plurality of units of the substrings. A light-shielding step driven along the line, a detection step for detecting a waveform pattern of a string current that changes with the driving of the light-shielding member, and a waveform pattern of the string current included in the detection result detected in the detection step. A determination step for determining an abnormality in a specific substring unit included in the solar cell module according to the location of a mismatch between the standard string current waveform pattern held in advance and the standard string current waveform pattern obtained by comparison. The standard string current waveform pattern is characterized by being comb-shaped .

According to the present invention, it is possible to easily detect a partially defective solar cell module while suppressing an increase in labor and cost required for the work.

It is a block diagram which shows the structure of the solar cell module diagnostic system which concerns on this embodiment. It is an enlarged view of the solar cell module applied to the solar cell module diagnostic system which concerns on this embodiment. It is explanatory drawing of the light shielding mechanism used in the solar cell module diagnostic system which concerns on this embodiment. It is a schematic diagram for demonstrating the light-shielding position by the light-shielding mechanism which the solar cell module diagnostic system which concerns on this embodiment has. It is explanatory drawing of the waveform pattern of the string current detected by driving the shading plate which the solar cell module diagnostic system which concerns on this embodiment has. It is a flow diagram for demonstrating the diagnosis method of the solar cell module in the solar cell module diagnosis system which concerns on this embodiment. It is explanatory drawing of an example of the waveform pattern of the string current of the solar cell module which has a defect detected in the solar cell module diagnostic system which concerns on this embodiment. It is explanatory drawing of an example of the waveform pattern of the string current of the solar cell module which has a defect detected in the solar cell module diagnostic system which concerns on this embodiment. It is explanatory drawing of an example of the waveform pattern of the string current of the solar cell module which has a defect detected in the solar cell module diagnostic system which concerns on this embodiment.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. The solar cell module diagnostic system according to the present embodiment (hereinafter, appropriately referred to as “diagnosis system”) is suitably used for diagnosing a solar cell module in a mega solar system, for example. In the following, a case where the diagnostic system according to the present embodiment is applied to a mega solar system will be described as an example. However, the target to which the diagnostic system according to the present embodiment is applied is not limited to the mega solar system, but can be applied to a smaller-scale photovoltaic power generation system.

FIG. 1 is a block diagram showing a configuration of a solar cell module diagnostic system (diagnosis system) 10 according to the present embodiment. Note that FIG. 1 shows only three solar cell arrays 11 to 13 out of a large number of solar cell arrays constituting the mega solar system for convenience of explanation.

As shown in FIG. 1, the diagnostic system 10 according to the present embodiment includes a plurality of solar cell arrays 11 to 13, a power conditioner 14, a string electrical characteristic measuring device (measuring device) 15, and a string electrical characteristic receiving server (reception). A server) 16, a diagnostic device 17, and a monitoring device 18 are included. The diagnostic system 10 detects the waveform pattern of the string current in the solar cell arrays 11 to 13 installed on the site, and diagnoses the abnormality of the solar cell modules 20 constituting the solar cell arrays 11 to 13 based on the detection result. It is something to do.

Each of the solar cell arrays 11 to 13 is configured as a solar cell array having a maximum output of 2250 W by connecting nine solar cell modules 20 having a maximum output of 250 W in series. The solar cell module 20 receives sunlight on the surface (module surface) and converts solar energy into electrical energy (DC). In addition, these solar cell modules 20 can also be called a solar cell panel.

The solar cell arrays 11 to 13 are arranged side by side in the site where the diagnostic system 10 is provided. In each of the solar cell arrays 11 to 13, the solar cell modules 20 are arranged side by side. FIG. 1 shows a case where three solar cell modules 20 arranged at regular intervals in the vertical direction shown in the figure are arranged in three rows in the left-right direction shown in the figure. The positions of the solar cell modules 20 in the respective solar cell arrays 11 to 13 are in the same state as each other. The solar cell arrays 11 to 13 are connected to the power conditioner 14 via backflow prevention diodes (blocking diodes) 21 to 23, respectively.

FIG. 2 is an enlarged view of the solar cell module 20 applied to the diagnostic system 10 according to the present embodiment. As shown in FIG. 2, the solar cell module 20 includes a plurality of solar cell 201. The solar cell 201 in the solar cell module 20 is an electric circuit all connected in series by soldering an interconnector. The solar cell module 20 is divided into a plurality of parallel circuits for the purpose of suppressing the influence of partial shadows and failures / malfunctions in the solar cell module 20. A bypass diode 202 is incorporated in these parallel circuits to prevent backflow of current. The partial solar cell group divided by these bypass diodes 202 may be referred to as a substring or a cluster. In the present specification, these solar cell groups are referred to as substring 203.

The power conditioner 14 controls the behavior of the solar cell arrays 11 to 13. Further, the power conditioner 14 converts the DC power generated by the solar cell arrays 11 to 13 into AC power. For example, the power conditioner 14 is connected to a commercial power source or load (not shown). In such a case, the electric power generated by the solar cell arrays 11 to 13 is consumed by the load or sold to a commercial power source.

Further, the power conditioner 14 controls to maximize the amount of power generation in the mega solar system (solar power generation system). For example, the power conditioner 14 performs maximum power point tracking (MPPT) control that maximizes the power that can be generated according to the characteristics of the solar cell arrays 11 to 13 (solar cell module 20). In MPPT control, a voltage (maximum power point) at which the maximum power can be drawn from the solar cell module 20 is obtained so that the output of the solar cell module 20 can always be maximized, and the solar cell module 20 is generated with that voltage.

In mega solar systems, the mountain climbing method is generally applied as MPPT control. In the hill climbing method, the voltage (string voltage) is changed (increased or decreased) by a certain amount at a fixed update interval, and the electric power after the change is obtained. Then, the power after the change is compared with the power before the voltage is changed, and the voltage having the larger power is selected. By such MPPT control (hill climbing method), the mega solar system can secure the maximum power generation amount while following the maximum power point that constantly fluctuates due to changes in weather conditions and the like.

The string electrical characteristic measuring device (hereinafter, appropriately referred to as “measuring device”) 15 measures the electrical characteristics of the solar cell arrays 11 to 13 of the mega solar system in string units. The electrical characteristics referred to here are the generated voltage and generated current in string units. Further, the measuring device 15 detects the waveform pattern of the generated current in the measured string unit. That is, the measuring device 15 functions as an example of the detecting means, and detects the waveform pattern of the string current in the solar cell arrays 11 to 13. Although the measuring device 15 is described here as an independent configuration, the measuring device 15 may be configured as an analog input unit of the diagnostic device 17 described later.

More specifically, the measuring device 15 detects the waveform pattern of the string current that changes during the shading control of the incident light by the shading control unit 171 of the diagnostic device 17, which will be described later. The measuring device 15 detects the waveform pattern of the string current according to the value of the string current that changes when the voltage of the MPPT control by the power conditioner 14 connected to the solar cell module 20 is updated. The details of the waveform pattern of this string current will be described later. The measuring device 15 may also be called a string monitoring unit.

The string electrical characteristic receiving server (hereinafter, appropriately referred to as “receiving server”) 16 is connected to the measuring device 15. The receiving server 16 stores the electrical characteristic data for each string measured by the measuring device 15 and the waveform pattern of the string current detected by the measuring device 15. For example, the receiving server 16 stores the current value, the voltage value, and the waveform pattern of the string current in string units as data. Further, as data other than the above, the receiving server 16 stores the determination result (normal / abnormal determination result) of the solar cell module 20 by the determination unit 173 of the diagnostic device 17 described later. The receiving server 16 can store data such as current and voltage measured values in string units for a certain period (for example, one month).

The diagnostic device 17 includes, for example, a shading control unit 171, a storage unit 172, a determination unit 173, a display unit 174, and a communication unit 175. The light-shielding control unit 171 constitutes a part of the light-shielding means, and by controlling the light-shielding mechanism 40 described later, the incident light to the solar cell module 20 is emitted by the substring 203 unit included in the solar cell module 20. It is configured to be able to block light. The detailed configuration of the light-shielding mechanism 40 will be described later.

The storage unit 172 stores various information necessary for determining normality / abnormality of the solar cell module 20. For example, the storage unit 172 stores a standard string current waveform pattern (hereinafter, appropriately referred to as “standard waveform pattern”). The standard waveform pattern is compared with the waveform pattern of the string current detected by the measuring device 15 (hereinafter, appropriately referred to as “detection waveform pattern”). For example, the standard waveform pattern includes a waveform pattern of string current when the solar cell module 20 is slid while blocking a certain area on the module surface of the solar cell module 20 for each expected amount of solar radiation in a normal state. Set.

Further, the storage unit 172 has a plurality of abnormal string current waveform patterns for determining by what factor the solar cell module 20 is abnormal by comparison with these standard waveform patterns (hereinafter, “abnormal waveform pattern” as appropriate). ") Can be memorized. In these abnormal waveform patterns, a waveform pattern for determining an abnormality of a specific substring included in the solar cell module 20 and a waveform pattern for determining an abnormality of a specific bypass diode 202 are set. Further, the storage unit 172 stores the determination result of the solar cell module 20 by the determination unit 173.

The determination unit 173 constitutes an example of the determination means, and determines whether the solar cell module 20 is normal or abnormal based on the detection result of the waveform pattern of the string current by the measuring device 15. For example, the determination unit 173 determines the normality / abnormality of the solar cell module 20 based on the comparison result between the detection waveform pattern detected by the measuring device 15 and the standard waveform pattern in the storage unit 172. More specifically, the determination unit 173 determines the normality / abnormality of the solar cell module 20 depending on whether or not they match. Further, the determination unit 173 can determine an abnormality of a specific substring or a bypass diode according to a state of disagreement between the detected waveform pattern and the standard waveform pattern. The determination unit 173 can generate image data (module state diagnosis image data) indicating normality / abnormality of the solar cell module 20.

The display unit 174 is composed of an output means such as a liquid crystal display, and displays the determination result by the determination unit 173. For example, the display unit 174 displays the module state diagnosis image data generated by the determination unit 173. It is preferable that the module state diagnosis image data includes information for specifying the position of the solar cell module 20 determined to be normal / abnormal in the solar cell arrays 11 to 13. For example, it is preferable as an embodiment to show the positions of all the solar cell modules 20 included in the solar cell arrays 11 to 13 and to display the solar cell modules 20 determined to be normal or abnormal in different colors.

The communication unit 175 communicates with the monitoring device 18 connected by wire or wirelessly. For example, the communication unit 175 transmits the determination result (normal / abnormal diagnosis result of the solar cell module 20) by the determination unit 173 to the monitoring device 18. The monitoring device 18 manages the determination result received from the communication unit 175. For example, the monitoring device 18 can use this determination result for diagnosing the aged deterioration of the solar cell module 20 or the solar cell arrays 11 to 13.

Here, the configuration of the shading mechanism used in such a diagnostic system 10 will be described with reference to FIG. FIG. 3 is an explanatory diagram of a light shielding mechanism 40 used in the diagnostic system 10 according to the present embodiment. FIG. 3 shows a case where the solar cell array 11 is viewed from the diagonally front side. Since the configuration of the light-shielding mechanism in the solar cell arrays 12 and 13 is common to the light-shielding mechanism 40 in the solar cell array 11, the description thereof will be omitted.

As shown in FIG. 3, the solar cell array 11 is installed, for example, on the upper surface of the gantry 30 in a state of being inclined by 10 to 20 degrees from the horizontal plane. In this case, the solar cell module 20 constituting the solar cell array 11 is installed on the gantry 30 with the light receiving portion (module surface) facing in the direction of sunlight.

The light shielding mechanism 40 is arranged so as to face the light receiving portion of the solar cell module 20. The light-shielding mechanism 40 constitutes a part of the light-shielding means, and plays a role of light-shielding (shielding) sunlight (natural light) to the light-receiving portion of the solar cell module 20. For example, the light-shielding mechanism 40 is arranged in a state of being supported by a guide frame 50 arranged outside the gantry 30. The guide frame 50 is installed at a position corresponding to a part of the gantry 30 (in FIG. 3, a row of solar cell modules 20a, 20b, 20c arranged on the gantry 30). The guide frame 50 serves to movably guide the light-shielding plate 41 of the light-shielding mechanism 40 along the surface of the solar cell module 20. The guide frame 50 can be configured to be movable along the surface of the gantry 30 (solar cell module 20) by a moving mechanism (not shown).

The guide frame 50 includes a pair of frame body portions 51 extending in the longitudinal direction, a pair of frame body portions 52 extending in the lateral direction orthogonal to these frame body portions 51, and a frame body portion 51 and a frame body portion 52. It has four legs 53 extending downward from the intersection of the above. The guide frame 50 has a shape that matches the inclination of the gantry 30, and the flat surface including the frame body portion 51 and the frame body portion 52 is provided with the gantry 30 (more specifically, the solar cell module 20). It is configured to be parallel to the installation surface).

The light-shielding mechanism 40 includes a light-shielding plate 41 having a flat plate shape, a drive unit 42 that drives the light-shielding plate 41 in the vertical direction, and a drive control unit 43 that controls the drive unit 42. The light-shielding plate 41 constitutes an example of a light-shielding member, and is made of, for example, wood, a resin material, or the like. The light-shielding plate 41 has, for example, a surface facing the solar cell module 20 having a generally rectangular shape, and is configured to shield a single substring 203 included in the solar cell module 20 (see FIG. 4). ). That is, the light-shielding plate 41 has a configuration capable of light-shielding in units of the substring 203 included in the solar cell module 20. A plurality of wheels (not shown) are provided on the lower surface of the light-shielding plate 41. These wheels rotate along the frame body portion 51 and contribute to the smooth vertical movement of the light-shielding plate 41.

The drive unit 42 drives the light-shielding plate 41 along the solar cell module 20 in the arrangement direction of the plurality of substrings 203. For example, the drive unit 42 includes a stepping motor, a speed reducer, a pulley, and a rope. One end of the rope is connected to the shading plate 41, while the other end of the rope is connected to a pulley connected to the stepping motor and reducer. The drive unit 42 drives the stepping motor under the control of the drive control unit 43, and moves the light-shielding plate 41 along the solar cell module 20 by winding or pulling out the rope with a pulley. The drive unit 42 may be configured to move the light-shielding plate 41 downward along the gantry 30 by utilizing the weight of the light-shielding plate 41.

The drive control unit 43 controls the drive unit 42 according to an instruction from the light-shielding control unit 171 of the diagnostic device 17. For example, the drive control unit 43 lowers the light-shielding plate 41 from the initial position provided near the upper end portion of the guide frame 50 in accordance with the instruction from the light-shielding control unit 171 to start the diagnosis, while the drive control unit 43 lowers the light-shielding plate 41 from the vicinity of the lower end portion of the guide frame 50. The shading plate 41 is raised and returned to the initial position. For example, the drive control unit 43 moves the light-shielding plate 41 at a speed of 1 m / 1 to 10 seconds.

Here, a case where the light-shielding plate 41 is driven in response to an instruction from the light-shielding control unit 171 of the diagnostic apparatus 17 will be described. However, the drive of the light-shielding plate 41 is not limited to this, and can be changed as appropriate. For example, the light-shielding mechanism 40 may be provided with an operation unit that receives an instruction from an operator, and the light-shielding plate 41 may be driven according to the content of the instruction input to the operation unit. In this case, the moving state of the light-shielding plate 41 can be operated while visually observing the solar cell module 20.

Here, the light-shielding position of the solar cell module 20 by the light-shielding mechanism 40 according to the present embodiment will be described with reference to FIG. FIG. 4 is a schematic diagram for explaining a light-shielding position by the light-shielding mechanism 40 of the diagnostic system 10 according to the present embodiment. In FIG. 4, for convenience of explanation, the nine solar cell modules 20 constituting the solar cell array 11 are designated by reference numerals 20a to 20i. Further, FIG. 4 shows a case where the guide frame 50 is arranged in the solar cell modules 20a to 20c. Further, in FIG. 4, for convenience of explanation, the substring 203 is shown only in the solar cell module 20c.

In the initial state, the light-shielding plate 41 is arranged at the upper end of the guide frame 50 at the initial position retracted from the solar cell modules 20a to 20c (state shown in FIG. 4). In this case, the light-shielding plate 41 is in a state of being arranged at the initial position by winding the rope around the pulley by the stepping motor constituting the drive unit 42. In the initial state, since the light-shielding plate 41 is retracted from the solar cell modules 20a to 20c in this way, the incident light is not shielded by the light-shielding mechanism 40.

As will be described in detail later, when a diagnostic instruction for an abnormality in the solar cell modules 20a to 20c is received from the diagnostic apparatus 17, the light-shielding mechanism 40 uses the light-shielding plate 41 as a guide frame 50 (more specifically) under the control of the light-shielding control unit 171. Specifically, it is lowered from the initial position along the frame body portion 51) (see FIG. 3). Then, after temporarily stopping at the retracted position provided at the lower end of the guide frame 50, the guide frame 50 is raised from the retracted position along the guide frame 50 and returned to the initial position. In FIG. 4, for convenience of explanation, the light-shielding plate 41 in a state where the substring 203 in the center of the solar cell module 20b is shielded and the light-shielding plate 41 in a state where the substring 203 is stopped at the retracted position are shown by broken lines.

By moving in the vertical direction along the solar cell modules 20a to 20c in this way, the light-shielding plate 41 moves while shielding the substrings 203 included in the solar cell modules 20a to 20c, respectively. When moving between adjacent substrings 203, the shading plate 41 is in a state of shielding a part of the upper substring 203 and a part of the lower substring 203.

When performing an abnormality diagnosis on the solar cell modules 20d to 20f and the solar cell modules 20g to 20i, the guide frame 50 is moved to the corresponding position by the operator. Then, as described above, the light-shielding plate 41 is lowered from the initial position along the guide frame 50, and then raised again to the initial position via the retracted position.

Next, the waveform pattern of the string current detected by driving the plate shading plate 41 will be described with reference to FIG. FIG. 5 is an explanatory diagram of a waveform pattern of a string current detected by driving a light-shielding plate 41 included in the diagnostic system 10 according to the present embodiment. FIG. 5 shows a waveform pattern of a string current in a state where the module surface is not contaminated by bird droppings or the like, or the module surface is not damaged by a collision of flying objects (normal state). The waveform pattern of the string current shown in FIG. 5 corresponds to a standard waveform pattern.

For convenience of explanation, in FIG. 5, a case where the light-shielding plate 41 moves on the two solar cell modules 20a and 20b will be described. Further, in FIG. 5, the substrings 203 included in the solar cell module 20a are shown as A1 to A3, and the substrings 203 included in the solar cell module 20b are shown as B1 to B3. Further, in FIG. 5, the arrangement of the solar cell module 20 shown in FIG. 4 is shown upside down.

The light-shielding plate 41 arranged in the initial position (the state shown in FIG. 5) moves on the substrings A1, A2, and A3 of the solar cell module 20a according to the diagnostic instruction, and then the substring of the solar cell module 20b. Move on B1, B2, B3 (downward movement). After that, the light-shielding plate 41 moves on the substrings B3, B2, and B1 of the solar cell module 20b, and then moves on the substrings A3, A2, and A1 of the solar cell module 20a (upward movement).

On the right side of FIG. 5, the position of the light-shielding plate 41 in the process of moving up and down from the initial position is shown. That is, in the initial state, the shading plate 41 is arranged at the initial position P0. With the downward movement, the shading plate 41 advances from the position P1 to the position P2, the position P3, and so on to the position P12. After that, the light-shielding plate 41 advances from the position P12 to the initial position P0 in the order of the position P11, the position P10, ... As the light-shielding plate 41 moves upward.

As described above, at the initial position P0, the light-shielding plate 41 is in a state of being retracted from the solar cell module 20a (more specifically, the substring A1). At the position P1, the light-shielding plate 41 is in a state of shielding a part of the substring A1. At the position P2, the light-shielding plate 41 is in a state of shielding only the substring A1. At the position P3, the light-shielding plate 41 is in a state of shielding a part of both the substrings A1 and A2. At the position P4, the light-shielding plate 41 is in a state of shielding only the substring A2. At the position P5, the light-shielding plate 41 is in a state of shielding a part of both the substrings A2 and A3. At the position P6, the light-shielding plate 41 is in a state of shielding only the substring A3.

At the position P7, the light-shielding plate 41 is in a state of shielding a part of both the substrings A3 and B1. At the position P8, the light-shielding plate 41 is in a state of shielding only the substring B1. At position P9, the light-shielding plate 41 is in a state of shielding a part of both substrings B1 and B2. At the position P10, the light-shielding plate 41 is in a state of shielding only the substring B2. At the position P11, the light-shielding plate 41 is in a state of shielding a part of both the substrings B2 and B3. At the position P12, the light-shielding plate 41 is in a state of shielding only the substring B3.

Here, for convenience of explanation, only a position (for example, position P2) that shields a specific substring and an intermediate position (for example, position P3) between adjacent substrings (for example, substrings A1 and A2) are used. Shows. At the time of actual movement of the shading plate 41, there is a state in which it is arranged at a position other than these and shields a part of both of the adjacent substrings, but those positions are omitted.

The waveform pattern of the string current generated by the vertical movement of the light-shielding plate 41 will be described. At the initial position P0, all the substrings A1 to A3 and B1 to B3 included in the solar cell modules 20a and 20b are not shielded. Therefore, the string current indicates a reference value (reference current value) X when the solar cell modules 20a and 20b appropriately generate power.

Since a part of the substring A1 is shielded at the position P1, the substring A1 is separated by the action of the bypass diode 202, and the string current is the reference value X-1 (from the reference value X to the inspection waveform) as a detection value. The value obtained by subtracting one unit) is shown. At position P2, since the entire substring A1 is shielded, the substring A1 is disconnected by the action of the bypass diode 202, and the string current shows a reference value X-1 as a detected value. At position P3, since a part of both substrings A1 and A2 is shielded, the substrings A1 and A2 are separated by the action of the bypass diode 202, and the string current is the reference value X-2 (reference value) as a detected value. A value obtained by subtracting 2 units of the inspection waveform from the value X) is shown.

As described above, the waveform pattern of the string current is detected according to the value of the string current that changes when the voltage of the MPPT control by the power conditioner 14 is updated. If an abnormality occurs in any one of the substrings 203 during the voltage update of the MPPT control, the string current value changes slightly. For example, a decrease in the current value of 0.4A to 0.7A is detected. The measuring device 15 detects a decrease in the current value in such a range as a unit of the inspection waveform. In this case, the measuring device 15 detects the reference value X-1 as the detected value of the string current value. Similarly, when an abnormality occurs in any two substrings 203, the measuring device 15 detects a decrease in the string current value of, for example, 0.8A to 1.4A. In this case, the measuring device 15 detects the reference value X-2 as the detected value of the string current. In the diagnostic system 10 according to the present embodiment, such a change in the string current is virtually created with the movement of the light-shielding plate 41, and the abnormality of the solar cell module 20 is determined from the waveform pattern thereof.

At the position P4, since the entire substring A2 is shielded, the substring A2 is separated by the action of the bypass diode 202, and the string current shows a reference value X-1 as a detected value. At position P5, since a part of both substrings A2 and A3 is shielded, the substrings A2 and A3 are separated by the action of the bypass diode 202, and the string current shows a reference value X-2 as a detected value. .. At position P6, since the entire substring A3 is shielded, the substring A3 is disconnected by the action of the bypass diode 202, and the string current shows a reference value X-1 as a detected value.

At position P7, since a part of both substrings A3 and B1 is shielded, the substrings A3 and B1 are separated by the action of the bypass diode 202, and the string current shows a reference value X-2 as a detected value. .. At position P8, since the entire substring B1 is shielded, the substring B1 is disconnected by the action of the bypass diode 202, and the string current shows a reference value X-1 as a detected value. At position P9, since a part of both substrings B1 and B2 are shielded, the substrings B1 and B2 are separated by the action of the bypass diode 202, and the string current shows a reference value X-2 as a detected value. ..

At position P10, since the entire substring B2 is shielded, the substring B2 is disconnected by the action of the bypass diode 202, and the string current shows a reference value X-1 as a detected value. At position P11, since a part of both substrings B2 and B3 are shielded, the substrings B2 and B3 are separated by the action of the bypass diode 202, and the string current shows a reference value X-2 as a detected value. .. At position P12, since the entire substring B3 is shielded, the substring B3 is disconnected by the action of the bypass diode 202, and the string current shows a reference value X-1 as a detected value. The above shows the string current value accompanying the downward movement of the light-shielding plate 41. In the upward movement of the light-shielding plate 41, the string current value changes in the reverse order of these.

As the light-shielding plate 41 moves in this way, the string current alternately repeats the reference value X-1 and the reference value X-2 as detection values, except when the string current is arranged at the position P1. That is, the waveform pattern of the string current generated by driving the light-shielding plate 41 is a waveform pattern in which the reference value X-1 and the reference value X-2 are alternately repeated as detection values in a certain section after the position P2. .. In other words, the waveform pattern of the string current constitutes a comb-shaped waveform pattern at positions P2 to P12. This waveform pattern constitutes a standard waveform pattern. The storage unit 172 of the diagnostic apparatus 17 stores such a standard waveform pattern.

Next, a method of diagnosing the solar cell module 20 in the diagnostic system 10 according to the present embodiment will be described with reference to FIG. FIG. 6 is a flow chart for explaining a diagnostic method of the solar cell module 20 in the diagnostic system 10 according to the present embodiment.

As shown in FIG. 6, when diagnosing the normality / abnormality of the solar cell module 20, first, the solar cell module 20 to be diagnosed is specified (step (hereinafter referred to as “ST”) 601). The solar cell module 20 to be diagnosed can be specified according to, for example, a periodic maintenance schedule or the like. The solar cell module 20 to be diagnosed may be specified from the difference between the measurement result of the string current by the measuring device 15 and the string current converted from the amount of solar radiation under the measurement condition.

When the solar cell module 20 to be diagnosed is specified, the guide frame 50 is arranged at a position corresponding to the solar cell module 20 by an operator or the like (see FIG. 3). The light-shielding plate 41 of the light-shielding mechanism 40 is arranged at the initial position of the guide frame 50. When the solar cell module 20 to be diagnosed is specified, the determination unit 173 instructs the light-shielding control unit 171 to start the diagnosis (ST602).

Upon receiving the instruction to start the diagnosis, the light-shielding control unit 171 executes the drive control of the light-shielding plate 41 via the drive control unit 43 of the light-shielding mechanism 40 (ST603). The drive unit 42 drives the light-shielding plate 41 along the solar cell module 20 in the arrangement direction of the substring 203 under the control of the drive control unit 43. As a result, the light-shielding plate 41 slides on the solar cell module 20 to be diagnosed and shields light as shown in FIG. In other words, the shading plate 41 moves along the solar cell module 20 while changing the shading region corresponding to the substring 203.

While the light-shielding plate 41 is being driven, the measuring device 15 measures the string current in the solar cell module 20 to be diagnosed. Further, the measuring device 15 detects the waveform pattern of the string current according to the measured string current. The string current measured by the measuring device 15 and the waveform pattern (detected waveform pattern) of the string current detected by the measuring device 15 are output to the receiving server 16 and stored.

After executing the light-shielding control, the determination unit 173 determines whether the drive control of the light-shielding plate 41 is completed (ST604). The determination unit 173 determines the end of the drive control of the light-shielding plate 41 based on the presence or absence of a notification from the light-shielding control unit 171 that the drive of the light-shielding plate 41 has been completed. Until the notification of the end of driving of the light-shielding plate 41 is received (ST604: No), the drive control of the light-shielding plate 41 by the light-shielding control unit 171 is continued.

When the drive control of the light-shielding plate 41 is completed (ST604: Yes), the determination unit 173 acquires the waveform pattern (detection waveform pattern) of the string current of the solar cell module 20 to be diagnosed from the receiving server 16 (ST605). .. The receiving server 16 stores the detected waveform pattern detected by driving the shading plate 41. Then, the determination unit 173 captures the standard waveform pattern (see FIG. 5) from the storage unit 172 (ST606). As described above, the standard waveform pattern is stored in the storage unit 172 in advance.

After capturing the standard waveform pattern, the determination unit 173 determines whether the detected waveform pattern acquired by ST605 and the standard waveform pattern match (ST607). By this determination process, the normality / abnormality of the solar cell module 20 to be diagnosed is specified.

When the detected waveform pattern and the standard waveform pattern match (ST607: Yes), the determination unit 173 determines that the solar cell module 20 to be diagnosed is normal (no abnormality) (ST608). Then, the determination unit 173 instructs the display unit 174 to output the determination result. In response to this, the display unit 174 outputs the determination result (ST609). After that, the determination unit 173 instructs the communication unit 175 to transmit the determination result to the monitoring device 18. In response to this, the communication unit 175 transmits the determination result to the monitoring device 18 (ST610).

On the other hand, when the detected waveform pattern and the standard waveform pattern do not match (ST607: No), the determination unit 173 determines that the solar cell module 20 to be diagnosed is abnormal. In this case, the determination unit 173 saves the measurement time and the determination result in this diagnosis in the receiving server 16 (ST611, ST612) in order to obtain statistics when it is diagnosed that there is an abnormality. After that, as in the case where the solar cell module 20 is determined to be normal, the determination unit 173 causes the display unit 174 to output the determination result (ST609), and the communication unit 175 transmits the determination result to the monitoring device 18 (ST610). ).

Here, an example of the detected waveform pattern determined to have an abnormality in ST607 shown in FIG. 6 will be described with reference to FIGS. 7 to 9. 7 to 9 are explanatory views of an example of the waveform pattern of the string current of the solar cell module 20 having a defect detected in the diagnostic system 10 according to the present embodiment. In FIGS. 7 to 9, the same reference numerals are given to the configurations common to those in FIGS. 5, and the description thereof will be omitted.

FIG. 7 shows a case where a defect occurs in the substring A2 included in the solar cell module 20a. When a defect occurs in the substring A2, the string current shows a reference value X-1 as a detection value even when the light-shielding plate 41 is arranged at the initial position P0. This is because the substring A2 is separated by the action of the bypass diode 202.

Since a part of the substring A1 is shielded at the position P1, the substrings A1 and A2 are separated by the action of the bypass diode 202, and the string current shows a reference value X-2 as a detected value. At the position P2, since the entire substring A1 is shielded, the substrings A1 and A2 are separated by the action of the bypass diode 202, and the string current shows a reference value X-2 as a detected value.

At position P3, since a part of both substrings A1 and A2 is shielded, the substrings A1 and A2 are separated by the action of the bypass diode 202, and the string current shows a reference value X-2 as a detected value. .. The substring A2 is separated according to the defect. Therefore, the string current at the position P3 is invariant to the string current at the position P2 regardless of the presence or absence of shielding by the light-shielding plate 41.

At the position P4, since the entire substring A2 is shielded, the substring A2 is separated by the action of the bypass diode 202, and the string current shows a reference value X-1 as a detected value. Since only the defective substring A2 is shielded by the light-shielding plate 41, the string current value is higher than that in the case where it is arranged at the position P3.

At position P5, since a part of both substrings A2 and A3 is shielded, the substrings A2 and A3 are separated by the action of the bypass diode 202, and the string current shows a reference value X-2 as a detected value. .. At position P6, since the entire substring A3 is shielded, the substrings A2 and A3 are separated by the action of the bypass diode 202, and the string current shows a reference value X-2 as a detected value.

At position P7, since a part of both substrings A3 and B1 is shielded, the substrings A2, A3, and B1 are separated by the action of the bypass diode 202, and the string current is the reference value X-3 as a detected value. Is shown. At position P8, since the entire substring B1 is shielded, the substrings A2 and B1 are separated by the action of the bypass diode 202, and the string current shows a reference value X-2 as a detected value. At position P9, since a part of both substrings B1 and B2 are shielded, the substrings A2, B1 and B2 are separated by the action of the bypass diode 202, and the string current is the reference value X-3 as a detected value. Is shown.

At the position P10, since the entire substring B2 is shielded, the substrings A2 and B2 are separated by the action of the bypass diode 202, and the string current shows a reference value X-2 as a detected value. At position P11, since a part of both substrings B2 and B3 is shielded, the substrings A2, B2, and B3 are separated by the action of the bypass diode 202, and the string current is the reference value X-3 as a detected value. Is shown. At position P12, since the entire substring B3 is shielded, the substrings A2 and B3 are separated by the action of the bypass diode 202, and the string current shows a reference value X-2 as a detected value. The above shows the string current value accompanying the downward movement of the light-shielding plate 41. In the upward movement of the light-shielding plate 41, the string current value changes in the reverse order of these.

When the substring A2 included in the solar cell module 20a has a defect, the detected waveform pattern is different from the standard waveform pattern at positions P1 to P5 as shown in FIG. 7. In other words, at positions P1 to P5, the detected waveform pattern is not a comb-shaped waveform pattern. Therefore, in ST607 shown in FIG. 6, it is determined that the detected waveform pattern and the standard waveform pattern (see FIG. 5) do not match, and an abnormality has occurred in the solar cell modules 20a and 20b to be diagnosed. Be identified.

FIG. 8 shows a case where a defect occurs in the substrings A2 and A3 included in the solar cell module 20a. When a problem occurs in the substrings A2 and A3, the string current shows a reference value X-2 as a detected value even when the light-shielding plate 41 is arranged at the initial position P0. This is because the substrings A2 and A3 are separated by the action of the bypass diode 202.

At the position P1, since a part of the substring A1 is shielded, the substrings A1 to A3 are separated by the action of the bypass diode 202, and the string current shows a reference value X-3 as a detected value. At the position P2, since the entire substring A1 is shielded, the substrings A1 to A3 are separated by the action of the bypass diode 202, and the string current shows a reference value X-3 as a detected value. At position P3, since a part of both substrings A1 and A2 is shielded, the substrings A1 to A3 are separated by the action of the bypass diode 202, and the string current shows a reference value X-3 as a detected value. ..

At the position P4, since the entire substring A2 is shielded, the substrings A2 and A3 are separated by the action of the bypass diode 202, and the string current shows a reference value X-2 as a detected value. Since only the defective substring A2 is shielded by the light-shielding plate 41, the string current value is higher than that in the case where it is arranged at the position P3. At position P5, since a part of both substrings A2 and A3 is shielded, the substrings A2 and A3 are separated by the action of the bypass diode 202, and the string current shows a reference value X-2 as a detected value. .. At position P6, since the entire substring A3 is shielded, the substrings A2 and A3 are separated by the action of the bypass diode 202, and the string current shows a reference value X-2 as a detected value.

At position P7, since a part of both substrings A3 and B1 is shielded, the substrings A2, A3, and B1 are separated by the action of the bypass diode 202, and the string current is the reference value X-3 as a detected value. Is shown. At position P8, since the entire substring B1 is shielded, the substrings A2, A3, and B1 are separated by the action of the bypass diode 202, and the string current shows a reference value X-3 as a detected value. At position P9, since a part of both substrings B1 and B2 are shielded, the substrings A2, A3, B1 and B2 are separated by the action of the bypass diode 202, and the string current is the reference value X as a detected value. -4 is shown.

At position P10, since the entire substring B2 is shielded, the substrings A2, A3, and B2 are separated by the action of the bypass diode 202, and the string current shows a reference value X-3 as a detected value. At position P11, since a part of both substrings B2 and B3 are shielded, the substrings A2, A3, B2, and B3 are separated by the action of the bypass diode 202, and the string current is the reference value X as a detected value. -4 is shown. At position P12, since the entire substring B3 is shielded, the substrings A2, A3, and B3 are separated by the action of the bypass diode 202, and the string current shows a reference value X-3 as a detected value. The above shows the string current value accompanying the downward movement of the light-shielding plate 41. In the upward movement of the light-shielding plate 41, the string current value changes in the reverse order of these.

When the substrings A2 and A3 included in the solar cell module 20a have a problem, the detected waveform pattern is different from the standard waveform pattern at the positions P1 to P8 as shown in FIG. In other words, at positions P1 to P8, the detected waveform pattern is not a comb-shaped waveform pattern. Therefore, in ST607 shown in FIG. 6, it is determined that the detected waveform pattern and the standard waveform pattern (see FIG. 5) do not match, and an abnormality has occurred in the solar cell modules 20a and 20b to be diagnosed. Be identified.

FIG. 9 shows a case where a problem occurs in the bypass diode 202A that bypasses the substring A2 included in the solar cell module 20a. Note that FIG. 9 shows an example of abnormality diagnosis at the time of an open failure in the bypass diode 202A as a defect of the bypass diode 202A. As shown in FIG. 9, even when the bypass diode 202A has a problem, if the light-shielding plate 41 is arranged at the initial position P0, the string current is not affected and the reference value X is used as the detected value. Is shown. This is because the substring A2 has no problem and the bypass diode 202A is not working.

At the position P1, since a part of the substring A1 is shielded, the substring A1 is separated by the action of the bypass diode 202, and the string current shows a reference value X-1 as a detected value. At position P2, since the entire substring A1 is shielded, the substring A1 is disconnected by the action of the bypass diode 202, and the string current shows a reference value X-1 as a detected value.

At position P3, parts of both substrings A1 and A2 are shielded. At this time, since the bypass diode 202A that bypasses the substring A2 has a problem, the string current of the solar cell module 20a becomes 0. Similarly, at positions P4 and P5, the string current of the solar cell module 20a becomes 0 because all or part of the substring A2 is shielded.

At the position P6, since the substring A2 is exceeded and the entire substring A3 is shielded, the substring A3 is disconnected by the action of the bypass diode 202, and the string current shows a reference value X-1 as a detected value. At position P7, since a part of both substrings A3 and B1 is shielded, the substrings A3 and B1 are separated by the action of the bypass diode 202, and the string current shows a reference value X-2 as a detected value. .. At position P8, since the entire substring B1 is shielded, the substring B1 is disconnected by the action of the bypass diode 202, and the string current shows a reference value X-1 as a detected value. At position P9, since a part of both substrings B1 and B2 are shielded, the substrings B1 and B2 are separated by the action of the bypass diode 202, and the string current shows a reference value X-2 as a detected value. ..

At position P10, since the entire substring B2 is shielded, the substring B2 is disconnected by the action of the bypass diode 202, and the string current shows a reference value X-1 as a detected value. At position P11, since a part of both substrings B2 and B3 are shielded, the substrings B2 and B3 are separated by the action of the bypass diode 202, and the string current shows a reference value X-2 as a detected value. .. At position P12, since the entire substring B3 is shielded, the substring B3 is disconnected by the action of the bypass diode 202, and the string current shows a reference value X-1 as a detected value. The above shows the string current value accompanying the downward movement of the light-shielding plate 41. In the upward movement of the light-shielding plate 41, the string current value changes in the reverse order of these.

When the bypass diode 202A connecting the substrings A2 and A3 included in the solar cell module 20a has a problem, the detected waveform pattern differs from the standard waveform pattern at positions P3 to P5 as shown in FIG. ing. In other words, at positions P3 to P5, the detected waveform pattern is not a comb-shaped waveform pattern. Therefore, in ST607 shown in FIG. 6, it is determined that the detected waveform pattern and the standard waveform pattern (see FIG. 5) do not match, and an abnormality has occurred in the solar cell modules 20a and 20b to be diagnosed. Be identified.

As described above, the defect of the bypass diode 202A shown in FIG. 9 shows an example of abnormality diagnosis at the time of an open failure in the bypass diode 202A. The diagnostic system 10 can specify not only such an open failure but also an abnormality diagnosis at the time of a short circuit failure of the bypass diode 202A. At the time of a short-circuit failure of the bypass diode 202A, the waveform pattern of the string current does not change regardless of the presence or absence of light-shielding control by the light-shielding plate 41. The determination unit 173 can determine an abnormality at the time of a short-circuit failure of the bypass diode 202A based on the detection of the waveform pattern of the string current that does not change regardless of the presence or absence of the light shielding control.

As described above, in the diagnostic system 10 according to the present embodiment, the waveform pattern of the string current is detected by the measuring device 15 as the light-shielding plate 41 capable of blocking light is driven in units of the substring 203, and the diagnostic device 17 is used. (Determining unit 173) determines an abnormality in the solar cell module 20 based on the detection result. Therefore, since the abnormality determination is performed in the solar cell module 20 units based on the waveform pattern of the string current, it is not necessary to stop the light-shielding member in the substring 203 units and drive it again. As a result, the labor required for determining the abnormality of the solar cell module 20 can be reduced, and the time required for determining the abnormality can be shortened. As a result, it becomes possible to easily detect the partially defective solar cell module 20 while suppressing an increase in labor and cost required for the work.

In particular, the determination unit 173 determines an abnormality in the solar cell module 20 by comparing the standard waveform pattern (see FIG. 5) previously held in the storage unit 172 with the detected waveform pattern. As a result, it is possible to detect minute changes in the string current due to a malfunction of the solar cell 201 included in the solar cell module 20 even in a noisy environment. As a result, it is possible to accurately detect the partially defective solar cell module 20 without being restricted by the measurement environment such as solar radiation fluctuation during the inspection and measurement period, or without requiring complicated processing for countermeasures against solar radiation fluctuation. Is possible.

Further, the determination unit 173 can determine an abnormality of a specific substring 203 included in the solar cell module 20 according to a portion of the detected waveform pattern that does not match the standard waveform pattern. For example, when the waveform pattern of the string current shown in FIG. 7 is detected as the detected waveform pattern, the determination unit 173 can identify the abnormality of the substring A2 by analyzing the waveform patterns of the positions P1 to P5. .. Further, when the waveform pattern of the string current shown in FIG. 8 is detected as the detected waveform pattern, the determination unit 173 identifies the abnormality of the substrings A2 and A3 by analyzing the waveform patterns of the positions P1 to P8. Can be done. As described above, since the determination unit 173 can determine the abnormality of the specific substring 203 according to the portion of the detected waveform pattern that does not match the standard waveform pattern, it is necessary for the work to analyze the defect of the solar cell module 20. Labor and cost can be reduced.

Further, when the waveform pattern of the string current shown in FIG. 9 is detected as the detected waveform pattern, the determination unit 173 can identify the abnormality of the bypass diode 202A by analyzing the waveform patterns of the positions P3 to P5. .. As described above, since the determination unit 173 can determine the abnormality of the specific bypass diode 202 according to the portion of the detected waveform pattern that does not match the standard waveform pattern, it is necessary for the work to analyze the defect of the solar cell module 20. Labor and cost can be reduced.

It should be noted that the abnormal waveform pattern corresponding to the type of defect may be stored in the storage unit 172 in advance and compared with the detected waveform pattern to specify the type of defect of the solar cell module 20. For example, when the waveform pattern of the string current shown in FIG. 7 is stored in the storage unit 172 as the abnormal waveform pattern, the determination unit 173 includes the detection waveform pattern shown in FIG. 7 and the abnormal waveform pattern stored in the storage unit 172. By determining the coincidence between the two, it is possible to easily identify that the substring A2 has a problem.

Further, the measuring device 15 detects the waveform pattern of the string current according to the value of the string current that changes when the voltage of the MPPT control by the power conditioner 14 connected to the solar cell module 20 is updated. Since the waveform pattern of the string current is detected according to the value of the string current that changes when the voltage of the MPPT control is updated in this way, the waveform pattern of the string current formed at regular intervals can be reliably detected.

The present invention is not limited to the above embodiment, and can be modified in various ways. In the above embodiment, the size, shape, and the like shown in the accompanying drawings are not limited to this, and can be appropriately changed within the range in which the effects of the present invention are exhibited. In addition, it can be appropriately modified and implemented as long as it does not deviate from the scope of the object of the present invention.

For example, in the above embodiment, the solar cell module 20 having a partial defect is determined according to the comparison result between the detected waveform pattern detected by the measuring device 15 and the standard waveform pattern stored in the storage unit 172. Explains the case of doing. However, the method for determining the abnormality of the solar cell module 20 is not limited to this, and can be appropriately changed. The diagnostic system 10 can apply an arbitrary determination method on the premise that the abnormality of the solar cell module 20 is determined based on the detected waveform pattern. for example,
Since one unit is formed at the light-shielding / exposure timing in the above-mentioned waveform formation, the detected value is converted to 0.1 as the reference value, integrated using the shift register function, and then compared with the standard integrated value. / Normality may be judged digitally.

As described above, the present invention has an effect that a partially defective solar cell module can be easily detected while suppressing an increase in labor and cost required for the work, and in particular, a mega solar. It is useful for diagnosing abnormalities in solar cell modules in large-scale photovoltaic power generation systems such as systems.

10 Solar cell module diagnostic system (diagnosis system)
11-13 Solar cell array 14 Power conditioner 15 String electrical characteristic measuring device (measuring device)
16 string electrical characteristics reception server (reception server)
17 Diagnostic device 171 Light-shielding control unit 172 Storage unit 173 Judgment unit 174 Display unit 175 Communication unit 18 Monitoring device 20, 20a to 20i Solar cell module 201 Solar cell 202 Bypass diode 203 Substring 21 to 23 Backflow prevention diode (blocking diode)
30 Stand 40 Light-shielding mechanism 41 Light-shielding plate 42 Drive unit 43 Drive control unit 50 Guide frame 51, 52 Frame body part 53 Legs

Claims (4)

A light-shielding means for driving a light-shielding member included in the solar cell module, which can block light incident on the solar cell module, in the arrangement direction of a plurality of the substring units along the solar cell module.
A detection means for detecting a waveform pattern of a string current that changes with the drive of the light-shielding member, and
The sun depends on the location of the discrepancy between the standard string current waveform pattern obtained by comparing the waveform pattern of the string current included in the detection result by the detection means and the standard string current waveform pattern held in advance. It is provided with a determination means for determining an abnormality in a specific substring unit included in the battery module.
The standard string current waveform pattern is a solar cell module diagnostic system characterized by having a comb-like shape . The solar cell module diagnosis according to claim 1, wherein the determination means determines an abnormality of a specific bypass diode included in the solar cell module according to a portion of mismatch with the standard string current waveform pattern. system. The detection means detects the waveform pattern of the string current according to the value of the string current that changes when the voltage of MPPT (Maximum Power Point Tracking) control by the power conditioner connected to the solar cell module is updated. The solar cell module diagnostic system according to claim 1. A light-shielding step for driving a light-shielding member that shields light incident on the solar cell module in units of substrings included in the solar cell module along the solar cell module in an arrangement direction of a plurality of the substring units.
A detection step for detecting a waveform pattern of a string current that changes with the drive of the light-shielding member, and a detection step.
Depending on the location of the discrepancy between the standard string current waveform pattern obtained by comparing the waveform pattern of the string current included in the detection result detected in the detection step and the standard string current waveform pattern held in advance. A determination step for determining an abnormality in a specific substring unit included in the solar cell module is provided .
The solar cell module diagnostic method , wherein the standard string current waveform pattern is comb-shaped .

Images