Abstract:
A solar photovoltaic panel disposed in a matrix for use, wherein the solar photovoltaic panel comprises a plurality of antennas configured to communicate with antennas placed on adjoining solar photovoltaic panels, a receptor configured to receive a search command via the plurality of antennas, a transmitter configured to transmit a search command from the antennas excluding the antenna having received the search command in response to the received search command, and a responder configured to create a response signal including the panel ID of its own solar photovoltaic panel and transmit the response signal from the antenna having received the search command when no response signal to the search command transmitted from the transmitter is received, and when a response signal to the search command transmitted from the transmitter is received, transmit the response signal with the addition of information from the antenna having received the search command.

Description:
TECHNICAL FIELD 
       [0001]    The present disclosure relates to a solar photovoltaic panel and solar photovoltaic system. 
       BACKGROUND ART 
       [0002]    In construction of a solar photovoltaic system, some variance may occur between the designed (planned) construction and the actual construction. Therefore, after the construction, the wiring and placement of solar photovoltaic panels are examined to obtain wiring path information and placement information. However, the examination task is not easy. 
         [0003]    Non Patent Literature 1 discloses a technique of facilitating the above examination task. The technique investigates the wiring paths and placement by applying high frequency signals to the wiring paths and examining the paths where the signals are detected. 
       CITATION LIST 
     Non Patent Literature 
       [0000]    
       
         Non Patent Literature 1: Solar Photovoltaic System Failure Case File, p 74, Nikkan Kogyo Shimbun Ltd. (Business &amp; Technology Daily News). 
       
     
       SUMMARY OF INVENTION 
     Technical Problem 
       [0005]    The technique disclosed in the Non Patent Literature 1 examines the high-frequency wave transmission paths within a constructed solar photovoltaic system. Therefore, rooftop work is required. Furthermore, the worker may have to be on the solar photovoltaic panels depending on the placement of solar photovoltaic panels. As just mentioned, the examination method described in the Non Patent Literature 1 is poor in workability. Furthermore, since the worker collects the data, the collected data are not so reliable. 
         [0006]    The present disclosure is made with the view of the above circumstance and an objective of the disclosure is to provide a technique making it possible to easily collect accurate construction information/placement information of solar photovoltaic panels. 
       Solution to Problem 
       [0007]    The solar photovoltaic panel according the present disclosure is a solar photovoltaic panel disposed in a matrix for use, wherein the solar photovoltaic panel comprises a plurality of antennas configured to communicate with antennas placed on adjoining solar photovoltaic panels; reception means for receiving a search command via the plurality of antennas; transmission means for transmitting a search command from the antennas excluding the antenna having received the search command in response to the received search command; and response means for creating a response signal including the panel ID of its own solar photovoltaic panel and transmit the response signal from the antenna having received the search command when no response signal to the search command transmitted from the transmission means is received, and when a response signal to the search command transmitted from the transmission means is received, transmit the response signal with the addition of information including the panel ID of its own solar photovoltaic panel from the antenna having received the search command. 
       Advantageous Effects of Invention 
       [0008]    The solar photovoltaic panel having the above-described configuration makes it possible to easily collect information of an individual panel, physical panel placement information, and wiring construction information such as series connection order of solar photovoltaic panels after the construction. Furthermore, the system configured to additionally have means for measuring the power generation states of individual panels so as to acquire the information via a short distance communication coil and wireless-transfer the information makes it possible to monitor the power generation operation of the panels along with the physical placement information and easily identify a panel failed in power generation, whereby the tasks regarding the operation/management of a solar photovoltaic system can be done efficiently. 
         [0009]    Furthermore, information of an individual panel identified by an ID can easily be retrieved, whereby it is easily possible to improve the traceability on the distribution channel from the shipping to installation of solar photovoltaic panels, detect/manage stolen products, and the like. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0010]      FIG. 1  is an illustration showing the configuration of the solar photovoltaic panel according to Embodiment 1 of the present disclosure; 
           [0011]      FIG. 2  is a block diagram of the solar photovoltaic panel according to Embodiment 1 of the present disclosure; 
           [0012]      FIG. 3  is an illustration showing an exemplary placement of the solar photovoltaic panels; 
           [0013]      FIG. 4  is an illustration showing the relationship between the coil positions and the magnetic flux; 
           [0014]      FIG. 5  is a block diagram of the measuring device; 
           [0015]      FIG. 6  is a flowchart of the procedure to examine the placement of multiple solar photovoltaic panels placed in a matrix; 
           [0016]      FIG. 7  is an illustration for explaining the proceeding to obtain the solar photovoltaic panel placement information; 
           [0017]      FIG. 8  is a block diagram of the solar photovoltaic panel in Embodiment 2 of the present disclosure; 
           [0018]      FIG. 9  is an illustration showing the configuration of the solar photovoltaic panel in Embodiment 2 of the present disclosure; 
           [0019]      FIG. 10  is a flowchart showing the procedure to examine the connection relationship of multiple series-connected solar photovoltaic panels; 
           [0020]      FIG. 11  is an illustration showing an exemplary display screen showing the connection relationship of multiple series-connected solar photovoltaic panels; 
           [0021]      FIG. 12  is a block diagram of the solar photovoltaic panel of Embodiments 3 and 4 of the present disclosure; 
           [0022]      FIG. 13  is an illustration showing an exemplary display image showing the operation states of solar photovoltaic panels; 
           [0023]      FIG. 14  is a block diagram of the solar photovoltaic panel in Modified Embodiment 3 of Embodiment 3 of the present disclosure; 
           [0024]      FIG. 15  is a block diagram of the solar photovoltaic panel in Embodiment 5 of the present disclosure; 
           [0025]      FIG. 16  is a block diagram of the reader device; 
           [0026]      FIG. 17  is a block diagram of the solar photovoltaic panel in Embodiment 5 of the present disclosure; 
           [0027]      FIG. 18  is an illustration showing the solar photovoltaic panel at an end of which a step is formed and a coil is placed; 
           [0028]      FIG. 19  is an illustration showing a case in which a coil is formed on the solar photovoltaic panel; 
           [0029]      FIG. 20  is an illustration showing the solar photovoltaic panels placed in a checkerboard pattern; 
           [0030]      FIG. 21  is an illustration showing the solar photovoltaic panel in another shape; and 
           [0031]      FIG. 22  is an illustration showing the outer frame of the solar photovoltaic panel and the coil structure. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0032]    The solar photovoltaic panel according to embodiments of the present disclosure is described hereafter with reference to the drawings. 
       Embodiment 1 
       [0033]    The solar photovoltaic panel  9  ( 9 A to  9 F) according to the embodiment is arrayed in a matrix for use as shown in  FIG. 3 . Each solar photovoltaic panel  9  comprises, as shown in  FIG. 1 , a photovoltaic cell module  1 , a + (positive) terminal box  1   a , a + (positive) output connector  1   b , a − (negative) terminal box  1   c , a − (negative) output connector  1   d , a current sensor  5 , a housing box  7 , an upper end coil  8   u , a lower end coil  8   d , a right end coil  8   r , and a left end coil  8   l.    
         [0034]    The photovoltaic cell module  1  comprises, for example, photovoltaic cells using silicon crystal, which is considered to contribute to highly efficient energy conversion, converting the light energy of sunlight and the like to electric power and outputting the electric power. The silicon-based photovoltaic cell includes those of crystalline silicon, polycrystal silicon, and amorphous silicon types. 
         [0035]    The + terminal box  1   a  and − terminal box  1   c  are connected to the + output terminal and − output terminal of the photovoltaic cell module  1 , respectively, as the lead-out ports for generated power output. 
         [0036]    The + output connector  1   b  and − output connector  1   d  are attached to the tips of the electric wires drawn out from the + terminal box  1   a  and − terminal box  1   c , respectively. Furthermore, the + output connector  1   b  and − output connector  1   d  are structured to be connectable to the output connectors of the opposite polarities of the adjoining solar photovoltaic panels  9 ; for example, one has a male structure and the other has a female structure. 
         [0037]    The current sensor  5  is provided on the electric wire between the − terminal box  1   c  and − output connector  1   d , measuring and outputting to the controller  2  described later the power generation current I of the photovoltaic cell module  1 . 
         [0038]    The housing box  7  houses devices for controlling the solar photovoltaic panel  9  such as the controller  2  and power source  3  described hereafter. The housing box  7  is described in detail hereafter with reference to  FIG. 2 . 
         [0039]    The upper end coil  8   u , lower end coil  8   d , right end coil  8   r , and left end coil  8   l  are placed at the upper end, lower end, right end, and left end of the solar photovoltaic panel  9 , respectively. As shown in  FIG. 3 , after the solar photovoltaic system is constructed, the upper end coil  8   u  faces the lower end coil  8   d  of the solar photovoltaic panel  9  adjoining in the upward direction. The lower end coil  8   d  faces the upper end coil  8   u  of the solar photovoltaic panel  9  adjoining in the downward direction. The right end coil  8   r  faces the left end coil  8   l  of the solar photovoltaic panel  9  adjoining on the right. The left end coil  8   l  faces the right end coil  8   r  of the solar photovoltaic panel  9  adjoining on the left. 
         [0040]    The upper end coil  8   u  to left end coil  8   l  and coils  8   p  and  8   m , which is described hereafter, are collectively termed the coils  8 . 
         [0041]    The coils  8  are placed with their magnetic flux orientation in parallel to the main surface of the solar photovoltaic panels  9  (perpendicular to the end face) as shown in a cross-section of  FIG. 4 . The magnetic resonance (mutual induction) between the facing coils  8  placed on adjoining solar photovoltaic panels  9  allows for signal transfer between the adjoining solar photovoltaic panels  9 . The coils  8  can be any coil as long as mutual magnetic coupling between the coils  8  of adjoin solar photovoltaic panels  9  is obtained. For example, the coils  8  can be an air core coil or cored coil. 
         [0042]    The devices housed in the housing box  7  are described hereafter with reference to  FIG. 2 . 
         [0043]    The housing box  7  houses a controller  2 , a power source  3 , an ID retainer  4 , and a temperature sensor  6 . 
         [0044]    The controller  2  comprises a CPU (central processing unit), a memory, an A/D (analog to digital) converter, and the like and controls the operation of the solar photovoltaic panel  9 . Voltages are applied to the S+ terminal and S− terminal of the controller  2  from the + terminal box  1   a  and − terminal box  1   c  of the photovoltaic cell module  1 . The controller  2  measures the voltage between the S+ terminal and S− terminal to measure the power generation voltage V of the photovoltaic cell module  1 . 
         [0045]    Furthermore, the controller  2  comprises a communicator  2   a . The communicator  2   a  supplies signals to the coils  8  so that the coils  8  generate and send to the facing coils  8  magnetic signals. Furthermore, when the coils  8  induce a voltage due to the magnetic signals sent from the other coils  8 , the communicator  2   a  detects the voltage and supplies a detection signal to the CPU. 
         [0046]    Furthermore, the controller  2  controls the solar photovoltaic panel  9  including protection operation based on the power generation voltage V of the photovoltaic cell module  1 , the power generation current I detected by the current sensor  5 , the temperature T measured by the temperature sensor  6 , and the like. 
         [0047]    The power source  3  takes in the electric power generated by the photovoltaic cell module  1 , and creates and supplies to the controller  2  an operation voltage Vcc and G (ground). 
         [0048]    The ID retainer  4  comprises a setting switch such as a nonvolatile memory and DIP switch and stores ID (identification information) given to the solar photovoltaic panel  9  (the panel ID, hereafter). 
         [0049]    The temperature sensor  6  measures and reports to the controller  2  the temperature T of the photovoltaic cell module  1 . 
         [0050]    A measuring device  10  used for acquiring construction information (connection information, placement information) of the solar photovoltaic panels  9  constituting the constructed solar photovoltaic system is described hereafter with reference to  FIG. 5 . 
         [0051]    The measuring device  10  comprises, as shown in  FIG. 5 , a coil  10   a , a power source circuit  10   b , a controller  10   c , and a radio module  10   d.    
         [0052]    The coil  10   a  is used as a communication medium (antenna) for communicating with the controller  2  via the coils  8  of the solar photovoltaic panels  9 . 
         [0053]    The power source circuit  10   b  takes in electric power from the power source  3  of the solar photovoltaic panel  9  and supplies operation power to the controller  10   c  and radio module  10   d.    
         [0054]    The controller  10   c  receives a search command from an operation terminal  11  via the radio module  10   d  and outputs the search command from the coil  10   a  as a magnetic signal. Furthermore, the controller  10   c  receives search results via the coil  10   a  and sends the received search results to the operation terminal  11  via the radio module  10   d.    
         [0055]    The radio module  10   d  is in charge of relay function for radio communication between the controller  10   c  and operation terminal  11 . 
         [0056]    The operation terminal  11  comprises any operation terminal capable of short distance radio communication, for example, a tablet terminal. The operation terminal  11  displays on the display  17  various kinds of information sent from the controller  10   c  via the radio module  10   d.    
         [0057]    The proceeding to examine the placement of solar photovoltaic panels  9  while the solar photovoltaic panels  9  are placed in a matrix as shown in  FIG. 3  is described hereafter. 
         [0058]    In preliminary preparation, the coil  10   a  of the measuring device  10  is faced with any one of those situated on the outer periphery of the matrix among the coils  8  of the solar photovoltaic panels  9  constituting the solar photovoltaic system. Furthermore, the power source circuit  10   b  is connected to the power source  3  to assure the power. 
         [0059]      FIG. 7  shows a case. In this configuration, six solar photovoltaic panels  9 A to  9 F are placed. Furthermore, the coil  10   a  of the measuring device  10  is faced with the lower end coil  8   d  of the solar photovoltaic panel  9 E. 
         [0060]    Subsequently, the worker sends a search command to the measuring device  10  from the operation terminal  11  through radio communication. 
         [0061]    The controller  10   c  of the measuring device  10  receives the search command via the radio module  10   d . The controller  10   c  sends a search command to the lower end coil  8   d  of the solar photovoltaic panel  9 E from the coil  10   a.    
         [0062]    The controller  2  of the solar photovoltaic panel  9 E receives the search command from the lower end coil  8   d  via the communicator  2   a.    
         [0063]    Receiving the search command, the controller  2  starts the placement examination procedure (panel placement examination procedure) shown in  FIG. 6 . 
         [0064]    The controller  2  determines whether a search command has been received within a predetermined reference time period (Step S 11 ). 
         [0065]    If a search command has been received (Step S 11 ; YES), the processing will be duplicated; therefore, the controller  2  sends (returns) a search rejection signal and ends this round of procedure (Step S 22 ). 
         [0066]    On the other hand, if no search command has been received within the reference time period (Step S 11 ; NO), the controller  2  selects one of the coils excluding the coil  8  having received the search command in a preset order and sends a search command to the coil (Step S 12 ). Any order, for example the clockwise or counterclockwise order from the coil  8  having received the search command, can be used. 
         [0067]    Subsequently, the controller  2  resets the timer and starts measuring the time (Step S 13 ). 
         [0068]    Then, it is determined whether a response signal is received from the adjoining solar photovoltaic panel  9  via the coil  8  to which the search command was sent (Step S 14 ). 
         [0069]    If no response signal is received (Step S 14 ; NO), it is determined whether a preset response waiting time has elapsed based on the time measured by the timer (Step S 15 ). 
         [0070]    If the response waiting time has not elapsed (Step S 15 ; NO), the controller  2  returns to the Step S 14  and waits for reception of a response signal. 
         [0071]    On the other hand, if a response signal is received in the Step S 14  (Step S 14 ; YES), it is determined whether the received response signal is a search rejection signal (Step S 18 ). 
         [0072]    If the received response signal is a search rejection signal (Step S 18 ; YES), the controller  2  proceeds to Step S 20 , described hereafter. 
         [0073]    On the other hand, if the received response signal is not a search rejection signal (Step S 18 ; NO), the controller  2  proceeds to Step S 19 . 
         [0074]    In the Step S 19 , the controller  2  adds the ID of the coil  8  that has received a search command and its own panel ID housed in the ID retainer  4  to the received response signal for including the transfer path (Step S 17 ). In other words, the controller  2  creates a new response signal=[(the received response signal), ID of the coil  8  that has received the response signal: Panel ID]. 
         [0075]    On the other hand, if the response waiting time has elapsed in the Step S 15  (Step S 15 ; YES), in other words if the response waiting time has elapsed without receiving a response signal since a search command was sent in the Step S 12 , it is determined whether the number of times of a search command being sent has reached a predetermined reference number (Step S 16 ). 
         [0076]    If the number of times of a search command being sent from the same coil  8  has not reached the reference number (Step S 16 ; NO), the controller  2  returns to the Step S 12  and resends a search command. 
         [0077]    On the other hand, if the same coil  8  has sent a search command as many times as the reference number (Step S 16 ; YES), a failure to receive a response signal has occurred and the controller  2  creates a response signal including the ID of the coil  8  to which a search command was sent, its own panel ID stored in the ID retainer  4 , and the ID of the coil  8  that has received a search command. In other words, the controller  2  creates a response signal [ID of the search command destination coil  8 : Panel ID: ID of the search command-receiving coil  8 ]. 
         [0078]    After the Step S 17  or S 19 , the controller  2  determines whether a search command is sent to all three coils excluding the search command-receiving coil  8  (Step S 20 ). If there is any coil to which no search command has been sent (Step S 20 ; NO), the controller  2  returns to the Step S 12 , selects a coil  8  to which no search command has been sent, and sends a search command to the selected coil  8 . 
         [0079]    On the other hand, if a search command has been sent to all coils excluding the search command-receiving coil  8  (Step S 20 ; YES), the controller  2  sends the response signal created in the Step S 17  or S 19  to the search command-receiving coil  8  (Step S 21 ). 
         [0080]    Then, the controller  2  of the solar photovoltaic panel  9 E ends this round of placement examination procedure. 
         [0081]    The controllers  2  of the solar photovoltaic panels  9 A to  9 D and  9 F other than the solar photovoltaic panel  9 E execute the same, above-described placement examination procedure when the controller  2  receives a search command from any coil  8 . 
         [0082]    The controller  10   c  of the measuring device  10  receives a response signal from the facing coil  8  of the solar photovoltaic panel  9 E via the coil  10   a.    
         [0083]    The received response signal includes the ID of the coil on the solar photovoltaic panel  9  that has received no response, the panel ID, and the ID of the search command-receiving coil  8  and additionally information indicating the transfer path of the response signal. 
         [0084]    The controller  10   c  analyzes the received response signal to obtain placement information indicating the placement/array of the solar photovoltaic panels  9 . 
         [0085]    The operation of the entire solar photovoltaic system and measuring device  10  after each solar photovoltaic panel  9  (the controller  2  thereof) executes the above-described placement examination procedure will be described hereafter based on the case in  FIG. 7 . 
         [0086]    For easier understanding, only the solar photovoltaic panels  9 B,  9 C,  9 E, and  9 F among the solar photovoltaic panels  9  ( 9 A to  9 F) shown in  FIG. 7  will be discussed. 
         [0087]    First, a search command is sent from the coil  10   a  of the measuring device  10  to the lower end coil  8   d  of the solar photovoltaic panel  9 E. 
         [0088]    The controller  2  of the solar photovoltaic panel  9 E receives the search command from the lower end coil  8   d . In response to the received search command, the controller  2  sends a search command to the right end coil  8   r  and upper end coil  8   u  in sequence (Step S 11 ). Here, a search command is sent also to the left end coil  8   l , which, however, is not discussed here as mentioned above. 
         [0089]    The controller  2  of the solar photovoltaic panel  9 F receives from the left end coil  8   l  the search command the controller  2  of the solar photovoltaic panel  9 E sent to the right end coil  8   r . In response to the received search command, the controller  2  of the solar photovoltaic panel  9 F sends a search command to the lower end coil  8   d , right end coil  8   r , and upper end coil  8   u  in sequence (Step S 12 ). 
         [0090]    Similarly, the controller  2  of the solar photovoltaic panel  9 B receives from the lower end coil  8   d  the search command the controller  2  of the solar photovoltaic panel  9 E sent to the upper end coil  8   u . In response to the received search command, the controller  2  of the solar photovoltaic panel  9 B sends a search command to the right end coil  8   r  and upper end coil  8   u  in sequence (Step S 12 ). 
         [0091]    The controller  2  of the solar photovoltaic panel  9 C receives the search commands sent by the solar photovoltaic panels  9 F and  9 B from the lower end coil  8   d  and left end coil  8   l . Here, it is assumed that the search command from the lower end coil  8   d  is received first. In response to the search command received from the lower end coil  8   d , the controller  2  sends a search command to the right end coil  8   r , upper end coil  8   u , and left end coil  8   l  in sequence (Step S 12 ). 
         [0092]    The controller  2  of the solar photovoltaic panel  9 C determines that no response signal is received from the right end coil  8   r  and upper end coil  8   u  (Step S 16 ; YES). Therefore, the controller  2  creates a response signal including [ID=r of the search command destination coil  8 : Panel ID=C: ID=d of the search command-receiving coil  8 ]. Similarly, the controller  2  creates a response signal including [ID=u of the search command destination coil  8 : Panel ID=C: ID=d of the search command-receiving coil  8 ]. The controller  2  transfers the two created response signals to the upper end coil  8   u  of the solar photovoltaic panel  9 F from the lower end coil  8   d.    
         [0093]    Furthermore, the controller  2  of the solar photovoltaic panel  9 C returns a search rejection signal in response to the search command received from the solar photovoltaic panel  9 B (Step S 22 ) 
         [0094]    The controller  2  of the solar photovoltaic panel  9 F determines that no response signal is received from the lower end coil  8   d  and right end coil  8   r  (Step S 16 : YES). Therefore, the controller  2  creates a response signal including [ID=d of the search command destination coil  8 : Panel ID=F: ID=1 of the search command-receiving coil  8 ]. Similarly, the controller  2  creates a response signal including [ID=r of the search command destination coil  8 : Panel ID=F: ID=1 of the search command-receiving coil  8 ]. Furthermore, the controller  2  adds the ID=u of the response signal-receiving coil  8  and the ID=F indicating the solar photovoltaic panel  9  to the response signals received from the solar photovoltaic panel  9 C. The controller  2  transfers the four response signals to the right end coil  8   r  of the solar photovoltaic panel  9 E from the left end coil  8   l.    
         [0095]    The controller  2  of the solar photovoltaic panel  9 B determines that no response signal is received from the upper end coil  8   u  (Step S 16 : YES). Therefore, the controller  2  creates a response signal including [ID=u of the search command destination coil  8 : Panel ID=B: ID=d of the search command-receiving coil  8 ], and transfers the response signal to the upper end coil  8   u  of the solar photovoltaic panel  9 E from the lower end coil  8   d.    
         [0096]    Furthermore, the controller  2  of the solar photovoltaic panel  9 B returns a search rejection signal in response to the search command from the solar photovoltaic panel  9 C (Step S 22 ). 
         [0097]    The controller  2  of the solar photovoltaic panel  9 E adds the ID=u of the response signal-receiving coil  8  and the panel ID=E to the one response signal received from the solar photovoltaic panel  9 B to create a new response signal. Furthermore, the controller  2  adds the ID=r of the response signal-receiving coil  8  and the panel ID=E to the four response signals received from the solar photovoltaic panel  9 F to create four new response signals. The controller  2  sends a total of five new response signals created to the measuring device  10  via the lower end coil  8   d.    
         [0098]    The measuring device  10  receives the above five response signals via the coil  10   a.    
         [0099]    The five response signals are as follows:
       (1) ((u: B: d), u: E)   (2) ((d: F: l), r: E)   (3) ((r: F: l), r: E)   (4) ((r: C: d), u: F, r: E)   (5) ((u: C: d), u: F, r: E)       
 
         [0105]    In the above, u presents the ID of the upper end coil  8   u ; d, the lower end coil  8   d ; r, the right end coil  8   r ; and  1 , the left end coil  8   l . Furthermore, A to F present the IDs of the solar photovoltaic panels  9 A to  9 F. 
         [0106]    The above (1) means that no response to a search command sent to the upper end coil  8   u  of the solar photovoltaic panel  9 B is detected, and a response signal is sent from the lower end coil  8   d  of the solar photovoltaic panel  9 B and received by the upper end coil  8   u  of the solar photovoltaic panel  9 E. 
         [0107]    The above (2) means that no response to a search command sent to the lower end coil  8   d  of the solar photovoltaic panel  9 F is detected, and a response signal is sent from the left end coil  8   l  of the solar photovoltaic panel  9 F and received by the right end coil  8   r  of the solar photovoltaic panel  9 E. 
         [0108]    The above (3) means that no response to a search command sent to the right end coil  8   r  of the solar photovoltaic panel  9 F is detected, and a response signal is sent from the left end coil  8   l  of the solar photovoltaic panel  9 F and received by the right end coil  8   r  of the solar photovoltaic panel  9 E. 
         [0109]    The above (4) means that no response to a search command sent to the right end coil  8   r  of the solar photovoltaic panel  9 C is detected, a response signal is sent from the lower end coil  8   d  of the solar photovoltaic panel  9 C, and the response signal is received by the upper end coil  8   u  of the solar photovoltaic panel  9 F and the right end coil  8   r  of the solar photovoltaic panel  9 E in sequence. 
         [0110]    The above (5) means that no response to a search command sent to the upper end coil  8   u  of the solar photovoltaic panel  9 C is detected, a response signal is sent from the lower end coil  8   d  of the solar photovoltaic panel  9 C, and the response signal is received by the upper end coil  8   u  of the solar photovoltaic panel  9 F and the right end coil  8   r  of the solar photovoltaic panel  9 E in sequence. 
         [0111]    It is determined from the above (1) that the solar photovoltaic panel  9 B is situated above the solar photovoltaic panel  9 E and there is nothing above the solar photovoltaic panel  9 B. 
         [0112]    It is determined from the above (2) that the solar photovoltaic panel  9 F is situated on the right of the solar photovoltaic panel  9 E and there is nothing below the solar photovoltaic panel  9 F. 
         [0113]    It is determined from the above (3) that the solar photovoltaic panel  9 F is situated on the right of the solar photovoltaic panel  9 E and there is nothing on the right of the solar photovoltaic panel  9 F. 
         [0114]    It is determined from the above (4) that the solar photovoltaic panel  9 F is situated on the right of the solar photovoltaic panel  9 E, the solar photovoltaic panel  9 C is situated above the solar photovoltaic panel  9 F, and there is nothing on the right of the solar photovoltaic panel  9 C. 
         [0115]    It is determined from the above (5) that the solar photovoltaic panel  9 F is situated on the right of the solar photovoltaic panel  9 E, the solar photovoltaic panel  9 C is situated above the solar photovoltaic panel  9 F, and there is nothing above the solar photovoltaic panel  9 C. 
         [0116]    The controller  10   c  analyzes the response signals as described above and obtains placement information indicating that the solar photovoltaic panel  9 B is placed above the solar photovoltaic panel  9 E, the solar photovoltaic panel  9 F is placed on the right of the solar photovoltaic panel  9 E, and the solar photovoltaic panel  9 C is placed on the solar photovoltaic panel  9 F. 
         [0117]    Furthermore, the controller  10   c  creates the placement chart shown in  FIG. 3  from the placement information and sends the placement information to the operation terminal  11  via the radio module  10   d . The operation terminal  11  visually displays the received placement information. The worker can easily know the placement of the solar photovoltaic panels  9  from the display. 
         [0118]    In the above explanation, a search command and the like are sent from the operation terminal  11  and the acquired information is displayed on the display  17  of the operation terminal  11 . It is possible to conduct an operation to issue a search command directly from the measuring device  10  and display the acquired information on the measuring device  10 . 
         [0119]    As described above, according to this embodiment, the worker can easily obtain the placement information of the solar photovoltaic panels  9 . In other words, the construction information indicating the construction state of a solar photovoltaic system can easily be obtained. Furthermore, the information acquisition task is automated, whereby the information is highly reliable. Moreover, the worker&#39;s task is simplified. 
       Modified Embodiment 1 
       [0120]    In the above embodiment, information regarding a search rejection signal is not transferred to the measuring device  10 . However, like a response signal, it is possible to transfer a search rejection signal to the measuring device  10  with the addition of information indicating the transfer path. As a result, it is possible to acquire not only the placement information of solar photovoltaic panels  9  but also information indicating the facing relationship between the coils  8 . 
       Embodiment 2 
       [0121]    In the above embodiment, a case in which the placement information indicating the physical placement of solar photovoltaic panels  9  is described. The present disclosure is not restricted thereto. The present disclosure is applicable to examination of the connection relationship (wiring path) of solar photovoltaic panels  9 . 
         [0122]    An embodiment of examining the connection relationship of solar photovoltaic panels  9  is described hereafter. 
         [0123]    In this embodiment, as shown in  FIGS. 8 and 9 , the + output connector  1   b  and − output connector  1   d  of a solar photovoltaic panel  9  have a coil  8   p  and a coil  8   m , respectively. As the + output connector  1   b  (or − output connector  1   d ) of an adjoining solar photovoltaic panel  9  and the − output connector  1   d  (or + output connector  1   b ) of an adjoining solar photovoltaic panel  9  are connected, the adjoining solar photovoltaic panels  9  are series-connected. Then, of the adjoining solar photovoltaic panels  9 , the coil  8   p  provided at the + output connector  1   b  and the coil  8   m  provided at the − output connector  1   d  face each other. 
         [0124]    In this state, the coil  10   a  of the measuring device  10  is placed near the coil  8   p  provided at the + output connector  1   b  or the coil  8   m  provided at the − output connector  11   d  of an end solar photovoltaic panel  9  and sends out a search command to examine the connection relationship and obtain the connection information (wiring information). 
         [0125]    The connection examination procedure will be described hereafter with reference to  FIG. 10 . 
         [0126]    First, the measuring device  10  sends a connection search command (simply a search command, hereafter) to the coil  8   p  or  8   m  of an end solar photovoltaic panel  9 . The controller  2  of the end solar photovoltaic panel  9  receives the search command via the coil  8   p  or  8   m  and communicator  2   a.    
         [0127]    In the following explanation, for easier understanding, it is assumed that a search command is sent to the coil  8   p  of an end solar photovoltaic panel  9 . 
         [0128]    First, the controller  2  sends a search command to the next coil  8   m  of the solar photovoltaic panel  9  via the communicator  2   a  (Step S 31 ). Subsequently, the controller  2  resets the timer and starts measuring the time (Step S 32 ). 
         [0129]    Subsequently, the controller  2  determines whether a response signal from the coil  8   m  is received (Step S 33 ). If not received (Step S 33 ; NO), it is determined whether a predetermined response waiting time has elapsed (Step S 34 ). 
         [0130]    If the response waiting time has not elapsed (Step S 34 ; NO), the controller  2  returns to the Step S 33  and waits for reception of a response signal. 
         [0131]    If a response signal is received (Step S 33 ; YES), the controller  2  reads its own panel ID from the ID retainer  4  and adds the ID to the received response signal (Step S 37 ). 
         [0132]    On the other hand, if the response waiting time has elapsed in the Step S 34  (Step S 34 ; YES), it is determined whether the number of times of a search command being sent has reached a predetermined reference number (Step S 35 ). If the number of times of being sent has not reached the reference number, the controller  2  returns to the Step S 31 . 
         [0133]    On the other hand, if a search command has been sent as many times as the reference number (Step S 35 ; YES), a failure to receive a response signal has occurred and the controller  2  creates a response signal including its own panel ID (Step S 36 ). 
         [0134]    After executing the Step S 36  or S 37 , the controller  2  sends the response signal to the measuring device  10  via the coil  8   p  that have received the search command (Step S 38 ), and ends this round of connection examination procedure. 
         [0135]    Receiving a search command sent from the coil  8   m  of the solar photovoltaic panel  9  in the preceding stage via the coil  8   p , the controllers  2  of the other solar photovoltaic panels  9  execute the same connection examination procedure. 
         [0136]    The measuring device  10  receives the response signal from the coil  2   p  of the end solar photovoltaic panel  9  and analyzes the response signal to obtain the connection information (wiring information) indicating the number and order of connections of solar photovoltaic panels  9 . The measuring device  10  sends the connection information to the operation terminal  11 . The operation terminal  11  creates an image showing the connection relationship of solar photovoltaic panels  9  based on the received connection information and displays the image on the display  17  as exemplified in  FIG. 11 . 
         [0137]    With the above configuration, the connection information of solar photovoltaic panels  9  can easily and reliably be acquired. 
       Modified Embodiment 2 
       [0138]    In Embodiments 1 and 2, the time of acquiring the placement information and/or connection information is not limited to when the construction of a solar photovoltaic system is completed. The above information can be acquired at any time. For example, the placement information and/or connection information can be obtained while the solar photovoltaic system is in operation. 
       Embodiment 3 
       [0139]    In the above embodiments, the measuring device  10  collects the placement information and/or connection information. The present disclosure is not confined thereto. The measuring device  10  can collect various kinds of information. 
         [0140]    An embodiment will be described hereafter in which various parameters indicating the operation state of each solar photovoltaic panel  9  are added to the panel ID and the measuring device  10  collects the various parameters along with the placement information and/or connection information. 
         [0141]    In this embodiment, in creating a response signal in the Step S 17  of  FIG. 6 , the controller  2  acquires an power generation voltage V, a power generation current I, and a temperature T, which are physical quantities indicating the power generation state of the photovoltaic cell module  1 , and creates a response signal comprising [ID of the search command destination coil: Panel ID, Power generation voltage V, Power generation current I, Temperature T: ID of the search command-receiving coil]. Furthermore, in adding its own panel ID to the received response signal in the Step S 19  of  FIG. 6 , the controller  2  adds [ID of the response signal-receiving coil: Panel ID, Power generation voltage V, Power generation current I, Temperature T]. 
         [0142]    Similarly, in creating a response signal in the Step S 36  of  FIG. 10 , the controller  2  creates a response signal including [Panel ID, Power generation voltage V, Power generation current I, Temperature T]. Furthermore, in adding its own panel ID to the received response signal in the Step S 37 , the controller  2  adds [Panel ID, Power generation voltage V, Power generation current I, Temperature T]. 
         [0143]    The measuring device  10  analyzes the response signal and collects the parameters indicating the operation state of each solar photovoltaic panel  9  such as the power generation voltage V, power generation current I, and temperature T along with the placement information and/or connection information. 
         [0144]    The measuring device  10  sorts out the collected parameters and, for example, creates and displays on the display  17  of the operation terminal  11  an image shown in  FIG. 13 . The worker can acquire the placement information and/or connection information of solar photovoltaic panels  9  and obtain the operation state of each solar photovoltaic panel  9 , for example, at the test operation stage after the solar photovoltaic system is completed. 
         [0145]    Moreover, the command to collect the parameters (collection command) can be separated from a search command. In such a case, upon receiving a search command, the controller  2  can exclude the ID of the coil  8  from a response signal but include the panel ID and measurement parameters in a response signal. 
         [0146]    Furthermore, it is possible that the controller  2  determines whether the solar photovoltaic panel  9  is normal/abnormal (failed) based on measurement data and includes state information indicating that it is normal/abnormal in the response signal. 
         [0147]    More specifically, when a solar photovoltaic panel  9  is failed, for example when some cell in the photovoltaic cell module  1  is disconnected or the power generation performance is deteriorated, the power generation voltage V and/or power generation current I becomes lower than a reference value. Furthermore, the generated power quantity of the photovoltaic cell module  1  depends on the amount of sunlight S. For example, the power generation current is nearly proportional to the amount of insolation. Furthermore, the power generation performance of the photovoltaic cell module  1  changes according to the operation temperature. 
         [0148]    Then, an additional sensor measuring the amount of sunlight S (the sunlight amount sensor, hereafter)  13  is provided on each solar photovoltaic panel  9  as shown in  FIG. 13 . Then, when the temperature T detected by the temperature sensor  6  falls within a reference range and the power generation voltage V and power generation current I lower than the reference values corresponding to the amount of sunlight S measured by the sunlight amount sensor  13  are not obtained, the controller  2  determines that some failure has occurred. 
         [0149]    In such a case, the controller  2  adds state information indicating the failure to the response signal along with the panel ID. 
         [0150]    With the above configuration, the worker can know whether the solar photovoltaic panels  9  are normal/abnormal on the operation terminal  11 . Furthermore, the state information can include the parameters such as the power generation voltage V, power generation current I, temperature T, amount of sunlight S, and the like at the time when a failure is determined. The measuring device  10  analyzes the response signal received from the solar photovoltaic panels  9  and upon detection of state information indicating a failure, transfers the ID of the failed panel and its placement information, connection information, power generation voltage V, power generation current I, temperature T, amount of sunlight S, and the like to the operation terminal  11 . 
         [0151]    The operation terminal  11  adds and displays the above information, for example, on the screen  17  shown in  FIG. 12 . 
         [0152]    With the above configuration, the user can know whether the solar photovoltaic panels  9  are normal/abnormal on the operation terminal  11 . 
         [0153]    Moreover, it is possible to provide a single sunlight amount sensor  13  to multiple solar photovoltaic panels  9  and supply data acquired by the single sunlight amount sensor  13  to the controllers  2  of the multiple solar photovoltaic panels  9 . 
         [0154]    Moreover, it is possible to provide (or connect) the sunlight amount sensor  13  to the measuring device  10  instead of placing on the solar photovoltaic panels  9 , and include in a search command (or collection command) and deliver to the solar photovoltaic panels  9  the amount of sunlight S measured by the sunlight amount sensor  13 . In such a case, the controller  2  of each solar photovoltaic panel  9  obtains the amount of sunlight S from the received search command and uses it for determining a failure. 
         [0155]    Moreover, it is also possible that the operation terminal  11  sends the amount of sunlight S to the measuring device  10  and the measuring device  10  includes in a search command and delivers the supplied amount of sunlight S. 
         [0156]    As described above, according to Embodiment 3, it is possible to measure the power generation voltage V, power generation current I, temperature T, and the like of each solar photovoltaic panel  9  and acquire those in association with the panel ID. Therefore, the operation and state of each solar photovoltaic panel  9  can easily be visualized and provided to the user. The user can easily identify the position of a failed panel, contributing to efficient inspection/replacement work. 
       Modified Embodiment 3 
       [0157]    In Embodiment 3, the inclination θ is useful as information included in the panel ID. 
         [0158]    In such a case, for including the inclination θ in the panel ID, as shown in  FIG. 14 , an additional sensor obtaining the inclination (the inclination sensor, hereafter)  13  is provided to the solar photovoltaic panels  9 . In order to increase the power generation efficiency of the solar power generation, the solar photovoltaic panels  9  are generally placed with an inclination of approximately 20 to 25 degrees. Therefore, the inclination sensor  13  determines the vertical placement state. If a solar photovoltaic panel  9  is placed upside down based on the determination information, the placement information of the upper end coil  8   u  and lower end coil  8   d  is corrected (exchanged) before processing. As a result, even if a solar photovoltaic panel  9  is placed upside down by mistake, the defective placement can easily be identified. 
         [0159]    It is assumed that the inclination sensor  13  determines that the solar photovoltaic panel  9 B is placed upside down. In such a case, the controller  2  of the solar photovoltaic panel  9 B creates, for example, a response signal [(u: B: d: inverted)]. Here, “inverted” means that the inclination sensor  13  determines that the lower end of a solar photovoltaic panel  9  is physically situated above the upper end. In such a case, the controller  10   c  of the measuring device  10  corrects the response signal to [d: B: u] before processing. 
       Embodiment 4 
       [0160]    In the above Embodiments 1 to 3, the coils  8  are used only as an antenna for magnetic communication. The coils  8  can simultaneously be used for other purposes. 
         [0161]    For example, the coils  8  can be used for power supply. 
         [0162]    In such a case, for example, as shown in  FIG. 12 , an inverter  12  is connected to the controller  2  and the AC output thereof is supplied to the coils  8   u ,  8   d ,  8   r , and  8   l.    
         [0163]    The controller  2  of the solar photovoltaic panels  9  activates the inverter  12 , for example, periodically, and supplies the power to the coils  8   u ,  8   d ,  8   r , and  8   l  intermittently. 
         [0164]    On the other hand, a device operating with the power supplied from the coils  8  comprises a coil causing mutual induction with the coils  8 . 
         [0165]    For using the device, the user makes the device coil face a coil  8 . 
         [0166]    As an AC power is supplied to the coil  8 , mutual induction with the coil  8  induces a voltage in the device coil. The device starts operating with the induced voltage and exchanges necessary information with the controller  2  via the coil. 
         [0167]    The controller  2  authenticates the device from the exchanged information and if the device is rightful, operates the inverter  12  continuously to continuously supply the power to the device via the coil  8 . 
         [0168]    With the above configuration, for example, it is possible to operate a device by acquiring the power through electromagnetic induction with a coil  8  exposed at an end face of the matrix of installed solar photovoltaic panels  9 . Moreover, communication between the device and controller  2  via the coil is available. 
       Embodiment 5 
       [0169]    In the above explanation, cases of collecting information after the construction are described. 
         [0170]    The present disclosure is not restricted thereto and the panel ID can be read upon factory shipping, at the transportation base stations or installation site, or the like. This makes it possible to track the product in case of missing on the distribution channel or replacement of something. In such a case, the panel ID can be read by exposing the solar photovoltaic panel  9  to light. 
         [0171]    However, the package has to be opened for exposing a solar photovoltaic panel  9  to light. In order to eliminate such a problem, it is possible in some configuration to supply operation power from outside. 
         [0172]    An embodiment of the above configuration will be described. 
         [0173]    In such a configuration, as shown in  FIG. 15 , a rectifier  14  is provided in the housing box  7 . The rectifier  14  rectifies and supplies to the controller  2  the induced electromotive force of the coils  8  as the operation power. 
         [0174]    On the other hand, a reader device  10  comprises an inverter circuit  15   e  as shown in  FIG. 16 . 
         [0175]    The operation will be described hereafter using the task of identifying the product ID upon factory shipping or upon delivery to the construction site by way of example. 
         [0176]    The controller  15   c  of the reader device  15  converts the electric power to an AC by the inverter circuit  15   e  of the power source  15   b  and supplies the AC to the coil  15   a.    
         [0177]    As the coil  15   a  of the reader device  15  is placed near any coil  8  of a solar photovoltaic panel  9 , an induced electromotive force is generated in the coil  8 . The rectifier  14  rectifies the induced electromotive force generated in the coil  8  and supplies the operation power to the controller  2 . 
         [0178]    As a result, the controller  2  starts operating. 
         [0179]    The controller  15   c  of the reader device  15  sends a search command to the coil  8  from the coil  15   a  in parallel to supply of the AC power to the coil  15   a.    
         [0180]    The controller  2  receives the search command via any coil  8  of a solar photovoltaic panel  9 . In response to the search command, the controller  2  executes the above-described placement examination procedure and sends response signals including its own panel ID to the reader device  15 . 
         [0181]    The controller  15   c  receives the panel ID via the coil  15   a  and sends the panel ID to the display  15   d . The display  15   d  displays the received panel ID. The worker views the display of response information including the ID on the display  15   d  and checks whether the solar photovoltaic panel  9  is a proper product for the construction. 
         [0182]    Moreover, it is possible for the purpose of power saving to normally apply an AC voltage to the coil  15   a  intermittently and apply an AC voltage to the coil  15   a  continuously when magnetic connection between the coil  15   a  and any coil  8  of a solar photovoltaic panel  9  is detected. 
         [0183]    With the panel ID being read as described above, noncontact checkup for a proper product or stolen product and distribution management in the process of product distribution are available without opening the package. 
         [0184]    Furthermore, in the above embodiment, the panel IDs of solar photovoltaic panels  9  are collected before the construction such as upon factory shipping or during the transportation of solar photovoltaic panels  9 , and at the construction site. The present disclosure is not confined thereto. Even after the solar photovoltaic panels  9  are installed, it is possible to track the product in case of missing on the distribution channel or replacement of something by placing the reader device  15  over the solar photovoltaic panel  9  and reading the panel ID. 
         [0185]    Moreover, as shown in  FIG. 17 , a configuration in which an alternating magnetic field is applied to a coil  8   p  provided at the + output connector  1   b  and a coil  8   m  provided at the − output connector  1   d  to supply the operation power to the controller  2  is also available. 
         [0186]    In the above embodiments, the coils  8  are placed at the end faces of a solar photovoltaic panel  9 . The coils  8  can be placed at any positions as long as mutual induction (communication) with an adjoining coil  8  is assured. 
         [0187]    For example, as shown in  FIG. 18 , it is possible to form steps at the ends of solar photovoltaic panels  9  and place the coils there. In such a case, a step is formed at two facing sides as shown in (a) of  FIG. 18  and a step is formed at two other sides as shown in (b) of  FIG. 18 . 
         [0188]    Alternatively, as shown in  FIG. 19 , when the photovoltaic cell module  1  is produced in a process similar to the semiconductor process of thin-film photovoltaic cells or the like, it is possible to create a coil pattern in the process of producing the electrodes of thin-film photovoltaic cells and use a part of the photovoltaic cell module  1  as a coil surface. 
         [0189]    In such a case, the coils are formed in the photovoltaic cell production process, whereby the communication function can be added without increasing the production cost.  FIG. 20  is an illustration showing an exemplary configuration of the solar photovoltaic panels  9  of which the coils are created as described above. In this case, the solar photovoltaic panels  9  are produced to overlap in a checkerboard pattern so that the coil parts overlap with each other after installed. With this configuration, the top and bottom coils formed on the panel surfaces are coupled to each other and enable efficient communication. Furthermore, although the coils are rectangular in  FIG. 19 , the coils can be in other shapes such as circular or triangular. 
         [0190]    Furthermore, although the panels are rectangular in  FIGS. 1 to 20 , the panels can be triangular, hexagonal, or the like as shown in  FIG. 21  as long as their sides can be overlapped. 
         [0191]    Furthermore, in the above embodiments, the coils are used as an antenna for magnetic communication. Any antenna can be used in place of the coils as long as short distance noncontact communication is available. Optical communication is also usable. 
         [0192]    From the viewpoint of protecting the solar photovoltaic panels  9 , as shown in  FIG. 22 , it is desirable to cover a solar photovoltaic panel  9  entirely or in part with an outer frame  16 . The outer frame  16  is desirably formed by a metal. However, an ordinary metal shields magnetic. Therefore, the outer frame  16  is made of a non-magnetic material such as aluminum so that the magnetic flux generated by the coil can pass through the outer frame  16 . Some resin such as plastics can be used as long as heat-resistance and strength is assured. 
         [0193]    The foregoing describes some example embodiments for explanatory purposes. Although the foregoing discussion has presented specific embodiments, persons skilled in the art will recognize that changes may be made in form and detail without departing from the broader spirit and scope of the invention. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense. This detailed description, therefore, is not to be taken in a limiting sense, and the scope of the invention is defined only by the included claims, along with the full range of equivalents to which such claims are entitled. 
       REFERENCE SIGNS LIST 
       [0000]    
       
           1  Photovoltaic cell module 
           1   a  + (positive) terminal box 
           1   b  + (positive) output connector 
           1   c  − (negative) terminal box 
           1   d  − (negative) output connector 
           2  Controller 
           2   a  Communicator 
           3  Power source 
           4  ID retainer 
           5  Current sensor 
           6  Temperature sensor 
           7  Housing box 
           8 ,  8   a ,  8   b ,  8   c ,  8   d ,  8   e ,  8   f ,  8   g ,  8   p ,  8   m , Coil 
           8   u  Upper end coil 
           8   d  Lower end coil 
           8   r  Right end coil 
           8   l  Left end coil 
           9 ,  9   a ,  9   b ,  9   c  Solar photovoltaic panel 
           10  Measuring device 
           10   a  Coil 
           10   b  Power source circuit 
           10   c  Controller 
           10   d  Radio module 
           11  Operation terminal 
           12  Inverter 
           13  Additional sensor 
           14  Rectifier 
           15  Reader device 
           15   a  Coil 
           15   b  Power source 
           15   c  Controller 
           15   d  Display 
           15   e  Inverter circuit 
           16  Outer frame 
           17  Display