Abstract:
An in-vehicle charging device is provided with: a recording unit ( 27 ) that accumulates vehicle information regarding a vehicle; a vehicle-side PLC communication control unit ( 26 ) that, when it is determined to be necessary to transmit vehicle information accumulated at the recording unit ( 27 ) to the outside of the vehicle, commands transmission of a control signal for closing an earth leakage circuit breaker (not shown in figure); and a charging control unit ( 25   b ) that transmits a control signal to the earth leakage circuit breaker on the basis of the command from the vehicle-side PLC communication control unit ( 26 ). When electrical energy is not being supplied to a storage battery ( 24 ), the vehicle-side PLC communication control unit ( 26 ) establishes PLC and batch transmits vehicle information when the earth leakage circuit breaker has been closed by the control signal transmitted from the charging control unit ( 25   b ).

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to an in-vehicle charging apparatus to be installed in a vehicle and supplies power for charging a storage battery installed in the vehicle, through a power line extending from an external power supply via an earth leakage circuit-breaker. More particularly, the invention relates to an in-vehicle charging apparatus capable of using the power line as a communication line. 
       BACKGROUND ART 
       [0002]    In recent years, hybrid electric vehicles (HEVs) and electric vehicles (EVs) have been generalized to some degree, and charging facilities for charging storage batteries installed in such vehicles are widely used along with the generalization of such vehicles. In this regard, as a related art, there has been disclosed a technique which turns On/Off a main relay of a charging cable (power line) using a control pilot line (CPLT line; communication control line) in order to control charging a storage battery installed in a vehicle (for example, see Patent Literature (hereinafter, abbreviated as PTL) 1). According to this technique, turning on the main relay of the charging cable in a time slot for which electric power charge is low, based on power information acquired from an external power supply of a vehicle through the CPLT line allows a storage battery of the vehicle to be appropriately charged while keeping the cost required for charging low. Note that, although a charging process flow using the CPLT line is defined in ISO/IEC 61851 standard and SAE J1772 standard, which are joint connect standards of EVs and HEVs, a description thereof will be omitted herein. 
         [0003]    In addition, as another related art, a technique that monitors the state of charge of a storage battery installed in a vehicle using power line communication (PLC) which uses a power line as a communication line has been disclosed (for example, see PTL 2). According to this technique, before the storage battery installed in the vehicle is charged, a communication connection using a power line with a vehicle ID, i.e., PLC is established. Then, disconnection of a charging cable (power line) or the like occurs during a charging process, a cable disconnection detection signal indicating disconnection of a changing cable during the charging process, monitoring information indicating the state of the vehicle, and the vehicle ID are transmitted from a charging control apparatus of the vehicle to an external charging station through communication (PLC) using the charging cable. Accordingly, when disconnection of a charging cable (power line) occurs during a charging process in an environment in which a plurality of vehicles are charged at a single charging station, a vehicle and a state in which the disconnection of the charging cable occurs can be instantly monitored and determined on the charging station side. As described above, the establishment of communication connections using PLC which transmits information signals while superimposing one on top of another in an overlapping manner between the vehicle and subscriber equipment (charging station) through an infrastructure facility (in other words, the power line) enables charging control while the storage battery installed in the vehicle is appropriately monitored. 
       CITATION LIST 
     Patent Literature 
       [0004]    PTL 1 
         [0005]    Japanese Patent Application Laid-Open No. 2010-004674 
         [0006]    PTL 2 
         [0007]    Japanese Patent Application Laid-Open No. 2011-010399 
       SUMMARY OF INVENTION 
     Technical Problem 
       [0008]    However, according to the technique disclosed in PTL 1 described above, when the storage battery installed in the vehicle is fully charged, a relay contact of a main circuit of an electric vehicle supply equipment (EVSE; equipment (in other words, the earth leakage circuit-breaker on the power supply side) connecting an external power supply and the vehicle) is open in accordance with a control signal flowing through the CPLT line. Accordingly, since a vehicle-side connection terminal of the power line (charging cable) supplied from the infrastructure side (power supply side) to the vehicle side is in a non-voltage state, the vehicle is electrically safe even when the vehicle-side connection terminal of the power line is separated from the vehicle. However, in this case, the power line connecting the power supply side and the vehicle side is physically cut off due to the relay contact of the main circuit of the EVSE, so that even when the vehicle-side connection terminal of the power line is connected to the vehicle, communication through PLC cannot be performed between an in-vehicle charging apparatus installed in the vehicle and the external power supply (subscriber equipment). In other words, no vehicle information can be transmitted from the vehicle side. 
         [0009]    In addition, according to the technique disclosed in PTL 2 described above, upon completion of charging of the storage battery installed in the vehicle, a relay contact of the earth leakage circuit-breaker disposed between the vehicle-side in-vehicle charging apparatus and the external charging station is open, so that the power line (charging cable) between the in-vehicle charging apparatus and the external charging station is physically cut off. Accordingly, no vehicle information can be transmitted from the vehicle side. 
         [0010]    An object of the present invention is to provide an in-vehicle charging apparatus capable of transmitting vehicle information from a vehicle side using power line communication even when an earth leakage circuit-breaker is turned off. 
       Solution to Problem 
       [0011]    According to an aspect of the present invention, there is provided an in-vehicle charging apparatus that charges a storage battery installed in a vehicle from a power supply provided outside the vehicle through a power line extending via an earth leakage circuit-breaker, the apparatus including: a storage section that stores vehicle information relating to the vehicle; and a vehicle-side PLC communication control section that outputs a control signal for closing the earth leakage circuit-breaker, then establish a PLC communication line using the power line as a communication line, and transmits the vehicle information stored in the storage section to the outside of the vehicle, when determining that the vehicle information stored in the storage section needs to be transmitted to the outside of the vehicle. 
       Advantageous Effects of Invention 
       [0012]    According to the present invention, when no electrical energy is supplied to a storage battery due to opening of an earth leakage circuit-breaker connected to a power line, in other words, when a storage battery is not charged, a PLC communication connection is established by closing the earth leakage circuit-breaker only at necessary timing, and vehicle information stored in a storage section of an in-vehicle charging apparatus is thereby transmitted to the outside. Accordingly, when the storage battery is not charged, the earth leakage circuit-breaker is open in a time slot other than a time slot in which the vehicle information is instantly transmitted through a PLC communication connection. Thus, a vehicle-side connection terminal of the power line is in a non-voltage state because the earth leakage circuit-breaker is open, whereby electrical safety is ensured. In addition, the condition for transmission timing of the vehicle information is any one of a condition for transmitting vehicle information having a predetermined size or greater altogether, a condition for transmitting vehicle information altogether in a case where vehicle information having a high priority level is detected, and a condition for transmitting vehicle information altogether in a case where an evaluation value acquired by “priority level coefficient×data size” is a predetermined value or greater. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0013]      FIG. 1  is a configuration diagram of a system for realizing an in-vehicle charging apparatus according to an embodiment of the present invention; 
           [0014]      FIG. 2  is a detailed circuit configuration diagram of an earth leakage circuit-breaker illustrated in  FIG. 1 ; 
           [0015]      FIG. 3  is a block diagram illustrating a detailed configuration of the in-vehicle charging apparatus illustrated in  FIG. 1 ; 
           [0016]      FIG. 4  is a flowchart illustrating the flow of a PLC process mainly determined and performed by a vehicle-side PLC communication control section of the in-vehicle charging apparatus according to Embodiment 1 of the present invention; 
           [0017]      FIG. 5  is a flowchart illustrating the flow of a PLC process mainly determined and performed by a charging control section of a charger according to Embodiment 2 of the present invention; 
           [0018]      FIG. 6  is a flowchart illustrating the flow of Pattern 1 of a transmission-start determining process in Step S 6  illustrated in  FIG. 4  or  5  according to Embodiment 3 of the present invention; 
           [0019]      FIG. 7  is a flowchart illustrating the flow of Pattern 2 of the transmission-start determining process in Step S 6  illustrated in  FIG. 4  or  5  according to Embodiment 3 of the present invention; 
           [0020]      FIG. 8  is a flowchart illustrating the flow of Pattern 3 of the transmission-start determining process in Step S 6  illustrated in  FIG. 4  or  5  according to Embodiment 3 of the present invention; 
           [0021]      FIG. 9  is a diagram illustrating Table A in which a priority level, a priority level coefficient, a data size example, and an evaluation value for vehicle information are compared with each other; 
           [0022]      FIG. 10  is a diagram illustrating Table B in which a command for each type and a content of each type of vehicle information are compared with each other; 
           [0023]      FIG. 11  is a flowchart illustrating the flow of the process of ending PLC by switching a leakage breaker relay to an Off sequence using a vehicle-side PLC communication control section in Embodiment 4 of the present invention; and 
           [0024]      FIG. 12  is a flowchart illustrating the flow of a PLC connection at the time of starting charging that is generally performed. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0025]    An in-vehicle charging apparatus according to an embodiment of the present invention decreases the number of times of turning on the relay contact of a main circuit of an earth leakage circuit-breaker (EVSE) interposed in a power line (charging cable) connecting an external power supply (in-house equipment) and the in-vehicle charging apparatus to each other as much as possible and keep the turning-on time short. Accordingly, the time during which the relay contact of the main circuit of the EVSE is turned off can be long whereby electrical safety of a vehicle-side connection terminal of the power line can be ensured. In other words, the relay contact of the main circuit of the EVSE is turned on only at the time when the connection of the power line supplying charged power (electrical energy) from the external power supply to the in-vehicle charging apparatus is necessary and only in a time slot in which an information signal (vehicle information) is transmitted and received through PLC between the external power supply and the in-vehicle charging apparatus during the stop of the charging power. Therefore, electrical safety of the vehicle-side connection terminal of the power line can be ensured. 
         [0026]    Stated differently, when the relay contact of the main circuit of the EVSE is turned off during a reservation for charging an in-vehicle storage battery or after the completion of charging, one of the following determines is made in accordance with a desired content for transmitting an information signal to the in-house equipment side including the external power supply from the in-vehicle charging apparatus side. In other words, it is determined whether to transmit an information signal from the in-vehicle charging apparatus to the in-house equipment side using PLC by immediately turning on the relay contact of the main circuit of the EVSE or to transmit an information signal from the in-vehicle charging apparatus to the in-house equipment side using PLC by turning on the relay contact after a predetermined amount of data is stored on the in-vehicle charging apparatus side. Accordingly, the number of times of turning on the relay contact of the main circuit of the EVSE an d the turning-on time of the relay contact can be minimized, whereby electrical safety of the vehicle-side connection terminal of the power line can be ensured. 
         [0027]    Hereinafter, in-vehicle charging apparatuses according to several embodiments of the present invention will be described in detail with reference to the drawings. In the all the drawings for describing the following embodiments, generally, the same reference signs are assigned to the same elements, and any redundant description thereof will be omitted as much as possible. 
       Embodiment 1 
       [0028]      FIG. 1  is a configuration diagram of a system for realizing an in-vehicle charging apparatus according to an embodiment of the present invention. As illustrated in  FIG. 1 , in-house equipment  1  of house  10  and in-vehicle charging apparatus  21  of vehicle  2  are connected to each other using charging cable (power line)  4  via earth leakage circuit-breaker (EVSE)  3 . One end of charging cable  4 , for example, is connected to in-house equipment  1  using plug/outlet  5  having three polarities configured by single-phase AC of AC 100 V and an earth line. In addition, the other end of charging cable  4 , although not particularly illustrated in the figure, is connected to a vehicle-side connection terminal having three polarities through a connection terminal, which includes a CPLT line terminal, having four polarities so as to be connected to in-vehicle charging apparatus  21  of vehicle  2 . 
         [0029]    There are a case where earth leakage circuit-breaker  3  is directly connected to charging cable  4  and a case where earth leakage circuit-breaker  3  is attached to a charging pole installed in advance. In any of the cases, plug/outlet  5  side of charging cable  4  including earth leakage circuit-breaker  3  is included in the infrastructure facility. 
         [0030]    In-house equipment  1  includes panel board  11 , house-side PLC terminal  12 , internet modem  13 , television set  14 , and personal computer (PC)  15 . Panel board  11  takes power from an outdoor power pole and branches power lines inside the house  10 . House-side PLC terminal  12  is connected to the power line branched from panel board  11  and controls the supply of charging power to vehicle  2  side or establishes PLC between vehicle  2  side and the in-house equipment side. Internet modem  13  is connected to house-side PLC terminal  12  and transmits/receives information signals (vehicle information) according to the PLC. Television set  14  and PC  15  are connected to internet modem  13 . 
         [0031]    Vehicle  2  includes: in-vehicle charging apparatus  21  that receives charging power transmitted from house-side PLC terminal  12  through charging cable  4  and controls charging of vehicle  2 ; camera  22 ; and air conditioner  23 , for example. In addition, in-vehicle charging apparatus  21  includes storage battery  24 , charger  25 , vehicle-side PLC communication control section  26 , storage section  27 , and the like, and such elements will be described later in detail. Here, a general driving apparatus for running vehicle  2  and/or the like do not directly relate to the present invention, so that the illustration thereof is omitted. In addition, while the above-described vehicle-side connection terminal having four polarities used for connecting charging cable  4  to in-vehicle charging apparatus  21  is disposed at a predetermined position of a body of vehicle  2 , the illustration of the vehicle-side connection terminal is omitted. 
         [0032]      FIG. 2  is a detailed circuit configuration diagram of earth leakage circuit-breaker  3  illustrated in  FIG. 1 . As illustrated in  FIG. 2 , earth leakage circuit-breaker  3  receives two single-phase AC lines (AC 1  and AC 2 ) and one ground line (GND) of charging cable  4  on in-house equipment  1  side and inputs two single-phase AC lines (AC 1  and AC 2 ) and one ground line (GND) to vehicle  2  side through contacts of leakage breaker relay  31  of earth leakage circuit-breaker  3  interposed between two single-phase AC lines (AC  1  and AC 2 ). Such a configuration is the same as that of a generally used earth leakage circuit-breaker, so that a detailed description thereof will be omitted. 
         [0033]    In an embodiment of the present invention, earth leakage circuit-breaker  3  further includes electric leakage detecting section  32  and relay control section  33 . Electric leakage detecting section  32  detects a change in a magnetic field of a coil changing in accordance with the occurrence of an electric leakage on power lines AC 1  and AC 2 . Relay control section  33  receives an electric leakage detecting signal detected by electric leakage detecting section  32  and a control signal Sg transmitted form vehicle  2  and controls On/Off of the contact of leakage breaker relay  31 . 
         [0034]    Upon detection of an electric leakage by electric leakage detecting section  32 , relay control section  33  turns off the contact of leakage breaker relay  31  regardless whether the control signal Sg is present on vehicle  2  side. In addition, in a case where a control signal Sg transmitted from vehicle  2  side represents an instruction for turning on the contact of leakage breaker relay  31  while an electric leakage is detected by electric leakage detecting section  32 , relay control section  33  performs control such that the contact of leakage breaker relay  31  is turned on at a moment and then is immediately turned off. In other words, when a leakage current is detected by electric leakage detecting section  32 , necessary vehicle information of vehicle  2  side is transmitted to in-house equipment  1  side during a momentary On period of leakage breaker relay  31 , and leakage breaker relay  31  is immediately turned off after the transmission of the vehicle information. Accordingly, a non-voltage state of the vehicle-side connection terminal of charging cable  4  is maintained as long as possible, whereby electrical safety is ensured. 
         [0035]      FIG. 3  is a block diagram illustrating a detailed configuration of in-vehicle charging apparatus  21  illustrated in  FIG. 1 . As illustrated in  FIG. 3 , in-vehicle charging apparatus  21  includes storage battery  24 , charger  25 , vehicle-side PLC communication control section  26 , storage section  27 , and storage battery relay  28 . Storage battery  24  supplies power for driving an electric motor (not illustrated in the figure) of vehicle  2  illustrated in  FIG. 1 . Charger  25  receives AC charging power transmitted from in-house equipment  1  illustrated in  FIG. 1  through charging cable  4 , converts the AC power into DC power, and charges storage battery  24 . Vehicle-side PLC communication control section  26  establishes PLC upon transmission of an information signal (vehicle information) of vehicle  2  side to in-house equipment  1  through charging cable  4 . Storage section  27  stores various kinds of vehicle information of vehicle  2  side. Storage battery relay  28  opens or closes the main circuit of storage battery  24 . 
         [0036]    In addition, charger  25  includes charger power supply circuit  25   a  that receives power of single-phase AC (AC 1  and AC 2 ) from earth leakage circuit-breaker  3  side illustrated in  FIG. 2 , converts the AC power into DC power, and charges storage battery  24  and charging control section  25   b  that detects the completion of preparation of storage battery  24  and charger power supply circuit  25   a  for charging and transmits a control signal Sg to relay control section  33  of earth leakage circuit-breaker  3 . In addition, the single-phase AC lines (AC 1  and AC 2 ) and the ground line (GND) of charging cable  4  are inputted to in-vehicle charging apparatus  21 . 
         [0037]    Next, the operation of the in-vehicle charging apparatus according to Embodiment 1 of the present invention will be described with reference to a flowchart. First, a flow of a case where a PLC process is mainly determined and performed by vehicle-side PLC communication control section  26  of in-vehicle charging apparatus  21  will be described.  FIG. 4  is a flowchart illustrating the flow of a PLC process mainly determined and performed by vehicle-side PLC communication control section  26  of in-vehicle charging apparatus  21  according to Embodiment 1 of the present invention. In other words, this flowchart illustrates a flow of the process that is performed between vehicle-side PLC communication control section  26  of in-vehicle charging apparatus  21  illustrated in  FIG. 3  and charging control section  25   b  of charger  25  and a process in which the vehicle information (data) of vehicle  2  is transmitted to in-house equipment  1  based on a determination mainly made by vehicle-side PLC communication control section  26 . 
         [0038]    As illustrated in  FIG. 4 , first, when a PLC transmission sequence for transmitting vehicle information of vehicle  2  to in-house equipment  1  side using charging cable  4  is started (Step S 1 ), vehicle-side PLC communication control section  26  detects the volume of the vehicle information stored in storage section  27  in a transmission memory buffer (Step S 2 ). Then, vehicle-side PLC communication control section  26  determines whether or not a PLC communication connection (communication line) between vehicle  2  and in-house equipment  1  (house-side PLC terminal  12 ) has been established using charging cable  4  (Step S 3 ). 
         [0039]    Here, in a case where a PLC communication connection between vehicle  2  and in-house equipment  1  has been established (Yes in Step S 3 ), the state is a normal charged state. Accordingly, vehicle-side PLC communication control section  26 , for example, exchanges a regular PLC packet between vehicle  2  and in-house equipment  1  or detects a voltage of the AC line of charging cable  4 . In this way, vehicle-side PLC communication control section  26  starts normal transmission for transmitting vehicle information (data) of vehicle  2  to in-house equipment  1  while continuously detecting whether or not the communication connection between vehicle  2  and in-house equipment  1  is normal (Step S 4 ). Then, vehicle-side PLC communication control section  26  performs a normal transmission process for a regular packet according to PLC while continuing to charge storage battery  24  (Step S 5 ). 
         [0040]    On the other hand, in a case where a PLC communication connection between vehicle  2  and in-house equipment  1  has not been established in Step S 3  (No in Step S 3 ), vehicle-side PLC communication control section  26  performs a transmission-start determining process (Step S 6 ). Here, the transmission-start determining process is a process of determining a condition (form) in which the vehicle information of vehicle  2  is transmitted to in-house equipment  1  so as to establish a PLC communication connection by turning on leakage breaker relay  31  of earth leakage circuit-breaker  3  only when the vehicle information is transmitted. In addition, the transmission-start determining process for the vehicle information is a process in which a transmission start time point is determined based on the condition (form) of the vehicle information. As examples of this process, there are a process in which vehicle information is transmitted when the capacity of the transmission memory buffer of the vehicle information stored in storage section  27  of in-vehicle charging apparatus  21  is full, a process in which vehicle information having a high priority level is transmitted, and a process in which vehicle information having a large evaluation value determined by priority level x data size is transmitted. The transmission-start determining process will be described later in detail. 
         [0041]    Referring back to  FIG. 4 , when the transmission-start determining process is performed in Step S 6 , vehicle-side PLC communication control section  26  requests charging control section  25   b  of charger  25  to turn on leakage breaker relay  31  of earth leakage circuit-breaker  3  illustrated in  FIG. 2  (Step S 7 ). Then, charging control section  25   b  receives the request for turning on leakage breaker relay  31  (Step S 8 ) and performs the request for turning on leakage breaker relay  31  by transmitting turning-on information of leakage breaker relay  31  to earth leakage circuit-breaker  3  as a control signal Sg through a control signal line (Step S 9 ) 
         [0042]    In this manner, vehicle-side PLC communication control section  26  determines whether a PLC communication connection has been established (Step S 10 ). Then, in a case where a PLC communication connection has not been established (No in Step S 10 ), vehicle-side PLC communication control section  26  determines that there is an abnormality in a certain portion of charging cable  4  and determines that transmission is impossible (Step S 11 ). On the other hand, in a case where a PLC communication connection has been established in Step S 10  (Yes in Step S 10 ), vehicle-side PLC communication control section  26  starts the process of transmitting the vehicle information (data) of vehicle  2  to in-house equipment  1  (Step S 12 ), and the process proceeds to a sequence (Step B) of turning off leakage breaker relay  31  to be described later when the transmission of predetermined vehicle information (data) is completed (Step S 13 ). 
       Embodiment 2 
       [0043]    Next, the operation of an in-vehicle charging apparatus according to Embodiment 2 of the present invention will be described with reference to a flowchart. In Embodiment 2, the flow of a case where a PLC process is mainly determined and performed by charging control section  25   b  of charger  25  will be described.  FIG. 5  is a flowchart illustrating the flow of a PLC process mainly determined and performed by charging control section  25   b  of charger  25  according to Embodiment 2 of the present invention. In other words, this flowchart illustrates a flow of the process that is performed between vehicle-side PLC communication control section  26  of in-vehicle charging apparatus  21  illustrated in  FIG. 3  and charging control section  25   b  of charger  25  and a process in which the vehicle information (data) of vehicle  2  is transmitted to in-house equipment  1  based on a determination mainly made by charging control section  25   b  of charger  25 . 
         [0044]    In the flowchart illustrated in  FIG. 5 , the same reference signs are assigned to the same steps as those of the flowchart illustrated in  FIG. 4 , and new reference signs are assigned to different steps represented as a portion surrounded by broken lines. Here, in describing the flow of the flowchart illustrated in  FIG. 5 , if a description is provided for only steps (steps of the portion surrounded by the broken lines) different from those illustrated in  FIG. 4 , it is difficult to understand the flow of the whole process. Thus, the steps used in both  FIGS. 4 and 5  will also be sequentially described along the flow of the process. 
         [0045]    As illustrated in  FIG. 5 , first, when a PLC transmission sequence for transmitting vehicle information of vehicle  2  to in-house equipment  1  side using charging cable  4  is started (Step S 1 ), vehicle-side PLC communication control section  26  detects the volume of the vehicle information stored in storage section  27  in a transmission memory buffer (Step S 2 ). 
         [0046]    Next, vehicle-side PLC communication control section  26  requests charging control section  25   b  to check whether or not charger  25  of in-vehicle charging apparatus  21  is in the middle of a charging process (Step S 21 ). Then, charging control section  25   b  of charger  25  replies to vehicle-side PLC communication control section  26  with a charging status (Step S 22 ). 
         [0047]    Accordingly, vehicle-side PLC communication control section  26  determines whether or not a leakage occurs during the charging process based on detection information acquired by electric leakage detecting section  32  of earth leakage circuit-breaker  3  (Step S 23 ). Here, when an electric leakage occurs in charging cable  4  (Yes in Step S 23 ), vehicle-side PLC communication control section  26  determines that the transmission of vehicle information (data) cannot be performed (Step S 24 ) and ends the transmission process. In other words, when an electric leakage occurs in charging cable  4 , the vehicle information (data) transmission process is immediately completed without turning on leakage breaker relay  31 . 
         [0048]    On the other hand, when no electric leakage occurs in charging cable  4  in Step S 23  (No in Step S 23 ), vehicle-side PLC communication control section  26  determines whether or not a charging process using charging cable  4  is in the middle of the process (Step S 25 ). Here, in a case where the charging process is currently in the middle of the process (Yes in Step S 25 ), a PLC communication connection between vehicle  2  and in-house equipment  1  has already been established. Accordingly, vehicle-side PLC communication control section  26  starts normal transmission for transmitting vehicle information (data) of vehicle  2  to in-house equipment  1  (Step S 4 ) and performs the normal transmission process through PLC (Step S 5 ). 
         [0049]    On the other hand, in a case where the charging process is not currently in the middle of the process in Step S 25  (No in Step S 25 ), a PLC communication connection between vehicle  2  and in-house equipment  1  has not been established. Accordingly, vehicle-side PLC communication control section  26  performs a transmission-start determining process (Step S 6 ). Here, the transmission-start determining process is a process of determining a condition (form) on which the vehicle information of vehicle  2  is transmitted to in-house equipment  1  so as to establish a PLC communication connection by turning on leakage breaker relay  31  of earth leakage circuit-breaker  3  only when the vehicle information is transmitted. In addition, the transmission-start determining is a process to determine a transmission start time point based on the condition (form) of the vehicle information (data). Examples of this process include: a process in which vehicle information is transmitted when the capacity of the transmission buffer of the vehicle information stored in storage section  27  of in-vehicle charging apparatus  21  is full; a process in which vehicle information having a high priority level is transmitted; and a process in which vehicle information having a large evaluation value determined by priority level×data size is transmitted. The transmission-start determining process will be described later in detail. 
         [0050]    Referring back to  FIG. 5 , when the transmission-start determining process for the vehicle information is performed in Step S 6 , vehicle-side PLC communication control section  26  requests charging control section  25   b  of charger  25  to perform PLC communication control using charger  25  by turning on leakage breaker relay  31  of earth leakage circuit-breaker  3  illustrated in  FIG. 2  (Step S 7 ). Then, charging control section  25   b  receives the request for turning on leakage breaker relay  31  (Step S 8 ) and performs the request for turning on leakage breaker relay  31  by transmitting turning-on information of leakage breaker relay  31  to earth leakage circuit-breaker  3  as a control signal Sg through the control signal line (Step S 9 ) 
         [0051]    In the manner described above, vehicle-side PLC communication control section  26  determines whether a PLC communication connection has been established (Step S 10 ). Then, in a case where a PLC communication connection has not been established (No in Step S 10 ), vehicle-side PLC communication control section  26  determines that there is an abnormality in a certain portion of charging cable  4  and determines that transmission is impossible (Step S 11 ). On the other hand, in a case where a PLC communication connection has been established in Step S 10  (Yes in Step S 10 ), vehicle-side PLC communication control section  26  starts transmitting the vehicle information (data) of vehicle  2  to in-house equipment  1  (Step S 12 ), and the process proceeds to a sequence of turning off leakage breaker relay  31  (Step B) to be described later, upon completion of the transmission of the vehicle information (data) (Step S 13 ). 
       Embodiment 3 
       [0052]    Next, several patterns of the transmission-start determining process for the vehicle information in Step S 6  illustrated in  FIGS. 4 and 5  will be described in detail as Embodiment 3 of the present invention. In other words, determination criteria for starting the transmission of the vehicle information include following three determination reference patterns (1) to (3).
   (1) The vehicle information is transmitted when the capacity of the transmission memory buffer of the vehicle information stored in storage section  27  of in-vehicle charging apparatus  21  is full.   (2) The vehicle information is transmitted when vehicle information having a high priority level is detected.   (3) The vehicle information is transmitted when an evaluation value which is determined based on priority level×data size (size of the vehicle information) exceeds a predetermined value. The vehicle information stored in storage section  27  is transmitted altogether based on any determination reference pattern of these three determination reference patterns.   
 
         [0056]      FIG. 6  is a flowchart illustrating the flow of Pattern  1  of the transmission-start determining process in Step S 6  illustrated in  FIG. 4  or  5  according to Embodiment 3 of the present invention. Here, the transmission-start determining process of Pattern 1 is a determination process for starting transmission using PLC when the capacity of the transmission memory buffer of the vehicle information stored in storage section  27  is full. 
         [0057]    As illustrated in  FIG. 6 , first, when the transmission determining process for the vehicle information is started (Step S 31 ), vehicle-side PLC communication control section  26  of in-vehicle charging apparatus  21  calculates the volume of the vehicle information, which has been stored in storage section  27 , in the transmission memory buffer (Step S 32 ). Then, vehicle-side PLC communication control section  26  determines whether or not the data size of the vehicle information, which has been stored, in the transmission memory buffer is a predetermined value or greater (Step S 33 ). Here, when the data size of data stored in the transmission memory buffer is the predetermined value or greater (Yes in Step S 33 ), vehicle-side PLC communication control section  26  ends the transmission determining process for the vehicle information (Step S 34 ), establishes PLC at a time point when the data size of the vehicle information stored in the transmission memory buffer is just the predetermined value or greater, and transmits data altogether. 
         [0058]    On the other hand, when the data size in the transmission memory buffer of the vehicle information that is stored in storage section  27  is not the predetermined value or greater in Step S 33  (No in Step S 33 ), the process is returned to Step S 2  illustrated in  FIGS. 4 and 5  (Step S 35 ), and the detection of the volume of the vehicle information, which is stored in storage section  27 , in the transmission memory buffer is continued. 
         [0059]    In other words, the flow of the transmission determining process for the vehicle information illustrated in Steps S 31  to S 34  described above represents the following. When no charging is performed, in other words, when leakage breaker relay  31  of earth leakage circuit-breaker  3  is blocked, and PLC is not established, leakage breaker relay  31  of earth leakage circuit-breaker  3  is turned on when the volume of the vehicle information is a predetermined amount or greater, a communication connection according to PLC is temporarily established, and data is transmitted to house-side PLC terminal  12  of in-house equipment  1  altogether. Then, after the data is instantly transmitted altogether, immediately, leakage breaker relay  31  of earth leakage circuit-breaker  3  is turned off so as to cause the vehicle-side connection terminal of charging cable  4  to be in the non-voltage state, whereby electrical safety is ensured. In addition, the vehicle information transmitted from in-vehicle charging apparatus  21  at the moment can be monitored using the screen of television set  14  or PC  15  of in-house equipment  1 . 
         [0060]      FIG. 7  is a flowchart illustrating the flow of Pattern  2  of the transmission-start determining process in Step S 6  illustrated in  FIG. 4  or  5  according to Embodiment 3 of the present invention. The transmission-start determining process of Pattern  2  is a determination process for assigning priority levels to vehicle information in advance and transmitting vehicle information having a high priority level using PLC. 
         [0061]    As illustrated in  FIG. 7 , first, when the transmission determining process for the vehicle information is started (Step S 41 ), vehicle-side PLC communication control section  26  of in-vehicle charging apparatus  21  calculates the volume of the vehicle information, which has been stored in storage section  27 , in the transmission memory buffer (Step S 42 ). Then, vehicle-side PLC communication control section  26  determines whether or not the data size of the vehicle information, which has been stored, in the transmission memory buffer is a predetermined value or greater (Step S 43 ). Here, when the data size of data stored in the transmission memory buffer is the predetermined value or greater (Yes in Step S 43 ), the transmission determining process ends (Step S 46 ). On the other hand, when the data size of data stored in the transmission memory buffer is not the predetermined value or greater (No in Step S 43 ), the priority level of newly stored data at the time of storing new vehicle information in storage section  27  is checked (Step S 44 ). 
         [0062]    In other words, in Step S 44 , as illustrated in  FIG. 9 , the priority level of newly stored data of vehicle information is checked based on Table A in which a priority level, a priority level coefficient, a data size example, and an evaluation value for each category of the vehicle information are compared with each other. For example, “breakdown detection information” and the like of the vehicle information have the highest priority level of “5,” and “running history” that is vehicle information regularly transmitted to a server and the like have the lowest priority level of “1.” Here, Table A illustrated in  FIG. 9  represents a table of a case where a command and vehicle information have one-to-one correspondence. 
         [0063]    As above, in Step S 44 , the priority level of newly stored data of vehicle information is checked based on Table A illustrated in  FIG. 9 , and whether or not there is vehicle information having a priority level of a specified value or greater (for example, a priority level of “4” or greater) is determined (Step S 45 ). Here, when vehicle information having a priority level of a specified value or greater (for example, a priority level of “4” or greater) is detected (Yes in Step S 45 ), the transmission determining process ends (Step S 46 ), PLC is established, and the vehicle information stored in the transmission memory buffer is transmitted altogether. Alternatively, when vehicle information having a priority level of a specified value or greater (for example, a priority level of “4” or greater) is detected, PLC may be established, and only vehicle information having a priority level of a specified value or greater (for example, a priority level of “4” or greater) may be transmitted. For example, based on Table A illustrated in  FIG. 9 , it is determined that there are breakdown detection information, battery leakage detection information, user-initiated communication request information, sensor camera screen (urgent), vehicle indoor temperature abnormality information, and charging rate reduction information as vehicle information having a priority level of “4” or greater, and only the vehicle information having a priority level of “4” or greater is immediately transmitted. 
         [0064]    On the other hand, when there is no vehicle information having a priority level of the specified value or greater (for example, a priority level of “4” or greater) in Step S 45  (No in Step S 45 ), the process is returned to Step S 2  illustrated in  FIGS. 4 and 5  (Step S 47 ), and the detection of the volume of the vehicle information, which is stored in storage section  27 , in the transmission memory buffer is continued. 
         [0065]    In other words, the flow of the transmission determining process for vehicle information illustrated in Steps S 41  to S 46  described above represents the following. When no charging is performed, that is, when PLC is not established due to blocking of leakage breaker relay  31  of earth leakage circuit-breaker  3 , leakage breaker relay  31  of earth leakage circuit-breaker  3  is turned on only when there is vehicle information having a priority level of a specified value or greater, a communication connection through PLC is temporarily established, and only data of the vehicle information having a priority level of the specified value or greater is transmitted to house-side PLC terminal  12  of in-house equipment  1  altogether. Then, after data having high priority levels is instantly transmitted altogether, immediately, leakage breaker relay  31  of earth leakage circuit-breaker  3  is turned off so as to cause the vehicle-side connection terminal of charging cable  4  to be in a non-voltage state, whereby electrical safety is ensured. In addition, the vehicle information having high priority levels, which has been transmitted at that time, can be monitored using the screen of television set  14  or PC  15  of in-house equipment  1 . 
         [0066]      FIG. 8  is a flowchart illustrating the flow of Pattern 3 of the transmission-start determining process in Step S 6  illustrated in  FIG. 4  or  5  according to Embodiment 3 of the present invention. Here, the transmission-start determining process of Pattern 3 is a determination process for assigning a priority level coefficient to vehicle information in advance and transmitting vehicle information having an evaluation value, which is determined based on “priority level coefficient×data size,” of a specified value or greater through PLC. 
         [0067]    As illustrated in  FIG. 8 , first, when the transmission determining process for vehicle information is started (Step S 51 ), vehicle-side PLC communication control section  26  of in-vehicle charging apparatus  21  calculates the volume of the vehicle information, which has been stored in storage section  27 , in the transmission memory buffer (Step S 52 ). Then, vehicle-side PLC communication control section  26  determines whether or not the data size of the vehicle information, which has been stored in storage section  27 , in the transmission memory buffer is a predetermined value or greater (Step S 53 ). Here, when the data size of data stored in the transmission memory buffer is the predetermined value or greater (Yes in Step S 53 ), the transmission determining process ends (Step S 56 ). On the other hand, when the data size of data stored in the transmission memory buffer is not the predetermined value or greater (No in Step S 53 ), an evaluation value (=priority level coefficient×data size) of the vehicle information that has been stored in storage section  27  is calculated (Step S 54 ). 
         [0068]      FIG. 9  is a diagram illustrating Table A in which a priority level, a priority coefficient, a data size example, and an evaluation value for vehicle information are compared with each other. In other words, in Step S 54  described above, as represented in Table A illustrated in  FIG. 9 , an evaluation value is calculated for each type (category) of vehicle information by multiplying a priority level coefficient and a data size together that are determined for each type (category) of the vehicle information. For example, as represented in Table A, when the vehicle information is sensor camera information (urgent), the priority level coefficient is 100, and the data size is 40,000 bytes, and accordingly, the evaluation value is calculated as 4,000,000. 
         [0069]    Referring back to  FIG. 8 , whether or not the evaluation value of the vehicle information calculated in Step S 54  as above is a specified value or greater is determined (Step S 55 ). When the evaluation value of the vehicle information is the specified value or greater (Yes in Step S 55 ), the transmission determining process ends (Step S 56 ), PLC is established, and only the vehicle information having an evaluation value of the specified value or greater is transmitted. For example, based on Table A illustrated in  FIG. 9 , it is determined that a sensor camera image (urgent) having an evaluation value 4,000,000 of the vehicle information, which is a specified value or greater, is present, the transmission determining process ends, and the vehicle information stored in storage section  27  is transmitted altogether using PLC. Alternatively, only the vehicle information of which the evaluation value is a specified value or greater may be configured to be transmitted. 
         [0070]    On the other hand, when there is no vehicle information of which the evaluation value is the specified value or greater in Step S 55  (No in Step S 55 ), the process is returned to Step S 2  illustrated in  FIGS. 4 and 5  (Step S 57 ), and the detection of the volume of the vehicle information, which is stored in storage section  27 , in the transmission memory buffer is continued. 
         [0071]    In other words, the flow of the transmission determining process for vehicle information illustrated in Steps S 51  to S 56  described above represents the following. When no charging is performed, in other words, when leakage breaker relay  31  of earth leakage circuit-breaker  3  is blocked and PLC is not established, leakage breaker relay  31  of earth leakage circuit-breaker  3  is turned on only when vehicle information of which the evaluation value is a specified value or greater is present, a communication connection through PLC is temporarily established, and only data of the vehicle information of which the evaluation value is the specified value or greater is transmitted to house-side PLC terminal  12  of in-house equipment  1  altogether. 
         [0072]    Then, immediately after the data having a high evaluation value is instantly transmitted altogether, leakage breaker relay  31  of earth leakage circuit-breaker  3  is turned off so as to cause the vehicle-side connection terminal of charging cable  4  to be in the non-voltage state, whereby electrical safety is ensured. In addition, the vehicle information having a high evaluation value transmitted at that time can be monitored using the screen of television set  14  or PC  15  of in-house equipment  1 . For example, when a suspicious person comes close to a vehicle parked in a garage at night, a sensor camera image (urgent) is immediately projected onto the screen of television set  14  or PC  15 . Thus, the image can be used for preventing vehicle theft or the like. 
         [0073]    As described above, the transmission determination criterion for vehicle information at a time when charging is stopped is determined as below.
   (1) When the volume of the vehicle information in the memory buffer exceeds a predetermined value, PLC is established, and the vehicle information is transmitted altogether.   (2) When vehicle information having a high priority level (for example, vehicle information having a priority level of 4 or greater in Table A illustrated in  FIG. 9 ) is present, PLC is established, and the vehicle information is transmitted, immediately.   (3) When vehicle information of which the evaluation value (=priority level coefficient x data size) is a predetermined value or greater (for example, vehicle information of which the evaluation value is 16,000 or greater in Table A illustrated in  FIG. 9 ) is present, PLC is established, and the vehicle information is transmitted, immediately.   
 
         [0077]    The advantage of using the evaluation value of vehicle information as a transmission determination criterion is as follows. For example, “sensor vibration detection information” of the vehicle information represented in Table A illustrated in  FIG. 9  has a priority level of “3” and a data size of 16 bytes. Accordingly, in a case where the condition of the transmission determination criterion is a priority level of “5” or a volume of the vehicle information of 256 Kbytes in the memory buffer, the transmission criterion is not satisfied unless data (16 bytes) of “sensor vibration detection information” is detected 16,000 times or more. Accordingly, the transmission criterion of the vehicle information is not reached unless a considerable number of vibrations are detected. Therefore, for example, even when a vehicle is parked on an unpaved rough road for charging, and a vibration is detected from a large-size car passing by the side thereof or the like, there is no concern that the “sensor vibration detection information” is frequently transmitted. 
         [0078]    However, for example, when the security level is raised as an anticrime measure for a high-priced vehicle, the threshold of the evaluation value of the vehicle information is set to 1,500. Thus, as represented in Table A illustrated in  FIG. 9 , the evaluation value of the “sensor vibration detection information” of the vehicle information is 1,600, and accordingly, the “sensor vibration detection information” of a first time satisfies the condition of the transmission determination criterion. Accordingly, since the evaluation value of the vehicle information is the predetermined value or greater, PLC is established, and the vehicle information of the “sensor vibration detection information” can be transmitted, immediately. 
         [0079]    In addition, when the vehicle indoor temperature rises during summertime, for example, “indoor temperature abnormality information” of the vehicle information represented in Table A illustrated in  FIG. 9  is a phenomenon which may occur on a daily basis, and accordingly, the priority level coefficient is set to be low (a priority level coefficient of 10), and the evaluation value of the vehicle information is suppressed to be low as 160. Thus, an advantage of lowering the transmission frequency of the vehicle information of the “indoor temperature abnormality” can be expected. 
         [0080]      FIG. 10  is a diagram illustrating Table B in which a command for each type and a content of each type of vehicle information are compared with each other. As the content of each type of the vehicle information, there are urgent information, maintenance information, warning information, user information, and regular transmission information. For example, the urgent information is information acquired by grouping related information such as vibration detection information of the vehicle, electric leakage detection information, and sensor camera image (urgent) information. 
         [0081]    In other words, a transmission determination may be performed based on the content of each type of the grouped vehicle information as Pattern 4 of the transmission determination criterion of vehicle information, as represented in Table B illustrated in  FIG. 10 , other than the transmission determination criterion of vehicle information from the three patterns described above. The criterion of the transmission determination in this case is as follows.
   (1) The priority of transmission is determined based on the command for each type. For example, when the command for each type is “01” in Table B, corresponding vehicle information is transmitted, immediately.   (2) The transmission timing is determined in accordance with the status at the time, as in a case in which the vehicle information is transmitted after 10 minutes when the command for each type is “02” or “03,” the vehicle information is immediately transmitted when the command for each type is “04,” and the vehicle information is transmitted after one hour when the command for each type is “05.”   
 
       Embodiment 4 
       [0084]    Next, as Embodiment 4, after vehicle information is started to be transmitted to the in-house equipment  1  in Step S 12  illustrated in  FIGS. 4 and 5 , and upon completion of transmission of a predetermined volume of vehicle information, the process of Step B at the time of transitioning to the sequence of turning off leakage breaker relay  31  in Step S 13  will be described.  FIG. 11  is a flowchart illustrating the flow of the process of ending PLC by switching leakage breaker relay  31  to an Off sequence using vehicle-side PLC communication control section  26  in Embodiment 4 of the present invention. 
         [0085]    As illustrated in  FIG. 11 , first, following Step S 13  illustrated in  FIGS. 4 and 5 , when the turning-off sequence of leakage breaker relay  31  is started (Step S 61 ), a packet is transmitted from the memory buffer including already stored data in storage section  27  (Step S 62 ), and it is determined whether the transmission of the packet is successful (Step S 63 ). Here, in a case where the transmission of the packet is successful (Yes in Step S 63 ), data that has been transmitted is removed from the memory buffer in which the data has been stored, so as to increase a free space of storage section  27  (Step S 64 ). 
         [0086]    Accordingly, vehicle-side PLC communication control section  26  determines whether or not the memory buffer including already stored data in storage section  27  has been emptied (Step S 65 ). Here, in a case where the memory buffer including already stored data in storage section  27  has been emptied (Yes in Step S 65 ), vehicle-side PLC communication control section  26  determines whether or not data is currently received (Step S 66 ). In a case where data is currently received (Yes in Step S 66 ), vehicle-side PLC communication control section  26  repeats the process of Step S 65  for determining whether or not the memory buffer including already stored data has been emptied and the process of Step S 66  for determining whether or not data is currently received and waits for the completion of the reception of data (Step S 67 ). 
         [0087]    On the other hand, when data is not currently received in Step S 66  (No in Step S 66 ), vehicle-side PLC communication control section  26  completes the transmission process for data (Step S 68 ) and requests charging control section  25   b  to transmit a control signal Sg for turning off leakage breaker relay  31  (Step S 69 ). 
         [0088]    Then, charging control section  25   b  receives the turning-off request signal for leakage breaker relay  31  (Step S 70 ) and requests relay control section  33  of earth leakage circuit-breaker  3  to turn off leakage breaker relay  31  (Step S 71 ). Accordingly, leakage breaker relay  31  is turned off, and the PLC communication connection is cut off (Step S 72 ), and the turning-off sequence of leakage breaker relay  31  ends (Step S 73 ). 
         [0089]    On the other hand, when the transmission of the packet is not successful in Step S 63  (No in Step S 63 ), whether or not a PLC communication connection has been established is determined (Step S 74 ). In a case where the PLC communication connection has been established (Yes in Step S 74 ), a process of retransmitting the packet is performed (Step S 75 ), and the process of determining whether or not the transmission of a packet is successful in Step S 63  described above is repeated. On the other hand, in a case where a PLC communication connection has not been established in Step S 74  (No in Step S 74 ), all the data of the memory buffer of storage section  27  is deleted (Step S 76 ) so as to empty the memory buffer for storing new updated information, and the process proceeds to a transmission completing step of Step S 68 . 
       Comparative Example 
       [0090]    Next, as a comparative example for reference, a description will be given of a PLC communication connection at the time of charging, which is generally performed.  FIG. 12  is a flowchart illustrating the flow of a PLC connection at the time of starting charging, which is generally performed. As illustrated in  FIG. 12 , when a charging starting sequence is started (Step S 81 ), first, charging cable  4  is connected to in-house equipment  1  on the input side of earth leakage circuit-breaker  3  (Step S 82 ). Then, relay control section  33  of earth leakage circuit-breaker  3  checks whether a constant voltage is supplied from in-house equipment  1  to earth leakage circuit-breaker  3  and whether the control signal line is in a conductive state (Step S 83 ). 
         [0091]    Meanwhile, charging control section  25   b  of in-vehicle charging apparatus  21  detects that charging cable  4  is connected to in-vehicle charging apparatus  21  side (Step S 84 ) and determines whether or not the preparation for charging has been completed (Step S 85 ). Here, in a case where the preparation for charging has not been completed (No in Step S 85 ), the process waits for the completion of the preparation for charging, and, when the preparation for charging is completed (Yes in Step S 85 ), charging control section  25   b  of in-vehicle charging apparatus  21  transmits a control signal Sg to relay control section  33  of earth leakage circuit-breaker  3  through the control signal line (Step S 86 ). 
         [0092]    Accordingly, relay control section  33  of earth leakage circuit-breaker  3  detects the control signal Sg and turns on leakage breaker relay  31  (Step S 87 ). Then, charging power (AC power) is supplied from in-house equipment  1  to in-vehicle charging apparatus  21 , and storage battery relay  28  is turned on by charging control section  25   b , whereby charging of storage battery  24  is started (Step S 88 ). Then, vehicle-side PLC communication control section  26  sets up a communication connection according to PLC between in-vehicle charging apparatus  21  and house-side PLC terminal  12  (Step S 89 ) and ends the charging starting sequence (Step S 90 ). Accordingly, communication according to PLC can be also performed during the charging process. 
       Conclusion  
       [0093]    As described above, according to in-vehicle charging apparatus  21  of an embodiment of the present invention, when earth leakage circuit-breaker  3  is open, and charging using charging cable  4  is not performed, a communication connection according to PLC is established only for a minimum required time in accordance with any one of the following three patterns, and only necessary vehicle information is transmitted to in-house equipment  1 . In addition, immediately after the transmission of the vehicle information is completed, the PLC communication connection is blocked, whereby electrical safety of the vehicle-side connection terminal is ensured. 
         [0094]    In other words, during the stop of charging, the following operations are performed.
   (1) The vehicle information desired to be communicated in accordance with PLC is stored (buffered) in the storage section  27 , and when the amount of the stored data exceeds a predetermined value, the vehicle information is transmitted together in accordance with PLC.   (2) A priority level is set for each type of data of the vehicle information, and when vehicle information having a priority level higher than a priority level that is specified in advance is present, stored data is transmitted together in accordance with PLC.   (3) An evaluation value (=priority level coefficient×data size) is set for each type of data of the vehicle information, and when there is data of the vehicle information of which the evaluation value is higher than an evaluation level that is specified in advance, stored data is transmitted altogether in accordance with PLC.   
 
         [0098]    Then, upon detection of the completion of data transmission of desired vehicle information, immediately, leakage breaker relay  31  of earth leakage circuit-breaker  3  is turned off so as to block the PLC communication connection (communication line). Accordingly, when charging is not performed, leakage breaker relay  31  of earth leakage circuit-breaker  3  is turned on only for a requisite minimum time so as to establish a PLC communication line, and stored data can be transmitted altogether. In addition, since the non-voltage state of the vehicle-side connection terminal of charging cable  4  can be maintained as long as possible, the electrical safety can be maintained at a relatively high level. 
         [0099]    In other words, vehicle-side PLC communication control section  26  constantly inquires charging control section  25   b  whether it is in the middle of a charging process. In a case where it is in the middle of the charging process, communication according to ordinary PLC is started, and the vehicle information is transmitted. On the other hand, in a case where it is not in the middle of the charging process, a process of transmitting the vehicle information altogether is performed at any one of timing when the data size of the vehicle information is a predetermined data size or greater, timing when vehicle information having a high priority level is present, and timing when there is vehicle information of which the evaluation value is high. In addition, when detecting whether or not charging is currently performed, vehicle-side PLC communication control section  26  does not need to determine again whether a communication line according to PLC is established. 
         [0100]    After the transmission of the vehicle information is completed, by deleting the vehicle information that has been completed to be transmitted from storage section  27 , the capacity of storage section  27  can be maximally used in an effective manner. In addition, when the transmission of the vehicle information cannot be completed and when a communication line according to PLC is not established, vehicle information having a priority level lower than a predetermined priority level is deleted. Accordingly, even when the transmission of the vehicle information is not completed, in a case where a communication line according to PLC cannot be established, an empty area of storage section  27  can be effectively secured by deleting vehicle information having a low priority level. 
         [0101]    In addition, when information representing the occurrence of an electric leakage is received from earth leakage circuit-breaker  3 , vehicle-side PLC communication control section  26  does not issue an instruction for turning on leakage breaker relay  31  to charging control section  25   b . In other words, when leakage breaker relay  31  is turned off due to the occurrence of an electric leakage in charging cable (power line)  4 , a malfunction for turning on leakage breaker relay  31  at least one moment by transmitting a control signal Sg used for turning on leakage breaker relay  31  can be prevented. 
         [0102]    As above, while several embodiments of the present invention have been specifically described, the present invention is not limited to each embodiment described above, but various changes can be made therein within a range not departing from the concept thereof. For example, the conditions for setting up a communication line according to PLC during the stop of charging are not limited to the conditions of three patterns described above, but may be changed to conditions desired by a user. In addition, in each embodiment described above, while the in-vehicle charging apparatus, which can be charged from the outside, installed in an EV or a HEV has been described, the present invention is not limited thereto, and it is apparent that the present invention can be applied to an in-vehicle charging apparatus used for charging a storage battery installed in an ordinary gasoline-powered vehicle. 
         [0103]    The disclosure of Japanese Patent Application No. 2011-072050, filed on Mar. 29, 2011, including the specification, drawings and abstract, is incorporated herein by reference in its entirety. 
       INDUSTRIAL APPLICABILITY 
       [0104]    The present invention can be not only used as an in-vehicle charging apparatus of an HEV or an EV but also can be used effectively as an in-vehicle charging apparatus of a general vehicle such as a gasoline-powered vehicle. 
       REFERENCE SIGNS LIST 
       [0105]      1  In-house equipment 
         [0106]      2  Vehicle 
         [0107]      3  Earth leakage circuit-breaker 
         [0108]      4  Charging cable (Power line) 
         [0109]      5  Plug/Outlet 
         [0110]      10  House 
         [0111]      11  Panel Board 
         [0112]      12  House-side PLC terminal 
         [0113]      13  Internet modem 
         [0114]      14  Television Set 
         [0115]      15  Personal computer 
         [0116]      21  In-vehicle charging apparatus 
         [0117]      22  Camera 
         [0118]      23  Air conditioner 
         [0119]      24  Storage battery 
         [0120]      25  Charger 
         [0121]      25   a  Charger power supply circuit 
         [0122]      25   b  Charging control section 
         [0123]      26  Vehicle-side PLC communication control section 
         [0124]      27  Storage section 
         [0125]      28  Storage battery relay 
         [0126]      31  Leakage breaker relay 
         [0127]      32  Electric leakage detecting section 
         [0128]      33  Relay control section