Patent Publication Number: US-2021178917-A1

Title: Vehicle

Description:
The present application claims priority to and incorporates by reference the entire contents of Japanese Patent Application No. 2019-224014 filed in Japan on Dec. 11, 2019. 
     BACKGROUND 
     The present disclosure relates to a vehicle. 
     JP 2012-085372 A discloses a power supply and demand system in which charge/discharge control is executed to transfer power between a power system provided in a facility such as housing and supplying power and a storage battery provided in a vehicle such as an electric vehicle. In this power supply and demand system, the vehicle includes: a vehicle-side charging/discharging unit coupled to a facility-side charging/discharging unit composing the power system, such that power may be transferred to/from the facility-side charging/discharging unit; a vehicle-side control unit that acquires storage battery information about a storage battery of the vehicle; and a detection unit that detects the presence or absence of a facility-side control unit that controls power in the power system. In the power supply and demand system, based on facility-side power information about the power of the power system and the storage battery information, one of the facility-side control unit and the vehicle-side control unit gives a command for charge/discharge control in accordance with a detection result from the detection unit. 
     SUMMARY 
     The power supply and demand system disclosed in JP 2012-085372 A is silent on how the detection unit provided in the vehicle specifically detects the presence or absence of the facility-side control unit. Meanwhile, in recent years, the form of charge/discharge control between the facility and the vehicle is not necessarily configured to transmit, from the facility side to the vehicle side, a signal distinctly indicating the presence of the facility-side control unit. Therefore, even if the facility-side control unit is provided in the facility, a signal distinctly indicating the presence of the facility-side control unit is not transmitted from the facility side to the vehicle side, so that the detection unit may erroneously detect that there is no facility-side control unit. Furthermore, if, in order to solve such a problem, the vehicle-side control unit is caused to give a command for charge/discharge control on the premise that there is no facility-side control unit, the charge/discharge control may not be executed appropriately in a case where the facility-side control unit is also actually controlling a facility-side charging/discharging unit to intervene in the charge/discharge control. 
     There is a need for a vehicle that is able to execute charge/discharge control appropriately regardless of the presence or absence of an intervention of a facility-side control device in the charge/discharge control. 
     According to one aspect of the present disclosure, there is provided a vehicle including: a storage battery; a vehicle-side charging/discharging device connected to a facility-side charging/discharging device composing a power system provided in a facility, the vehicle-side charging/discharging device being configured to transfer power to/from the facility-side charging/discharging device; and a vehicle-side controller configured to control the vehicle-side charging/discharging device, wherein the facility-side charging/discharging device and the vehicle-side charging/discharging device are coupled to execute charge/discharge control between the power system and the storage battery, the vehicle-side controller is configured to determine, based on information about power transferred between the facility-side charging/discharging device and the vehicle-side charging/discharging device, presence or absence of an intervention of a facility-side control device, which controls power in the power system, in the charge/discharge control, and the charge/discharge control is executed based on the presence or the absence of the intervention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram illustrating a schematic configuration of a power supply and demand system using a vehicle according to a first embodiment; 
         FIG. 2  is a flowchart illustrating a first example of control executed by an ECU; 
         FIG. 3  is a flowchart illustrating a second example of the control executed by the ECU; and 
         FIG. 4  is a flowchart illustrating a third example of the control executed by the ECU. 
     
    
    
     DETAILED DESCRIPTION 
     A first embodiment of a vehicle will be described below. The present disclosure is not limited by the present embodiments. 
       FIG. 1  is a diagram illustrating a schematic configuration of a power supply and demand system  100  using a vehicle  2  according to the first embodiment. As illustrated in  FIG. 1 , the power supply and demand system  100  according to the first embodiment transfers power between a facility  1  and the vehicle  2 . The facility  1  includes a power system composed of a distribution board  11 , electric devices  12 , a facility-side charging/discharging device  13 , a power control device  14 , a facility-side communication device  15 , etc. 
     The distribution board  11  distributes and supplies commercial power (AC power) from commercial power supply equipment  3  installed outside the facility  1 , to the electric devices  12 , the facility-side charging/discharging device  13 , the power control device  14 , the facility-side communication device  15 , etc. 
     The facility-side charging/discharging device  13  is a charging station that is electrically connected to a vehicle-side charging/discharging device  25  (described below) of the vehicle  2  via a power cable  4  to transfer power between the facility  1  and the vehicle  2 . The power cable  4  not only conducts power between the facility-side charging/discharging device  13  and the vehicle-side charging/discharging device  25 , but also allows communication between the facility-side charging/discharging device  13  and the vehicle-side charging/discharging device  25 . For example, a communication line for communication may be provided separately from a power line for conducting power through the power cable  4 . Alternatively, the power cable  4  may be configured so as to enable power line communication (Power Line Communication) in which communication using a power line for conducting power is performed. The facility-side charging/discharging device  13  has, for example, the function of directly supplying AC commercial power to the vehicle  2  side without conversion (normal charging), and the function of converting AC commercial power into DC power and supplying it to the vehicle  2  side (rapid DC charging). Further, the facility-side charging/discharging device  13  also has a bidirectional function capable of converting power supplied from the vehicle  2  side into power in directions reverse to those of the above-described two functions. The facility-side charging/discharging device  13  also has a current interruption function that interrupts electrical connection with the vehicle-side charging/discharging device  25  via the power cable  4 . 
     The power control device  14  is a facility-side control device that controls actuation of the facility-side charging/discharging device  13  composing the power system and thereby performs power transfer that meets user&#39;s request. The power control device  14  is in wire connection or wireless connection with the electric devices  12 , the facility-side charging/discharging device  13 , and the facility-side communication device  15  so as to be communicable with them. 
     The facility-side communication device  15  is in wire connection or wireless connection with a facility server  5  and exchanges information about power control, which is executed by the power control device  14 , with the facility server  5 . 
     The vehicle  2  includes a motor generator  21 , a power control unit (PCU)  22 , a battery  23 , an electronic control unit (ECU)  24 , a vehicle-side charging/discharging device  25 , an input device  26 , a vehicle-side communication device  27 , etc. The vehicle  2  is an electric vehicle that uses, for example, at least the motor generator  21  as a drive source for travel. 
     The motor generator  21  is electrically connected to the battery  23  via the PCU  22  and is driven by power from the battery  23 . The motor generator  21  functions as an electric motor serving as a drive source for travel with power from the battery  23  and also has a function as a generator that generates power by being driven with rotational drive force of the wheels when the vehicle  2  is decelerated. 
     The PCU  22  is electrically connected to the motor generator  21  and the battery  23 . This PCU  22  converts DC power from the battery  23  into AC power and supplies the AC power to the motor generator  21 , thereby driving the motor generator  21 . The PCU  22  also converts AC power generated by the motor generator  21  into DC power and supplies the DC power to the battery  23 , thereby charging the battery  23 . 
     The battery  23  is a high-voltage (for example, 200 V) storage battery. 
     The ECU  24  is a vehicle-side control device that is communicably connected to the motor generator  21 , the PCU  22 , the battery  23 , the vehicle-side charging/discharging device  25 , the input device  26 , the vehicle-side communication device  27 , etc. The ECU  24  performs, for example, actuation control on the motor generator  21  and the PCU  22  related to traveling of the vehicle  2 , detection of the remaining capacity of the battery  23 , and actuation control on vehicle-side charging/discharging device  25 , the input device  26 , and the vehicle-side communication device  27  related to charging/discharging of the battery  23 . In addition, the ECU  24  has a determination unit  241  that determines whether the power control device  14  is intervening in charge/discharge control, which will be described later. 
     The vehicle-side charging/discharging device  25  performs power conversion when power (DC power) from the battery  23  is supplied to the facility  1  side or power is supplied from the facility  1  to the vehicle  2  side, in order to transfer power to/from the facility-side charging/discharging device  13  of the facility  1 . 
     The vehicle-side charging/discharging device  25  includes, for example, the function of converting commercial power (AC power) from the facility  1  into DC power and receiving the DC power (normal charging) and the function of receiving DC power into which commercial power (AC power) from the facility  1  has been converted by the facility-side charging/discharging device  13  as it is without performing conversion (rapid DC charging). The vehicle-side charging/discharging device  25  also includes a bidirectional function capable of performing power conversion in directions reverse to those of the above-described two functions when power is supplied from the vehicle  2  to the facility  1 . 
     The input device  26  is a charging request information input unit allowing a user to input information such as a traveling schedule, including charging request information for the battery  23 , and is composed of, for example, a dedicated input panel, car navigation, etc. 
     The vehicle-side communication device  27  is wirelessly connected to a vehicle server  6  provided outside the vehicle  2  and, based on charging request information and a traveling schedule input through the input device  26  by the user, exchanges information about a charge/discharge plan for the vehicle  2  with the vehicle server  6 . 
     In the vehicle  2  according to the first embodiment, the ECU  24  executes charge/discharge control in which, based on a charge/discharge plan set in advance, power is transferred between the facility  1  side and the vehicle  2  side while the facility-side charging/discharging device  13  and the vehicle-side charging/discharging device  25  are kept connected by the power cable  4 . At this time, the ECU  24  performs an observation mode in which information about power transferred between the facility  1  and the vehicle  2  is observed. In parallel with the normal charge/discharge mode in which the battery  23  of the vehicle  2  is charged with power from the facility  1  or in which power is output from the battery  23  of the vehicle  2  to the facility  1 , the observation mode also includes a state of observing information about the power. 
     In the observation mode in the first embodiment, as information about power transferred between the facility  1  and the vehicle  2 , an upstream voltage (a vehicle input voltage that is input to the vehicle-side charging/discharging device  25  from the facility-side charging/discharging device  13  via the power cable  4 ) is measured. In the first embodiment, the “upstream” is the side that extends toward a key system (the commercial power supply equipment  3 ) along the power cable  4  connected to the vehicle-side charging/discharging device  25  of the vehicle  2 . In a case where a voltage behavior satisfying any one of the conditions (1) to (4) described below is observed, the determination unit  241  of the ECU  24  determines that there is an intervention of the power control device  14  in the charge/discharge control. 
     (1) In a case where the upstream voltage has become lower than 80[%] of the reference voltage. 
     (2) In a case where the upstream voltage has become lower than 70[%] of the reference voltage. 
     (3) In a case where the state of the upstream voltage dropping lower than 80% of the reference voltage has continued for more than 0.5 seconds. 
     (4) In a case where the state of the upstream voltage dropping lower than 70[%] of the reference voltage has continued for more than 0.5 seconds. 
     The reference voltage is the voltage of the facility-side charging/discharging device  13  in normal times. For example, in Japan, AC voltage is 101 [V] or 202 [V] and DC voltage (CHAdeMO (registered trademark): output 50 [kW]) is rated voltage (500 [V]). 
     The behaviors of the upstream voltage satisfying the conditions (1) to (4) described above are based on the frequencies of instantaneous voltage drops in the Japanese power system, making it possible to substantially avoid erroneously determining an instantaneous voltage drop in the power system as an intervention of the power control device  14  in the charge/discharge control. If any of the conditions (1) to (4) described above is satisfied, the upstream voltage is 0[%] of the reference voltage, for example, in the control in which power transferred between the facility-side charging/discharging device  13  and the vehicle-side charging/discharging device  25  via the power cable  4  is interrupted by the facility-side charging/discharging device  13 , which is executed by the power control device  14 ; therefore, a determination of an intervention of the power control device  14  in the charge/discharge control is made. Therefore, based on the fact that at least the upstream voltage is lower than 80[%] or lower than 70[%] of the reference voltage, in other words, at least an upstream voltage drop is limited to 20% to 30% of the reference voltage, the ECU  24  may determine that there is an intervention of the power control device  14  in the charge/discharge control. In addition, under the condition (3) or (4) described above, it is possible to improve the accuracy with which the ECU  24  determines the presence or absence of an intervention of the power control device  14  in the charge/discharge control. 
     Therefore, in the vehicle  2  according to the first embodiment, even if a signal distinctly indicating the presence of the power control device  14  is not transmitted from the facility  1  side to the vehicle  2  side, whether or not the power control device  14  is intervening in the charge/discharge control may be determined. Therefore, by executing the charge/discharge control based on the result of the determination of whether or not the power control device  14  is intervening in the charge/discharge control, the vehicle  2  according to the first embodiment is able to execute charge/discharge control appropriately regardless of the presence or absence of an intervention of the power control device  14  in the charge/discharge control. 
       FIG. 2  is a flowchart illustrating a first example of the control executed by the ECU  24 . 
     First, the ECU  24  executes the observation mode (step S 1 ) and measures an upstream voltage (a vehicle input voltage) (step S 2 ). Next, the determination unit  241  of the ECU  24  determines whether or not the state of the upstream voltage dropping lower than 70[%] of the reference voltage has continued for more than 0.5 seconds (step S 3 ). In a case where it is determined that the state of the upstream voltage dropping lower than 70[%] of the reference voltage has continued for more than 0.5 seconds (Yes in step S 3 ), the determination unit  241  of the ECU  24  determines that the power control device  14  provided in the facility  1  is intervening in the charge/discharge control between the power system and the battery  23  (step S 4 ). 
     Next, the ECU  24  determines whether an aspect of the charge/discharge control, specifically, a charge/discharge plan needs to be changed (step S 5 ). For example, in a case where the charge/discharge plan for the vehicle  2  is a time-linked plan (scheduled charging), the charge/discharge plan is changed. Meanwhile, in a case where the charge/discharge plan for the vehicle  2  is the shortest charge/discharge (to reach a target amount of charge/discharge in the shortest possible time), the charge/discharge plan is not changed. 
     In a case where it is determined that the charge/discharge plan needs to be changed (Yes in step S 5 ), the ECU  24  changes the charge/discharge plan (step S 6 ) and ends the series of controls. To change the charge/discharge plan, for example, the ECU  24  receives a charge/discharge plan corresponding to the measured upstream voltage from the vehicle server  6  via the vehicle-side communication device  27  and changes the charge/discharge plane to the shortest charge/discharge plan or changes the charge/discharge plan so that the time to complete charge/discharge is made earlier than the initial plan. This is because, in order to complete charge/discharge in a target time under an intervention of the power control device  14  of the facility  1  in control, it is necessary to have a charge/discharge plan that, taking account of the influence of the intervention of the power control device  14  in the control, may achieve a target amount of charge/discharge earlier than in the initial charge/discharge plan. 
     Conversely, in a case where it is determined in step S 5  that the charge/discharge plan does not need to be changed (No in step S 5 ), the ECU  24  ends the series of controls without changing the charge/discharge plan. In a case where the charge/discharge plan is not changed, for example, the shortest charge/discharge may be achieved by maintaining the highest possible charge/discharge output in accordance with the intervention of the power control device  14  in the control. 
     In a case where it is determined in step S 3  that the state of the upstream voltage dropping lower than 70[%] of the reference voltage has not continued for more than 0.5 seconds (No in step S 3 ), the determination unit  241  of the ECU  24  determines that the power control device  14  provided in the facility  1  is not intervening in the charge/discharge control between the power system and the battery  23  (step S 7 ), and ends the series of controls. 
     In the flowchart illustrated in  FIG. 2 , in step S 3 , any of the following may be determined; whether the upstream voltage has become lower than 80[%] of the reference voltage, whether the upstream voltage has become lower than 70[%] of the reference voltage, and whether the state of the upstream voltage dropping lower than 80[%] of the reference voltage has continued for more than 0.5 seconds. 
     The aspect of the charge/discharge control determined in step S 5  is not limited to the charge/discharge plan and may be the content or method of the charge/discharge control executed when the determination is made. Then, in a case where it is determined that the content or method of the charge/discharge control needs to be changed, the content or method of charge/discharge control is changed. Conversely, in a case where it is determined that the content or method of the charge/discharge control does not need to be changed, the content or method of the charge/discharge control is not changed. 
     A second embodiment will be described below. The descriptions of the portions common to those of the first embodiment will be omitted as appropriate. 
     The second embodiment assumes charge/discharge in which a facility-side charging/discharging device  13  does not have the function (CPLT: control pilot) of signal communication with a vehicle  2  and, therefore, the vehicle  2  is not provided with information about the range of charge/discharge current usable between the facility  1  and the vehicle  2 . Therefore, in the second embodiment, a charge/discharge current is directly measured and, based on the behavior of the charge/discharge current, the presence or absence of an intervention of a power control device  14  in control is determined. 
     In an observation mode in the second embodiment, a charge/discharge current (a vehicle input/output current) is measured as information about power transferred between the facility  1  and the vehicle  2 . In a case where a current behavior satisfying any one of the conditions (5) to (8) described below is observed, a determination unit  241  of an ECU  24  determines that there is an intervention of the power control device  14  in the charge/discharge control. 
     (5) In a case where the charge/discharge current has become lower than 80[%] of the vehicle-indicating current value. 
     (6) In a case where the charge/discharge current has become lower than 70[%] of the vehicle-indicating current value. 
     (7) In a case where the state of the charge/discharge current dropping lower than 80[%] of the vehicle-indicating current value has continued for more than 0.5 seconds. 
     (8) In a case where the state of the charge/discharge current dropping lower than 70[%] of the vehicle-indicating current value has continued for more than 0.5 seconds. 
     The vehicle-indicating current value is a current value that may be indicated to the facility-side charging/discharging device  13  forming a connection system connected to a vehicle-side charging/discharging device  25  via the power cable  4 . For example, in a case where the facility-side charging/discharging device  13  has a specification of AC 200 [V] and a rating of 6 [kW], the vehicle-indicating current value is set to 30 [A]. Using a method such as measuring, with a voltmeter (not illustrated) provided in the vehicle  2 , the voltage of power supplied from the facility-side charging/discharging device  13  to the vehicle-side charging/discharging device  25  via the power cable  4 , the ECU  24  determines, as appropriate, what kind of specification of the connection system (the facility-side charging/discharging device) is connected to the vehicle-side charging/discharging device  25  via the power cable  4 . 
     If any of the conditions (5) to (8) described above is satisfied, the charge/discharge current is 0[%] of the vehicle-indicating current value, for example, in the control in which power transferred between the facility-side charging/discharging device  13  and the vehicle-side charging/discharging device  25  via the power cable  4  is interrupted by the facility-side charging/discharging device  13 , which is executed by the power control device  14 ; therefore, a determination of an intervention of the power control device  14  in the charge/discharge control is made. In addition, unless there are any particular malfunctions in the power systems of the facility  1  and vehicle  2 , the charge/discharge current is unlikely to drop lower than 70[%] of the vehicle-indicating current value and, therefore, erroneous determination of an intervention of the power control device  14  in the charge/discharge control may be substantially avoided. Therefore, based on the fact that at least the charge/discharge current is lower than 80[%] or lower than 70[%] of the vehicle-indicating current value, in other words, at least a charge/discharge current drop is limited to 20% to 30% of the vehicle-indicating current value, the ECU  24  may determine that there is an intervention of the power control device  14  in the charge/discharge control. In addition, under the condition (7) or (8) described above, it is possible to improve the accuracy with which the ECU  24  determines the presence or absence of an intervention of the power control device  14  in the charge/discharge control. 
     Therefore, in the vehicle  2  according to the second embodiment, even if a signal distinctly indicating the existence of the power control device  14  is not transmitted from the facility  1  side to the vehicle  2  side, whether or not the power control device  14  is intervening in the charge/discharge control may be determined. Therefore, by executing the charge/discharge control based on the result of the determination of whether or not the power control device  14  is intervening in the charge/discharge control, the vehicle  2  according to the second embodiment is able to execute charge/discharge control appropriately regardless of the presence or absence of an intervention of the power control device  14  in the charge/discharge control. 
       FIG. 3  is a flowchart illustrating a second example of the control executed by the ECU  24 . 
     First, the ECU  24  executes an observation mode (step S 11 ) and measures a charge/discharge current (step S 12 ). Next, a determination unit  241  of the ECU  24  determines whether or not the state of the charge/discharge current dropping lower than 70[%] of the vehicle-indicating current value has continued for more than 0.5 seconds (step S 13 ). In a case where it is determined that the state of the charge/discharge current dropping lower than 70[%] of the vehicle-indicating current value has continued for more than 0.5 seconds (Yes in step S 13 ), the determination unit  241  of the ECU  24  determines that the power control device  14  provided in the facility  1  is intervening in charge/discharge control between a power system and a battery  23  (step S 14 ). 
     Next, the ECU  24  determines whether an aspect of the charge/discharge control, specifically, a charge/discharge plan needs to be changed (step S 15 ). For example, in a case where the charge/discharge plan for the vehicle  2  is a time-linked plan in which charge/discharge is planned to be completed at a time set in advance, the charge/discharge plan is changed. Meanwhile, in a case where the charge/discharge plan for the vehicle  2  is the shortest charge/discharge plan in which the charge/discharge is planned to be completed in the shortest time, the charge/discharge plan is not changed. 
     In a case where it is determined that the charge/discharge plan needs to be changed (Yes in step S 15 ), the ECU  24  changes the charge/discharge plan (step S 16 ) and ends the series of controls. To change the charge/discharge plan, for example, the ECU  24  receives a charge/discharge plan corresponding to the measured upstream voltage from the vehicle server  6  via the vehicle-side communication device  27  and changes the charge/discharge plane to the shortest charge/discharge plan or changes the charge/discharge plan so that the time to complete charge/discharge is made earlier than the initial plan. 
     Conversely, in a case where it is determined in step S 15  that the charge/discharge plan does not need to be changed (No in step S 15 ), the ECU  24  ends the series of controls without changing the charge/discharge plan. In a case where the charge/discharge plan is not changed, for example, the shortest charge/discharge may be achieved by maintaining the highest possible charge/discharge output in accordance with the intervention of the power control device  14  in the control. 
     Conversely, in a case where it is determined in step S 13  that the state of the charge/discharge current dropping lower than 70[%] of the vehicle-indicating current value has not continued for more than 0.5 seconds (No in step S 13 ), the determination unit  241  of the ECU  24  determines that the power control device  14  provided in the facility  1  is not intervening in the charge/discharge control between the power system and the battery  23  (step S 17 ), and ends the series of controls. 
     In the flowchart illustrated in  FIG. 3 , in step S 13 , any of the following may be determined; whether the charge/discharge current has become lower than 80[%] of the vehicle-indicating current value, whether the charge/discharge current has become lower than 70[%] of the vehicle-indicating current value, and whether the state of the charge/discharge current dropping lower than 80[%] of the vehicle-indicating current value has continued for more than 0.5 seconds. 
     The aspect of the charge/discharge control determined in step S 15  is not limited to the charge/discharge plan and may be the content or method of the charge/discharge control executed when determination is made. Then, in a case where it is determined that the content or method of the charge/discharge control needs to be changed, the content or method of charge/discharge control is changed. Conversely, in a case where it is determined that the content or method of the charge/discharge control does not need to be changed, the content or method of the charge/discharge control is not changed. 
     A third embodiment will be described below. The descriptions of the portions common to those of the first embodiment will be omitted as appropriate. 
     The third embodiment assumes charge/discharge in which a facility-side charging/discharging device  13  has the function (CPLT) of signal communication with a vehicle  2  and in which notification of a limit value signal for a charge/discharge current is given to a vehicle-side charging/discharging device  25  from the facility-side charging/discharging device  13  via the power cable  4 . The limit value signal for the charge/discharge current is a signal variable in limit value. The vehicle  2  generally performs charge/discharge with a charge/discharge current value in a range smaller than an upper limit value that is the limit value of the charge/discharge control and is notified by the facility-side charging/discharging device  13 . Therefore, in the third embodiment, based on the behavior of the limit value signal for the charge/discharge current whose notification is given from the facility-side charging/discharging device  13  to the vehicle-side charging/discharging device  25 , the presence or absence of an intervention of a power control device  14  in the charge/discharge control is determined. 
     In an observation mode in the third embodiment, as information about the power transferred between the facility  1  and the vehicle  2 , the limit value signal for the charge/discharge current whose notification is given from the facility-side charging/discharging device  13  to the vehicle-side charging/discharging device  25 , is measured. In a case where the behavior of the limit value of the charge/discharge current, satisfying any one of the conditions (9) and (10) described below is observed, a determination unit  241  of an ECU  24  determines that there is an intervention of the power control device  14  in the charge/discharge control. 
     (9) In a case where a change in the limit value of the charge/discharge current has become 20[%] or more with respect to the reference limit value of the charge/discharge current. 
     (10) In a case where a change in the limit value of the charge/discharge current has become 30[%] or more with respect to the reference limit value of the charge/discharge current. 
     The reference limit value of the charge/discharge current is an initial value when the charge/discharge control starts or is a rated value set in a system. 
     If the condition (9) or (10) described above is satisfied, the limit value (the upper limit value) of the charge/discharge current is 0 [A] and a change in the limit value is 100[%] with respect to the reference limit value of the charge/discharge current, for example, in the control in which power transferred between the facility-side charging/discharging device  13  and the vehicle-side charging/discharging device  25  via the power cable  4  is interrupted by the facility-side charging/discharging device  13 , which is executed by the power control device  14 ; therefore, a determination of an intervention of the power control device  14  in the charge/discharge control is made. Therefore, based on the fact that a change in the limit value of the charge/discharge current is 20[%] or more or 30[%] or more with respect to the reference limit value of the charge/discharge current, the ECU  24  may determine that there is an intervention of the power control device  14  in the charge/discharge control. 
     Therefore, in the vehicle  2  according to the third embodiment, even if a signal distinctly indicating the presence of the power control device  14  is not transmitted from the facility  1  side to the vehicle  2  side, whether or not the power control device  14  is intervening in the charge/discharge control may be determined. Therefore, by executing the charge/discharge control based on the result of the determination of whether or not the power control device  14  is intervening in the charge/discharge control, the vehicle  2  according to the third embodiment is able to execute charge/discharge control appropriately regardless of the presence or absence of an intervention of the power control device  14  in the charge/discharge control. 
       FIG. 4  is a flowchart illustrating a third example of the control executed by the ECU  24 . 
     First, the ECU  24  executes an observation mode (step S 21 ) and receives a limit value signal for a charge/discharge current from the facility-side charging/discharging device  13  (step S 22 ). Next, the determination unit  241  of the ECU  24  determines whether a change in the limit value of the charge/discharge current has become 30[%] or more with respect to the reference limit value of the charge/discharge current (step S 23 ). In a case where it is determined that the change in the limit value of the charge/discharge current has become 30[%] or more with respect to the reference limit value of the charge/discharge current (Yes in step S 23 ), the determination unit  241  of the ECU  24  determines that there is an intervention of the power control device  14  in charge/discharge control between a power system and a battery  23  (step S 24 ). 
     Next, the ECU  24  determines whether the aspect of the charge/discharge control, specifically, a charge/discharge plan needs to be changed (step S 25 ). For example, in a case where the charge/discharge plan for the vehicle  2  is a time-linked plan (scheduled charging), the charge/discharge plan is changed. Meanwhile, in a case where the charge/discharge plan for the vehicle  2  is the shortest charge/discharge (to reach a target amount of charge/discharge in the shortest possible time), the charge/discharge plan is not changed. 
     In a case where it is determined that the charge/discharge plan needs to be changed (Yes in step S 25 ), the ECU  24  changes the charge/discharge plan (step S 26 ) and ends the series of controls. To change the charge/discharge plan, for example, the ECU  24  receives a charge/discharge plan corresponding to the measured upstream voltage from the vehicle server  6  via the vehicle-side communication device  27  and changes the charge/discharge plane to the shortest charge/discharge plan or changes the charge/discharge plan so that the time to complete charge/discharge is made earlier than the initial plan. 
     Conversely, in a case where it is determined in step S 25  that the charge/discharge plan does not need to be changed (No in step S 25 ), the ECU  24  ends the series of controls without changing the charge/discharge plan. In a case where the charge/discharge plan is not changed, for example, the shortest charge/discharge may be achieved by maintaining the highest possible charge/discharge output in accordance with the intervention of the power control device  14  in the control. 
     Conversely, in a case where it is determined in step S 23  that a change in the limit value of the charge/discharge current has not become 30[%] or more with respect to the reference limit value of the charge/discharge current (No in step S 23 ), the determination unit  241  of the ECU  24  determines that there is no intervention of the power control device  14  in the charge/discharge control between the power system and the battery  23  (step S 27 ), and ends the series of controls. 
     In the flowchart illustrated in  FIG. 4 , in step S 23 , a determination may be made as to whether a change in the limit value of the charge/discharge current has become 20[%] or more with respect to the reference limit value of the charge/discharge current. 
     The aspect of the charge/discharge control determined in step S 25  is not limited to the charge/discharge plan and may be the content or method of the charge/discharge control executed when determination is made. Then, in a case where it is determined that the content or method of the charge/discharge control needs to be changed, the content or method of charge/discharge control is changed. Conversely, in a case where it is determined that the content or method of the charge/discharge control does not need to be changed, the content or method of the charge/discharge control is not changed. 
     In the vehicle according to the present disclosure, based on the information about power transferred between the facility-side charging/discharging device and the vehicle-side charging/discharging device in executing the charge/discharge control, the determination unit determines the presence or absence of an intervention of the facility-side control device in the charge/discharge control. Therefore, in the vehicle according to the present disclosure, even if a signal distinctly indicating the existence of the facility-side control device is not transmitted from the facility side to the vehicle side, whether or not the facility-side control device is intervening in the charge/discharge control may be determined. Therefore, by executing the charge/discharge control based on the result of the determination of whether or not the facility-side control device is intervening in the charge/discharge control, the vehicle according to the present disclosure is able to execute the charge/discharge control appropriately regardless of the presence or absence of an intervention of the facility-side control device in the charge/discharge control. 
     The facility-side control device controls power in the power system provided in the facility and, in a case where the input voltage from the facility-side charging/discharging device to the vehicle-side charging/discharging device has become lower than a predetermined value with respect to the reference voltage, the determination unit may determine that there is an intervention of the facility-side control device in the charge/discharge control. 
     The facility-side control device controls power in the power system provided in the facility and, in a case where the charge/discharge current of power transferred between the facility-side charging/discharging device and the vehicle-side charging/discharging device has become lower than a predetermined value with respect to the vehicle-indicating current value set in advance, the determination unit may determine that there is an intervention of the facility-side control device in the charge/discharge control. 
     According to the present disclosure, it may be possible to improve the accuracy with which the determination unit determines the presence or absence of an intervention of the facility-side control device in the charge/discharge control. 
     The facility-side control device controls power in the power system provided in the facility and, in a case where a change in the limit value of the charge/discharge current of power transferred between the facility-side charging/discharging device and the vehicle-side charging/discharging device has become a predetermined proportion or more with respect to the reference limit value set in advance, the determination unit may determine that there is an intervention of the facility-side control device in the charge/discharge control. 
     Taking account of the influence of an intervention of the facility-side control device in the charge/discharge control, the aspect of the charge/discharge control may be changed with respect to the initial aspect of the charge/discharge control so as to achieve a target amount of charge/discharge. 
     In the vehicle according to the present disclosure, based on information about power transferred between a facility-side charging/discharging device and a vehicle-side charging/discharging device in executing the charge/discharge control, a determination unit determines the presence or absence of an intervention of a facility-side control device in charge/discharge control. Therefore, in the vehicle according to the present disclosure, even if a signal distinctly indicating the existence of the facility-side control device is not transmitted from the facility side to the vehicle side, whether or not the facility-side control device is intervening in the charge/discharge control may be determined. Therefore, the vehicle according to the present disclosure has an advantageous effect that, by executing the charge/discharge control based on the result of the determination of whether or not the facility-side control device is intervening in the charge/discharge control, charge/discharge control may be executed appropriately regardless of the presence or absence of an intervention of the facility-side control device in the charge/discharge control. 
     Although the disclosure has been described with respect to specific embodiments for a complete and clear disclosure, the appended claims are not to be thus limited but are to be construed as embodying all modifications and alternative constructions that may occur to one skilled in the art that fairly fall within the basic teaching herein set forth.