Charging device and power system equipped with the charging device

Abstract

To provide a power system capable of expanding a management target of a centralized control device to a charging device whose charging power cannot be controlled, and a charging device used in the power system.SOLUTION: A charging device A that switches between an energized state in which a connected electric vehicle B is charged and a non-connected state in which charging is not performed includes: a switch 12 that switches between the energized state and the non-energized state; a determination index calculation unit 111 that includes a priority setting unit 119 that sets a parameter k which is a value corresponding to the priority of the energized state, and calculates a determination index X for determining whether to bring the state into the energized state or the non-connected state on the basis of a guidance index pr input from a centralized control device F that manages the charging device A, a parameter k, and a preset optimization problem; and a determination unit 112 that instructs switching of the switch 12 on the basis of a comparison result of comparing the determination index X with a predetermined value.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a charging device for charging an electric vehicle or the like, and to a power system including the charging device. [Background technology]

[0002] In recent years, power systems that manage multiple power devices connected to a power grid and control the power transmitted and received between the power grid and the grid have become increasingly common. For example, Patent Document 1 discloses an example of a power system that includes a centralized management device and multiple power devices and controls output power using an autonomous distributed cooperative control method. The centralized management device calculates a guide index for controlling the output power of the entire power system to a target power. The multiple power devices use the common guide index calculated by the centralized management device to calculate target values ​​for their own output power based on their respective optimization problems. Then, the power devices control their own output power so that the output power reaches the target value. Each power device autonomously controls its output power based on the guide index, thereby controlling the output power of the entire power system to the target power. The centralized management device simply calculates and transmits the index without understanding the status of each power device, thereby reducing the computational and communication burden. This eliminates the need for a high-performance, expensive centralized management device, thereby reducing initial installation costs. Furthermore, expanding the power system does not require major modifications to the centralized management device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-148627 Summary of the Invention [Problem to be solved by the invention]

[0004] In Patent Document 1, the power devices are assumed to be a photovoltaic power generation device capable of controlling output power and a power storage device capable of charging and discharging and capable of controlling input and output power. The centralized control device cannot include power devices that cannot control input and output power in the management target. For example, a small-scale charging device for electric vehicles cannot control the charging power to the connected electric vehicle. Therefore, the centralized control device cannot include such charging devices in the management target.

[0005] The present invention has been devised in light of the above-mentioned circumstances, and aims to provide a power system in which the objects managed by a centralized management device can be expanded to include charging devices that cannot control charging power, and a charging device used in such a power system. [Means for solving the problem]

[0006] A charging device provided by a first aspect of the present invention is a charging device that can be switched between an energized state in which a connected electric vehicle or the like is charged, and an unenergized state in which charging is not performed, and is equipped with a switch that switches between the energized state and the unenergized state, a priority setting unit that sets a priority parameter that is a value according to the priority of changing to the energized state, and a judgment index calculation unit that calculates a judgment index for determining whether to change to the energized state or the unenergized state based on an induction index input from a centralized management device that manages the charging device, the priority parameter, and a preset optimization problem, and a judgment unit that instructs the switch whether to change to the energized state or the unenergized state based on the comparison result of the judgment index with a predetermined value.

[0007] "Electric vehicles, etc." are mobile vehicles equipped with an electric motor as a power source and a storage battery that supplies power to the motor. Therefore, "electric vehicles, etc." includes not only so-called electric vehicles powered solely by an electric motor, but also plug-in hybrid vehicles equipped with an internal combustion engine. Furthermore, "electric vehicles, etc." includes not only automobiles, but also other vehicles such as two-wheeled vehicles (electric motorcycles, electrically assisted bicycles), and also unmanned guided vehicles.

[0008] In a preferred embodiment of the present invention, the priority setting unit sets the priority parameter so that the priority is higher in the powered state than in the powered state.

[0009] In a preferred embodiment of the present invention, the device further includes an on-count counting unit that counts the number of times the device is switched from the non-conductive state to the conductive state, and the judgment unit does not instruct switching between the conductive state and the non-conductive state when the judgment index is within a predetermined range based on the predetermined value, and the greater the number of on-counts, the wider the predetermined range is, and when the number of on-counts reaches an upper limit, the judgment unit instructs the device to switch to the conductive state.

[0010] In a preferred embodiment of the present invention, the priority setting unit sets the priority parameter so that the shorter the time until the electric vehicle or the like begins to be used, the higher the priority.

[0011] In a preferred embodiment of the present invention, the priority setting unit sets the priority parameters so that the priority is increased as the planned travel distance of the electric vehicle or the like increases.

[0012] In a preferred embodiment of the present invention, the priority setting unit sets the priority parameter so as to increase the priority in accordance with a preset priority level.

[0013] In a preferred embodiment of the present invention, the device further includes a connection detection unit that detects that the electric vehicle or the like has been connected, and when the connection detection unit detects the connection of the electric vehicle or the like, the determination unit issues an instruction to enter the energized state and causes the energized state to continue for a first time period.

[0014] In a preferred embodiment of the present invention, when the determination unit switches from the non-conductive state to the conductive state, the determination unit continues the conductive state for a second time period.

[0015] In a preferred embodiment of the present invention, the determination unit issues an instruction to switch to the power-on state when the time until the electric vehicle or the like begins to be used is equal to or less than the time until the charging rate of the electric vehicle or the like reaches a requested charging rate.

[0016] In a preferred embodiment of the present invention, the determination unit issues an instruction to switch to the energized state when the guidance indicator is not input from the centralized control device.

[0017] A power system provided by a second aspect of the present invention includes a plurality of charging devices provided by the first aspect of the present invention, and the centralized control device that outputs a common induction indicator to each of the charging devices. [Effects of the Invention]

[0018] According to the present invention, the judgment index calculation unit calculates a judgment index based on a common guidance index input from the centralized management device, a set priority parameter, and a preset optimization problem. The judgment unit then compares the judgment index with a predetermined value and instructs whether to switch the charging device to a powered state or a powered-off state based on the comparison result. That is, the charging device autonomously switches between a powered state (ON) and a powered-off state (OFF) based on the guidance index. Therefore, the centralized management device can cause charging devices that cannot control charging power to perform on / off control based on the guidance index. This allows the scope of management by the centralized management device in the power system to be expanded to include charging devices that cannot control input / output power. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a block diagram showing the overall configuration of a power system according to a first embodiment. [Figure 2] 1 is a block diagram showing the internal configuration of a charging device according to a first embodiment. [Figure 3] FIG. 10 is a characteristic diagram showing the change characteristics of a judgment index relative to a guidance index. [Figure 4] FIG. 10 is a diagram for explaining a method for setting each parameter. [Figure 5] FIG. 10 is a diagram for explaining differences in the change characteristics of the judgment index X when the parameter k7 is set according to the priority level of the electric vehicle. [Figure 6] 10 is an example of a flowchart illustrating an on / off process performed by a control unit. DETAILED DESCRIPTION OF THE INVENTION

[0020] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0021] FIG. 1 is a block diagram showing the overall configuration of a power system according to a first embodiment. A power system G is connected to a power grid E and can transmit and receive power from the power grid E. The power system G controls output power using an autonomous distributed cooperative control method so that power at a connection point between the power system G and the power grid E (hereinafter referred to as "connection point power") becomes a target power. In the following description, when the power system G transmits power to the power grid E (reverse power flow), the connection point power is taken as a positive value. On the other hand, when the power system G receives power from the power grid E, the connection point power is taken as a negative value. The power system G includes a centralized management device F, power conditioners C1 to Cn, power conditioners D1 to Dm, charging devices A1 to Ak, and a user information database H. In this embodiment, the power system G is a power system installed in a business establishment, and the charging devices A1 to Ak constitute a charging station located in the business establishment's parking lot, where they charge employees' commuting vehicles, business vehicles, and the like.

[0022] The centralized control device F monitors the connection point power and calculates an index for instantaneous value control of the connection point power to the target power. In this embodiment, the centralized control device F uses the power value detected at the connection point between the power system G and the power grid E as the connection point power P(t). The centralized control device F may receive the detected values ​​of input / output power detected by each of the power conditioners C1 to Cn, D1 to Dm and each of the charging devices A1 to Ak, and use the total value calculated from these detected values ​​as the connection point power P(t). The centralized control device F calculates the connection point power P(t) based on the set target power P c and the connection point power P(t), a guide index pr is calculated, and a common guide index pr is transmitted to each of the power conditioners C1 to Cn, D1 to Dm and each of the charging devices A1 to Ak. Note that the communication method is not limited, and may be wired communication or wireless communication.

[0023] Each of the power conditioners C1 to Cn is connected to a solar cell, and converts DC power generated by the solar cell into AC power and outputs it. Each of the power conditioners C1 to Cn includes a target power calculation unit 91 and an output control unit 92. The target power calculation unit 91 uses the guidance index pr received from the centralized management device F to calculate a target power value P ref The output control unit 92 calculates the target power value P ref Based on this, the output power is controlled.

[0024] Each of the power conditioners D1 to Dm is connected to a storage battery and charges and discharges the storage battery. Although not shown in Fig. 1, each of the power conditioners D1 to Dm includes a target power calculation unit 91 and an output control unit 92, similar to the power conditioners C1 to Cn. An optimization problem suitable for charging and discharging the storage battery is set in advance in the target power calculation unit 91 of each of the power conditioners D1 to Dm.

[0025] Charging devices A1 to Ak are devices that charge the connected electric vehicles B1 to Bk, respectively. In the following, when the charging devices A1 to Ak are described without distinction, they will be referred to as "charging device A." When the electric vehicles B1 to Bk are described without distinction, they will be referred to as "electric vehicle B." Electric vehicle B is a vehicle that can run using an electric motor as a power source, and includes vehicles also equipped with an internal combustion engine (for example, plug-in hybrid vehicles). Electric vehicle B is equipped with a storage battery 3. Charging device A charges the storage battery 3 installed in electric vehicle B, which is connected to it by a charging cable 2. The electric motor of electric vehicle B operates using power stored in storage battery 3.

[0026] Each charging device A cannot control the charging power, and switches between a powered state in which the connected electric vehicle B is connected to the power grid E and charged, and a disconnected state in which the connected electric vehicle B is disconnected and not charged. The charging device A switches between the powered state and the disconnected state based on the guidance indicator pr received from the centralized control device F. In this embodiment, the charging device A switches between the powered state and the disconnected state taking into account the priority of charging, as will be described later. Each charging device A may also have a function to discharge the storage battery 3 of the connected electric vehicle B. Details of the charging device A will be described later.

[0027] The user information database H stores various information related to the user of each electric vehicle B. The user information database H communicates with each charging device A and transmits necessary information to each charging device A. The communication method is not limited and may be wired communication or wireless communication. The various information includes the use time of the electric vehicle B, the planned driving distance, the battery capacity, the required charging rate, and the priority level. For example, if the electric vehicle B is a commuter vehicle, the use time is set as the user's return home time, and the planned driving distance is set as the user's commuting distance. Furthermore, if the electric vehicle B is a commercial vehicle, the use time is set as the user's business start time, and the planned driving distance is set as the driving distance according to the user's destination. The information included in the various information is not limited to these.

[0028] Based on the common induction index pr received from the centralized control device F, each power conditioner C1 to Cn, D1 to Dm autonomously controls the input / output power, and each charging device A1 to Ak autonomously switches between a power-on state and a power-off state. As a result, the output power (connection point power P(t)) of the entire power system G reaches the target power P c In this embodiment, the centralized control device F controls the node power P(t) to be equal to or greater than the target power P c If it is larger, the induction index pr is increased, and the connection point power P(t) becomes equal to the target power P c If the induction index pr is smaller, the induction index pr is reduced. Each of the power conditioners C1 to Cn, D1 to Dm and each of the charging devices A1 to Ak operates to reduce the connection point power P(t) as the induction index pr received from the centralized control device F increases, and operates to increase the connection point power P(t) as the induction index pr decreases. Detailed description of the power conditioners C1 to Cn, D1 to Dm and the centralized control device F will be omitted.

[0029] Next, details of charging device A will be described. Charging device A and electric vehicle B are connected by a charging cable 2. The charging connector of charging cable 2 is connected to the charging port of electric vehicle B, and the charging plug is connected to the charging outlet of charging device A. Charging device A communicates with user information database H and receives various information from user information database H. In this embodiment, charging device A also communicates with electric vehicle B connected by charging cable 2, and receives information from electric vehicle B such as the current state of charge (SoC) and storage battery capacity of storage battery 3. Note that the communication method is not limited, and may be wired communication or wireless communication. In the case of wired communication, a communication line arranged separately from the power line of charging cable 2 may be used, or PLC (Power Line Communication) communication in which a communication signal is superimposed on the power line may be performed.

[0030] 2 is a block diagram showing the internal configuration of the charging device A. The charging device A includes a control unit 11, a switch 12, a charging outlet 13, a connection detection unit 14, and a receiving unit 15.

[0031] Charging outlet 13 is an outlet for connecting electric vehicle B to charging device A, and is connected to a charging plug of charging cable 2 connected to electric vehicle B. Connection detection unit 14 detects that electric vehicle B has been connected to charging device A. Specifically, connection detection unit 14 detects whether the charging plug of charging cable 2 connected to electric vehicle B is connected to charging outlet 13. Note that connection detection unit 14 may detect that electric vehicle B has been connected to charging device A using other methods. Connection detection unit 14 outputs the detection result to control unit 11. Receiving unit 15 receives guidance indicator pr from centralized management device F, and receives information from electric vehicle B and user information database H. Receiving unit 15 outputs the received guidance indicator pr and various information to control unit 11.

[0032] The switch 12 is disposed inside the charging device A on a connection line connected to the charging outlet 13 of the charging device A, and is a switch that switches between a powered state in which the electric vehicle B is charged and a powered-off state in which the electric vehicle B is not charged. When the switch 12 is in a closed state (on), the charging device A is in a powered-on state and the electric vehicle B is charged. On the other hand, when the switch 12 is in an open state (off), the charging device A is in a powered-off state and the electric vehicle B is not charged. The switch 12 switches based on the determination result input from the control unit 11.

[0033] The control unit 11 makes a decision to switch the switch 12 based on the guidance index pr and various information input from the receiving unit 15 and the detection result input from the connection detecting unit 14, and outputs the decision result to the switch 12. The control unit 11 includes a decision index calculating unit 111, a decision unit 112, a charging rate acquiring unit 113, a battery capacity acquiring unit 114, an on-count counting unit 115, a user information acquiring unit 116, and a guidance index acquiring unit 117.

[0034] The charging rate acquisition unit 113 acquires the charging rate of the storage battery 3 of electric vehicle B received from electric vehicle B from the information input from the receiving unit 15. The charging rate acquisition unit 113 outputs the acquired charging rate to the judgment index calculation unit 111 and the judgment unit 112. The storage battery capacity acquisition unit 114 acquires the storage battery capacity of electric vehicle B received from electric vehicle B from the information input from the receiving unit 15. Note that the storage battery capacity acquisition unit 114 may acquire the storage battery capacity from information received from the user information database H. The storage battery capacity acquisition unit 114 outputs the acquired storage battery capacity to the judgment index calculation unit 111 and the judgment unit 112.

[0035] The on-count counting unit 115 counts the number of times (on-count) that the determination unit 112 switches the switch 12 from an open state (off) to a closed state (on). The on-count is initialized to "0" every day (24 hours). That is, the on-count counting unit 115 counts the number of times the switch 12 is turned on in a day. The on-counting unit 115 outputs the on-count to the determination index calculation unit 111 and the determination unit 112. The user information acquisition unit 116 acquires information received from the user information database H out of the information input from the receiving unit 15. The user information acquisition unit 116 outputs the acquired information to the determination index calculation unit 111 and the determination unit 112. The guidance index acquisition unit 117 acquires the guidance index pr input from the receiving unit 15. The guidance index acquisition unit 117 outputs the acquired guidance index pr to the determination index calculation unit 111 and the determination unit 112.

[0036] The judgment index calculation unit 111 calculates a judgment index X for determining whether to make the device energized or deenergized based on a preset optimization problem, using the induction index pr input from the induction index acquisition unit 117. This optimization problem includes an evaluation function.

[0037] The judgment index calculation unit 111 is set with the following calculation formula (1) derived from the set evaluation function, and calculates the judgment index X by this calculation formula. lmtare values ​​that define the maximum and minimum values ​​of the guidance index pr calculated by the centralized control device F. a1, a2, and k are setting parameters that are set appropriately depending on the characteristics of the storage battery 3 of electric vehicle B, the priority of charging electric vehicle B, and the like. Parameter a1 is a value that mainly adjusts the amount of change in judgment index X in response to changes in guidance index pr, and is set to a value greater than 0. Parameter a2 is a value that mainly adjusts the guidance index pr at which the judgment index X starts to change. In this embodiment, parameters a1 and a2 are set to "1." Note that parameters a1 and a2 are not limited. Also, parameters a1 and a2 may be set to different values ​​when guidance index pr is a positive value and when it is a negative value. Parameter k is a value that sets the priority of charging electric vehicle B. In this embodiment, parameter k is set to a smaller value as the priority increases. A specific method for calculating parameter k will be described later. The judgment index calculation unit 111 outputs the calculated judgment index X to the judgment unit 112. The judgment index calculation unit 111 may calculate the judgment index X by solving a set evaluation function instead of using the calculation formula shown in the following formula (1).

number

[0038] FIG. 3 is a characteristic diagram (see solid line) showing the change characteristics of the judgment index X with respect to the induction index pr when the parameters a1 and a2 are set to "1" and the parameter k is set to "0" (priority reference value). In the figure, the horizontal axis is the induction index pr and the vertical axis is the judgment index X. As shown in the figure, the change characteristics of the judgment index X are proportional to the induction index pr, becoming smaller as the induction index pr increases, and becoming "0" when the induction index pr is "0". In addition, when the induction index pr is set to the maximum value pr lmt When the induction index pr reaches its minimum value (-pr lmt ) is set to "1".

[0039] Parameter k, which sets the priority of charging electric vehicle B, is set to a smaller value as the priority increases. The smaller the value set by parameter k, the smaller the judgment index X when the guidance index pr is "0," and the straight line showing the change characteristics of judgment index X in Figure 3 moves downward in parallel in the figure (see the dashed line in Figure 3).

[0040] The determination index calculation unit 111 includes a priority setting unit 119. The priority setting unit 119 calculates and sets a parameter k. The determination index calculation unit 111 receives the charging rate from the charging rate acquisition unit 113, the battery capacity from the battery capacity acquisition unit 114, the number of on times from the on-number count unit 115, and information from the user information acquisition unit 116, and calculates the parameter k. In this embodiment, the parameter k is calculated based on parameters k1 to k7.

[0041] The parameter k1 is set based on the charging rate input from the charging rate acquisition unit 113. In this embodiment, the priority setting unit 119 sets the parameter k1 to a smaller value as the charging rate decreases, as shown in Fig. 4(a). Note that Fig. 4(a) is just an example, and the method for setting the parameter k1 is not limited.

[0042] The parameter k2 is set based on the time of use of electric vehicle B input from the user information acquisition unit 116. In this embodiment, the priority setting unit 119 calculates the time from the current time until the start of use of electric vehicle B. Then, as shown in FIG. 4(b), the priority setting unit 119 sets the parameter k2 to "0" when the time until the start of use is equal to or longer than a predetermined time, and sets a smaller value as the time until the start of use is shorter when the time until the start of use is less than the predetermined time. Note that FIG. 4(b) is just an example, and the method of setting the parameter k2 is not limited.

[0043] The parameter k3 is set based on the storage battery capacity input from the storage battery capacity acquisition unit 114. In this embodiment, as shown by the solid line in FIG. 4(c), the priority setting unit 119 sets parameter k3 to "0" when the storage battery capacity is equal to or greater than a first predetermined value. When the storage battery capacity is less than the first predetermined value, the parameter k3 is set to a smaller value as the storage battery capacity increases. When the storage battery capacity is equal to or less than a second predetermined value that is smaller than the first predetermined value, the parameter k3 is set to a fixed value. Note that FIG. 4(c) is an example, and the method for setting parameter k3 is not limited. In this embodiment, the priority setting unit 119 sets parameter k3 to a smaller value as the storage battery capacity increases. This is based on the idea that a battery with a large capacity increases its charging rate slowly during charging, and therefore the battery is given priority for charging. On the other hand, a battery with a small capacity requires a smaller amount of charge to be fully charged. Therefore, the battery with a small capacity is charged first, thereby reducing the number of electric vehicles B that need to be charged. Based on this idea, the priority setting unit 119 may set the parameter k3 to a smaller value as the storage battery capacity decreases, as indicated by the dashed line in FIG. 4(c).

[0044] Parameter k4 is set based on the planned traveling distance of electric vehicle B input from user information acquisition unit 116. In this embodiment, as shown in FIG. 4(d), priority setting unit 119 sets parameter k4 to "0" when the planned traveling distance is equal to or greater than a first distance, sets parameter k4 to a smaller value as the planned traveling distance increases when the planned traveling distance is less than a first predetermined value, and sets parameter k4 to a fixed value when the planned traveling distance is equal to or less than a second distance that is smaller than the first distance. Note that FIG. 4(d) is just an example, and the method for setting parameter k4 is not limited.

[0045] The parameter k5 is set based on whether the charging device A is in a powered state or a disconnected state. The priority setting unit 119 acquires information on whether the charging device A is in a powered state or a disconnected state from the determination unit 112 (whether the determination unit 112 has the switch 12 in an open state or a closed state). When the charging device A is in a powered state, the priority setting unit 119 sets the parameter k5 to a smaller value than when the charging device A is in a disconnected state. Note that the value set for the parameter k5 in each case is not limited.

[0046] The parameter k6 is set based on the number of times that charging device A switches between a powered state and a disconnected state. The priority setting unit 119 receives the number of times that charging device A switches between a powered state and a disconnected state. The priority setting unit 119 receives the number of times that charging device A switches between a powered state and a disconnected state. In this embodiment, as shown by the solid line in FIG. 4(e), the priority setting unit 119 sets the parameter k6 to "0" when the number of times that charging device A switches between a powered state and a disconnected state. When the number of times that charging device A switches between a powered state and a disconnected state, the priority setting unit 119 sets the parameter k6 to "0" when the number of times that charging device A switches between a powered state and a disconnected state. When the number of times that charging device A switches between a powered state and a disconnected state, the priority setting unit 119 may set the parameter k6 to a larger value when the number of times that charging device A switches between a powered state and a disconnected state, as shown by the dashed line in FIG. 4(e). In this case, the priority of charging by the charging device A is lowered, making it difficult for the charging device A to be switched to the energized state.

[0047] The parameter k7 is set based on the priority level of the electric vehicle B input from the user information acquisition unit 116. In the present embodiment, three priority levels are provided: level 1, which increases the priority; level 3, which decreases the priority; and level 2, which does not modify the priority. The user registers one of the levels in the user information database H as the priority level of the electric vehicle B. Note that level 3 is pre-registered in the user information database H, and the user may change the level to level 1 or level 2 as needed. When the priority level is level 1, the priority setting unit 119 sets the parameter k7 to a value smaller than that for level 2. When the priority level is level 3, the priority setting unit 119 sets the parameter k7 to a value larger than that for level 2. Note that the number of priority levels is not limited to three, and may be two, four, or more. The priority setting unit 119 may set the parameter k7 based on a priority level set according to other factors, rather than the priority level registered in the user information database H. Such a priority level may be set, for example, according to the number of on-states counted by the on-state counting unit 115.

[0048] In this embodiment, the priority setting unit 119 calculates parameter k' by adding parameters k1 to k6, and normalizes parameter k' so that it falls within the range of (-1≦k≦1). Normalization corrects parameter k' so that the sum of the maximum values ​​that each of parameters k1 to k6 can take becomes 1, and the sum of the minimum values ​​that each of parameters k1 to k6 can take becomes -1. Then, the priority setting unit 119 adds parameter k7 to the normalized parameter k' to calculate parameter k.

[0049] FIG. 5 is a diagram illustrating differences in the change characteristics of the judgment index X when the parameter k7 is set according to the priority level of the electric vehicle B. FIG. 5 shows the change characteristics of the judgment index X when the parameter k' is "0." The solid line shows the change characteristics of the judgment index X when the priority level is level 2 and the parameter k7 is "0." The dashed line shows the change characteristics of the judgment index X when the priority level is level 1 and the parameter k7 is "-α." The dashed-dotted line shows the change characteristics of the judgment index X when the priority level is level 3 and the parameter k7 is "α." As shown in FIG. 5, even if the parameter k' is the same "0," the range R1 of the guidance index pr where X≦0 at level 1 (see dashed line) is different from the range R3 of the guidance index pr where X≦0 at level 3 (see dashed-dotted line). In other words, the range of the guidance index pr where X≦0 can be changed depending on whether the priority level is set to level 1, 2, or 3.

[0050] The calculation of parameter k in priority setting unit 119 is not limited to using all of parameters k1 to k7, but may use at least one of them. Furthermore, the calculation method of parameter k in priority setting unit 119 is not limited to the above-mentioned method.

[0051] The judgment unit 112 compares the judgment index X input from the judgment index calculation unit 111 with a predetermined value to judge whether to make the state conductive or non-conductive. The judgment unit 112 outputs the judgment result to the switch 12. If the judgment index X is equal to or less than the predetermined value, the judgment unit 112 judges to make the state conductive, and instructs the switch 12 to make the closed state (ON) as the judgment result. On the other hand, if the judgment index X is greater than the predetermined value, the judgment unit 112 judges to make the state non-conductive, and instructs the switch 12 to make the open state (OFF) as the judgment result. In this embodiment, the predetermined value for comparison is "0". The predetermined value is not limited.

[0052] As is clear from the above formula (1), the judgment index X is proportional to the guide index pr, and decreases as the guide index pr increases (see FIG. 3). Therefore, as the guide index pr increases, the judgment index X decreases and falls below a predetermined value (e.g., "0"), causing the switch 12 to switch from the open state to the closed state. This causes charging of the electric vehicle B to begin, the consumed power increases, and the connection point power P(t) decreases. On the other hand, as the guide index pr decreases, the judgment index X increases and exceeds a predetermined value (e.g., "0"), causing the switch 12 to switch from the closed state to the open state. This causes charging of the electric vehicle B to stop, the consumed power decreases, and the connection point power P(t) increases.

[0053] Furthermore, the timing at which the switch 12 switches between the open state and the closed state varies depending on the parameter k. The parameter k is set to a smaller value as the priority of charging the electric vehicle B increases. In FIG. 3, the determination index X when the parameter k is set to "0" is shown by a solid line, and the determination index X when the parameter k is set to "-0.5" is shown by a dashed line. The determination index X shown by the dashed line becomes equal to or less than a predetermined value (e.g., "0") when the guidance index pr is smaller than the determination index X shown by the solid line, and therefore the switch 12 is more likely to switch to the closed state. In other words, the higher the priority (the smaller the parameter k), the earlier the timing of switching from the open state to the closed state when the guidance index pr increases, and the later the timing of switching from the closed state to the open state when the guidance index pr decreases.

[0054] In this embodiment, the determination unit 112, in a predetermined case, takes priority over the determination based on the determination index X and forcibly switches the switch 12 to the closed state (ON) to bring the charging device A into the energized state.

[0055] If charging does not start when electric vehicle B is connected to charging device A, the user may think that electric vehicle B or charging device A is malfunctioning. To prevent this, in this embodiment, when electric vehicle B is connected to charging device A, the determination unit 112 switches charging device A to a powered state and maintains the powered state for a while. Specifically, when a signal indicating that electric vehicle B has been connected is input from the connection detection unit 14, the determination unit 112 instructs the switch 12 to close the circuit and maintains the closed state for a predetermined time T1. As a result, when electric vehicle B is connected, charging device A switches to a powered state, starts charging, and continues charging for the predetermined time T1.

[0056] When charging device A switches from a non-conductive state to a conductive state, power consumption increases, and thus the guidance indicator pr decreases. If charging device A is switched to a non-conductive state accordingly, chattering, in which the charging state and the non-conductive state are repeatedly switched back and forth in a short period of time, may occur. To prevent this, in this embodiment, when charging device A switches to a conductive state and starts charging, the determination unit 112 maintains the conductive state for a while. Specifically, when the determination unit 112 switches the switch 12 from an open state to a closed state, the determination unit 112 maintains the closed state for a predetermined time T2. As a result, when charging device A switches to a conductive state and starts charging, charging device A continues charging for the predetermined time T2.

[0057] If the charging rate of electric vehicle B becomes insufficient while electric vehicle B is traveling, electric vehicle B will be unable to travel. To prevent this, in this embodiment, the user registers the required charging rate in advance in the user information database H as a required charging rate. The determination unit 112 has a function of forcibly switching the switch 12 to a closed state so that the charging rate of electric vehicle B will reach the required charging rate by the time of use of electric vehicle B. Specifically, the determination unit 112 calculates the time Tx [minutes] until the start of use of electric vehicle B from the use time input from the user information acquisition unit 116 and the current time. The determination unit 112 also determines whether electric vehicle B can be charged to the required charging rate by the time of use based on the current charging rate S1 [%] input from the charging rate acquisition unit 113, the required charging rate S2 [%] input from the user information acquisition unit 116, and the storage battery capacity W [kWh] input from the storage battery capacity acquisition unit 114. The charging power of charging device A is set in advance and is assumed to be Px [kW]. If, for example, the inequality in the following equation (2) holds, the judgment unit 112 judges that the charging time will be insufficient and instructs the switch 12 to close the circuit. When the switch 12 is in the open state, it switches to the closed circuit state, and when it is in the closed circuit state, it maintains the closed circuit state. As a result, charging device A is forced to enter a conducting state and charges electric vehicle B, so that electric vehicle B is charged to the required charging rate at the time of use.

number

[0058] If a communication failure occurs between the charging device A and the centralized control device F, the charging device A cannot receive the guidance index pr from the centralized control device F. In this case, the judgment index calculation unit 111 cannot calculate the judgment index X, and the judgment unit 112 cannot output the judgment result to the switch 12. Therefore, when the switch 12 is in the open state, the judgment unit 112 cannot switch the switch 12 to the closed-circuit state even if it should be switched to the closed-circuit state. As a result, the charging device A cannot charge the electric vehicle B. To prevent this, in this embodiment, the judgment unit 112 switches the charging device A to the energized state when it cannot receive the guidance index pr from the centralized control device F. Specifically, when the guidance index pr is not input from the guidance index acquisition unit 117, the judgment unit 112 instructs the switch 12 to switch to the closed-circuit state. When the switch 12 is in the open state, it switches to the closed-circuit state, and when it is in the closed-circuit state, it maintains the closed-circuit state. As a result, the charging device A is always in the energized state when it cannot receive the guidance index pr.

[0059] An upper limit is set for the number of times that the switch 12 switches from the open state to the closed state in one day. If the number of times that the switch 12 switches exceeds this upper limit, the operating life of the switch 12 may be shortened. To prevent this, in this embodiment, the determination unit 112 prevents the charging device A from switching to the non-conductive state when the number of times that the switch 12 switches from the open state to the closed state reaches the upper limit. Specifically, the determination unit 112 receives an input of the number of on-counts from the on-count count unit 115. When the number of on-counts reaches the upper limit, the determination unit 112 keeps the switch 12 in the closed state. As a result, the charging device A is always in a conductive state when the number of on-counts reaches the upper limit.

[0060] 6 is an example of a flowchart for explaining the on / off process performed by the control unit 11. The on / off process is a process for determining whether to put the charging device A into a powered state or a powered off state, and outputting the determination result to the switch 12. The on / off process is started when the charging device A is started.

[0061] First, it is determined whether electric vehicle B has been connected (S1). Specifically, the determination unit 112 determines whether a signal indicating that electric vehicle B has been connected has been input from the connection detection unit 14. If electric vehicle B has not been connected (S1: NO), the process returns to step S1 and the determination in step S1 is repeated. That is, the process waits for electric vehicle B to be connected. If electric vehicle B has been connected (S1: YES), the switch 12 is switched to a closed state (ON), and the closed state is maintained for a predetermined time T1 (S2). Specifically, the determination unit 112 instructs the switch 12 to switch to the closed state, and maintains the instruction to maintain the closed state for the predetermined time T1.

[0062] Next, it is determined whether the switch 12 has been switched to a closed circuit state (ON) (S3). Specifically, the determination unit 112 determines whether the switch 12 has been instructed to change from an open state to a closed circuit state. If the switch 12 has been switched to a closed circuit state (S3: YES), the closed circuit state is maintained for a predetermined time T2 (S4), and the process proceeds to step S5. Specifically, the determination unit 112 continues the instruction to change to a closed circuit state for the predetermined time T2. On the other hand, if the switch 12 has not been switched to a closed circuit state (S3: YES), the process of step S4 is not performed, and the process proceeds to step S5.

[0063] Next, it is determined whether the charging rate of electric vehicle B can be increased to the required charging rate (S5). Specifically, the determination unit 112 calculates the time Tx [minutes] until the start of use of electric vehicle B, and determines whether the inequality in equation (2) above is satisfied based on the current charging rate S1 [%], the required charging rate S2 [%], the battery capacity W [kWh], and the charging power Px [kW] of the charging device A. If charging to the required charging rate is not possible (S5: NO), that is, if the inequality in equation (2) above is satisfied, the determination unit 112 instructs the switch 12 to close (ON) (S11), and the process returns to step S3. If charging to the required charging rate is possible (S5: YES), it is determined whether the guidance indicator pr has been received (S6). Specifically, the determination unit 112 determines whether the guidance indicator pr has been input from the guidance indicator acquisition unit 117. If the guidance indicator pr has not been received (S6: NO), the determination unit 112 instructs the switch 12 to switch to a closed circuit state (ON) (S11), and the process returns to step S3. If the guidance indicator pr has been received (S6: YES), it is determined whether the number of times the switch is turned on (the number of times the switch is switched from an open state to a closed circuit state) has reached an upper limit (S7). Specifically, the determination unit 112 determines whether the number of times the switch is turned on input from the ON count unit 115 is equal to or greater than the upper limit. If the number of times the switch is turned on has reached the upper limit (S7: YES), the determination unit 112 instructs the switch 12 to switch to a closed circuit state (ON) (S11), and the process returns to step S3.

[0064] If the number of times of ON has not reached the upper limit (S7: NO), a parameter k is calculated (S8). Specifically, the priority setting unit 119 sets parameters k1 to k7, respectively, and calculates the parameter k based on the parameters k1 to k7. Next, a judgment index X is calculated (S9). Specifically, the judgment index calculation unit 111 calculates the judgment index X based on the calculation formula shown in the above formula (1), the parameter k calculated by the priority setting unit 119, and the guidance index pr input from the guidance index acquisition unit 117.

[0065] Next, it is determined whether the judgment index X is smaller than a predetermined value "0" (S10). Specifically, the determination unit 112 determines whether the judgment index X input from the judgment index calculation unit 111 is smaller than "0". If the judgment index X is smaller than the predetermined value "0" (S10: YES), the determination unit 112 instructs the switch 12 to be in a closed state (ON) (S11), and the process returns to step S3. On the other hand, if the judgment index X is equal to or greater than the predetermined value "0" (S10: NO), the determination unit 112 instructs the switch 12 to be in an open state (OFF) (S12), and the process returns to step S3.

[0066] The on / off process is terminated when electric vehicle B is fully charged, when electric vehicle B is disconnected, etc. The process shown in the flowchart of Fig. 6 is an example, and the on / off process performed by control unit 11 is not limited to the one described above.

[0067] Next, the operation and effects of the charging device A and the power system G according to this embodiment will be described.

[0068] According to this embodiment, the judgment index calculation unit 111 calculates the judgment index X based on the common guidance index pr received from the centralized control device F and a preset optimization problem. Then, the judgment unit 112 compares the judgment index X with a predetermined value to judge whether to establish a power-on state or a power-off state, and outputs the judgment result to the switch 12. The switch 12 switches between a closed state (ON) and an open state (OFF) based on the judgment result input from the judgment unit 112. In other words, based on the guidance index pr received from the centralized control device F, the charging device A autonomously switches between a power-on state in which the connected electric vehicle B is charged and a power-off state in which the connected electric vehicle B is not charged. Therefore, the centralized control device F can cause the charging device A, which cannot control the charging power, to perform on / off control based on the guidance index pr. This allows the objects managed by the centralized control device F in the power system G to be expanded to include charging devices that cannot control the charging power.

[0069] Furthermore, according to this embodiment, the charging priority of each charging device A is set by the parameter k set by the priority setting unit 119. Therefore, each charging device A can vary the timing of switching between the powered state and the disconnected state depending on the priority. This prevents multiple charging devices A from being switched to the powered state or the disconnected state at the same time. This prevents chattering, in which multiple charging devices A repeatedly switch between the powered state and the disconnected state in a short period of time. Furthermore, charging devices A with higher priorities are more likely to be powered, and therefore can charge electric vehicle B with priority.

[0070] Furthermore, according to this embodiment, when the charging rate of electric vehicle B is low, the priority setting unit 119 sets parameter k1 to a small value to decrease parameter k, thereby increasing the priority of charging by charging device A. This allows electric vehicle B with a low charging rate to be charged preferentially. This prevents electric vehicle B from being left with a low charging rate.

[0071] Furthermore, according to this embodiment, when the time until electric vehicle B begins to be used is short, the priority setting unit 119 sets parameter k2 to a small value to decrease parameter k, thereby increasing the priority of charging by charging device A. This allows electric vehicle B, which is about to begin to be used, to be charged preferentially. Therefore, it is possible to prevent electric vehicle B from being charged to an insufficient rate when use begins.

[0072] Furthermore, according to this embodiment, the priority setting unit 119 sets parameter k3 to a small value when the storage battery capacity is large, thereby decreasing parameter k, thereby increasing the priority of charging by charging device A. This allows electric vehicle B, which has a large storage battery capacity, to be charged preferentially. This makes it possible to prevent the charging rate of electric vehicle B, which takes a long time to charge, from being insufficient at the start of use.

[0073] Furthermore, according to this embodiment, the priority setting unit 119 sets parameter k4 to a small value and decreases parameter k when the planned traveling distance is long, thereby increasing the priority of charging by charging device A. This allows electric vehicle B, which has a long planned traveling distance, to be charged preferentially. This makes it possible to prevent the charging rate of electric vehicle B from becoming insufficient while the vehicle is traveling.

[0074] Furthermore, according to this embodiment, when charging device A is in a powered state, priority setting unit 119 sets parameter k5 to a small value to decrease parameter k, thereby increasing the priority of charging by charging device A. As a result, charging device A is more likely to remain in a powered state when it is in a powered state. On the other hand, when charging device A is in a powered-off state, priority setting unit 119 sets parameter k5 to a large value to increase parameter k, thereby decreasing the priority of charging by charging device A. As a result, charging device A is more likely to remain in a powered-off state when it is in a powered-off state. In other words, charging device A performs hysteresis operation. This makes it possible to suppress chattering, thereby suppressing a shortening of the life of switch 12 due to chattering.

[0075] Furthermore, according to this embodiment, when the number of on-times is large, the priority setting unit 119 sets the parameter k6 to a small value to decrease the parameter k, thereby increasing the priority of charging by the charging device A. As a result, the more the number of on-times is, the less likely the charging device A is to be switched to the disconnected state, so that it is possible to prevent the number of on-times from becoming too large.

[0076] Furthermore, according to this embodiment, the priority setting unit 119 adjusts the parameter k by setting the parameter k7 according to the priority level registered in advance by the user, thereby adjusting the priority of charging by the charging device A. This allows the user to change the priority according to their convenience.

[0077] Furthermore, according to this embodiment, when electric vehicle B is connected to charging device A, the determination unit 112 switches charging device A to a powered state and keeps the powered state on for a while, giving priority to the determination based on determination index X. This makes it possible to prevent a situation in which charging does not start even when electric vehicle B is connected.

[0078] Furthermore, according to this embodiment, when charging device A is switched to the energized state, determination unit 112 continues the energized state for a while, giving priority to the determination based on determination index X. This prevents charging device A from being switched to the non-energized state immediately after being switched to the energized state, thereby suppressing the occurrence of chattering.

[0079] Furthermore, in this embodiment, the determination unit 112 places charging device A in a powered state, giving priority to the determination based on determination index X, so that the charging rate will reach the required charging rate by the time electric vehicle B is used. As a result, electric vehicle B is charged to the required charging rate at the time of use, and the charging rate is prevented from becoming insufficient while the vehicle is traveling.

[0080] Furthermore, according to this embodiment, the determination unit 112 puts the charging device A into a power-on state when it is unable to receive the guidance indicator pr from the centralized management device F. This prevents the electric vehicle B from being unable to be charged when the charging device A is unable to receive the guidance indicator pr.

[0081] Furthermore, according to this embodiment, when the number of times the charging device is turned on reaches the upper limit, the determination unit 112 places the charging device A in a power-on state, taking priority over the determination based on the determination index X. As a result, the power-on state continues and the charging device A is not switched to a power-off state, so the number of times the charging device is turned on does not increase. Therefore, the number of times the charging device is turned on can be prevented from increasing beyond the upper limit.

[0082] In the present embodiment, the determination unit 112 determines whether to set the charging device A to a powered state or a power-off state by comparing the determination index X input from the determination index calculation unit 111 with a predetermined value (e.g., "0"). However, this is not limiting. To prevent chattering from occurring in the charging device A, the determination unit 112 may set a predetermined range based on a predetermined value, for example, a range of -0.1 to 0.1 when the predetermined value is "0." The predetermined range is not limited. When the determination index X is in the power-on state or the power-off state, the determination unit 112 does not switch the charging device A between a powered state and a power-off state. However, if the power-off state is set too wide, chattering can be suppressed but precise control becomes impossible. In other words, the setting of the power-off state is a trade-off between chattering suppression and precise control. The power-off state is set so as to prevent frequent chattering while allowing precise control to a certain extent. The range of the power-off state may not be fixed but may be variable. For example, instead of setting the parameter k6 according to the number of times the ON-state is detected by the ON-state counting unit 115, the range of the dead zone may be widened as the number of times the ON-state is increased. In this case, when the number of times the ON-state is small, finer control becomes possible, and when the number of times the ON-state is large, chattering can be further suppressed. In addition, an increase in the number of times the ON-state is suppressed.

[0083] In the present embodiment, the case where charging device A charges electric vehicle B via charging cable 2 has been described, but the present invention is not limited to this. For example, charging device A may charge electric vehicle B using a contactless power transmission technology. That is, charging may be performed by magnetically coupling a power transmitting coil provided in charging device A with a power receiving coil provided in electric vehicle B, and supplying power from charging device A to electric vehicle B in a contactless manner. In this case, connection detection unit 14 may detect that the power receiving coil of electric vehicle B has entered a range where it can receive power from the power transmitting coil of charging device A.

[0084] In this embodiment, the case where charging device A communicates with electric vehicle B to receive the charging rate and storage battery capacity has been described, but this is not limiting. If charging device A does not have a function for communicating with electric vehicle B, the user of electric vehicle B may manually input the storage battery capacity and current charging rate by operating an operation means (not shown) of charging device A. In this case, charging device A may update the charging rate from the storage battery capacity and charging power as needed during charging.

[0085] In this embodiment, the case where charging device A charges electric vehicle B has been described, but this is not limiting. Instead of electric vehicle B, charging device A may charge vehicles such as two-wheeled vehicles (electric motorcycles, electrically assisted bicycles) equipped with an electric motor as a power source, and automated guided vehicles.

[0086] In the present embodiment, the power system G is described as including power conditioners C1-Cn connected to solar cells and power conditioners D1-Dm connected to storage batteries, but this is not limiting. The power system G may not include power conditioners C1-Cn or power conditioners D1-Dm. Furthermore, the power system G may include other power devices, and the centralized management device F may include these power devices in its management targets.

[0087] The charging device and power system according to the present invention are not limited to the above-described embodiment, and the specific configurations of the components of the charging device and power system according to the present invention can be freely designed and modified in various ways. [Explanation of symbols]

[0088] A: charging device, 111: judgment index calculation unit, 119: priority setting unit, 112: judgment unit, 115: on-count count unit, 12: switch, 14: connection detection unit, B: electric vehicle, F: centralized control unit, G: power system

Claims

1. A charging device that can be switched between a powered state in which a connected electric vehicle or the like is charged and a powered-off state in which charging is not performed, a switch that switches between the energized state and the non-energized state; a judgment index calculation unit that has a priority setting unit that sets a priority parameter that is a value according to the priority of setting the power-on state, and calculates a judgment index for determining whether to set the power-on state or the power-off state based on an induction index input from a centralized management device that manages the charging device, the priority parameter, and a preset optimization problem; a determination unit that instructs the switch whether to put the switch into the energized state or the non-energized state based on a comparison result obtained by comparing the determination index with a predetermined value; Equipped with the priority setting unit sets the priority parameter so that the priority is higher in the powered state than in the powered state. Charging device.

2. A charging device that can be switched between a powered state in which a connected electric vehicle or the like is charged and a powered-off state in which charging is not performed, a switch that switches between the energized state and the non-energized state; a judgment index calculation unit that has a priority setting unit that sets a priority parameter that is a value according to the priority of setting the power-on state, and calculates a judgment index for determining whether to set the power-on state or the power-off state based on an induction index input from a centralized management device that manages the charging device, the priority parameter, and a preset optimization problem; a determination unit that instructs the switch whether to put the switch into the energized state or the non-energized state based on a comparison result obtained by comparing the determination index with a predetermined value; an ON counting unit that counts the number of times the non-conductive state is switched to the conductive state; Equipped with the priority setting unit sets the priority parameter based on switching information between the powered state and the powered-off state or information acquired from outside the priority setting unit; The determination unit When the determination index is within a predetermined range based on the predetermined value, no instruction is given to switch between the energized state and the non-energized state; The greater the number of times the ON state is, the wider the predetermined range is set. When the number of times of turning on reaches the upper limit, an instruction to switch to the energized state is given. Charging device.

3. A charging device that can be switched between a powered state in which a connected electric vehicle or the like is charged and a powered-off state in which charging is not performed, a switch that switches between the energized state and the non-energized state; a judgment index calculation unit that has a priority setting unit that sets a priority parameter that is a value according to the priority of setting the power-on state, and calculates a judgment index for determining whether to set the power-on state or the power-off state based on an induction index input from a centralized management device that manages the charging device, the priority parameter, and a preset optimization problem; a determination unit that instructs the switch whether to put the switch into the energized state or the non-energized state based on a comparison result obtained by comparing the determination index with a predetermined value; Equipped with the priority setting unit sets the priority parameter based on switching information between the powered state and the powered-off state or information acquired from outside the priority setting unit; the determination unit issues an instruction to switch to the energized state when the time until the start of use of the electric vehicle or the like is equal to or shorter than the time until the charging rate of the electric vehicle or the like reaches a requested charging rate. Charging device.

4. the priority setting unit sets the priority parameter so that the shorter the time until the start of use of the electric vehicle or the like is, the higher the priority is.

4. The charging device according to claim 1.

5. the priority setting unit sets the priority parameter so that the priority is increased as the planned traveling distance of the electric vehicle or the like is increased.

5. The charging device according to claim 1.

6. the priority setting unit sets the priority parameter so as to increase the priority in accordance with a preset priority level.

6. The charging device according to claim 1.

7. A plurality of charging devices according to any one of claims 1 to 6; the centralized control device that outputs the common guidance indicator to each of the charging devices; An electric power system comprising:

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