JP7189861B2 - Charging device and charging method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a storage battery charging device and charging method, and more particularly to a storage battery charging device and charging method capable of rapid charging while suppressing power from an external power system.

With the spread of electric vehicles (EVs), there are more opportunities for charging while traveling between a departure point and a destination, that is, route charging, and charging devices used for route charging are becoming more popular. In route charging, it is required to shorten the time required to charge the storage battery. In order to shorten the time required for charging, it is conceivable to perform charging by a charging method that shortens the charging time of each EV storage battery. However, a charging method that imposes an excessive burden on the storage battery is not desirable because it rapidly deteriorates the battery condition.

As a method of charging in a relatively short period of time with less load on the storage battery, there is rapid charging by a constant-current constant-voltage method in which charging is performed by shifting to constant-voltage charging after constant-current charging. FIG. 6 shows an example of temporal changes in the charging current and the charging rate of the storage battery when charging is performed by the constant current constant voltage method. The horizontal axis is the charging time, and the vertical axis is the current value or the _charging rate of the storage battery. 4 shows a charging current that indicates a change in charging current when charging. Curves 105, 106, and 107 show changes in the charging rate when charging storage batteries having charging rates of 25%, 35%, and 50%, respectively, at the start of charging (t ₀ ).

The rapid charging method will be described by taking as an example a charging current curve 101 of a storage battery whose charging rate is 25% at the start of charging (t ₀ ). First, charging is performed at a constant current value I _max from the start of charging (t ₀ ) to the transition point (t ₂ ). Although the current value _Imax can be set arbitrarily, it is generally set to the rated output current value of the charging device from the viewpoint of efficiency. At the same time, do not exceed the maximum rated current that the storage battery can accept.

At the time of transition (t2), constant _- current charging is shifted to constant-voltage charging, and charging is continued until the end of charging ₍ t5). Constant voltage charging is a method of charging by controlling the charging current so that the voltage across the terminals of the storage battery is constant. The charging current 101 gradually decreases as the charging rate 105 increases. The timing of shifting from constant-current charging to constant-voltage charging is generally determined in consideration of the charging rate, the characteristics of the storage battery, and the like. In FIG. 6, the timing of the transition is set according to the initial charging rate, so that the charging of the 35% battery (charging current curve 102) transitions to constant voltage charging at _a shorter t1. . However, the charging current exceeding the current value _Imax must be prevented from flowing when switching to constant voltage charging.

The charging end time (t ₅ ) can also be arbitrarily set, but in general, charging is often terminated when a predetermined charging rate is reached. In FIG. 6, charging is terminated when the charging rate reaches approximately 80%. This is because if the battery is charged to a state where the charging rate is close to 100%, the life of the storage battery will rather be shortened. The charging current value 101 becomes 0 by the end of charging (t ₅ ).

Rapid charging by the constant-current constant-voltage method can shorten the charging time of the EV storage battery, but the power received from the external power system (contract power) increases, making it unprofitable. Therefore, charging control that determines the number of chargers that can be used under the maximum available power among the chargers included in the facility, with the smaller one of the contract power and the power facility capacity of the facility as the maximum available power. A device has been proposed (Patent Document 1). In Patent Literature 1, an in-facility storage battery is provided as auxiliary power while ensuring profitability by keeping the number of charged electric vehicles within the range of the contracted power. In Patent Literature 1, an electric vehicle 60 is economically charged by charging an in-facility storage battery in a time period when power demand is low and electricity rates are low, and using the stored electricity to charge the electric vehicle. is.

However, in the charging control device of Patent Document 1, which charges the in-facility storage battery during times when power demand is low and electricity rates are low, a large amount of power is still required from the external power system during rapid charging, especially during constant current charging. is required, the effect of reducing the contract demand is insufficient.

Further, as a power control system using an in-facility storage battery as auxiliary power, a charger for supplying power to equipment, a secondary battery connected to the charger, a load connected to a system power supply, and the A power control system has been proposed that includes a power control controller that is provided in a charger and controls power supplied from the secondary battery to the device and power supplied from the system power supply to the device (Patent Reference 2). In Patent Literature 2, a secondary battery is used as supplementary power during a period of time when power consumption increases so as not to exceed the contracted power. When the SOC of the secondary battery falls below a predetermined threshold, when a predetermined time zone (such as nighttime) when power usage decreases occurs, or based on the past power usage record, the tendency of the power used is determined. is calculated in advance, and the battery is charged when the time when the total amount of power used is low.

However, even in the power control system of Patent Document 2, which charges the secondary battery according to the timing when the power usage decreases and the SOC value, there is still a large amount of power from the external power system during rapid charging, especially during constant current charging. Since it is necessary to supply electric power, the effect of reducing the contract demand is insufficient.

Further, conventionally, a technique has been proposed in which the amount of electric power used by the charging device is monitored and controlled to keep the electric power below the contracted electric power even during quick charging without using a stationary power storage device. However, with this method, there is a problem that the charging speed decreases during times of high power demand. Conventionally, a method of charging a stationary power storage device at a low speed has also been proposed in order to perform rapid charging while suppressing received power. However, in this method, after the stationary power storage device discharges and quickly charges an electric vehicle or the like, a certain time interval must be left before the next electric vehicle or the like can be quickly charged. is required.

Furthermore, it is possible to perform rapid charging appropriately by acquiring various information including the charging status of the stationary power storage device and adjusting the power consumption of the charging device. Since it is necessary to acquire and process information such as charging information and electric power demand prediction, there is a problem that the equipment becomes expensive and complicated.

JP 2012-228041 A JP 2017-184326 A

From the above circumstances, the present invention enables stable charging with a simple facility while reducing the power received from an external power system, and can shorten the interval between charging and the next charging. An object of the present invention is to provide a device and a charging method.

In the present invention, when the charging power required from the storage battery becomes larger than a predetermined value (threshold value) during charging of the storage battery to be charged by the charging device, the power received from the external power system and the charging power The power discharged from the stationary power storage device provided in the device is used as a charging current to charge the storage battery. Further, when the charging power required from the storage battery drops below a predetermined value (threshold) during charging of the storage battery, discharging from the stationary storage device is stopped, and the stationary storage battery is supplied from the external power system. By supplying current to the device, the stationary power storage device is charged in advance in preparation for charging the next storage battery.

The gist of the configuration of the present invention is as follows.
[1] a DC bus or AC bus connected to an external power system;
a stationary power storage device connected to the DC bus or the AC bus;
a battery connectable charger connected to the DC bus or the AC bus;
a control unit that controls charging and discharging of the stationary power storage device and charging of a storage battery connected to the charger;
with
The control unit
determining whether or not the amount of current supplied from the DC bus or the AC bus exceeds a power threshold preset in the control unit;
supplying a charging current from the stationary power storage device to the charger via the DC bus or the AC bus when the amount of current exceeds the power threshold;
A charging device configured to supply current from the DC bus or the AC bus to the stationary power storage device when the amount of current falls below the power threshold.
[2] a power converter connectable to the external power system;
the DC bus connected to the power converter;
a bidirectional DC/DC converter connected to the DC bus;
the stationary power storage device connected to the bidirectional DC/DC converter;
a DC/DC converter connected to the DC bus;
the charger connected to the DC/DC converter;
the control unit controlling charging and discharging of the stationary power storage device and charging of a storage battery connected to the charger by controlling the bidirectional DC/DC converter and the DC/DC converter;
with
The control unit
Determining whether the amount of current supplied from the DC bus exceeds a power threshold preset in the control unit,
supplying a charging current from the stationary power storage device to the charger through the DC bus when the amount of current exceeds the threshold value of electric power;
The charging device according to [1], configured to supply current from the DC bus to the stationary power storage device when the amount of current becomes equal to or less than the threshold value of power.
[3] a second DC/DC converter connected to the DC bus;
a photovoltaic power generation device connected to the second DC/DC converter;
further comprising
The charging device according to [2], wherein the controller controls the second DC/DC converter.
[4] a third DC/DC converter connected to the DC bus;
a connector connected to the third DC/DC converter and connectable to a mobile power generation device;
further comprising
The charging device according to [2] or [3], wherein the control unit controls the third DC/DC converter.
[5] The charging device according to any one of [1] to [4], wherein the charger is one or more.
[6] The charging device according to any one of [1] to [5], wherein the threshold of power is equal to or less than an arbitrary contract power.
[7] The charging device according to [6], wherein the contract power is equal to or less than the average power of the charging current supplied to the charger.
[8] The control unit is configured to start charging the storage battery with constant current charging, and decrease the amount of charging current to the storage battery as the charging rate increases [1] to The charging device according to any one of [7].
[9] The charging device according to [2], wherein the power converter supplies power at a constant current or constant power, and the stationary power storage device charges and discharges so that the DC bus has a constant voltage.
[10] The charging device according to any one of [1] to [9], wherein the stationary power storage device is a lithium-ion battery or a lead-acid battery.
[11] The charging device according to any one of [1] to [10], wherein the storage battery is installed in an electric vehicle (EV).
[12] The charging device according to [2], wherein the power converter is an AC/DC converter that converts AC power of an AC power system into DC power or a DC/DC converter connected to a DC power system. .
[13] a DC or AC bus connected to an external power grid;
a stationary power storage device connected to the DC bus or the AC bus;
and a charger connectable to the storage battery, the charging device being connected to the DC bus or the AC bus, the method comprising:
determining whether the amount of current being supplied from the DC bus or the AC bus exceeds a preset power threshold;
supplying current from the stationary power storage device to the charger via the DC bus or the AC bus when the amount of current exceeds the power threshold;
and charging the stationary power storage device when the amount of current becomes equal to or less than the threshold value of electric power.
[14] After the step of charging the stationary power storage device when the current amount is equal to or less than the power threshold, the sum of the power charged to the storage battery and the power charged to the stationary power storage device is power. The charging method according to [13], further comprising the step of determining whether or not the threshold of is exceeded.
[15] further comprising the step of stopping charging to the stationary power storage device when a sum of power to be charged to the storage battery and power to be charged to the stationary power storage device exceeds the power threshold; [14] ] charging method.

Here, the “power converter” is a converter that converts power of the power system outside the charging device and DC power of the DC bus. When the external power system is an AC power system, it is an AC/DC converter, and when the external power system is a DC power system, it is a DC/DC converter. It may be a unidirectional power converter from the power system to the DC bus, or a power converter that performs bidirectional power conversion.

In the present invention, when charging a storage battery to be charged by the charging device, the charging device is provided with a stationary power storage device that can be charged and discharged according to the magnitude of the charging power required from the storage battery. The power supplied from the grid is reduced below the charging power required from the storage battery. That is, when the charging power required from the storage battery to be charged by the charging device exceeds a predetermined value (threshold value), the power received from the external power system and the power discharged from the stationary power storage device is used as a charging current to charge the storage battery, and even if the storage battery to be charged is being charged, the stationary type The power storage device is charged. Therefore, according to the aspect of the present invention, stable charging is possible while reducing the power received from the external power system, and the interval between charging and the next charging can be shortened.

Further, according to the aspect of the present invention, the stationary power storage device is charged and discharged based on a predetermined value (threshold value) of electric power set in advance. Efficient operation is possible even when there is no charger or when only one charger that can be connected to the storage battery is installed.

According to the aspect of the present invention, by further including the photovoltaic power generation device, it is possible to further reduce the power supplied from the external power system and reduce the load on the stationary power storage device.

According to the aspect of the present invention, by further providing a connector that can be connected to the mobile power generation device, even if the power supply from the external power system is stopped by connecting the mobile power generation device to the connector, charging is possible. The target storage battery can be charged.

According to the aspect of the present invention, the power threshold is equal to or less than the contract power, and the contract power is equal to or less than the average power of the charging current supplied to the charger. is improved, and the interval between charging and the next charging can be shortened while further reducing the power received from the external power system.

1 is a schematic configuration diagram of a charging device that is a first embodiment of the present invention; FIG. 1 is a flow chart of a charging method according to a first embodiment of the present invention; FIG. 2 is a schematic configuration diagram of a charging device that is a second embodiment of the present invention; FIG. 3 is a schematic configuration diagram of a charging device that is a third embodiment of the present invention; FIG. 4 is a schematic configuration diagram of a charging device that is a fourth embodiment of the present invention; It is explanatory drawing of charge by a constant current constant voltage method.

<First embodiment>
FIG. 1 shows a schematic configuration diagram of a charging device 1 that is a first embodiment of the present invention. The charging device 1 is connectable to an external AC power system 10, and includes an AC/DC converter 11 that converts AC power input from the AC power system 10 into DC power and outputs the DC power, and the AC/DC converter 11. a DC bus 19 connected to the output; a DC/DC converter 13 connected to the DC bus 19 that converts the DC power input from the DC bus 19 into a charging voltage of a storage battery to be charged and outputs the voltage; A charger (EV charger 17 in the charging device 1) connected to the /DC converter 13 and connectable to the storage battery to be charged, and DC power connected to the DC bus 19 and inputted from the DC bus 19 into the charging voltage of the stationary power storage device 14 and outputting the same. In the charging device 1, the storage battery is, for example, an onboard storage battery 18 that is a storage battery mounted on an electric vehicle (EV). The output of the DC/DC converter 13 is connected to the EV charger 17, and the onboard storage battery 18 is connected to the EV charger 17 to charge the onboard storage battery 18. The stationary power storage device 14 is an in-facility power storage device of the charging device 1 .

The charging device 1 includes one stationary power storage device 14 and one EV charger 17, respectively.

Furthermore, the charging device 1 includes a control unit 16 . The control unit 16 includes an MPU, a memory and a communication interface connected to the MPU, and communicates with the bidirectional DC/DC converter 12 and the DC/DC converter 13 via a network such as DIO or Ethernet (registered trademark). Connected and in control.

The AC/DC converter 11 is controlled by the control unit 16 so as not to take in power exceeding the upper limit to the external AC power system 10 .

Also, the rated output currents of the bidirectional DC/DC converter 12 and the DC/DC converter 13 are equal to or higher than the rated output current of the AC/DC converter 11 . In the charging device 1 of the first embodiment, the rated output currents of the bidirectional DC/DC converter 12 and the DC/DC converter 13 are the same as the rated output current of the AC/DC converter 11 .

Moreover, the charging device 1 may further include a communication unit (not shown) connected to the control unit 16 . The communication unit is connected to the control unit 16 and the EV charger 17 and can communicate with the EV charger 17 connected to the vehicle-mounted storage battery 18 (for example, CAN communication). The communication unit detects the connection state between the EV charger 17 and the on-vehicle storage battery 18, monitors the battery state of the on-vehicle storage battery 18 and provides the information to the control unit 16, and also receives information from the control unit 16 to the EV charger. 17 to the in-vehicle storage battery 18.

By controlling the bidirectional DC/DC converter 12 and the DC/DC converter 13, the control unit 16 controls charging/discharging of the stationary power storage device 14 and charging of the vehicle-mounted storage battery 18 connected to the EV charger 17. do. The control unit 16 executes the charging process by executing program instructions stored in the memory with the MPU. Details of the charging process will be described later. The control unit 16 monitors and controls input/output current, input/output voltage and input/output power of the bidirectional DC/DC converter 12 and the DC/DC converter 13 . For example, the amount of charging current during constant-current charging in rapid charging is supplied by the controller 16 controlling the output current amounts of the bidirectional DC/DC converter 12 and the DC/DC converter 13 . Further, during constant-voltage charging in rapid charging, the control unit 16 controls the input power of the bidirectional DC/DC converter 12 and the output voltage of the DC/DC converter 13, and the power supplied from the DC/DC converter 13 Get the amount of current flowing.

Next, the operation of the charging device 1, which is one embodiment of the charging method according to the present invention, will be described with reference to the flowchart 20 of FIG. The user of the charging device 1 stops the electric vehicle (EV) at the installation location of the charging device 1, connects the onboard storage battery 18 of the electric vehicle to the EV charger 17, and starts charging the electric vehicle from the operation unit of the charging device 1. is requested to the charging device 1. When the control unit 16 receives an instruction to start charging from the operation unit of the charging device 1 and confirms the connection of the on-vehicle storage battery 18 to the EV charger 17 from the communication unit of the charging device 1, The charging process to the storage battery 18 is started (step 21). Next, the control unit 16 determines whether or not the amount of current flowing from the EV charger 17 to the vehicle-mounted storage battery 18 is equal to or less than a threshold (step 22). The power threshold determined by the control unit 16 is preset in the control unit 16 . The power threshold preset in the control unit 16 is set to an arbitrary contract power or less from the point of view of profitability.

For example, in rapid charging, as shown in FIG. 6, a large amount of electric power must be supplied during constant current charging immediately after the start of charging. Then, the controller 16 controls the bidirectional DC/DC converter 12 to supply power of a predetermined value from the stationary storage battery 14 to the DC bus 19, and the power supplied from the stationary storage battery 14 to the DC bus 19 is charged. It is supplied to the EV charger 17 as current. In step 27, the difference between the required power for constant current charging and the power threshold is supplemented with the power supplied from the stationary storage battery 14 to the DC bus 19, that is, the power discharged by the stationary storage battery 14.

Next, the control unit 16 determines whether or not charging from the EV charger 17 to the vehicle-mounted storage battery 18 has been completed (step 28). When the control unit 16 determines that the charging is not completed, the process returns to step 22, and the control unit 16 again determines whether or not the current amount from the EV charger 17 to the vehicle-mounted storage battery 18 is equal to or less than the threshold. (step 22). If the charging device 1 is still performing constant-current charging, the controller 16 determines that the amount of current from the EV charger 17 to the vehicle-mounted storage battery 18 exceeds the threshold value. Power supply from the stationary storage battery 14 to the DC bus 19 is continued.

When the charging device 1 performs rapid charging, the control unit 16 starts charging the vehicle-mounted storage battery 18 with constant current charging, and adjusts the current amount of the charging current to the vehicle-mounted storage battery 18 according to the increase in the charging rate of the vehicle-mounted storage battery 18. is configured to reduce From the above, charging from the charging device 1 increases the charging rate of the vehicle-mounted storage battery 18, the charging device 1 shifts from constant-current charging to constant-voltage charging, and the amount of current from the EV charger 17 to the vehicle-mounted storage battery 18 increases. When the amount of current has decreased to the fixed amount, the controller 16 determines in step 22 that the amount of current from the EV charger 17 to the vehicle-mounted storage battery 18 is equal to or less than the threshold, so the process proceeds to step 23 . In step 22, the charging rate of the vehicle-mounted battery 18 when the controller 16 determines that the amount of current from the EV charger 17 to the vehicle-mounted battery 18 is equal to or less than the threshold is, for example, a range of 40% to 60%. A range of 50% to 60% is preferred.

Next, the control unit 16 controls the bidirectional DC/DC converter 12 to supply power of a predetermined value from the DC bus 19 to the stationary storage battery 14, and charging of the stationary storage battery 14 is started. At this time, constant voltage charging from the EV charger 17 to the vehicle-mounted storage battery 18 is also performed in parallel (step 23). In step 23, the control unit 16 controls the DC voltage so that the sum of the amount of current from the EV charger 17 to the vehicle-mounted storage battery 18 and the amount of current from the DC bus 19 to the stationary storage battery 14 (total amount of current) is equal to or less than a threshold value. The amount of current flowing from the bus 19 to the stationary storage battery 14 is controlled. Electric power is supplied from the DC bus 19 to the stationary storage battery 14 and the stationary storage battery 14 is charged, so that the stationary storage battery 14 prepares for the charging of the next electric vehicle. The AC/DC converter 11, which is a power converter, supplies power to the DC bus 19 at a constant current or constant power, and the stationary power storage device 14 charges and discharges so that the voltage of the DC bus 19 becomes a constant voltage. I do.

Next, the control unit 16 determines whether the sum of the amount of current from the EV charger 17 to the vehicle-mounted storage battery 18 and the amount of current from the DC bus 19 to the stationary storage battery 14 (total amount of current) is maintained below a threshold value. is monitored (step 24). If the total amount of current remains below the threshold, the process returns to step 23 to continue power supply from the EV charger 17 to the vehicle-mounted storage battery 18 and power supply from the DC bus 19 to the stationary storage battery 14, Go to step 28.

Next, the control unit 16 determines whether or not charging from the EV charger 17 to the vehicle-mounted storage battery 18 has been completed (step 28). When the control unit 16 determines that the charging is completed, the charging of the vehicle-mounted storage battery 18 is terminated. At this time, when the power supply to the stationary storage battery 14 is not sufficient, the power supply to the stationary storage battery 14 is continued, and the control unit 16 determines that the charging of the stationary storage battery 14 is completed. Then, the charging process of the charging device 1 ends.

On the other hand, when it is detected in step 24 that the total amount of current exceeds the threshold value due to a change in the state of charge of the vehicle-mounted storage battery 18 or the like, the process proceeds to step 25 . At step 25, the control unit 16 stops power supply from the DC bus 19 to the stationary storage battery 14, and controls the amount of current from the DC bus 19 to be equal to or less than the threshold. Instead of stopping the power supply from the DC bus 19 to the stationary storage battery 14, the amount of current flowing from the DC bus 19 to the stationary storage battery 14 is suppressed so that the total amount of current is less than or equal to the threshold. good too.

Next, the control unit 16 monitors whether or not the amount of current from the DC bus 19 is maintained below the threshold (step 26). If the amount of current from the DC bus 19 remains below the threshold, the control unit 16 returns to step 22 and determines whether the amount of current from the EV charger 17 to the vehicle-mounted storage battery 18 is below the threshold. Determine (step 22). In step 22, when the control unit 16 determines that the amount of current from the EV charger 17 to the vehicle-mounted storage battery 18 is equal to or less than the threshold, the process proceeds to step 23, where power supply from the DC bus 19 to the stationary storage battery 14 is resumed, and the stationary storage battery 14 is Charging of the type storage battery 14 proceeds. At this time, constant voltage charging from the EV charger 17 to the vehicle-mounted storage battery 18 is also maintained in parallel. On the other hand, if the amount of current from the DC bus 19 cannot be maintained below the threshold value due to a change in the state of charge of the vehicle-mounted storage battery 18 or the like, the process proceeds to step 27 .

In step 27, as described above, the control unit 16 controls the bidirectional DC/DC converter 12 to supply power of a predetermined value from the stationary storage battery 14 to the DC bus 19, and from the stationary storage battery 14 to the DC bus 19. The supplied power is supplied to the EV charger 17 as charging current.

Next, the control unit 16 determines whether or not charging from the EV charger 17 to the vehicle-mounted storage battery 18 has been completed (step 28). When the control unit 16 determines that charging is completed, charging is terminated.

Examples of the stationary power storage device 14 include a lithium ion storage battery, a lead storage battery, and the like. As the stationary power storage device 14, a power storage device other than a storage battery, such as a superconducting flywheel power storage system, an electric double layer capacitor, or the like, may be used.

As described above, the charging device 1 includes the stationary power storage device 14 that can be charged and discharged according to the amount of charging power required from the on-board storage battery 18 when charging the on-board storage battery 18 to be charged. Thus, the power supplied from the external AC power system 10 can be reduced below the charging power required from the vehicle-mounted storage battery 18 . When the charging power required from the vehicle-mounted storage battery 18 exceeds the threshold value set in advance in the charging device 1, the power received from the external AC power system 10 and the power discharged from the stationary power storage device 14 are combined. is used as a charging current to charge the vehicle-mounted storage battery 18, and even if the vehicle-mounted storage battery 18 is being charged, the stationary power storage device 14 is charged at the timing when the charging power required from the vehicle-mounted storage battery 18 drops below the threshold. is charged. Therefore, the charging device 1 can stably charge the vehicle-mounted storage battery 18 while reducing the power received from the external AC power system 10, and charge the vehicle-mounted storage battery 18 and the next vehicle-mounted storage battery 18. interval can be shortened.

In addition, the charging device 1 charges and discharges the stationary power storage device 14, which is an in-facility charging device, based on a preset power threshold. Therefore, the structure of the charging device 1 can be simplified, and even if there is no load equipment other than the charging equipment or only one EV charger 17 that can be connected to the on-board storage battery 18 is provided, the on-board storage battery can be efficiently charged. 18 charges can be made.

Further, in the charging device 1, the EV charger 17 takes in power from the DC bus 19 via the DC/DC converter 13 and charges the onboard storage battery 18 independently according to the demand of the electric vehicle. Therefore, in the charging device 1, by performing control to maintain the voltage of the DC bus 19, the vehicle-mounted storage battery 18 can be stably charged independently of other loads.

As described above, the power threshold is equal to or less than the arbitrary contract power, but the charge/discharge balance of the stationary power storage device 14 is improved, and the power received from the external AC power system 10 is further reduced. The power threshold is set below the average value of the power of the charging current supplied to the EV charger 17 in order to shorten the interval between the charging of the storage battery 18 and the next charging of the on-vehicle storage battery 18. is preferred.

<Second embodiment>
FIG. 3 shows a schematic configuration diagram of a charging device 2 that is a second embodiment of the present invention. In the charging device 1 of the first embodiment, the power from the DC bus 19 and the power discharged from the stationary power storage device 14 are supplied to the EV charger 17 to charge the vehicle-mounted storage battery 18 . On the other hand, as shown in FIG. 3, in the charging device 2 of the second embodiment, the DC bus 39 is further connected with a photovoltaic panel 40 . A photovoltaic panel 40 is connected to the DC bus 39 via a second DC/DC converter 43 . Electric power generated by the photovoltaic panel 40 is supplied to the DC bus 39 and supplied from the DC bus 39 to the EV charger 37 to charge the vehicle-mounted storage battery 38 connected to the EV charger 37 . That is, the photovoltaic panel 40 is a power source of the charging device 2 that can be used together with the external AC power system 30 .

The control unit 36 controls the bidirectional DC/DC converter 32 connected to the stationary storage battery 34, the DC/DC converter (first DC/DC converter 33) connected to the EV charger 37, and the second It is connected with the DC/DC converter 43 . In addition to monitoring and controlling the input/output current, input/output voltage, and input/output power of the bidirectional DC/DC converter 32 and the first DC/DC converter 33, the control unit 36 also monitors and controls the second Input/output current, input/output voltage and input/output power of the DC/DC converter 43 are also monitored and controlled.

The connection relationship of the external AC power system 30, the AC/DC converter 31, the DC bus 39, the bidirectional DC/DC converter 32, and the first DC/DC converter 33 of the charging device 2 is the same as that of the charging device 1. , external AC power system 10 , AC/DC converter 11 , DC bus 19 , bidirectional DC/DC converter 12 and DC/DC converter 13 .

In the charging device 2, even if the electric power required from the on-vehicle storage battery 38 exceeds the threshold value set in the charging device 2 during the day, the on-vehicle power is When the storage battery 38 can be charged and the power required from the vehicle-mounted storage battery 38 falls below the threshold set in the charging device 2, power is supplied from the photovoltaic panel 40 to the stationary power storage device 34. The type storage device 34 can be charged. Also, at night, power generation from the photovoltaic power generation panel 40 can be switched to power supply from the external AC power system 30 . Note that the charging device 2 can also use the photovoltaic panel 40 as a supplementary power source.

Since the charging device 2 further includes the photovoltaic power generation panel 40 , the power supplied from the external AC power system 30 can be further reduced, and the load on the stationary power storage device 34 can be reduced.

<Third embodiment>
FIG. 4 shows a schematic configuration diagram of a charging device 2 that is a third embodiment of the present invention. In the charging device 1 of the first embodiment, the power from the DC bus 19 and the power discharged from the stationary power storage device 14 are supplied to the EV charger 17 to charge the vehicle-mounted storage battery 18 . On the other hand, as shown in FIG. 4, in the charging device 3 of the third embodiment, the DC bus 59 is further connected with a connector 61 that can be connected to a mobile power generator 60 . Connector 61 is connected to DC bus 59 via a third DC/DC converter 63 . The electric power generated by the mobile power generator 60 is supplied to the DC bus 59, is supplied from the DC bus 59 to the EV charger 57, and charges the vehicle-mounted storage battery 58 connected to the EV charger 57. That is, the mobile power generator 60 is an emergency power source when the power supply from the external AC power system 50 is stopped.

The control unit 56 controls the bidirectional DC/DC converter 52 connected to the stationary storage battery 54, the DC/DC converter (first DC/DC converter 53) connected to the EV charger 57, and the third It is connected with the DC/DC converter 63 . In addition to monitoring and controlling the input/output current, input/output voltage, and input/output power of the bidirectional DC/DC converter 52 and the first DC/DC converter 53, the control unit 56 also monitors and controls the third Input/output current, input/output voltage and input/output power of the DC/DC converter 63 are also monitored and controlled.

The connection relationship among the external AC power system 50, the AC/DC converter 51, the DC bus 59, the bidirectional DC/DC converter 52, and the first DC/DC converter 53 of the charging device 3 is the same as that of the charging device 1. , external AC power system 10 , AC/DC converter 11 , DC bus 19 , bidirectional DC/DC converter 12 and DC/DC converter 13 .

In the charging device 3, the portable power generator 60 brought in from the outside is connected to the connector 61, and the mobile power generator 60 is operated. Also, even if the electric power required from the vehicle-mounted storage battery 58 exceeds the threshold set in the charging device 3, the vehicle-mounted storage battery 58 can be charged by the power generation from the mobile power generator 60 and the discharge from the stationary storage battery 54. When the electric power required from the storage battery 58 becomes equal to or less than the threshold set in the charging device 3, electric power is supplied from the mobile power generator 60 to the stationary electric storage device 54 to charge the stationary electric storage device 54. be able to.

The charging device 3 further includes a connector 61 that can be connected to the mobile power generation device 60. By connecting the mobile power generation device 60 to the connector 61, power supply from the external AC power system 50 is stopped. can also charge the in-vehicle storage battery 58 in the same charging process as the charging device 1 .

<Fourth embodiment>
FIG. 5 shows a schematic configuration diagram of a charging device 4 that is a fourth embodiment of the present invention. In the charging device 1 of the first embodiment, the number of installed EV chargers 17 to which the in-vehicle storage battery 18 is connected is one. On the other hand, as shown in FIG. 5, in the charging device 4 of the fourth embodiment, a plurality of EV chargers 77 are installed. In addition, in the charging device 4, in response to the fact that a plurality of EV chargers 77 are installed, a DC/DC converter that converts the DC power input from the DC bus 79 into a charging voltage to be charged and outputs the voltage is output. 73 are provided. In the charging device 4, the number of EV chargers 77 installed is two (EV chargers 77a and 77b), and the EV chargers 77a and 77b are connected to corresponding DC/DC converters 73a and 73b, respectively. there is Power supplied from the external AC power system 70 is supplied to a DC bus 79, supplied from the DC bus 79 to a plurality of EV chargers 77a and 77b, and connected to the plurality of EV chargers 77a and 77b, respectively. are charged in parallel.

The control unit 76 is connected to a bidirectional DC/DC converter 72 connected to a stationary storage battery 74 and to DC/DC converters 73a and 73b connected to EV chargers 77a and 77b, respectively. Also, the control unit 76 monitors and controls the input/output current, input/output voltage and input/output power of the bidirectional DC/DC converter 72 and the two DC/DC converters 73a and 73b.

The connection relationship of the external AC power system 70, the AC/DC converter 71, the DC bus 79, the bidirectional DC/DC converter 72, and the plurality of DC/DC converters 73a and 73b of the charging device 4 is the same as that of the charging device 1. 1, the external AC power system 10, the AC/DC converter 11, the DC bus 19, the bidirectional DC/DC converter 12, and the DC/DC converter 13. In addition, in the charging device 4 having a plurality of EV chargers 77a and 77b, a stationary storage battery 74 capable of supplying power larger than that of the stationary storage battery 14 of the charging device 1 may be installed as necessary.

Even if a plurality of EV chargers 77a and 77b are provided like the charging device 4, the charging process similar to that of the charging device 1 can stably charge the plurality of on-vehicle storage batteries 78a and 78b in parallel independently of other loads. can be charged.

Next, another embodiment of the charging device of the present invention will be described. In each of the above embodiments, the DC buses 19, 39, 59 and 79 are provided, respectively, but AC buses may be used instead. By using the AC bus, it is possible to provide a charging device that does not need to include an AC/DC converter, which is a power converter, and does not need to include a DC/DC converter. A charging device having an AC bus includes a stationary power storage device connected to the AC bus and an EV charger connectable to an on-vehicle storage battery connected to the AC bus. Depending on the usage conditions of the charging device of the present invention, the DC/DC converter 13 connected to the chargers 17, 37, 57, 77 that can be connected to the storage battery to be charged in each of the above embodiments. , 33, 53, 77 may be bidirectional DC/DC converters. In addition, in each of the above embodiments, the EV chargers 17, 37, 57, 77 were connected to the onboard storage batteries 18, 38, 58, 78 of the electric vehicle. The charging device of the present invention may charge the vehicle-mounted storage battery (that is, non-contact charging).

Moreover, in the charging apparatuses 1, 2, 3, and 4 of the above-described embodiments, there is one stationary storage battery 14, 34, 54, and 74, which is the in-facility storage battery. A plurality of stationary storage batteries 14, 34, 54, 74 may be provided.

Further, a charging device including a connector 61 connectable to a mobile power generator 60 and a photovoltaic panel 40 may be used as a power source other than an external power system.

Although the charging device and charging method of the present invention have been described above, the present invention is not limited to the charging device and charging method according to the above-described embodiments. For example, the charging device and charging method of the present invention The present invention can also be applied to charging storage batteries other than on-board storage batteries for electric vehicles, such as storage batteries for home and business use.

1, 2, 3, 4 charging device 11, 31, 51, 71 AC/DC converter 12, 32, 52, 72 bidirectional DC/DC converter 14, 34, 54, 74 stationary storage battery 16, 36, 56 , 76 control unit 17, 37, 57, 77a, 77b EV charger 19, 39, 59, 79 DC bus

Claims (15)

a DC or AC bus connected to an external power grid;
a stationary power storage device connected to the DC bus or the AC bus;
a battery connectable charger connected to the DC bus or the AC bus;
a control unit that controls charging and discharging of the stationary power storage device and charging of a storage battery connected to the charger;
with
The control unit
determining whether or not the amount of current supplied from the DC bus or the AC bus exceeds a power threshold preset in the control unit;
supplying a charging current from the stationary power storage device to the charger via the DC bus or the AC bus when the amount of current exceeds the power threshold;
When the amount of current becomes equal to or less than the threshold value of electric power, current is supplied from the DC bus or the AC bus to the stationary power storage device to charge the storage battery to be charged next. Charge the stationary power storage device
A charging device configured to: a power converter connectable to the external power system;
the DC bus connected to the power converter;
a bidirectional DC/DC converter connected to the DC bus;
the stationary power storage device connected to the bidirectional DC/DC converter;
a DC/DC converter connected to the DC bus;
the charger connected to the DC/DC converter;
the control unit controlling charging and discharging of the stationary power storage device and charging of a storage battery connected to the charger by controlling the bidirectional DC/DC converter and the DC/DC converter;
with
The control unit
Determining whether the amount of current supplied from the DC bus exceeds a power threshold preset in the control unit,
supplying a charging current from the stationary power storage device to the charger through the DC bus when the amount of current exceeds the threshold value of electric power;
When the amount of current becomes equal to or less than the threshold value of power, the stationary power storage device is supplied with current from the DC bus to charge the next storage battery to be charged. charge the
The charging device according to claim 1, configured as: a second DC/DC converter connected to the DC bus;
a photovoltaic power generation device connected to the second DC/DC converter;
further comprising
The charging device according to claim 2, wherein the controller controls the second DC/DC converter. a third DC/DC converter connected to the DC bus;
a connector connected to the third DC/DC converter and connectable to a mobile power generation device;
further comprising
The charging device according to claim 2 or 3, wherein the controller controls the third DC/DC converter. 5. The charging device according to any one of claims 1 to 4, wherein the charger is one or more. 6. The charging device according to any one of claims 1 to 5, wherein said threshold of power is equal to or less than any contracted power. 7. The charging device according to claim 6, wherein the contract power is equal to or less than the average power of the charging current supplied to the charger. 8. The control unit according to any one of claims 1 to 7, wherein the control unit is configured to start charging the storage battery with constant current charging and reduce the amount of charging current to the storage battery as the charging rate increases. 1. The charging device according to 1. 3. The charging device according to claim 2, wherein the power converter supplies power at a constant current or constant power, and the stationary power storage device charges and discharges so that the DC bus has a constant voltage. The charging device according to any one of claims 1 to 9, wherein the stationary power storage device is a lithium ion storage battery or a lead storage battery. The charging device according to any one of claims 1 to 10, wherein the storage battery is a storage battery mounted on an electric vehicle (EV). The charging device according to claim 2, wherein the power converter is an AC/DC converter that converts AC power of an AC power system into DC power or a DC/DC converter connected to a DC power system. a DC or AC bus connected to an external power grid;
a stationary power storage device connected to the DC bus or the AC bus;
and a charger connectable to the storage battery, the charging device being connected to the DC bus or the AC bus, the method comprising:
determining whether the amount of current being supplied from the DC bus or the AC bus exceeds a preset power threshold;
supplying current from the stationary power storage device to the charger via the DC bus or the AC bus when the amount of current exceeds the power threshold;
A step of charging the stationary power storage device when the amount of current becomes equal to or less than the threshold value of electric power, and charging the stationary power storage device toward charging of the next storage battery to be charged. and charging methods. After the step of charging the stationary power storage device when the current amount becomes equal to or less than the power threshold, the sum of the power charged to the storage battery and the power charged to the stationary power storage device is the power threshold. 14. The charging method according to claim 13, further comprising the step of determining whether or not . 15. The method according to claim 14, further comprising the step of stopping charging to said stationary power storage device when a sum of power to be charged to said storage battery and power to be charged to said stationary power storage device exceeds said power threshold. charging method.

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