Charging device

Abstract

To provide a charging device that can change the charging voltage. [Solution] A charging device 32 that supplies AC charging power to a vehicle 40, which can switch the output of the charging power to either high-voltage AC power or low-voltage AC power.

Description

[Technical Field]

[0001] The present disclosure relates to a charging device that supplies AC charging power to a vehicle. [Background Art]

[0002] Electric vehicles such as electric vehicles and plug-in hybrid vehicles can be charged from grid power or the like to a power storage device such as an on-board secondary battery by connecting an external charger.

[0003] Here, on the vehicle side, in addition to the type that receives direct current power (DC), there is also a type that is provided with an on-board charger (OBC) including an AC / DC converter in the vehicle and receives AC power. Two types of AC chargers are commercially available: 200V-compatible and 100V-compatible.

[0004] A 200V-compatible charger enables rapid charging at 6kW. On the other hand, a 100V-compatible charger only supports charging up to 3kW, but is often inexpensive. [Prior Art Literature] [Patent Literature]

[0005] [Patent Literature 1] Japanese Unexamined Patent Publication No. 2022-146593 [Summary of the Invention] [Problem to be Solved by the Invention]

[0006] Here, in facilities such as houses provided with solar cells that use power from solar cells (PV power), there is a demand to charge a vehicle with the surplus PV power. That is, when PV power is greater than the power consumption of the facility-side load, the surplus power is sold to an electric power company. However, the purchase price for feed-in tariff is lower than the price for purchasing power from an electric power company, so there is a demand to charge the vehicle without selling the surplus power.

[0007] However, the amount of surplus PV power is often insufficient, and in such cases, the surplus PV power is not being used efficiently, indicating room for improvement. [Means for solving the problem]

[0008] The charging device according to this disclosure is a charging device that supplies AC charging power to a vehicle and can switch the output of the charging power to either high-voltage AC power or low-voltage AC power. [Effects of the Invention]

[0009] The charging device according to this disclosure can output either high-voltage (e.g., 200V) or low-voltage (e.g., 100V) AC power. Therefore, the user can change the vehicle's charging voltage depending on the situation. [Brief explanation of the drawing]

[0010] [Figure 1] This is a block diagram showing the configuration of a power management system. [Figure 2] This diagram shows the inlet and connector configuration. [Figure 3] This diagram shows the relationship between the duty cycle [%] of the CPLT signal and the supplied current. [Figure 4] This flowchart shows the operation when charging using surplus PV power. [Figure 5] Flowchart of the operation when charging with surplus PV power [Figure 6] This diagram shows the configuration for switching the charging voltage using other configurations. [Figure 7] This diagram shows the configuration for switching the charging voltage using other configurations. [Modes for carrying out the invention]

[0011] The embodiments of this disclosure will be described below with reference to the drawings. The embodiments described below are not limiting to this disclosure, and configurations formed by selectively combining multiple examples are also included in this disclosure.

[0012] "System Configuration" Figure 1 is a block diagram showing the configuration of a power management system. System 10 is the power company's transmission equipment, which supplies 100V or 200V AC power to facilities (e.g., houses). System 10 is connected to a switch 14 via a smart meter 12. The smart meter 12 measures the input and output of power. The input to the facility is purchased power, and the output to the system is sold power.

[0013] The equipment-side load 18 is connected to the switch 14 via the distribution board 16. Therefore, power from the grid can be supplied to the equipment-side load 18.

[0014] The switch 14 can switch the distribution board 16 between the grid-connected side, which is connected in grid-connected mode, and the standalone side, which is connected in standalone mode. The grid-connected side is connected to the grid 10 via the smart meter 12 and also to the power conditioner 20, while the standalone side is connected only to the power conditioner 20. In grid-connected mode, the power from the grid 10 and the power from the power conditioner 20 are connected to manage the power supply to equipment-side loads 18, etc.

[0015] The independent side supplies power to the equipment-side load 18 only from the power conditioner 20, without power from grid 10.

[0016] The power conditioner 20 has an inverter (INV) 22 inside. The inverter has a DC / AC conversion function, and the AC side is connected to the switch 14.

[0017] The DC side of the inverter is connected to the solar cell 30 via a DC / DC converter 24. Therefore, power from the solar cell 30 can be supplied to the inverter 22 at a predetermined DC voltage.

[0018] A charging / discharging device 32 is connected to a DC line to which an inverter 22 and a DC / DC converter 24 are connected. The charging / discharging device 32 has a DC / AC conversion function, and converts DC power from one or both of the inverter 22 and the DC / DC converter 24 into AC power, which is 100V AC or 200V AC. An electric vehicle (EV) 40 is connected to the charging / discharging device 32. The electric vehicle 40 includes an OBC (on-board charger) 42, which converts AC power supplied from the charging / discharging device 32 into DC power to charge a power storage device such as an on-vehicle battery, and outputs discharge power from the power storage device as AC power.

[0019] Additionally, AC power output from the electric vehicle 40 side can also be supplied to the switch 14 via the charging / discharging device 32 and the inverter 22.

[0020] Note that a cable called a TYPE 1 cable is provided on the vehicle side of the charging / discharging device 32, and a connector is provided at the tip of the cable. The electric vehicle 40 is provided with an inlet into which the connector can be fitted, and the inlet is connected to the OBC 42.

[0021] Further, the charging / discharging device 32 and the OBC 42 are connected via an AC power line and a plurality of signal lines. Accordingly, charging and discharging of the electric vehicle 40 can be controlled by signals supplied through the signal lines.

[0022] Additionally, a control unit 26 is provided in the power conditioner 20, and the control unit 26 can control the operation of the DC / DC converter 24 and the inverter 22.

[0023] Furthermore, information such as input / output power from the smart meter 12, input / output power of the inverter 22 and the (grid-interconnection side) switch 14, and information about power supplied from the solar cell 30 to the DC / DC converter 24 is supplied to the control unit 26.

[0024] In such a system, the power from the solar cell 30 and the grid 10 can be supplied to the facility-side load 18, and can be used to charge the power storage device of the electric vehicle 40. In addition, the power from the solar cell 30 can be supplied to the facility-side load 18 or used to charge the power storage device of the electric vehicle 40. Power from the electric vehicle 40 can also be supplied to the facility-side load 18.

[0025] The power conditioner 20 and the charging / discharging device 32 constitute an EVPS (EV Power Station) 50, which can be installed independently on the premises of a residence.

[0026] <PV surplus charging mode> Here, chargers equipped with a PV surplus charging mode that charges only using PV surplus power are known. In this mode, a current sensor is attached to the main trunk from the grid 10 to detect whether power sale occurs, and when power sale is occurring, charging is performed on the vehicle such that the amount of sold power becomes zero. That is, in the PV surplus charging mode, charging is not performed during power purchasing, and the vehicle is charged only when PV surplus power is generated.

[0027] "Regarding the Connector" FIG. 2 is a diagram showing the configuration of the vehicle-side OBC inlet 48 and the facility-side connector 34. The inlet 48 includes five sockets into which the five pins of the connector 34 are inserted and connected. L1 and L2 are for connecting AC power (AC1, AC2), CS is for connecting the Proximity signal, CP is for connecting the CPLT signal, and PE is for connecting the ground GND. In addition, the connector 34 has a latch 36 on the side inserted into the inlet 48, which is inserted into the latch receiver 52 of the inlet 48 and mechanically latched. The connector 34 also has a latch release button 38, and pressing down the latch release button 38 releases the latching of the latch 36 with respect to the latch receiver 52.

[0028] "Regarding the CPLT Signal" In this embodiment, a TYPE1 cable is used to connect the charge / discharge device 32 and the OBC 42, and CPLT signals are exchanged between the vehicle side and the equipment side.

[0029] The CPLT signal is a control signal that can instruct the equipment side on the conditions for discharge from the vehicle side. By controlling the frequency of the CPLT signal via a control circuit, the discharge voltage from the vehicle side can be instructed, and the vehicle side can signal the start of discharge, etc., by controlling the voltage of the CPLT signal.

[0030] For example, regarding the frequency of the CPLT signal, a frequency of 125Hz means a discharge voltage of 100VAC, a frequency of 166Hz means a discharge voltage of 200VAC, and a frequency of 1kHz means charging.

[0031] Figure 3 shows the relationship between the duty cycle [%] of the CPLT signal and the supplied current. Thus, the relationship is duty cycle [%] = current [A] / 0.6, meaning a 10% duty cycle corresponds to 6A and a 50% duty cycle corresponds to 30A. Furthermore, a duty cycle of 10% or higher is usable, while anything below 10% cannot be used.

[0032] Therefore, the CPLT signal cannot specify a current of 6A or less. Consequently, if the surplus power of the solar cell 30, i.e., the PV surplus power, is less than 6A, the vehicle cannot be charged with the PV surplus power, and this surplus power will have to be sold back to the grid.

[0033] "Charging control" The control unit 26 of the power conditioner 20 detects the power generation status of the solar cells 30, the power input / output status (electricity purchase, electricity sale) of the main circuit connected to the grid 10, and the power exchange status between the inverter 22 and the switch 14. Alternatively, it may also detect the power usage status of the equipment-side load 18.

[0034] Then, based on these conditions, the system determines what type of charging should be performed when charging the vehicle and creates a charging request. The system then controls the charging from the charge / discharge device 32 according to this charging request.

[0035] Figure 4 is a flowchart showing the operation of the control unit 26 when charging with surplus PV power. First, it determines whether 200V charging is being performed (S11), and if yes, it determines whether the surplus PV power is 6A (200V × 6A = 1.2kW) or less (S12). If the result of this determination is no, there is no problem and the process ends. On the other hand, if charging started at 200V because there was sufficient surplus PV power, but the amount of power that can be supplied to the charge / discharge device 32 decreases due to an increase in the power consumption of the equipment-side load 18 or a decrease in the power generation of the solar cell 30, the determination in S12 will be yes. In this case, the DC / AC converter in the charge / discharge device 32 is controlled to change the output voltage to 100V. As a result, charging is switched from 1.2kW-6kW to 600W-3kW. Therefore, 600W-1.2kW of surplus PV power can be used for charging.

[0036] Furthermore, the S12 decision can be conditional on the "Yes" state remaining for a certain period of time. This prevents frequent switching.

[0037] This will change the charging power from 1.2kW or more to 600W or more, allowing charging to continue.

[0038] Figure 5 is a flowchart showing the operation of the control unit 26 when charging with surplus PV power. First, it determines whether 100V charging is being performed (S21), and if yes, it determines whether the surplus PV power is 30A (100V × 30A = 3kW) or more (S22). If the result of this determination is no, there is no problem and the process ends. On the other hand, if charging started at 100V because there was not much surplus PV power, but the amount of power that can be supplied to the charge / discharge device 32 increases due to a decrease in the power consumption of the equipment-side load 18 or an increase in the power generation of the solar cell 30, the determination in S22 will be yes. In this case, the DC / AC converter in the charge / discharge device 32 is controlled to change the output voltage to 200V.

[0039] Furthermore, the S22 decision can be conditional on the "Yes" state remaining for a certain period of time. This prevents frequent switching.

[0040] This allows charging to switch from 600W-1.2kW to 1.2kW-6kW, enabling high-capacity charging. In other words, rapid charging at 200V x 30A = 6kW becomes possible.

[0041] "Switching between 100V and 200V" Figure 6 shows a configuration for switching the charging voltage using a different setup. In this example, the charge / discharge device 32 contains an inverter (DC / AC converter) 32-1 and an AC / DC converter 32-2. The charge / discharge device 32 is supplied with 200V single-phase three-wire AC power from the house. The inverter 32-1 converts this to appropriate DC power. The AC / DC converter 32-2 converts the DC power to AC power and supplies it to the OBC 42 on the vehicle side. By controlling the AC / DC converter 32a, the output voltage can be switched between 100V and 200V.

[0042] Figure 7 shows a configuration for switching the charging voltage using another configuration. In this example, the charge / discharge device 32 has a changeover switch 32-3. The charge / discharge device 32 is supplied with 200V AC power from a single-phase three-wire system on the house side. By selecting both lines with the changeover switch 32-3, a 200V output is obtained, and by selecting the upper line and the middle line, a 100V output is obtained. By controlling the changeover switch 32-3 in this way, the output voltage can be switched between 100V and 200V.

[0043] In the two examples above, a single-phase three-wire power line is connected from the house to the charge / discharge device 32. Power from the solar panels 30 can be supplied to the house from the power conditioner 20.

[0044] "others" According to the configuration of an example of the charging device according to this embodiment, 200V single-phase three-wire AC power is input, and by switching a changeover switch, either 200V single-phase AC or 100V single-phase AC power can be output. Therefore, the user can change the vehicle's charging voltage depending on the situation.

[0045] Furthermore, the voltage switching of the output AC power can be performed using a power converter such as an inverter.

[0046] Voltage switching can be performed by a manual switch or an external command signal. The command signal can be determined according to the amount of surplus power in the power conditioner. In other words, the amount of power supplied from the solar panels should be monitored, and if it falls below a predetermined amount, the charging voltage should be changed from 200V to 100V.

[0047] Furthermore, the voltage can be switched by selecting between 200V and 100V power supplied from the grid.

[0048] Charging and discharging devices can be equipped with a unit to measure the amount of charging power, allowing them to automatically stop charging when the amount of charging power exceeds a preset level.

[0049] During charging at a low voltage (e.g., 100V), if the required charging power, as determined by the energy management control of the power conditioner 20, exceeds the maximum current, it is advisable to temporarily stop the current charging and then start charging at a higher voltage (e.g., 200V). In this case, if the required charging power remains above the maximum current for a certain period of time, it may be preferable to temporarily stop the current charging and then start charging at a higher voltage.

[0050] If, during high-voltage charging, the required charging power determined by energy management control falls below the minimum current, it is advisable to temporarily stop the current charging and restart charging at a lower voltage. In this case, if charging continues at the minimum charging current for a certain period, including the power purchased from the grid, the current charging can be temporarily stopped and restarted at a lower voltage.

[0051] When the required charging power, as determined by energy management control, exceeds the maximum current at a low voltage, it is advisable to temporarily stop the current charging and restart it at a higher voltage. In this case, if the required charging power remains above the maximum current for a certain period of time, it is advisable to temporarily stop the current charging and restart it at a higher voltage.

[0052] When connecting a vehicle to a charger, if the situation is such that surplus power is expected to increase (time of day, weather forecast, past power generation status, past load usage status), and the current surplus power is a certain percentage (e.g., 80%) or more of [low voltage × maximum current], then the vehicle can be connected at a high voltage and charging can begin.

[0053] When connecting a vehicle to a charger, if the surplus power is expected to decrease (depending on the time of day, weather forecast, past power generation data, and past load conditions), and the current surplus power is below a certain percentage (e.g., 40%) of [high voltage × minimum current], then charging can be started by connecting to the vehicle at a lower voltage.

[0054] The above fixed percentage should be calculated considering the ratio of low voltage to high voltage. For example, it can be set as follows: low voltage = 100V, high voltage = 200V, surplus increase: 50% or more, surplus decrease: 50% or less (100V / 200V). [Explanation of Symbols]

[0055] 10 System, 12 Smart meter, 14 Switch, 16 Distribution board, 18 Equipment-side load, 20 Power conditioner, 22 Inverter, 24 DC / DC converter, 26 Control unit, 30 Solar cell, 32 Charge / discharge device, 32-1 Inverter, 32-2 AC / DC converter, 32-3 Changeover switch, 32a AC / DC converter, 34 Connector, 36 Latch, 38 Latch release button, 40 Vehicle, 40 Electric vehicle, 48 Inlet, 52 Latch receiver

Claims

1. A charging device that supplies AC charging power to a vehicle, The charging power can be switched to output either high-voltage AC power or low-voltage AC power. Charging device.

2. A charging device according to claim 1, High-voltage AC power is 200V AC power, and low-voltage AC power is 100V AC power. Charging device.

3. A charging device according to claim 2, A 200V AC power input is received, and by switching a switch, it can output either 200V AC power or 100V AC power. Charging device.

4. A charging device according to claim 2, An AC / DC converter that converts AC power to DC power in one direction and DC power to AC power in the other direction, Includes a DC / AC converter that converts DC power from an AC / DC converter to AC power, By controlling the operation of either or both the AC / DC converter and the DC / AC converter, the DC / AC converter outputs either 200V AC power or 100V AC power. Charging device.

5. A charging device according to claim 4, Furthermore, the output of the solar cell is connected to the DC line to which the AC / DC converter and the DC / AC converter are connected, including the solar cell. Charging device.

6. A charging device according to claim 5, The DC power from the solar panel can be supplied to the load as AC power via an AC / DC converter in the other direction, and can also be supplied to the vehicle as AC power via a DC / AC converter. In the other direction, AC power is supplied to the load via an AC / DC converter, and the remaining surplus power is supplied to the vehicle via a DC / AC converter. The DC / AC converter outputs 100V AC power when the surplus power is less than a predetermined amount, and outputs 200V AC power when the surplus power is greater than a predetermined amount. Charging device.

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