Charging device and charging system

Abstract

To provide a charging device capable of charging using a power transmitting device for non-contact charging without the need to attach a power receiving device to each electric vehicle.SOLUTION: A charging device A1 that charges a storage battery 91 of an electric mobile object 9 that moves by driving an electric motor using electric power of the storage battery 91 includes a power receiving coil 11 that receives power contactlessly from a power transmitting coil 24, a power conversion circuit (rectifier circuit 12, inverter circuit 13) that converts the power received by the power receiving coil 11, and a charging connector 191 that is connected to the electric mobile object 9 and supplies the electric power output by the power conversion circuit to the electric mobile object 9.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 a charging system.

Background Art

[0002] In recent years, with the popularization of electric vehicles, the development of charging devices for charging the batteries of electric vehicles has been progressing. Generally, the charging device connects a charging connector arranged at the tip of a charging cable to the plug-in connector of an electric vehicle, and supplies power to the electric vehicle via the charging cable. When charging a large electric vehicle such as a truck or a bus, the arrangement position of the charging device and the position of the plug-in connector of the electric vehicle may be greatly separated. For example, when loading a truck with cargo, the truck backs up close to the loading position and stops. And it is conceivable to perform charging while loading the cargo. The charging device is arranged near the loading position so as not to interfere with parking. On the other hand, the plug-in connector is arranged in front of the truck body (for example, the front of the vehicle). Therefore, the charging device and the plug-in connector are greatly separated. The length of the charging cable connecting the charging device and the charging connector is determined so that any type of truck can be charged. When the charging cable becomes long, handling and storage become difficult. In addition, there is a risk that the charging cable during charging may be stepped on by other vehicles, and there is a risk that an operator may catch their foot on the charging cable.

[0003] Patent Document 1 discloses a winding device for a charging cable. This winding device suspends the charging cable with a suspension device attached to a support wire, and the winding unit winds the charging cable back up by winding the support wire, and extends the charging cable by pulling out the support wire. Using this winding device makes it easier to handle and store the charging cable. However, in order to prevent the charging cable from lying on the ground even when the charging device and the plug-in connector of the electric vehicle are far apart, the charging device and winding device must be placed at a high position. Another method is to suspend the charging cable from the ceiling with a spring balancer or the like, but this requires a large amount of equipment, and the presence and strength of the ceiling become issues. In addition, with these methods, a long charging cable must be used, which increases power loss due to internal resistance. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2018-82594 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] Using contactless charging (wireless charging) technology can solve the problems mentioned above. However, it is necessary to install a receiving device with a receiving coil in each electric vehicle. Furthermore, in order to charge properly, the vehicle must be parked so that the position of the receiving coil aligns with the position of the transmitting coil. Also, since the height of electric vehicles differs, the height position of the receiving coil will also differ. The transmitting device needs to be adjusted so that charging can be performed even if the height position of the receiving coil differs.

[0006] This invention was conceived under the circumstances described above, and its purpose is to provide a charging device that does not require the installation of a power receiving device on each electric vehicle and can perform charging using a power transmission device for contactless charging. [Means for solving the problem]

[0007] To solve the above problems, the present invention employs the following technical means.

[0008] A charging device provided by a first aspect of the present invention is a charging device for charging the battery of an electric mobile body that moves by driving an electric motor with the power of the battery, comprising: a receiving coil that receives power from a transmitting coil in a non-contact manner; a power conversion circuit that performs power conversion of the power received by the receiving coil; and a charging connector connected to the electric mobile body that supplies power output by the power conversion circuit to the electric mobile body. .

[0009] Furthermore, "electric mobile vehicles" refer to mobile vehicles that move by driving an electric motor with power from a storage battery, and include not only so-called electric vehicles but also hybrid vehicles. In addition, "electric mobile vehicles" include not only so-called automobiles but also other vehicles such as motorcycles, ships, and airplanes, as well as unmanned mobile vehicles such as automated guided vehicles and drones.

[0010] In a preferred embodiment of the present invention, the device further comprises a housing that houses the power receiving coil and the power conversion circuit and is portable by the user, and a charging cable that electrically connects the power conversion circuit and the charging connector, wherein the housing includes a storage section capable of housing the charging cable and the charging connector.

[0011] In a preferred embodiment of the present invention, the power conversion circuit includes a rectifier circuit that rectifies the power received by the power receiving coil and outputs DC power, and an inverter circuit that converts the DC power input from the rectifier circuit into AC power.

[0012] In a preferred embodiment of the present invention, the power conversion circuit includes a rectifier circuit that rectifies the power received by the power receiving coil and outputs DC power, and a converter circuit that transforms the DC power input from the rectifier circuit.

[0013] A charging system provided by a second aspect of the present invention comprises a charging device provided by a first aspect of the present invention and a power transmission device for non-contact transmission of power to the charging device, wherein the power transmission device comprises a power transmission coil for non-contact transmission of power to the power receiving coil and a power supply circuit for supplying high-frequency power to the power transmission coil.

[0014] In a preferred embodiment of the present invention, a power transmission cable is further provided to electrically connect the power supply circuit and the power transmission coil, and the power transmission cable and the power transmission coil are buried. [Effects of the Invention]

[0015] The charging device according to the present invention includes a receiving coil that receives power from a transmitting coil in a non-contact manner. As a result, the charging device according to the present invention can charge an electric mobile device to which a charging connector is connected by positioning the receiving coil on the transmitting coil so that it can receive power.Therefore, it is not necessary to attach the receiving device to the electric mobile device, and charging can be performed using a plug-in connector provided on the electric mobile device.In addition, since the charging device is simply placed on the transmitting coil, the alignment of the transmitting coil and the receiving coil is easy, and the height position of the receiving coil is constant.

[0016] Other features and advantages of the present invention will become more apparent from the detailed description below with reference to the accompanying drawings. [Brief explanation of the drawing]

[0017] [Figure 1] (a) is a perspective view showing the overall configuration of a charging system equipped with a charging device according to the first embodiment, and (b) is a block diagram showing the internal configuration of the charging system. [Figure 2] This is a simplified perspective view of the charging device according to the first embodiment. [Figure 3] This is a block diagram showing the internal configuration of a charging system equipped with a charging device according to the second embodiment. [Figure 4]It is a perspective view showing the overall configuration of the charging system according to the third embodiment.

Mode for Carrying Out the Invention

[0018] Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings.

[0019] 〔First Embodiment〕 FIGS. 1 and 2 are diagrams for explaining a charging system B1 including a charging device A1 according to the first embodiment. FIG. 1(a) is a perspective view showing the overall configuration of the charging system B1. FIG. 1(b) is a block diagram showing the internal configuration of the charging system B1. FIG. 2 is a simplified perspective view of the charging device A1.

[0020] The charging system B1 is equipment for charging an electric vehicle 9. The electric vehicle 9 is an automobile equipped with an electric motor as a power source and a storage battery 91 for supplying power to the electric motor, and includes not only a so-called electric vehicle having only an electric motor as a power source but also a hybrid vehicle equipped with an internal combustion engine. The charging system B1 includes a power transmission device 2 and a charging device A1.

[0021] The power transmission device 2 transmits power to the charging device A1 in a non-contact manner. The power transmission device 2 includes a rectifier circuit 21, an inverter circuit 22, a control circuit 23, a power transmission coil 24, and a power transmission cable 25.

[0022] The rectifier circuit 21 converts three-phase AC power supplied from the power system into DC power. The rectifier circuit 21 includes, for example, a full-wave rectifier circuit in which six semiconductor rectifying elements are connected in a bridge and a smoothing circuit for smoothing the voltage level after full-wave rectification. Note that the configuration of the rectifier circuit 21 is not limited. Further, the power transmission device 2 may include a filter circuit such as a low-pass filter for removing noise and harmonics from the AC power input from the power system before the rectifier circuit 21.

[0023] The inverter circuit 22 converts the DC power input from the rectifier circuit 21 into high-frequency power of a predetermined frequency based on a drive signal input from the control circuit 23. The inverter circuit 22 is composed of a well-known voltage-controlled inverter circuit, for example, in which four switching elements are connected in a bridge configuration. As the switching elements, semiconductor switching elements such as bipolar transistors, field-effect transistors, thyristors, IGBTs, and MOSFETs can be used. The inverter circuit 22 converts the DC power input from the rectifier circuit 21 into high-frequency power by switching the on and off states of each switching element in response to the drive signal input from the control circuit 23. The inverter circuit 22 supplies high-frequency power to the power transmission coil 24 via the power transmission cable 25. The configuration of the inverter circuit 22 is not limited.

[0024] The control circuit 23 is implemented, for example, by a microcomputer, and controls the inverter circuit 22. The control circuit 23 performs feedback control so that the detected output current of the inverter circuit 22 reaches a target value. For example, the control circuit 23 generates a drive signal based on the deviation between the output current and the target value and outputs it to the inverter circuit 22. The control method performed by the control circuit 14 is not limited.

[0025] The power transmission coil 24 transmits high-frequency power supplied from the inverter circuit 22 to the charging device A1 (the power receiving coil 11 described later) in a contactless manner. The power transmission coil 24 is, for example, a spiral-wound planar coil, and is positioned so that the coil surface is substantially parallel to the floor surface. The type and shape of the power transmission coil 24 are not limited. In addition, a resonant capacitor (not shown) for forming a resonant circuit may be connected in series or in parallel to the power transmission coil 24. The power transmission cable 25 conducts electrical connections between the inverter circuit 22 and the power transmission coil 24. In this embodiment, as shown in Figure 1, the power transmission cable 25 and the power transmission coil 24 are buried under the floor surface. Therefore, the power transmission cable 25 is not in danger of being run over by other vehicles, nor is there any risk of workers tripping over it. Marks indicating the location of the buried power transmission coil 24 are displayed on the floor surface.

[0026] The configuration of the power transmission device 2 is not limited to those described above. For example, the AC power supplied from the power grid to the power transmission device 2 is not limited to three-phase AC power, but may be single-phase AC power. The power transmission device 2 can utilize an existing general-purpose power transmission device for wireless charging.

[0027] The charging device A1 charges the electric vehicle 9. The charging device A1 is portable and can be moved by the user, and is used by being placed in the location where the power transmission coil 24 of the power transmission device 2 is embedded. The charging device A1 receives power from the power transmission device 2 contactlessly, converts the received power into power suitable for charging, and supplies it to the electric vehicle 9. The charging device A1 comprises a power receiving coil 11, a rectifier circuit 12, an inverter circuit 13, a control circuit 14, a charging cable 19, a charging connector 191, and a housing 16.

[0028] The receiving coil 11 receives power from the transmitting coil 24 in a non-contact manner. The receiving coil 11 is, for example, a spiral-wound planar coil, and is positioned so that the coil surface is substantially parallel to the floor surface. The type and shape of the receiving coil 11 are not limited. In addition, a resonant capacitor (not shown) for forming a resonant circuit may be connected to the receiving coil 11 in series or in parallel.

[0029] The rectifier circuit 12 rectifies the high-frequency power received by the receiving coil 11 and converts it into DC power. The rectifier circuit 12 includes, for example, a full-wave rectifier circuit with four semiconductor rectifier elements connected in a bridge configuration, and a smoothing circuit that smooths the voltage level after full-wave rectification. The configuration of the rectifier circuit 12 is not limited.

[0030] The inverter circuit 13 converts the DC power input from the rectifier circuit 12 into AC power of a predetermined frequency (for example, 50Hz or 60Hz, which is the system frequency of the power grid) based on a drive signal input from the control circuit 14. The inverter circuit 13 is composed of a well-known voltage-controlled inverter circuit, for example, with four switching elements connected in a bridge configuration. As the switching elements, semiconductor switching elements such as bipolar transistors, field-effect transistors, thyristors, IGBTs, and MOSFETs can be used. The inverter circuit 13 converts the DC power input from the rectifier circuit 12 into AC power by switching the on and off states of each switching element in response to the drive signal input from the control circuit 14. The inverter circuit 13 supplies AC power to the electric vehicle 9, to which the charging connector 191 is connected, via the charging cable 19. The configuration of the inverter circuit 13 is not limited.

[0031] The control circuit 14 controls the inverter circuit 13. The control circuit 14 performs feedback control so that the detected output current of the inverter circuit 13 reaches a target value. For example, the control circuit 14 generates a drive signal based on the deviation between the output current and the target value and outputs it to the inverter circuit 13. The control method performed by the control circuit 14 is not limited.

[0032] The charging cable 19 is connected to the electric vehicle 9 by connecting the charging connector 191 located at its tip to the plug-in connector 92 of the electric vehicle 9. The charging cable 19 supplies power output by the inverter circuit 13 to the connected electric vehicle 9. The electric vehicle 9 charges its battery 91 with the supplied power.

[0033] The charging device A1 may also include a communication unit for sending and receiving signals with the electric vehicle 9. In this case, the charging cable 19 will have signal lines for sending and receiving signals in addition to power lines for transmitting power.

[0034] As shown in Figure 2, the housing 16 houses the power receiving coil 11, power conversion unit 15, charging cable 19, and charging connector 191, and is portable by the user. The power conversion unit 15 is a circuit unit in which a printed circuit board equipped with a rectifier circuit 12, an inverter circuit 13, and a control circuit 14 is covered with a metal box that does not allow magnetic flux to pass through. The rectifier circuit 12, inverter circuit 13, and control circuit 14 may each be housed individually in the housing 16.

[0035] The housing 16 comprises a main body 161, a lid 162, a handle 163, and a storage compartment 164. The main body 161 is, for example, a hollow cylindrical shape, and houses a power receiving coil 11 and a power conversion unit 15 inside. The power receiving coil 11 is positioned at the bottommost side of the main body 161, with its coil surface approximately parallel to the bottom surface. The power conversion unit 15 is housed above the power receiving coil 11. The top of the main body 161 is open, and a storage compartment 164 capable of accommodating a charging cable 19 and a charging connector 191 is provided therein. The lid 162 covers the open upper portion (storage compartment 164) of the main body 161 and is fixed to the main body 161 so as to be openable and closable. The user can carry the charging device A1 by fixing the lid 162 to the main body 161 in the closed position with a fastener (not shown) and grasping the handle 163 fixed to the lid 162. Furthermore, the user opens the lid 162 and takes out the charging cable 19 and charging connector 191 stored in the storage compartment 164 for use.

[0036] The material of the housing 16 is not particularly limited, but at least the bottom surface of the main body 161 must be made of a material that allows magnetic flux to pass through. The configuration of the housing 16 is not limited to those described above. For example, the shape of the main body 161 is not limited to a cylindrical shape, but may be a rectangular prism shape. Also, the bottom (bottom) side of the main body 161 is open, and the power receiving coil 11 may be fitted into this open portion.

[0037] As shown in Figure 1(a), the charging device A1 is positioned directly above the power transmission coil 24 of the power transmission device 2. As a result, the receiving coil 11 is positioned so that it overlaps with the power transmission coil 24 when viewed from above. When a high-frequency current flows through the power transmission coil 24, the magnetic flux changes, and a high-frequency current flows through the receiving coil 11, which is linked to this magnetic flux. This allows power to be transmitted from the power transmission device 2 to the charging device A1 without contact. The charging system B1 is a so-called conventional charging device in which the power transmission device 2 is supplied with power from the power grid, and the charging device A1 supplies AC power with the same frequency as the grid frequency to the electric vehicle 9.

[0038] Next, the operation and effects of the charging device A1 and charging system B1 according to this embodiment will be described.

[0039] According to this embodiment, the charging device A1 is equipped with a receiving coil 11 that receives power from the transmitting coil 24 in a non-contact manner. As a result, the charging device A1 is positioned on the transmitting coil 24 so that the receiving coil 11 can receive power, and can charge the electric vehicle 9 to which the charging connector 191 is connected. Therefore, there is no need to attach a power receiving device to the electric vehicle 9, and the charging device A1 can perform charging using the plug-in connector 92 provided on the electric vehicle 9.

[0040] Furthermore, in charging system B1, since the charging device A1 is simply placed on the power transmission coil 24, alignment between the power transmission coil 24 and the power receiving coil 11 is easy, and the height of the power receiving coil 11 remains constant. Therefore, charging system B1 can increase the coupling coefficient between the power transmission coil 24 and the power receiving coil 11, thereby reducing current loss. In addition, in charging system B1, the electric vehicle 9 can be parked near the power transmission coil 24 for charging, so there is no need to lengthen the charging cable 19. Therefore, routing and storing the charging cable 19 is easy. Moreover, charging device A1 can reduce the risk of the charging cable 19 being run over by other vehicles and the risk of workers tripping over the charging cable 19.

[0041] Furthermore, according to this embodiment, the charging device A1 includes a housing 16, which houses the various components of the charging device A1 and is portable by the user. Therefore, the user can easily carry the charging device A1 and place it in the location where the power transmission coil 24 is embedded. The housing 16 also includes a storage compartment 164. Therefore, the user can carry the charging device A1 with the charging cable 19 and charging connector 191 stored in the storage compartment 164, and can take the charging cable 19 and charging connector 191 out of the storage compartment 164 for use.

[0042] Furthermore, according to this embodiment, the charging device A1 can output AC power at a predetermined frequency (for example, 50Hz or 60Hz, which is the system frequency of the power grid) using the inverter circuit 13. Therefore, as a normal charging device, the charging device A1 can charge the electric vehicle 9 by utilizing the configuration for normal charging that the electric vehicle 9 has.

[0043] In this embodiment, the case in which the power transmission coil 24 is buried has been described, but it is not limited to this. The power transmission coil 24 may be placed on the floor surface.

[0044] Furthermore, although this embodiment describes the case in which the charging device A1 charges an electric vehicle 9, it is not limited to this. The charging device A1 may also charge a mobile device other than the electric vehicle 9. Other examples of such mobile devices include, for example, motorcycles (electric motorcycles, electric-assist bicycles), ships, airplanes and other vehicles, or unmanned mobile devices such as automated guided vehicles and drones.

[0045] [Second Embodiment] Figure 3 is a block diagram showing the internal configuration of a charging system B2 equipped with a charging device A2 according to the second embodiment. In Figure 3, elements that are the same as or similar to those in the first embodiment are denoted by the same reference numerals as those in the first embodiment. The charging device A2 according to this embodiment differs from the charging device A1 according to the first embodiment in that it is equipped with a converter circuit 17 instead of an inverter circuit 13.

[0046] The converter circuit 17 transforms the DC power input from the rectifier circuit 12 to a predetermined voltage based on the drive signal input from the control circuit 14. The converter circuit 17 includes, for example, a step-up / step-down chopper to boost or step down the input DC voltage and output it. The converter circuit 17 supplies DC power to the electric vehicle 9, to which the charging connector 191 is connected, via the charging cable 19. The configuration of the converter circuit 17 is not limited.

[0047] The control circuit 14 controls the converter circuit 17. The control circuit 14 performs feedback control so that the detected output voltage of the converter circuit 17 reaches a target value. For example, the control circuit 14 generates a drive signal based on the deviation between the output voltage and its target value and outputs it to the converter circuit 17. The control method performed by the control circuit 14 is not limited.

[0048] The charging device A2 may also include a communication unit for sending and receiving signals with the electric vehicle 9. In this case, the charging cable 19 will have signal lines for sending and receiving signals in addition to power lines for transmitting power.

[0049] The charging system B2 is a so-called rapid charging system in which the power transmission device 2 receives power from the power grid, and the charging device A2 supplies DC power of a predetermined voltage to the electric vehicle 9.

[0050] In this embodiment as well, the charging device A2 includes a receiving coil 11 that receives power from the transmitting coil 24 in a non-contact manner. As a result, the charging device A2 is positioned on the transmitting coil 24 so that the receiving coil 11 can receive power, enabling it to charge the electric vehicle 9 to which the charging connector 191 is connected. Therefore, there is no need to attach a power receiving device to the electric vehicle 9, and the charging device A2 can perform charging using the plug-in connector 92 provided on the electric vehicle 9. Furthermore, the charging device A2 and charging system B2 have a configuration common to the charging device A1 and charging system B1, and thus achieve the same effects as the charging device A1 and charging system B1. In addition, the charging device A2 can output DC power of a predetermined voltage through the rectifier circuit 12 and the converter circuit 17. Therefore, as a rapid charger, the charging device A2 can charge the electric vehicle 9 by utilizing the rapid charging configuration provided on the electric vehicle 9.

[0051] [Third Embodiment] Figure 4 is a perspective view showing the overall configuration of the charging system B3 according to the third embodiment. In Figure 4, elements that are the same as or similar to those in the first embodiment are denoted by the same reference numerals as those in the first embodiment. The charging system B3 according to this embodiment differs from the charging system B1 according to the first embodiment in the configuration of the power transmission coil 24 of the power transmission device 2.

[0052] The power transmission device 2 according to the third embodiment comprises a plurality of rectangular power transmission coils 24 arranged side by side. The plurality of power transmission coils 24 are embedded in a region 5 on the floor surface. The charging device A1 can receive power from the power transmission device 2 regardless of where it is placed on the region 5, because the receiving coil 11 will overlap with one of the power transmission coils 24.

[0053] In this embodiment, the same effects as in the first embodiment can be achieved. Furthermore, according to this embodiment, since the charging device A1 can receive power from the power transmission device 2 regardless of where it is positioned on the area 5, the alignment of the power transmission coil 24 and the power receiving coil 11 is easier. In addition, the degree of freedom in the parking position of the electric vehicle 9 is increased.

[0054] In this embodiment, the case in which multiple power transmission coils 24 are arranged in a straight line has been described, but this is not the only case. The arrangement of the multiple power transmission coils 24 is not limited, and they may be arranged in a grid pattern, for example.

[0055] The charging device and charging system according to the present invention are not limited to the embodiments described above. The specific configuration of each part of the charging device and charging system according to the present invention can be modified in various ways. [Explanation of Symbols]

[0056] A1, A2: Charging device, 11: Receiving coil, 12: Rectifier circuit, 13: Inverter circuit, 14: Control unit, 16: Housing, 164: Storage compartment, 17: Converter circuit, 19: Charging cable, 191: Charging connector, 2: Power transmission device, 22: Inverter circuit, 24: Power transmission coil, 9: Electric vehicle, 91: Storage battery, B1, B3: Charging system

Claims

1. A charging device for charging the battery of an electric mobile vehicle that moves by driving an electric motor with the power of the battery, A receiving coil that receives power from a transmitting coil in a non-contact manner, The power conversion circuit performs power conversion of the power received by the power receiving coil, A housing that houses the power receiving coil and the power conversion circuit and is portable by the user, A charging connector connected to the aforementioned electric mobile device, which supplies power output by the power conversion circuit to the electric mobile device, A charging cable that electrically connects the power conversion circuit and the charging connector, Equipped with, The power receiving coil is positioned on the bottommost side of the housing, such that the coil surface is substantially parallel to the bottom surface. The power conversion circuit has an inverter circuit that converts DC power to AC power, is covered by a box that does not allow magnetic flux to pass through, and is positioned above the power receiving coil. The housing is made of a material that allows magnetic flux to pass through, at least on its bottom surface, and includes a storage compartment capable of accommodating the charging cable and the charging connector. Charging device.

2. The housing is provided with a handle for the user to grip and carry, The charging device according to claim 1.

3. A charging device according to claim 1 or 2, A power transmission device that transmits power to the aforementioned charging device in a non-contact manner, Equipped with, The aforementioned power transmission device is The power transmission coil transmits power to the power receiving coil without contact, A power supply circuit that supplies high-frequency power to the aforementioned power transmission coil, It is equipped with Charging system.

4. The power supply circuit and the power transmission coil are further connected by a power transmission cable, The aforementioned power transmission cable and power transmission coil are buried. The charging system according to claim 3.

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