Charging and discharging device and electric vehicle charger

Abstract

A charging and discharging device is coupled with a power grid through a first cable and a plug, and is coupled with an electric vehicle through a second cable and a connecting end. The charging and discharging device comprises a charging circuit, a feed circuit and a controller, the charging circuit provides a charging path for transmitting power of the power grid from the plug to the connecting end, and the feed circuit provides a feed path for transmitting power of the carrier from the connecting end to the plug. In a charging mode, the controller sets a first current that can flow through the charging path. In the feed mode, the controller sets a second current that can flow through the feed path. The invention further relates to an electric vehicle charger.

Description

Technical Field

[0001] The present disclosure relates to a charging and discharging device and an electric vehicle charger, particularly a portable charging and discharging device and an electric vehicle charger. Background Art

[0002] Currently, due to the emphasis on energy conservation and carbon reduction, electric vehicles are gradually replacing fuel-driven vehicles with electric-driven ones. Among them, the power source of an electric vehicle (generally referred to as an electric vehicle) is a battery, so the battery needs to be charged to maintain the endurance of the electric vehicle. Generally speaking, common electric vehicle chargers include the following Figures 1A to 1C configuration architectures. In Figure 1A the charging technology is to use a simple extension cord to charge at home from a standard power outlet. Specifically, this type of electric vehicle charger 100 involves electrically connecting the electric vehicle 300 to a standard household socket 200A, and the electric vehicle charger 100 usually has only a single cable connecting the electric vehicle 300 and the socket 200A. This type of electric vehicle charger 100 is generally applicable to light vehicles (such as electric motorcycles) due to its simple architecture.

[0003] In Figure 1B the charging technology involves using a dedicated charging station or a home wall-mounted charging box (collectively referred to as the grid-side charging device 100B) to charge the electric vehicle 300. Since the connection cable is provided by the grid-side charging device 100B, the electric vehicle 300 does not need to use a dedicated cable for charging, so it is currently the preferred choice for home charging. In Figure 1C the charging technology is usually called "DC fast charging", or simply "fast charging" for short. This type of charging usually requires a charging pile 100C and can usually provide high-power charging. Specifically, such an electric vehicle charger 100 generally provides direct current to charge the electric vehicle 300, and the current can reach hundreds of amperes and the power can reach hundreds of kW.

[0004] However, the current electric vehicle charger 100 only supports the technology of charging the electric vehicle, but does not include the technology of feeding electricity back to the grid. On the other hand, currently Figure 1B all electric vehicle chargers 100 are fixed at homes or specific locations and cannot be moved, and they also cannot effectively support the grid. Therefore, how to design a portable charging and discharging device and an electric vehicle charger to combine the advantages of the two and eliminate the disadvantages, so as to enable the vehicle owner to more easily feed the electricity of the electric vehicle back to the grid and provide a two-way charging function is a major research topic for the creator of this case. Summary of the Invention

[0005] To solve the above problems, the present disclosure provides a charging and discharging device to overcome the problems of the prior art. Therefore, the charging and discharging device of the present disclosure is coupled to the power grid through a first cable and a plug, and is coupled to an electric vehicle through a second cable. The charging and discharging device includes a charging circuit, a power feeding circuit, and a controller. The charging circuit and the power feeding circuit are respectively coupled to the first cable and the second cable. The charging circuit provides a charging path for transmitting grid power from the plug to the connection end, and the power feeding circuit can provide a power feeding path for transmitting vehicle power from the connection end to the plug. The controller is coupled to the charging circuit and the power feeding circuit, and transmits current information and operation commands to the electric vehicle through the second cable to determine whether the electric vehicle is to operate in a charging mode or a power feeding mode according to the operation commands. Among them, in the charging mode, the controller sets a first current that can flow through the charging path and charges the electric vehicle according to the first current. In the power feeding mode, the controller sets a second current that can flow through the power feeding path and feeds power to the power grid according to the second current.

[0006] To solve the above problems, the present disclosure provides an electric vehicle charger to overcome the problems of the prior art. Therefore, the portable electric vehicle charger of the present disclosure includes a plug, a first cable, a second cable, and a charging and discharging device. The first cable is coupled to the plug, and the second cable is coupled to the connection end. The charging and discharging device is coupled to the first cable and the second cable, and the charging and discharging device includes a charging circuit and a power feeding circuit. The charging circuit is coupled to the first cable and the second cable and includes a first switch. The charging circuit provides a charging path for transmitting grid power from the plug to the connection end, one end of the first switch is coupled to the first cable, and the other end of the first switch is coupled to the second cable. The power feeding circuit is coupled to the first cable and the second cable, and the power feeding circuit includes a second switch, a conversion circuit, and a third switch. The power feeding circuit can provide a power feeding path for transmitting vehicle power from the connection end to the plug, one end of the second switch is coupled to the first cable, and one end of the conversion circuit is coupled to the second switch. One end of the third switch is coupled to the other end of the conversion circuit, and the other end of the third switch is coupled to the second cable.

[0007] The main purpose and effect of the present disclosure is that the electric vehicle charger of the present disclosure can provide a two-way charging function. That is to say, through the charging and discharging operation of the electric vehicle charger, in addition to charging the electric vehicle with the grid power provided by the power grid, the vehicle power provided by the electric vehicle can also be fed back to the power grid to achieve the effect of two-way power supply.

[0008] To further understand the technologies, means, and effects adopted by the present disclosure to achieve the predetermined purpose, please refer to the following detailed description and drawings of the present disclosure. It is believed that the purpose, features, and characteristics of the present disclosure can be deeply and specifically understood therefrom. However, the attached drawings are only for reference and illustration, and are not used to limit the present disclosure. Description of the Drawings

[0009] Figure 1A Configuration architecture diagram of the first embodiment of an existing electric vehicle charger;

[0010] Figure 1B Configuration architecture diagram of the second embodiment of an existing electric vehicle charger;

[0011] Figure 1C Configuration architecture diagram of the third embodiment of an existing electric vehicle charger;

[0012] Figure 2 Circuit block diagram of the portable electric vehicle charger of the present disclosure;

[0013] Figure 3 More detailed circuit block diagram of the portable electric vehicle charger of the present disclosure;

[0014] Figure 4A Schematic diagram of the current direction of the charging mode of the portable electric vehicle charger of the present disclosure;

[0015] Figure 4B Schematic diagram of the current direction of the power feeding mode of the portable electric vehicle charger of the present disclosure; and

[0016] Figure 5 Even more detailed circuit block diagram of the portable electric vehicle charger of the present disclosure.

[0017] Among them, the reference numerals are explained as follows:

[0018] 100B: Grid-end charging device

[0019] 100C: Charging pile

[0020] 100: Electric vehicle charger

[0021] 1: Plug

[0022] NTC: Thermistor

[0023] [[ID=5I]]R: Detection resistor

[0024] 2: First cable

[0025] 3: Second cable

[0026] 4: Charge and discharge device

[0027] 42: Charging circuit

[0028] SW1: First switch

[0029] 44: Power feeding circuit

[0030] SW2: Second switch

[0031] Q1: First switch Note: In the above translation, "5I" should be "51" in the original text, which is likely a typo. The translation is adjusted accordingly.

[0032] Q2: The second switch

[0033] SW3: The third switching switch

[0034] Q3: The third switch

[0035] Q4: The fourth switch

[0036] 442: Conversion circuit

[0037] AC / DC: AC-DC conversion circuit

[0038] DC / AC: DC-AC conversion circuit

[0039] 46: Controller

[0040] 48: Auxiliary circuit

[0041] CP: Control guide pin

[0042] PP: Connection guide pin

[0043] 5: Connection terminal

[0044] Lc: Charging path

[0045] I1: The first current

[0046] Lf: Feeding path

[0047] I2: The second current

[0048] 200: Power grid

[0049] [[ID=S3]]200A: Socket

[0050] 300: Electric vehicle

[0051] 300A: Connection terminal

[0052] Pac: Power grid power

[0053] Pv: Vehicle power

[0054] Pcc: Working power

[0055] Pdc: DC power

[0056] Is: Specification information

[0057] Ic: Current information

[0058] Co: Operation command

[0059] A1, A2: Arrow direction Detailed implementation manners

[0060] Regarding the technical content and detailed description of the present disclosure, it is described below in conjunction with the drawings:

[0061] Please refer to Figure 2 which is a circuit block diagram of a portable electric vehicle charger of the present disclosure, and also refer to Figures 1A to 1C . The portable electric vehicle charger 100 (hereinafter simply referred to as the electric vehicle charger 100) is coupled to the power grid 200 and the electric vehicle 300, and includes a plug 1, a first cable 2, a second cable 3, a charge and discharge device 4, and a connection end 5. The plug 1 can be coupled to the power grid 200 by plugging into the socket 200A, and the connection end 5 can be coupled to the electric vehicle 300 by plugging into the connection end 300A of the electric vehicle 300. One end of the first cable 2 is coupled to the plug 1, and the other end of the first cable 2 is coupled to one end of the charge and discharge device 4. One end of the second cable 3 is coupled to the connection end 5, and the other end of the second cable 3 is coupled to the other end of the charge and discharge device 4. Among them, the electric vehicle charger 100 does not include a grid-side charging device 100B as Figure 1B or a charging pile 100C as Figure 1C , but uses a conventional plug 1 (such as, but not limited to, US standard, European standard, etc.) to plug into a conventional socket 200A to obtain the grid power Pac.

[0062] Furthermore, the main purpose and efficacy of the present disclosure is that the electric vehicle charger 100 of the present disclosure can provide a function of bidirectional charging. That is to say, through the charge and discharge operations of the electric vehicle charger 100, in addition to charging the electric vehicle 300 with the grid power Pac provided by the power grid 200, the vehicle power Pv provided by the electric vehicle 300 can also be fed back to the power grid 200. Among them, the charge and discharge device 4 includes a charge path Lc and a feed path Lf. When the grid power Pac charges the electric vehicle 300, the grid power Pac is provided to the electric vehicle 300 through the path of the plug 1, the first cable 2, the charge path Lc of the charge and discharge device 4, the second cable 3, and the connection end 5. Conversely, when the vehicle power Pv is fed back to the power grid 200, the vehicle power Pv is fed back to the power grid 200 through the connection end 5, the second cable 3, the feed path Lf of the charge and discharge device 4, the first cable 2, and the plug 1. The plug 1, the first cable 2, the charge and discharge device 4, the second cable 3, and the connection end 5 can be assembled into an integrated electric vehicle charger 100, or can also be a split-type electric vehicle charger 100. Specifically, when it is a split-type electric vehicle charger 100, the plug 1 and the first cable 2 are of a modular structure, and the connection between the first cable 2 and the charge and discharge device 4 is a pluggable (replaceable) connection structure. The charge and discharge device 4 can receive the specification information Is of the plug 1 through the first cable 2, and the specification information Is depends on the type of the plug 1 currently plugged into the charge and discharge device 4 through the first cable 2. Moreover, the charge and discharge device 4 can also transmit the current information Ic and the operation command Co to the electric vehicle 300 through the second cable 3. Among them, the charge and discharge device 4 can know the currently plugged-in plug 1 through the specification information Is, for example but not limited to, whether it conforms to the relevant specifications of the electric vehicle charger 100, and the specifications of the plug 1 (such as US standard, European standard, etc.), whether the voltage of the power grid is three-phase / single-phase, 110V / 220V, the upper limit of the current (usually determined according to the voltage magnitude), the frequency, the phase, and other information.

[0063] On the other hand, the electric vehicle 300 and the charge and discharge device 4 can confirm and set how much current can be drawn and discharged by transmitting the current information Ic, and the operation command Co is mainly used to let the electric vehicle 300 and the charge and discharge device 4 know what the current operation is. For example but not limited to, the electric vehicle 300 and the charge and discharge device 4 can confirm whether the electric vehicle 300 is correctly coupled to the charge and discharge device 4 through the operation command Co, and whether the plug 1 is correctly plugged into the socket 200A to determine whether it is in a standby state. In addition, through the transmission of the operation command Co, the charge and discharge device 4 can also judge what mode the electric vehicle 300 wants to operate in (for example but not limited to, the charging mode or the feeding mode), so as to selectively provide the corresponding path (that is, the charge path Lc is provided in the charging mode, and the feed path Lf is provided in the feeding mode) to perform the corresponding operation.

[0064] After the plug 1 is inserted into the socket 200A, the charging and discharging device 4 can receive the specification information Is of the plug 1 through the first cable 2. During the operation in the charging mode, the charging and discharging device 4 first confirms whether the electric vehicle 300 is correctly coupled to the connection end 5 and whether the plug 1 is correctly inserted into the socket 200A. When both are correctly coupled, the operation command Co instructs the charging and discharging device 4 to be in the standby state, and the electric vehicle 300 and the charging and discharging device 4 can know the current state is the standby state according to the instruction of the operation command Co. Then, the value of the operation command Co can be adjusted according to the requirements of the electric vehicle 300, and the charging and discharging device 4 then judges whether the electric vehicle 300 wants to operate in the charging mode or the power feeding mode according to the value of the operation command Co.

[0065] Among them, the charging path Lc is in parallel with the power feeding path Lf, and the paths of the charging path Lc and the power feeding path Lf are different (independent of each other) and the currents are opposite. In the charging mode, the charging and discharging device 4 forms the charging path Lc and opens the power feeding path Lf to prevent the current on the charging path Lc from flowing to the power feeding path Lf and causing additional power consumption. On the contrary, in the power feeding mode, the charging and discharging device 4 opens the charging path Lc and forms the power feeding path Lf to convert the vehicle power Pv into the grid power Pac through the power feeding path Lf. When the power feeding path Lf converts the vehicle power Pv into the grid power Pac, the power feeding path Lf can convert the three-phase or single-phase vehicle power Pv into the three-phase or single-phase grid power Pac. For example but not limited to, the power feeding path Lf can convert the three-phase vehicle power Pv into the single-phase grid power Pac, or convert the single-phase vehicle power Pv into the three-phase grid power Pac. In this way, the adaptive power conversion can be made according to the requirements of the grid 200 and the electric vehicle 300 to avoid the situation that they cannot be used due to the wiring differences between the two.

[0066] The operation command Co is preferably a voltage value, and the current operation state of the charging and discharging device 4 is set by adjusting the voltage value. For example, when the electric vehicle 300 is not correctly coupled to the connection end 5 or the plug 1 is not correctly inserted into the socket 200A, the voltage value of the operation command Co is a specific value (such as but not limited to 0V), so that the electric vehicle 300 can know that the charging and discharging device 4 has not entered the standby state based on this specific value, and vice versa (such as but not limited to 5V) to know that the charging and discharging device 4 has entered the standby state.

[0067] In addition, when the electric vehicle 300 is to operate in the charging mode or the power feeding mode, the electric vehicle 300 can set the mode by adjusting the value of the operation command Co. For example, when the general charging and discharging device 4 has entered the standby state (in the same example above, the value of the operation command Co is 5V), the standby state is preset as the charging mode. Conversely, after the charging and discharging device 4 has entered the standby state, the electric vehicle 300 can inform the charging and discharging device 4 to operate in the power feeding mode by adjusting the value of the operation command Co (for example, but not limited to, the electric vehicle 300 adjusts the value of the operation command Co from 5V to 3V). Herein, the operation command Co is not limited to the voltage value. For example, but not limited to, the operation command Co can also be a signal in digital form (for example, but not limited to, logic 011 corresponds to the power feeding mode), or a pulse width modulation signal (PWM), and the operation mode is adjusted by the duty cycle (for example, but not limited to, a duty cycle of 50% corresponds to the power feeding mode), and so on, which will not be elaborated herein.

[0068] Taking the charging mode as an example, when the charging and discharging device 4 is coupled to the plug 1 through the first cable 2, the charging and discharging device 4 receives the specification information Is of the plug 1 through the first cable 2 to know the upper limit value of the charging current (i.e., the first current I1) of the charging and discharging device 4 (for example, but not limited to 18A, which usually varies according to the voltage of the power grid and the tolerance of the plug 1). Then, the charging and discharging device 4 adjusts the current information Ic according to the upper limit value of the charging current, and the current information Ic corresponds to the first current I1 that can flow through the charging path Lc (generally preset as the current upper limit value). When the charging and discharging device 4 is coupled to the electric vehicle 300 through the second cable 3, the charging and discharging device 4 can communicate with the electric vehicle 300 by transmitting the current information Ic to inform the upper limit value of the current that can flow through the charging path Lc currently. Then, the electric vehicle 300 can determine the first current I1 for final charging by adjusting the current information Ic (for example, but not limited to, after the charging and discharging device 4 informs the electric vehicle 300 of the upper limit value of 18A, the electric vehicle 300 finally selects a value of 15A for charging). Finally, the charging and discharging device 4 sets the first current I1 that can flow through the charging path Lc through the adjusted current information Ic.

[0069] Among them, the current information Ic can preferably be a pulse width modulation signal (PWM), and the magnitude of the first current I1 is changed by adjusting the duty cycle (DUTY) (for example, but not limited to, a duty cycle of 30% corresponds to a first current I1 of 18 A), but it is not limited thereto. For example, but not limited to, the current information Ic can also be a signal in digital form (for example, but not limited to, logic 011 corresponds to a first current I1 of 18 A), or a voltage value (for example, but not limited to, a voltage of 5 V corresponds to a first current I1 of 18 A) to indicate the magnitude of the first current I1, and so on, which will not be elaborated here. Finally, after the operation mode and the first current I1 are determined, the charge and discharge device 4 provides a corresponding charging path Lc to perform a charging operation to charge the electric vehicle 300 according to the first current I1. On the other hand, after the operation command Co instructs the charge and discharge device 4 to be in a standby state, the charge and discharge device 4 can set a second current I2 that can flow through the feed path Lf through the current information Ic, and after the operation mode and the second current I2 are determined, the charge and discharge device 4 provides a corresponding feed path Lf to perform a feeding operation to feed the power grid 200 according to the second current I2. In addition, the operations of the remaining feeding modes are similar to the above-mentioned charging mode, which will not be elaborated here.

[0070] Please refer to Figure 3 FIG. 2 is a more detailed circuit block diagram of the portable electric vehicle charger of the present disclosure. Please also refer to FIG. 2. In Figure 3 only the preferred embodiments Figure 2 under the architecture are shown, but it is not limited thereto. In Figure 3 the charge and discharge device 4 includes a charging circuit 42, a feeding circuit 44, and a controller 46, and the charging circuit 42 is connected in parallel with the feeding circuit 44. The charging circuit 42 is coupled to the first cable 2 and the second cable 3, and provides a charging path Lc for the grid power Pac to be transmitted from the plug 1 to the connection end 5. The feeding circuit 44 is coupled to the first cable 2 and the second cable 3, and provides a feeding path Lf for the vehicle power Pv to be transmitted from the electric vehicle 300 through the connection end 5 to the plug 1. The controller 46 is coupled to the charging circuit 42 and the feeding circuit 44, and includes a protection pin, an identification pin, a control pilot pin CP, and a proximity pilot pin PP. The identification pin and the protection pin are coupled to the plug 1 through the first cable 2, and the plug 1 preferably includes a thermistor NTC and a detection resistor R (RecognizeResistance).

[0071] The protection pin is coupled to the thermistor NTC through the first cable 2 to determine whether to perform over-temperature protection on the charging and discharging device 4 according to the change in the resistance value of the thermistor NTC. The identification pin is coupled to the detection resistor R through the first cable 2, so that the controller 46 obtains the specification information Is through the detection resistor R. Therefore, when the plug 1 uses the detection resistor R, the identification pin can provide a constant current source, for example but not limited to, to generate a specific voltage across the detection resistor R, and this specific voltage is the specification information Is. The control pilot pin CP is coupled to the electric vehicle 300 through the second cable 3, and the control pilot pin CP and the electric vehicle 300 transmit the current information Ic to each other, so that the controller 46 and the electric vehicle 300 set and adjust the first current I1 that can flow through the charging path Lc according to the current information Ic, and charge the electric vehicle 300 according to the first current I1, or set and adjust the second current I2 that can flow through the feeding path Lf according to the current information Ic, and feed electricity to the power grid 200 according to the second current I2. The connection pilot pin PP is coupled to the electric vehicle 300 through the second cable 3, and the connection pilot pin PP and the electric vehicle 300 transmit the operation command Co to each other, so that the controller 46 and the electric vehicle 300 judge the current operation state through the operation command Co.

[0072] It is worth mentioning that in an embodiment, the controller 46 can be a control chip, which can be a microcontroller, a signal processor, etc., but the controller 46 can also be a control circuit composed of circuits or logic gates. In addition, Figure 3 The presented controller 46 may not only include a control chip. It may also include circuits and circuit elements for detecting and transmitting signals (such as but not limited to, analog-to-digital conversion circuits, resistors, etc.). Since these un-presented circuits and circuit elements are not the main features of the present disclosure, they will not be elaborated here. On the other hand, the controller may also have a wireless communication function, such as but not limited to, Wifi, Bluetooth, mobile communication (such as: 2 / 3 / 4 / 5G, etc.), so that the portable electric vehicle charger can communicate with the outside world.

[0073] Among them, the charging circuit 42 includes a first switching switch SW1. One end of the first switching switch SW1 is coupled to the first cable 2, and the other end of the first switching switch SW1 is coupled to the second cable 3. The controller 46 is coupled to the control end of the first switching switch SW1 to control the conduction / turn-off of the first switching switch SW1 by providing a control signal. In the charging mode, the controller 46 controls the first switching switch SW1 to conduct, so that the charging circuit 42 forms and provides a charging path Lc. Conversely, when the controller 46 controls the first switching switch SW1 to turn off (such as but not limited to standby state or power feeding mode, etc.), the two ends of the charging circuit 42 are open-circuited to prevent current from being wrongly provided from the power grid 200 to the electric vehicle 300. Among them, the first switching switch SW1 is preferably a switch such as a relay that can allow a large current to flow through, and has the effects of no leakage current when it is turned off and simple configuration.

[0074] The charging and discharging device 4 further includes an auxiliary circuit 48, and the auxiliary circuit 48 is coupled to the path between the first switching switch SW1 and the first cable 2. Whether the charging and discharging device 4 operates in the standby state, charging mode or discharging mode, the auxiliary circuit 48 converts the grid power Pac into working power Pcc to continuously supply power to the controller 46 after the plug 1 is coupled to the power grid 200. Generally speaking, the controller 46 usually belongs to a device that receives direct current, so the auxiliary circuit 48 can be a converter for converting alternating current to direct current. Preferably, the auxiliary circuit 48 can couple the grid power Pac on the path between the first switching switch SW1 and the first cable 2 through, for example but not limited to, the coupling of an isolation transformer to electrically isolate the controller 46 from the main power transmission path.

[0075] On the other hand, the power feeding circuit 44 includes a second switching switch SW2, a conversion circuit 442, and a third switching switch SW3. One end of the second switching switch SW2 is coupled to the first cable 2, and the other end of the second switching switch SW2 is coupled to the conversion circuit 442. One end of the third switching switch SW3 is coupled to the other end of the conversion circuit 442, and the other end of the third switching switch SW3 is coupled to the second cable 3. The controller 46 is coupled to the control terminals of the second switching switch SW2 and the third switching switch SW3 to control the conduction / turn-off of the second switching switch SW2 and the third switching switch SW3 by providing control signals. In the power feeding mode, the controller 46 controls the second switching switch SW2 and the third switching switch SW3 to conduct, and enables the conversion circuit 442 to form a power feeding path Lf. Therefore, the vehicle power Pv can be provided to the conversion circuit 442 through the third switching switch SW3, and after the conversion circuit 442 converts the vehicle power Pv into grid power Pac, it is provided to the plug 1 through the second switching switch SW2. Among them, the convertible three-phase or single-phase vehicle power Pv is three-phase or single-phase grid power Pac. When the controller 46 controls the second switching switch SW2 and the third switching switch SW3 to turn off and disables the conversion circuit 442 (such as but not limited to standby state or charging mode, etc.), both ends of the power feeding circuit 44 are open-circuited to prevent current from being wrongly provided from the electric vehicle 300 to the grid 200.

[0076] Furthermore, the conversion circuit 442 preferably may include an AC / DC conversion circuit, a DC / AC conversion circuit, and an energy storage capacitor (not shown in the figure). One end of the AC / DC conversion circuit is coupled to the third switching switch SW3, and the other end is coupled to the energy storage capacitor (not shown in the figure). One end of the DC / AC conversion circuit is coupled to the energy storage capacitor (not shown in the figure), and the other end is coupled to the second switching switch SW2. Among them, the controller 46 controls the AC / DC conversion circuit to convert the vehicle power Pv into DC power Pdc to store the DC power Pdc in the energy storage capacitor (not shown in the figure). Then, the controller 46 controls the DC / AC conversion circuit to convert the DC power Pdc into grid power Pac to feed power to the grid 200.

[0077] Since the conversion circuit 442 includes an energy storage capacitor (not shown in the figure), the conversion circuit 442 can perform arbitrary conversion between three-phase / single-phase power. Preferably, the AC / DC conversion circuit can convert the three-phase vehicle power Pv into DC power Pdc, and the DC / AC conversion circuit then converts the DC power Pdc into single-phase grid power Pac. Alternatively, the AC / DC conversion circuit converts the single-phase vehicle power Pv into DC power Pdc, and the DC / AC conversion circuit then converts the DC power Pdc into three-phase grid power Pac. In this way, the power conversion can be adapted to the requirements of the power grid 200 and the electric vehicle 300, avoiding the situation where the connection difference between the two causes inoperability. It is worth mentioning that in one embodiment, the AC / DC conversion circuit and the DC / AC conversion circuit can be conversion circuits without an isolation transformer (such as, but not limited to, Buck, Boost and other conversion circuits without an isolation transformer at the input and output ends). The reason is that the voltage and current magnitudes at both ends of the conversion circuit 442 are similar, so a relatively large isolation transformer can be dispensed with, but this is not the limit. In addition, the AC / DC conversion circuit and the DC / AC conversion circuit may not include an energy storage capacitor and its DC link (such as, but not limited to, a current source type or matrix type AC / AC converter) to save the volume occupied by the energy storage capacitor.

[0078] Please refer to Figure 4A which is a schematic diagram of the current direction of the charging mode of the portable electric vehicle charger of the present disclosure, and also refer to Figures 2 to 3 . In Figure 4A the current direction of the charging mode is shown, and the arrow direction A1 represents the flowing direction of the first current I1. Specifically, when the plug 1 is inserted into the socket 200A, the auxiliary circuit 48 receives the grid power Pac and converts the grid power Pac into working power Pcc to supply power to the controller 46. After the controller 46 is powered on and operates normally, the controller 46 can receive the specification information Is of the plug 1 through the first cable 2 to obtain the upper limit values of the charging current (i.e., the first current I1) and the feeding current (i.e., the second current I2) of the charging and discharging device 4 (which usually varies according to the voltage magnitude of the power grid and the tolerance of the plug 1).

[0079] When the controller 46 confirms that the electric vehicle 300 is correctly coupled to the connection terminal 5 and the plug 1 is correctly inserted into the socket 200A, the controller 46 adjusts the value of the operation command Co to indicate that the charging and discharging device 4 is in a standby state. After the standby state, the controller 46 further determines whether the electric vehicle 300 is to operate in the charging mode or the power feeding mode according to the value of the operation command Co. On the other hand, after the standby state, the controller 46 can also set the first current I1 and the second current I2 that can flow through the charging path Lc through the current information Ic. When the controller 46 determines that the operation mode is the charging mode and the magnitude of the first current I1 is also set (by transmitting the current information Ic with the electric vehicle 300), the controller 46 turns on the first switching switch SW1 to form a charging path for the charging circuit 42.

[0080] Please refer to Figure 4B FIG. is a schematic diagram of the current direction in the power feeding mode of the portable electric vehicle charger of the present disclosure. Please also refer to Figures 2 to 4A . In Figure 4B , the current direction in the power feeding mode is shown, and the arrow direction A2 represents the flowing direction of the second current I2. Figure 4A The difference from Figure 4B is that when the controller 46 determines that the operation mode is the power feeding mode and the magnitude of the second current I2 is also set (by transmitting the current information Ic with the electric vehicle 300), the controller 46 turns on the second switching switch SW2 and the third switching switch SW3 and enables the conversion circuit 442 to form a power feeding path Lf. It is worth mentioning that in an embodiment, Figure 4B the operation manners not described are similar to Figure 4A and will not be elaborated here.

[0081] Please refer to Figure 5 FIG. is a more detailed circuit block diagram of the portable electric vehicle charger of the present disclosure. Please also refer to Figures 2 to 4B . In Figure 5 , in addition to including the above-mentioned Figures 2 to 4B elements that have been described, it further includes a plurality of drivers, detectors (circuits), etc. Since most of these circuits are only for protecting the electric vehicle charger 100 and are not the main features of the present disclosure, these circuits will not be elaborated one by one. Therefore, the electric vehicle charger 100 of the present disclosure still has protection functions such as leakage current, overcurrent, voltage, frequency, and ground detection during the charging and power feeding processes to ensure the safety of users, electric vehicles, residences, and the mains. In addition, in Figure 5Among them, the second switching switch SW2 preferably may include a first switch Q1 and a second switch Q2 connected in series, and the third switching switch SW3 preferably may include a third switch Q3 and a fourth switch Q4 connected in series. When the controller 46 controls the second switching switch SW2 to conduct, the first switch Q1 and the second switch Q2 conduct, and vice versa. The purpose and effect of the second switching switch SW2 including the first switch Q1 and the second switch Q2 connected in series are that the first switch Q1 and the second switch Q2 can provide the function of mutual redundant disconnection.

[0082] Specifically, since when exiting the power feeding mode, the controller 46 controls the second switching switch SW2 to turn off. At this time, when the second switching switch SW2 fails to turn off smoothly due to failure, the grid power Pac will be wrongly provided to the conversion circuit 442. Therefore, through the redundant function of the first switch Q1 and the second switch Q2, when one of them fails to turn off smoothly, the other non-failed switch can still perform redundant disconnection, so that the path from the first cable 2 to the conversion circuit 442 can still be normally disconnected. Similarly, when the controller 46 controls the third switching switch SW3 to conduct, the third switch Q3 and the fourth switch Q4 conduct, and vice versa. Its operation mode and the achievable effect are similar to those of the second switching switch SW2, and will not be elaborated here.

[0083] The above description is only a detailed description and diagram of the preferred specific embodiments of the present disclosure, but the features of the present disclosure are not limited thereto, and are not intended to limit the present disclosure. The entire scope of the present disclosure shall be subject to the following claims. All embodiments that conform to the spirit of the claims of the present disclosure and their similar variations shall be included in the scope of the present disclosure. Any changes or modifications that can be easily conceived by those skilled in the art within the field of the present disclosure can be covered by the patent scope of the present case below.

Claims

1. A charging and discharging device is coupled to a power grid through a first cable and a plug, and is coupled to an electric vehicle through a second cable and a connection end. The charging and discharging device includes: A charging circuit, coupled to the first cable and the second cable, and providing a charging path for transmitting grid power from the plug to the connection end; A power feeding circuit, coupled to the first cable and the second cable, and capable of providing a power feeding path for transmitting vehicle power from the connection end to the plug; And A controller, coupled to the charging circuit and the power feeding circuit, and transmitting a current information and an operation command to the electric vehicle through the second cable, so as to determine whether the electric vehicle is to operate in a charging mode or a power feeding mode according to the operation command; Wherein, in the charging mode, the controller sets a first current that can flow through the charging path, and charges the electric vehicle according to the first current; in the power feeding mode, the controller sets a second current that can flow through the power feeding path, and feeds power to the power grid according to the second current.

2. The charging and discharging device according to claim 1, wherein the plug and the first cable are of a modular structure, and the connection between the first cable and the charging and discharging device is a pluggable connection structure; the controller receives a specification information of the plug through the first cable, and provides the current information according to the specification information, so as to set the first current and the second current accordingly.

3. The charging and discharging device according to claim 1, wherein the charging circuit includes: A first switching switch, one end of which is coupled to the first cable, and the other end of which is coupled to the second cable; Wherein, in the charging mode, the controller turns on the first switching switch to form the charging path.

4. The charging and discharging device according to claim 3, further including: An auxiliary circuit, coupled to the first switching switch and the first cable; Wherein, in the charging mode or the power feeding mode, the auxiliary circuit converts the grid power into a working power to supply power to the controller.

5. The charging and discharging device according to claim 1, wherein the power feeding circuit includes: A second switching switch, one end of which is coupled to the first cable; A conversion circuit, one end of which is coupled to the second switching switch; And A third switching switch, one end of which is coupled to the other end of the conversion circuit, and the other end of which is coupled to the second cable; Wherein, in the power feeding mode, the controller turns on the second switching switch and the third switching switch, and enables the conversion circuit to form the power feeding path.

6. The charging and discharging device according to claim 5, wherein the second switching switch includes a first switch and a second switch connected in series; the third switching switch includes a third switch and a fourth switch connected in series.

7. The charging and discharging device according to claim 5, wherein the conversion circuit includes: An AC-DC conversion circuit, coupled to the third switching switch; And A DC-AC conversion circuit, coupled to the second switching switch and the AC-DC conversion circuit; Wherein, the controller controls the AC-DC conversion circuit to convert the vehicle power into a DC power, and controls the DC-AC conversion circuit to convert the DC power into the grid power.

8. The charging and discharging device according to claim 5, wherein the conversion circuit converts the three-phase vehicle power into single-phase grid power, or converts the single-phase vehicle power into three-phase grid power.

9. The charging and discharging device according to claim 5, wherein after the controller instructs the charging and discharging device to be in a standby state through the operation command, the controller then determines whether the electric vehicle is to operate in the charging mode or the power feeding mode according to a value of the operation command.

10. The charging and discharging device according to claim 9, wherein after the standby state, the controller sets a first current that can flow through the charging path through the current information, and turns on a first switching switch of the charging circuit.

11. The charging and discharging device according to claim 9, wherein after the standby state, the controller sets a second current that can flow through the power feeding path through the current information, turns on a second switching switch and a third switching switch of the power feeding circuit, and enables the conversion circuit.

12. An electric vehicle charger, comprising: a plug; a first cable coupled to the plug; a second cable coupled to a connection end; a charging and discharging device coupled to the first cable and the second cable, and comprising: a charging circuit coupled to the first cable and the second cable, and providing a charging path for transmitting grid power from the plug to the connection end, the charging circuit comprising: a first switching switch, one end of which is coupled to the first cable and the other end of which is coupled to the second cable; and a power feeding circuit coupled to the first cable and the second cable, and capable of providing a power feeding path for transmitting vehicle power from the connection end to the plug, and the power feeding circuit comprising: a second switching switch, one end of which is coupled to the first cable; a conversion circuit, one end of which is coupled to the second switching switch; and a third switching switch, one end of which is coupled to the other end of the conversion circuit and the other end of which is coupled to the second cable.

13. The electric vehicle charger according to claim 12, wherein the charging and discharging device receives a specification information of the plug through the first cable, and transmits a current information and an operation command to an electric vehicle through the second cable, so as to determine whether the electric vehicle is to operate in a charging mode or a power feeding mode according to the operation command.

14. The electric vehicle charger according to claim 13, wherein in the charging mode, the charging and discharging device provides the current information according to the specification information to set a first current that can flow through the charging path, and charges the electric vehicle according to the first current; in the power feeding mode, the charging and discharging device provides the current information according to the specification information to set a second current that can flow through the power feeding path, and feeds power to a grid according to the second current.

15. The electric vehicle charger according to claim 12, wherein the charging path is in parallel with the power feeding path, and in a charging mode, a controller of the charging and discharging device turns on the first switching switch, and turns off the second switching switch, the third switching switch and disables the conversion circuit.

16. The electric vehicle charger as claimed in claim 12, wherein the charging path is in parallel with the power feeding path, and in a power feeding mode, a controller of the charging and discharging device turns off the first switching switch, turns on the second switching switch, the third switching switch and enables the conversion circuit.

17. The electric vehicle charger as claimed in claim 16, wherein the power feeding path converts the three-phase vehicle power into single-phase grid power, or converts the single-phase vehicle power into three-phase grid power.

18. The electric vehicle charger as claimed in claim 14, wherein the plug and the first cable are of a modular structure, and the connection between the first cable and the charging and discharging device is a pluggable connection structure; when the charging and discharging device is coupled to the plug through the first cable, the charging and discharging device receives the specification information of the plug through the first cable, and sets the first current that can flow through the charging path or the second current that can flow through the power feeding path according to the specification information.

19. The electric vehicle charger as claimed in claim 14, wherein after the operation command indicates that the charging and discharging device is in a standby state, the charging and discharging device further determines whether the electric vehicle is to operate in the charging mode or the power feeding mode according to a value of the operation command.

20. The electric vehicle charger as claimed in claim 19, wherein after the standby state, the charging and discharging device sets the first current that can flow through the charging path through the current information and forms the charging path, or after the standby state, the charging and discharging device sets the second current that can flow through the power feeding path through the current information and forms the power feeding path.

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