Charging and discharging apparatus, and electric-vehicle charger

Abstract

A charging and discharging apparatus (4), which is coupled to a power grid by means of a first cable (2) and a plug (1), and is coupled to an electric vehicle (300) by means of a second cable (3) and a connection end (5). The charging and discharging apparatus comprises a charging circuit (42), a feed circuit (44) and a controller (46), wherein the charging circuit provides a charging path for transmitting the electric power of the power grid from the plug to the connection end, and the feed circuit provides a feed path for transmitting the electric power of the vehicle from the connection end to the plug. The present application also relates to an electric-vehicle charger (100), which comprises a plug, a first cable, a second cable and a charging and discharging apparatus.

Description

Charging and discharging device and electric vehicle charger Technical Field

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

[0002] Currently, electric vehicles are gradually being replaced by electric drives instead of fuel drives due to the emphasis on energy conservation and carbon reduction. Among them, the power source of electric vehicles (generally referred to as electric vehicles) is batteries, so the batteries need to be charged to maintain the endurance of the electric vehicles. Generally speaking, common electric vehicle chargers include the following configuration architectures of Figures 1A to 1C. The charging technology in Figure 1A is to use a simple extension cord for home charging from a standard power outlet. Specifically, this type of electric vehicle charger 100 involves 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 suitable for light vehicles (such as electric motorcycles) due to its simple structure.

[0003] The charging technology in Figure 1B involves using a dedicated charging station or a home wall-mounted charging box (collectively referred to as a grid-side charging device 100B) to charge the electric vehicle 300. Since the connecting 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 first choice for home charging. The charging technology in Figure 1C is generally referred to as "DC fast charging", or simply "fast charging". This type of charging usually requires the inclusion of a charging pile 100C, and can generally provide high-power charging. Specifically, this type of electric vehicle charger 100 generally provides DC power to charge the electric vehicle 300, and the current can reach hundreds of amperes and the power can reach hundreds of kW.

[0004] However, current electric vehicle chargers 100 only support charging technology for electric vehicles, but do not include technology for feeding power back to the grid. Furthermore, the current electric vehicle chargers 100 shown in FIG1B are fixed to a home or specific location and cannot be moved, nor can they effectively support the grid. Therefore, the authors of this project sought to design a portable charging and discharging device and electric vehicle charger that combines the advantages of both while eliminating their disadvantages, allowing owners to easily feed electric vehicle power back to the grid and providing bidirectional charging functionality.

[0005] Summary of the Invention

[0006] In order 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 the electric vehicle through a second cable and a connection end. The charging and discharging device includes a charging circuit, a feeding circuit and a controller, and the charging circuit and the feeding circuit are coupled to the first cable and the second cable respectively. The charging circuit provides a charging path for the power of the power grid to be transmitted from the plug to the connection end, and the feeding circuit can provide a feeding path for the power of the vehicle to be transmitted from the connection end to the plug. The controller couples the charging circuit and the 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 charging mode or feeding mode according to the operation command. 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 feeding mode, the controller sets a second current that can flow through the feeding path, and feeds power to the power grid according to the second current.

[0007] In order 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 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 the grid power to be transmitted from the plug to the connection end, and 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 feeding circuit is coupled to the first cable and the second cable, and the feeding circuit includes a second switch, a conversion circuit and a third switch. The feeding circuit can provide a feeding path for the vehicle power to be transmitted 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.

[0008] The primary purpose and effectiveness of the present disclosure is to provide a bidirectional charging function for the electric vehicle charger. This means that, through the charging and discharging operations of the electric vehicle charger, the grid power provided by the grid can be used to charge the electric vehicle, and the vehicle power provided by the electric vehicle can also be fed back to the grid, thereby achieving a bidirectional power supply effect.

[0009] In order to further understand the technologies, means and effects adopted by the present disclosure to achieve the intended objectives, please refer to the following detailed description and drawings of the present disclosure. It is believed that the objectives, features and characteristics of the present disclosure can be understood in depth and in detail. However, the drawings are provided for reference and illustration only and are not intended to limit the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] FIG1A is a configuration diagram of a first embodiment of a conventional electric vehicle charger;

[0011] FIG1B is a configuration diagram of a second embodiment of a conventional electric vehicle charger;

[0012] FIG1C is a configuration diagram of a third embodiment of a conventional electric vehicle charger;

[0013] FIG2 is a circuit block diagram of the portable electric vehicle charger disclosed herein;

[0014] FIG3 is a more detailed circuit block diagram of the portable electric vehicle charger disclosed herein;

[0015] FIG4A is a schematic diagram illustrating the current direction of the portable electric vehicle charger in the charging mode of the present invention;

[0016] FIG4B is a schematic diagram of the current direction of the portable electric vehicle charger in the feeding mode of the present disclosure; and

[0017] FIG5 is a circuit block diagram of a portable electric vehicle charger in more detail according to the present disclosure.

[0018] Among them, the figure marks are explained as follows: 100B: grid-end charging device 100C: charging pile 100: electric vehicle charger 1: plug NTC: thermistor R: detection resistor 2: first cable 3: second cable 4: charging and discharging device 42: charging circuit SW1: first switching switch 44: feeding circuit SW2: second switching switch Q1: first switch Q2: second switch SW3: third switching switch Q3: third switch Q4: fourth switch 442: conversion circuit AC / DC: AC-DC conversion circuit DC / AC: DC-AC conversion circuit 46: controller 48: auxiliary circuit CP: control guide pin PP: connection guide pin 5: connection end Lc: charging path I1: first current Lf: feeding path I2: second current 200: grid 200A: socket 300: electric vehicle 300A: connection end Pac: grid power Pv: vehicle power Pcc: working power Pdc: DC power Is: specification information Ic: current information Co: operation command A1, A2: arrow direction DETAILED DESCRIPTION

[0019] The technical content and detailed description of the present disclosure are as follows, with accompanying drawings:

[0020] Please refer to Figure 2 for a circuit block diagram of the portable electric vehicle charger disclosed herein, and refer to Figures 1A to 1C in conjunction therewith. The portable electric vehicle charger 100 (hereinafter referred to as the electric vehicle charger 100) couples the power grid 200 and the electric vehicle 300, and includes a plug 1, a first cable 2, a second cable 3, a charging and discharging device 4, and a connection terminal 5. The plug 1 can be coupled to the power grid 200 by plugging into the socket 200A, and the connection terminal 5 can be coupled to the electric vehicle 300 by plugging into the connection terminal 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 charging and discharging device 4. One end of the second cable 3 is coupled to the connection terminal 5, and the other end of the second cable 3 is coupled to the other end of the charging and discharging device 4. The electric vehicle charger 100 does not include a grid-side charging device 100B as shown in FIG. 1B or a charging pile 100C as shown in FIG. 1C , but instead uses a conventional plug 1 (such as, but not limited to, US or European standard) plugged into a conventional socket 200A to obtain grid power Pac.

[0021] Furthermore, the primary purpose and utility of the present disclosure lies in the ability of the electric vehicle charger 100 of the present disclosure to provide bidirectional charging functionality. That is, through the charging and discharging operations of the electric vehicle charger 100, the grid power Pac provided by the power grid 200 can be used to charge the electric vehicle 300. Furthermore, the vehicle power Pv provided by the electric vehicle 300 can be fed back to the power grid 200. The charging and discharging device 4 includes a charging path Lc and a feeding path Lf. When the grid power Pac is used to charge the electric vehicle 300, the grid power Pac is provided to the electric vehicle 300 via the path of the plug 1, the first cable 2, the charging path Lc of the charging and discharging device 4, the second cable 3, and the connection terminal 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 via the connection terminal 5, the second cable 3, the feeding path Lf of the charging and discharging device 4, the first cable 2, and the plug 1. The plug 1, first cable 2, charging and discharging device 4, second cable 3, and connection end 5 can form an integrated electric vehicle charger 100, or a split electric vehicle charger 100. Specifically, in the split electric vehicle charger 100, the plug 1 and first cable 2 have a modular structure, and the connection between the first cable 2 and the charging and discharging device 4 is a pluggable (replaceable) connection structure. The charging and discharging device 4 can receive specification information Is from the plug 1 via the first cable 2. The specification information Is depends on the type of plug 1 currently connected to the charging and discharging device 4 via the first cable 2. In addition, the charging and discharging device 4 can also transmit current information Ic and operation commands Co to the electric vehicle 300 via the second cable 3. Among them, the charging and discharging device 4 can use the specification information Is to obtain information such as, but not limited to, whether the currently connected plug 1 complies with the relevant specifications of the electric vehicle charger 100, the specifications of the plug 1 (US standard, European standard, etc.), the voltage of the power grid (three-phase / single-phase, 110V / 220V), the upper limit of the current (usually determined by the voltage), frequency, phase, etc.

[0022] On the other hand, the electric vehicle 300 and the charging and discharging device 4 can transmit current information Ic to allow the electric vehicle 300 to confirm and set the amount of current that can be drawn, and the operation command Co is mainly used to let the electric vehicle 300 and the charging and discharging device 4 know each other's current operation. For example, but not limited to, the electric vehicle 300 and the charging and discharging device 4 can confirm whether the electric vehicle 300 is correctly coupled to the charging and discharging device 4 and whether the plug 1 is correctly plugged into the socket 200A through the operation command Co to determine whether it is in the standby state. In addition, through the transmission of the operation command Co, the charging and discharging device 4 can also determine which mode the electric vehicle 300 intends to operate in (for example, but not limited to, charging mode or feeding mode) to selectively provide the corresponding path (i.e., charging mode provides charging path Lc, and feeding mode provides feeding path Lf) to perform the corresponding operation.

[0023] When the plug 1 is plugged 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 operation in the charging mode, the charging and discharging device 4 first confirms whether the electric vehicle 300 is correctly coupled to the connection terminal 5 and whether the plug 1 is correctly plugged 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 that the current state is the standby state based on the instruction of the operation command Co. Then, the value of the operation command Co can be adjusted according to the needs of the electric vehicle 300, and the charging and discharging device 4 can determine whether the electric vehicle 300 is to operate in the charging mode or the feeding mode based on the value of the operation command Co.

[0024] The charging path Lc is connected in parallel with the feeding path Lf, and the charging path Lc and the feeding path Lf are different (independent) and have opposite currents. In charging mode, the charging and discharging device 4 forms the charging path Lc and disconnects the feeding path Lf to prevent the current on the charging path Lc from flowing into the feeding path Lf and causing additional power consumption. Conversely, in feeding mode, the charging and discharging device 4 disconnects the charging path Lc and forms the feeding path Lf to convert the vehicle power Pv into the grid power Pac via the feeding path Lf. When the feeding path Lf converts the vehicle power Pv into the grid power Pac, the feeding path Lf can convert three-phase or single-phase vehicle power Pv into three-phase or single-phase grid power Pac. For example, but not limited to, the feeding path Lf can convert three-phase vehicle power Pv into single-phase grid power Pac, or convert single-phase vehicle power Pv into three-phase grid power Pac. In this way, adaptive power conversion can be performed according to the needs of the power grid 200 and the electric vehicle 300, avoiding the situation where the power grid 200 and the electric vehicle 300 are unusable due to the wiring difference between the two.

[0025] The operation command Co is preferably a voltage value, and the current operating state of the charge-discharge device 4 is set by adjusting the voltage value. For example, when the electric vehicle 300 is not properly coupled to the connection terminal 5, or the plug 1 is not properly plugged 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 based on this specific value that the charge-discharge device 4 has not entered the standby state. Conversely, if it is a value (such as but not limited to 5V), it can be known that the charge-discharge device 4 has entered the standby state.

[0026] Furthermore, when the electric vehicle 300 wishes to operate in either charging mode or feeding mode, the electric vehicle 300 can adjust the value of the operation command Co to set the mode. For example, when the general charging and discharging device 4 has entered the standby state (as in the above example, the value of the operation command Co is 5V), the standby state is preset to the charging mode. Conversely, after the charging and discharging device 4 has entered the standby state, the electric vehicle 300 can adjust 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) to inform the charging and discharging device 4 that it needs to operate in the feeding mode. The operation command Co is not limited to a voltage value. For example, but not limited to, the operation command Co can also be a digital signal (for example, but not limited to, logic 011 corresponding to feeding mode) or a pulse width modulated signal (PWM), and the operation mode is adjusted by the duty cycle (for example, but not limited to, a duty cycle of 50% corresponding to feeding mode), and so on, and the details are not further described here.

[0027] Taking the charging mode as an example, when the charging and discharging device 4 is coupled to the plug 1 via the first cable 2, the charging and discharging device 4 receives the plug 1 specification information Is through the first cable 2 to determine the upper limit 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 generally varies depending on the voltage of the power grid and the capacity of the plug 1). The charging and discharging device 4 then adjusts the current information Ic based on the upper limit of the charging current. The current information Ic corresponds to the first current I1 that can flow through the charging path Lc (generally preset to the upper limit of the current). When the charging and discharging device 4 is coupled to the electric vehicle 300 via the second cable 3, the charging and discharging device 4 communicates the current information Ic to the electric vehicle 300, notifying it of the current upper limit that can flow through the charging path Lc. The electric vehicle 300 then adjusts the current information Ic to determine the final first charging current I1 (for example, but not limited to, after the charging and discharging device 4 notifies the electric vehicle 300 of the upper limit of 18A, the electric vehicle 300 ultimately selects 15A for charging). Finally, the charge and discharge device 4 sets the first current I1 that can flow through the charging path Lc according to the adjusted current information Ic.

[0028] The current information Ic can preferably be a pulse width modulation signal (PWM), and the magnitude of the first current I1 can be 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 18A), but is not limited to this. For example, but not limited to, the current information Ic can also be a digital signal (for example, but not limited to, logic 011 corresponds to a first current I1 of 18A), or a voltage value (for example, but not limited to, a voltage of 5V corresponds to a first current I1 of 18A) to indicate the magnitude of the first current I1, and so on, which will not be repeated here. Finally, after the operating mode and the first current I1 are determined, the charging and discharging device 4 provides a corresponding charging path Lc to perform charging operations to charge the electric vehicle 300 according to the first current I1. On the other hand, after the operation command Co instructs the charging and discharging device 4 to enter the standby state, the charging and discharging device 4 can set the second current I2 that can flow through the feeding path Lf based on the current information Ic. After the operation mode and the second current I2 are determined, the charging and discharging device 4 provides the corresponding feeding path Lf to perform the feeding operation, thereby feeding power to the power grid 200 according to the second current I2. Other than this, the operations of the remaining feeding modes are similar to those of the charging mode described above and will not be further described here.

[0029] Please refer to FIG3 for a more detailed circuit block diagram of the portable electric vehicle charger disclosed herein, and refer to FIG2 in conjunction therewith. FIG3 only shows a preferred embodiment of the architecture of FIG2 , but is not limited thereto. In FIG3 , the charging and discharging 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 couples the first cable 2 and the second cable 3, and provides a charging path Lc for transmitting the grid power Pac from the plug 1 to the connection terminal 5. The feeding circuit 44 couples the first cable 2 and the second cable 3, and provides a feeding path Lf for transmitting the vehicle power Pv from the electric vehicle 300 to the plug 1 via the connection terminal 5. The controller 46 couples 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 may preferably include a thermistor NTC and a detection resistor R (Recognize Resistance).

[0030] The protection pin is coupled to a thermistor NTC via a first cable 2 to determine whether to initiate over-temperature protection of the charging and discharging device 4 based on changes in the NTC's resistance. The identification pin is coupled to a detection resistor R via a first cable 2 to enable the controller 46 to obtain specification information Is through the detection resistor R. Therefore, if the plug 1 uses the detection resistor R, the identification pin can, for example but not limited to, provide a constant current source to generate a specific voltage across the detection resistor R, and this specific voltage serves as the specification information Is. The control guide pin CP is coupled to the electric vehicle 300 via a second cable 3. The control guide pin CP and the electric vehicle 300 transmit current information Ic to each other, allowing the controller 46 and the electric vehicle 300 to set and adjust a first current I1 flowing through the charging path Lc based on the current information Ic and charge the electric vehicle 300 based on the first current I1, or to set and adjust a second current I2 flowing through the feeding path Lf based on the current information Ic and feed power to the grid 200 based on the second current I2. The connecting guide pin PP is coupled to the electric vehicle 300 via the second cable 3 , and the connecting guide pin PP and the electric vehicle 300 transmit an operation command Co to each other, so that the controller 46 and the electric vehicle 300 determine the current operation status according to the operation command Co.

[0031] It is worth mentioning that in one 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, the controller 46 shown in Figure 3 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 circuits and circuit elements not shown are not the main features of the present disclosure, they will not be described in detail here. On the other hand, the controller may also have a wireless communication function, such as but not limited to Wifi, Bluetooth, mobile communications (such as: 2 / 3 / 4 / 5G, etc.), so that the portable electric vehicle charger can communicate with the outside world.

[0032] 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 on / 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 be turned on, so that the charging circuit 42 is formed and provides a charging path Lc. On the contrary, when the controller 46 controls the first switching switch SW1 to be turned off (for example, but not limited to the standby state or feeding mode, etc.), the two ends of the charging circuit 42 are disconnected to prevent the current from being mistakenly provided from the power grid 200 to the electric vehicle 300. The first switching switch SW1 is preferably a switch such as a relay that can allow large current to flow through, and provides the effect of no leakage current when it is turned off and simple configuration.

[0033] The charging and discharging device 4 further includes an auxiliary circuit 48 coupled to the path between the first switch SW1 and the first cable 2. Regardless of whether the charging and discharging device 4 is operating in standby mode, charging mode, or discharging mode, the auxiliary circuit 48 converts grid power Pac into operating power Pcc, thereby continuously powering the controller 46 after the plug 1 is coupled to the grid 200. Generally speaking, the controller 46 is a device that receives direct current (DC), so the auxiliary circuit 48 may be a converter that converts AC to DC. Preferably, the auxiliary circuit 48 couples the grid power Pac between the first switch SW1 and the first cable 2 via, for example, but not limited to, an isolation transformer, thereby electrically isolating the controller 46 from the main power transmission path.

[0034] On the other hand, the feeding circuit 44 includes a second switch SW2, a conversion circuit 442, and a third switch SW3. One end of the second switch SW2 is coupled to the first cable 2, and the other end of the second switch SW2 is coupled to the conversion circuit 442. One end of the third switch SW3 is coupled to the other end of the conversion circuit 442, and the other end of the third switch SW3 is coupled to the second cable 3. The controller 46 is coupled to the control ends of the second switch SW2 and the third switch SW3 to control the on / off state of the second switch SW2 and the third switch SW3 by providing control signals. In the feeding mode, the controller 46 controls the second switch SW2 and the third switch SW3 to be conductive and activates the conversion circuit 442 to form the feeding path Lf. Therefore, the load power Pv can be provided to the conversion circuit 442 via the third switch SW3. The conversion circuit 442 converts the load power Pv into grid power Pac, which is then provided to the plug 1 via the second switch SW2. The three-phase or single-phase vehicle power Pv can be converted into the three-phase or single-phase grid power Pac. When the controller 46 controls the second switch SW2 and the third switch SW3 to be turned off and the conversion circuit 442 is disabled (for example, but not limited to, in standby mode or charging mode), the two terminals of the feed circuit 44 are disconnected to prevent the electric vehicle 300 from incorrectly supplying current to the grid 200.

[0035] Furthermore, the conversion circuit 442 preferably includes an AC / DC conversion circuit, a DC / AC conversion circuit, and an energy storage capacitor (not shown). One end of the AC / DC conversion circuit is coupled to the third switch SW3, and the other end is coupled to the energy storage capacitor (not shown). One end of the DC / AC conversion circuit is coupled to the energy storage capacitor (not shown), and the other end is coupled to the second switch SW2. The controller 46 controls the AC / DC conversion circuit to convert the vehicle power Pv into DC power Pdc, so as to store the DC power Pdc in the energy storage capacitor (not shown). Then, the controller 46 controls the DC / AC conversion circuit to convert the DC power Pdc into grid power Pac, so as to feed power to the grid 200.

[0036] Since the conversion circuit 442 includes an energy storage capacitor (not shown), the conversion circuit 442 can perform arbitrary conversion between three-phase and 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 can then convert the DC power Pdc into a single-phase grid power Pac. Alternatively, the AC / DC conversion circuit can convert the single-phase vehicle power Pv into DC power Pdc, and the DC / AC conversion circuit can then convert the DC power Pdc into a three-phase grid power Pac. In this way, adaptive power conversion can be performed in response to the needs of the grid 200 and the electric vehicle 300, avoiding the situation where the two cannot be used due to wiring differences. It is worth mentioning that in one embodiment, the AC / DC conversion circuit and the DC / AC conversion circuit can be conversion circuits without isolation transformers (for example, but not limited to, Buck, Boost, etc., which do not have isolation transformers at the input and output ends). This is because the voltage and current at both ends of the conversion circuit 442 are similar, thus eliminating the need for a bulky isolation transformer. Furthermore, the AC / DC converter circuit and the DC / AC converter circuit may not include a storage capacitor and its DC link (e.g., but not limited to, a current source or matrix AC / AC converter) to save space on the storage capacitor.

[0037] Please refer to FIG4A for a schematic diagram of the current direction of the charging mode of the portable electric vehicle charger disclosed herein, and refer to FIG2 to FIG3 in conjunction. FIG4A shows the current direction of the charging mode, and the arrow direction A1 represents the flow direction of the first current I1. Specifically, when the plug 1 is plugged into the socket 200A, the auxiliary circuit 48 receives the grid power Pac and converts the grid power Pac into working power Pcc to power the controller 46. When the controller 46 is powered and operates normally, the controller 46 can receive the specification information Is of the plug 1 through the first cable 2 to know 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 vary according to the voltage of the grid and the capacity of the plug 1).

[0038] When the controller 46 confirms that the electric vehicle 300 is correctly coupled to the connection terminal 5 and the plug 1 is correctly plugged 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 the standby state. After the standby state, the controller 46 determines whether the electric vehicle 300 is to operate in the charging mode or the feeding mode based on 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 size of the first current I1 is also set (by transmitting the current information Ic to and from the electric vehicle 300), the controller 46 turns on the first switching switch SW1 so that the charging circuit 42 forms a charging path.

[0039] Please refer to FIG4B for a schematic diagram of the current direction of the feeding mode of the portable electric vehicle charger disclosed herein, and refer to FIG2 to FIG4A in conjunction. FIG4B shows the current direction of the feeding mode, and the arrow direction A2 represents the flow direction of the second current I2. The difference between FIG4A and FIG4B is that when the controller 46 determines that the operating mode is the feeding mode and the magnitude of the second current I2 is also set (by transmitting current information Ic to and from 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 feeding path Lf. It is worth mentioning that, in one embodiment, the operation method not described in FIG4B is similar to that in FIG4A and will not be repeated here.

[0040] Please refer to Figure 5 for a more detailed circuit block diagram of the portable electric vehicle charger disclosed herein, and refer to Figures 2 to 4B in conjunction. In addition to the components described in Figures 2 to 4B above, Figure 5 also includes multiple 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, they will not be described in detail. Therefore, the electric vehicle charger 100 disclosed herein still has protection functions such as leakage current, overcurrent, voltage, frequency, and ground detection during the charging and feeding process, ensuring the safety of users, electric vehicles, homes, and the mains. In addition, in Figure 5, the second switch SW2 preferably includes a first switch Q1 and a second switch Q2 connected in series, and the third switch SW3 preferably includes a third switch Q3 and a fourth switch Q4 connected in series. When the controller 46 controls the second switch SW2 to be turned on, the first switch Q1 and the second switch Q2 are turned on, and otherwise they are turned off. The purpose and effect of the second switch SW2 including the first switch Q1 and the second switch Q2 connected in series is that the first switch Q1 and the second switch Q2 can provide a mutual backup circuit breaker effect.

[0041] Specifically, when exiting the power feeding mode, the controller 46 controls the second switch SW2 to turn off. If the second switch SW2 fails and cannot be shut down, the grid power Pac will be incorrectly provided to the conversion circuit 442. Therefore, through the redundancy function of the first switch Q1 and the second switch Q2, if one of the switches fails and cannot be shut down, the remaining switch can still be shut down as a backup, thereby maintaining the normal circuit breakers from the first cable 2 to the conversion circuit 442. Similarly, when the controller 46 controls the third switch SW3 to turn on, the third switch Q3 and the fourth switch Q4 are connected; otherwise, they are turned off. The operation and the effects achieved are similar to those of the second switch SW2 and will not be further described here.

[0042] However, the above description is merely a detailed description and drawings of 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 full 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 similar variations thereof shall be included in the scope of the present disclosure. Any changes or modifications that can be easily conceived by anyone familiar with the art within the field of the present disclosure shall be covered by the patent scope of the following case.

Claims

1. A charging and discharging device, coupled to a power grid via a first cable and a plug, and coupled to an electric vehicle via a second cable and a connection end, the charging and discharging device comprising: a charging circuit coupling the first cable and the second cable and providing a charging path for transmitting grid power from the plug to the connection end; a feeding circuit coupling the first cable and the second cable and providing a feeding path for transmitting the carrier power from the connection end to the plug; and a controller coupled to the charging circuit and the feeding circuit, and transmitting 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 feeding mode according to the operation command; 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 feeding mode, the controller sets a second current that can flow through the feeding path and feeds the power grid according to the second current.

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

3. The charging and discharging device as claimed in claim 1 , wherein the charging circuit comprises: a first switch, one end of which is coupled to the first cable, and the other end of which is coupled to the second cable; In the charging mode, the controller turns on the first switch to form the charging path.

4. The charge-discharge device according to claim 3, further comprising: an auxiliary circuit coupling the first switch and the first cable; In the charging mode or the feeding mode, the auxiliary circuit converts the grid power into working power to supply power to the controller.

5. The charge-discharge device as claimed in claim 1 , wherein the feed circuit comprises: a second switch, one end of which is coupled to the first cable; a conversion circuit, one end of which is coupled to the second switch; and a third 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; In the feeding mode, the controller turns on the second switch and the third switch, and enables the conversion circuit to form the feeding path. 6 . The charging and discharging device as claimed in claim 5 , wherein the second switch comprises a first switch and a second switch connected in series; and the third switch comprises a third switch and a fourth switch connected in series.

7. The charge-discharge device as claimed in claim 5, wherein the conversion circuit comprises: an AC-DC conversion circuit coupled to the third switch; and a DC-AC conversion circuit, coupling the second switch and the AC-DC conversion circuit; The controller controls the AC-DC conversion circuit to convert the vehicle power into DC power, and controls the DC-AC conversion circuit to convert the DC power into the grid power.

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

9. The charging and discharging device as described in 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 feeding mode based on a value of the operation command. 10 . The charging and discharging device of claim 9 , wherein after the standby state, the controller sets the first current that can flow through the charging path according to the current information and turns on a first switch of the charging circuit.

11. The charging and discharging device of claim 9, wherein after the standby state, the controller sets the second current that can flow through the feeding path according to the current information, turns on a second switch and a third switch of the 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 is coupled to the first cable and the second cable, and includes: A charging circuit is coupled to the first cable and the second cable, and provides a charging path for transmitting grid power from the plug to the connection end. The charging circuit includes: a first switch having one end coupled to the first cable and the other end coupled to the second cable; and A feeding circuit is coupled to the first cable and the second cable, and can provide a feeding path for transmitting a carrier power from the connection end to the plug, and the feeding circuit includes: a second switch, one end of which is coupled to the first cable; a conversion circuit, one end of which is coupled to the second switch; and A third switch has one end coupled to the other end of the conversion circuit and the other end coupled to the second cable.

13. The electric vehicle charger as described in claim 12, wherein the charging and discharging device receives specification information of the plug through the first cable, and transmits 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 feeding mode according to the operation command.

14. The electric vehicle charger as claimed in 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 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 feeding path, and feeds power to a power grid according to the second current. 15 . The electric vehicle charger as claimed in claim 12 , wherein the charging path is connected in parallel with the feeding path, and in a charging mode, a controller of the charging and discharging device turns on the first switch, turns off the second switch, the third switch, and disables the conversion circuit. 16 . The electric vehicle charger as claimed in claim 12 , wherein the charging path is connected in parallel with the feeding path, and in a feeding mode, a controller of the charging and discharging device turns off the first switch, and turns on the second switch and the third 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 the single-phase grid power, or converts the single-phase vehicle power into the three-phase grid power.

18. The electric vehicle charger according to claim 14, wherein the plug and the first cable are modular in 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 via the first cable, the charging and discharging device receives the specification information of the plug via the first cable and sets the first current that can flow through the charging path or the second current that can flow through the feeding path based on the specification information.

19. The electric vehicle charger as claimed in claim 14, wherein when the operation command instructs the charging and discharging device to be in a standby state, the charging and discharging device determines whether the electric vehicle is to operate in the charging mode or the 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 charge-discharge device sets the first current that can flow through the charging path based on the current information and forms the charging path, or after the standby state, the charge-discharge device sets the second current that can flow through the feeding path based on the current information and forms the feeding path.

Images