Distribution box with off-grid power supply function and distribution system

Abstract

The utility model provides a power distribution box with an off-grid power supply function and a power distribution system, and relates to the technical field of V2X. The storage battery is arranged in the power distribution box, when the power grid is powered on (in a grid-connected state), the power distribution box connects the bidirectional charging and discharging pile with the power grid, and the bidirectional charging and discharging pile is started based on electric energy provided by the power grid; electric energy provided by the power grid is transmitted to the electric vehicle, or the electric energy stored in the electric vehicle is fed back to the power grid, or the electric energy stored in the electric vehicle is transmitted to target equipment; when the power grid is powered off (in an off-grid state), the distribution box cuts off the electrical connection between the bidirectional charging and discharging pile and the power grid and connects the bidirectional charging and discharging pile and the storage battery, and the bidirectional charging and discharging pile is started based on the electric energy stored in the storage battery and transmits the electric energy stored in the electric vehicle to target equipment. Therefore, the power supply for the target equipment in the off-grid state is realized. Therefore, the discharging function of the bidirectional charging and discharging pile in the off-grid state can be ensured.

Description

Technical Field

[0001] The present application relates to the technical field of V2X (vehicle to X, two-way energy flow between an electric vehicle and X), and particularly relates to a distribution box and a power distribution system with an off-grid power supply function. Background Art

[0002] V2X means two-way energy flow between an electric vehicle and X. X can be either an energy source or an electrical load, and the two-way flowing energy can be either alternating current or direct current. Taking a power distribution system composed of a power grid, a distribution box, a bi-directional charging and discharging pile, an electric vehicle, etc. as an example, V2X can not only use the bi-directional charging and discharging pile to deliver the electric energy of the power grid to the electric vehicle, but also feedback the electric energy stored in the electric vehicle to the power grid through the bi-directional charging and discharging pile. Even the electric vehicle can be used as a power supply and supply power to other external devices through the bi-directional charging and discharging pile, thus realizing two-way energy flow.

[0003] In the related art, in the grid-connected state, the distribution box can cooperate with the bi-directional charging and discharging pile for two-way charging / discharging. However, when the power grid is powered off, that is, when entering the off-grid state, the distribution box cannot supply power to the bi-directional charging and discharging pile, resulting in the bi-directional charging and discharging pile being unable to start, and the electric vehicle cannot be used as a power supply and supply power to other external devices through the bi-directional charging and discharging pile, seriously restricting the discharging function of the bi-directional charging and discharging pile. Summary of the Utility Model

[0004] The present application provides a distribution box and a power distribution system with an off-grid power supply function, aiming to solve the problem that the discharging function of the bi-directional charging and discharging pile is severely restricted in the off-grid state in the related art.

[0005] To solve the above technical problems existing in the related art, a first aspect of the present application provides a distribution box with an off-grid power supply function, including a grid switch, a control unit, a switch unit, a contactor, and a battery. The contactor is used for electrically connecting between a bidirectional charging and discharging pile and the grid switch. The grid switch is used for electrically connecting to the grid. A voltage detection point is arranged between the contactor and the grid switch. The voltage detection point, the grid switch, and the contactor are respectively electrically connected to the control unit. The battery is electrically connected to the control unit through the switch unit. The control unit is used for electrically connecting to the bidirectional charging and discharging pile, and the bidirectional charging and discharging pile is used for electrically connecting to an electric vehicle and a target device. Specifically, in the grid-connected state, the control unit controls the grid switch to close, so that the grid is connected to the voltage detection point. The control unit obtains the detected voltage of the voltage detection point and determines whether the detected voltage conforms to the corresponding grid-connected voltage rule. When the detected voltage conforms to the grid-connected voltage rule, the control unit controls the contactor to close to connect the bidirectional charging and discharging pile to the grid, so that the bidirectional charging and discharging pile starts based on the electric energy provided by the grid; in the grid-connected state, when the control unit determines that the detected voltage conforms to the preset off-grid voltage rule, it is determined to enter the off-grid state from the grid-connected state. The control unit controls the contactor to disconnect to cut off the electrical connection between the bidirectional charging and discharging pile and the grid, and outputs a first prompt message about the off-grid state to the user. The switch unit connects the battery and the control unit under the user's operation. The control unit delivers the electric energy stored in the battery to the bidirectional charging and discharging pile, and the bidirectional charging and discharging pile starts based on the electric energy stored in the battery; in the off-grid state, when the control unit determines that the detected voltage conforms to the grid-connected voltage rule, it is determined to enter the grid-connected state from the off-grid state. The control unit outputs a second prompt message about the grid-connected state to the user. The switch unit cuts off the electrical connection between the battery and the control unit under the user's operation, so that the control unit stops delivering the electric energy stored in the battery to the bidirectional charging and discharging pile. And after cutting off the electrical connection between the battery and the control unit, the control unit controls the contactor to close to connect the bidirectional charging and discharging pile to the grid, so that the bidirectional charging and discharging pile starts based on the electric energy provided by the grid.

[0006] A second aspect of the present application provides a power distribution system, which includes a grid, a bidirectional charging and discharging pile, at least one electric vehicle, at least one target device, and the distribution box mentioned in the first aspect of the present application. The grid is electrically connected to the bidirectional charging and discharging pile through the distribution box, and the bidirectional charging and discharging pile is electrically connected to at least one electric vehicle and at least one target device.

[0007] Through the implementation of the above technical solutions of the present application, a storage battery is provided inside the distribution box. When the power grid is powered on (in the grid-connected state), the distribution box will connect the bidirectional charging and discharging pile to the power grid, enabling the bidirectional charging and discharging pile to start based on the electric energy provided by the power grid. At this time, the bidirectional charging and discharging pile can transmit the electric energy provided by the power grid to the electric vehicle, or feedback the electric energy stored in the electric vehicle to the power grid, or transmit the electric energy stored in the electric vehicle to the target device. When the power grid is powered off (in the off-grid state), the distribution box will cut off the electrical connection between the bidirectional charging and discharging pile and the power grid, and connect the bidirectional charging and discharging pile to the storage battery, enabling the bidirectional charging and discharging pile to start based on the electric energy stored in the storage battery. At this time, the bidirectional charging and discharging pile can transmit the electric energy stored in the electric vehicle to the target device, thereby realizing power supply to the target device in the off-grid state. It can be seen that when the power grid is powered off and enters the off-grid state accordingly, the distribution box can still supply power to the bidirectional charging and discharging pile, that is, the bidirectional charging and discharging pile can still be normally started. In this way, the electric vehicle can be used as a power supply and supply power to the target device through the bidirectional charging and discharging pile, thus ensuring the discharging function of the bidirectional charging and discharging pile in the off-grid state. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] In order to more clearly illustrate the related art or the technical solutions in the embodiments of the present application, the drawings required for the description of the related art or the embodiments of the present application will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, rather than all embodiments. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0009] Figure 1 It is a block diagram of the power distribution system provided by the embodiment of the present application;

[0010] Figure 2 It is the first block diagram of the distribution box provided by the embodiment of the present application;

[0011] Figure 3 It is the second block diagram of the distribution box provided by the embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0012] In order to make the objectives, technical solutions and advantages of the present application more obvious and understandable, the present application will be clearly and completely described below in conjunction with the embodiments of the present application and the corresponding drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions from beginning to end. It should be understood that the various embodiments of the present application described below are only used to explain the present application and are not used to limit the present application. That is, based on the various embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present application. In addition, the technical features involved in the various embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0013] In the related art, in the grid-connected state, the distribution box can cooperate with the bi-directional charging and discharging pile for bi-directional charging / discharging. However, when the power grid is powered off, the distribution box cannot supply power to the bi-directional charging and discharging pile, resulting in the inability to start the bi-directional charging and discharging pile, and the electric vehicle cannot be used as a power source and supply power to other external devices through the bi-directional charging and discharging pile, seriously restricting the discharging function of the bi-directional charging and discharging pile. For this reason, the present application proposes a distribution box with off-grid power supply function and a power distribution system applying the distribution box in the embodiments below. In this power distribution system, when the power grid is powered off and enters the off-grid state accordingly, the distribution box can still supply power to the bi-directional charging and discharging pile, that is, the bi-directional charging and discharging pile can still be normally started. In this way, the electric vehicle can be used as a power source and supply power to other external devices through the bi-directional charging and discharging pile, thus ensuring the discharging function of the bi-directional charging and discharging pile in the off-grid state, and the electric energy stored in the electric vehicle can also be better utilized in the off-grid state.

[0014] Figure 1It is a block diagram of a power distribution system. In some embodiments, the power distribution system includes a power grid 100, a power distribution box 200, a bidirectional charging and discharging pile 300, one or more electric vehicles 400, and one or more target devices 500. The power grid 100 is electrically connected to the bidirectional charging and discharging pile 300 through the power distribution box 200, and the bidirectional charging and discharging pile 300 is electrically connected to the electric vehicle 400 and the target device 500 (which may include, but is not limited to, household appliances such as refrigerators, air conditioners, televisions, and washing machines). Specifically, an auxiliary power supply is provided inside the power distribution box 200. When the power grid 100 is powered on, that is, in the grid-connected state, the power distribution box 200 will connect the bidirectional charging and discharging pile 300 to the power grid 100. The bidirectional charging and discharging pile 300 is started based on the electric energy provided by the power grid 100, and the electric energy provided by the power grid 100 is transmitted to the electric vehicle 400, or the electric energy stored on the electric vehicle 400 is fed back to the power grid 100, or the electric energy stored on the electric vehicle 400 is transmitted to the target device 500. When the power grid 100 is powered off, that is, in the off-grid state, the power distribution box 200 will cut off the electrical connection between the bidirectional charging and discharging pile 300 and the power grid 100, and connect the bidirectional charging and discharging pile 300 to the auxiliary power supply. The bidirectional charging and discharging pile 300 is started based on the electric energy provided by the auxiliary power supply, and the electric energy stored on the electric vehicle 400 is transmitted to the target device 500, so as to realize power supply to the target device 500 in the off-grid state. It can be seen that in the power distribution system of the present application, when the power grid 100 is powered off and enters the off-grid state accordingly, the power distribution box 200 can still supply power to the bidirectional charging and discharging pile 300, that is, the bidirectional charging and discharging pile 300 can still be normally started. In this way, the bidirectional charging and discharging pile 300 can supply power to the target device 500 based on the electric energy stored on the electric vehicle 400, thus ensuring the discharging function of the bidirectional charging and discharging pile 300 in the off-grid state and enabling the electric energy stored on the electric vehicle 400 to be fully utilized in the off-grid state.

[0015] Figure 2It is the first modular block diagram of the distribution box. In some embodiments, the distribution box 200 includes a grid switch 210, a control unit 220, a switch unit 260, a contactor 230, and a storage battery 240 (i.e., the auxiliary power supply described above). The grid switch 210 is electrically connected to the power grid 100. The contactor 230 is electrically connected between the bidirectional charging and discharging pile 300 and the grid switch 210. A voltage detection point 250 is provided between the contactor 230 and the grid switch 210. The voltage detection point 250, the grid switch 210, and the contactor 230 are respectively electrically connected to the control unit 220. The storage battery 240 is electrically connected to the control unit 220 through the switch unit 260. The control unit 220 is electrically connected to the bidirectional charging and discharging pile 300. The bidirectional charging and discharging pile 300 is electrically connected to the target device 500 and the electric vehicle 400. The control unit 220 is the core of the distribution box 200. All kinds of operations of the distribution box 200 need to be carried out under the control of the control unit 220. In addition, it should be noted that the storage battery 240 can be, but is not limited to, lead-acid batteries, lithium-ion batteries, and nickel-metal hydride batteries; the storage battery 240 is not limited to being presented in a single form, and it can also be replaced by a storage battery pack composed of several storage batteries 240; regardless of the type or form of the storage battery 240 (i.e., a single storage battery 240 or a storage battery pack), it can be selected according to actual needs, and the present application does not make a unique limitation on this.

[0016] In the actual power distribution process, when the power grid 100 is energized, that is, in the grid-connected state, the control unit 220 can control the grid switch 210 to close, so that the power grid 100 is connected to the voltage detection point 250. Subsequently, the control unit 220 can obtain the detected voltage of the voltage detection point 250 and determine whether the detected voltage conforms to the corresponding grid-connected voltage law (for example, reaching a non-zero preset voltage threshold). When the detected voltage conforms to the grid-connected voltage law, the control unit 220 can control the contactor 230 to close to connect the bi-directional charging and discharging pile 300 to the power grid 100. At this time, the bi-directional charging and discharging pile 300 starts based on the electric energy provided by the power grid 100 and delivers the electric energy provided by the power grid 100 to the electric vehicle 400 to charge the electric vehicle 400, or feedback the electric energy stored on the electric vehicle 400 to the power grid 100, or deliver the electric energy stored on the electric vehicle 400 to the target device 500 to supply power to the target device 500. In the grid-connected state, when the control unit 220 determines that the detected voltage conforms to the preset off-grid voltage law (for example, the detected voltage is zero, indicating a power outage; or the detected voltage is much lower than the preset voltage threshold, indicating undervoltage), the control unit 220 determines to enter the off-grid state from the grid-connected state. Subsequently, the control unit 220 can control the contactor 230 to open to cut off the electrical connection between the bi-directional charging and discharging pile 300 and the power grid 100, and at the same time output a first prompt message about the off-grid state to the user. After receiving the first prompt message, the user can operate the switch unit 260 to connect the battery 240 to the control unit 220. Subsequently, the control unit 220 can deliver the electric energy stored in the battery 240 to the bi-directional charging and discharging pile 300, so that the bi-directional charging and discharging pile 300 starts based on the electric energy stored in the battery 240 and delivers the electric energy stored on the electric vehicle 400 to the target device 500 to supply power to the target device 500. In the off-grid state, when the control unit 220 determines that the detected voltage conforms to the grid-connected voltage law, the control unit 220 determines to enter the grid-connected state from the off-grid state. Subsequently, the control unit 220 outputs a second prompt message about the grid-connected state to the user. After receiving the second prompt message, the user can operate the switch unit 260 to cut off the electrical connection between the battery 240 and the control unit 220. In this way, the control unit 220 will stop delivering the electric energy stored in the battery 240 to the bi-directional charging and discharging pile 300. After the user cuts off the electrical connection between the battery 240 and the control unit 220 through the switch unit 260, the control unit 220 can control the contactor 230 to close to connect the bi-directional charging and discharging pile 300 to the power grid 100. At this time, the bi-directional charging and discharging pile 300 starts based on the electric energy provided by the power grid 100 and delivers the electric energy provided by the power grid 100 to the electric vehicle 400 to charge the electric vehicle 400, or feedback the electric energy stored on the electric vehicle 400 to the power grid 100, or deliver the electric energy stored on the electric vehicle 400 to the target device 500 to supply power to the target device 500.

[0017] As can be seen from the above, in the present application, the transition between the grid-connected state and the off-grid state is determined by the control unit 220 in the distribution box 200 according to the detected voltage of the voltage detection point 250. When the grid-connected state changes to the off-grid state or the off-grid state changes to the grid-connected state, the control unit 220 can output corresponding prompt messages (i.e., the first prompt message or the second prompt message) to prompt the user to operate the switch unit 260 to connect the battery 240 and the control unit 220, or to cut off the electrical connection between the battery 240 and the control unit 220. At the same time, the control unit 220 will also control the grid switch 210, the contactor 230, etc. on its own, and finally achieve the purpose of supplying power to the bidirectional charging and discharging pile 300 based on the electric energy provided by the power grid 100 in the grid-connected state and supplying power to the bidirectional charging and discharging pile 300 based on the electric energy stored in the battery 240 in the off-grid state. That is to say, when the power grid 100 is powered off and enters the off-grid state accordingly, although the power grid 100 cannot supply power to the bidirectional charging and discharging pile 300 to start the bidirectional charging and discharging pile 300, the battery 240 in the distribution box 200 can still supply power to the bidirectional charging and discharging pile 300, which enables the bidirectional charging and discharging pile 300 to start normally in the off-grid state. In this way, the bidirectional charging and discharging pile 300 can supply power to the target device 500 based on the electric energy stored in the electric vehicle 400, thus ensuring the discharging function of the bidirectional charging and discharging pile 300 in the off-grid state and enabling the electric energy stored in the electric vehicle 400 to be fully utilized in the off-grid state. In addition, it should be noted that the contactor 230 of the present application can be single or multiple. Taking two contactors 230 as an example, that is, as Figure 3 shown by the first contactor 231 and the second contactor 232, the first contactor 231 and the second contactor 232 are connected in series between the bidirectional charging and discharging pile 300 and the grid switch 210. The two contactors 230 can form double insulation between the bidirectional charging and discharging pile 300 and the power grid 100, and the safety in the off-grid state is higher.

[0018] As one of the embodiments, Figure 3It is the second module block diagram of the distribution box. The voltage detection point 250 of the present application includes a two-way electricity meter 251 and a lightning arrester 252. The contactor 230 is electrically connected to the grid switch 210 through the two-way electricity meter 251. One end of the lightning arrester 252 is grounded, and the other end is electrically connected between the two-way electricity meter 251 and the grid switch 210. The control unit 220 is electrically connected to the two-way electricity meter 251. During the actual power distribution process, the control unit 220 can obtain the voltage value displayed by the two-way electricity meter 251, and match the voltage value displayed by the two-way electricity meter 251 with the grid-connected voltage law or the off-grid voltage law, so as to judge whether it is in the grid-connected state or the off-grid state at present. That is to say, the detected voltage described above is the voltage value displayed by the two-way electricity meter 251. Preferably, the lightning arrester 252 in this embodiment uses a varistor, and the function of lightning protection (also known as surge protection) can be achieved through a single varistor.

[0019] As one of the embodiments, please refer to Figure 3 , in addition to the structures listed above, the distribution box 200 further includes a load switch 270. The load switch 270 is electrically connected between the bidirectional charging and discharging pile 300 and the target device 500, and the load switch 270 is also electrically connected to the control unit 220; during the actual power distribution process, whether it is in the grid-connected state or the off-grid state, as long as the target device 500 is powered by the electric energy stored in the electric vehicle 400, the control unit 220 will control the load switch 270 to close to connect the bidirectional charging and discharging pile 300 and the target device 500, so that the bidirectional charging and discharging pile 300 can deliver the electric energy stored in the electric vehicle 400 to the target device 500. Further, the distribution box 200 further includes a maintenance switch 280. One end of the maintenance switch 280 is electrically connected between the grid switch 210 and the power grid 100, the other end of the maintenance switch 280 is electrically connected between the load switch 270 and the target device 500, and the maintenance switch 280 is also electrically connected to the control unit 220; during the actual power distribution process, when it is necessary to perform line maintenance between the grid switch 210 and the load switch 270, that is, when performing line maintenance between the grid switch 210 and the load switch 270, the control unit 220 can control both the grid switch 210 and the load switch 270 to be disconnected, and control the maintenance switch 280 to close, so that the target device 500 is connected to the power grid 100, thereby using the electric energy provided by the power grid 100 to power the target device 500, which not only ensures the normal use of the target device 500 during the line maintenance process, but also improves the safety and convenience during the line maintenance process.

[0020] As one of the embodiments, please refer to Figure 3, the switch unit 260 includes a button 262 and a single-pole single-throw switch 261. The button 262 is disposed on the outer wall of the distribution box 200, and the single-pole single-throw switch 261 is disposed inside the distribution box 200. The control unit 220 is electrically connected to the battery 240 through the single-pole single-throw switch 261, and the button 262 is linked to the handle of the single-pole single-throw switch 261. During the actual power distribution process, when the power grid 100 is powered off and enters the off-grid state accordingly, the user can press the button 262 in response to the first prompt message. During the process of the user pressing the button 262, the button 262 will push the handle of the single-pole single-throw switch 261, ultimately causing the single-pole single-throw switch 261 to close, thereby connecting the battery 240 and the control unit 220, enabling the control unit 220 to deliver the electrical energy stored in the battery 240 to the bidirectional charging and discharging pile 300. At this time, the bidirectional charging and discharging pile 300 starts based on the electrical energy stored in the battery 240 and delivers the electrical energy stored in the electric vehicle 400 to the target device 500, thus realizing the power supply to the target device 500 in the off-grid state. Correspondingly, when entering the grid-connected state from the off-grid state, the user can reset the button 262 in response to the second prompt message. During the process of resetting the button 262, the button 262 will pull the handle of the single-pole single-throw switch 261, ultimately causing the single-pole single-throw switch 261 to open, thereby cutting off the electrical connection between the battery 240 and the control unit 220, enabling the control unit 220 to stop delivering the electrical energy stored in the battery 240 to the bidirectional charging and discharging pile 300. Then, the control unit 220 can control the contactor 230 to close, thereby connecting the bidirectional charging and discharging pile 300 and the power grid 100, enabling the bidirectional charging and discharging pile 300 to start based on the electrical energy provided by the power grid 100, and then delivering the electrical energy provided by the power grid 100 to the electric vehicle 400 to charge the electric vehicle 400 in the grid-connected state, or feeding back the electrical energy stored in the electric vehicle 400 to the power grid 100, or delivering the electrical energy stored in the electric vehicle 400 to the target device 500 to realize the power supply to the target device 500.

[0021] Furthermore, in addition to the aforementioned structures, the distribution box 200 further includes a monitoring unit 2100 and a timing unit 290. The timing unit 290 is electrically connected to the control unit 220, which is in turn electrically connected to the monitoring unit 2100, which is in turn electrically connected to the target device 500. During actual power distribution, when the power grid 100 loses power and enters an off-grid state, the monitoring unit 2100 can obtain power usage information (e.g., voltage, current, power, etc.) of the target device 500. The control unit 220 can determine whether the target device 500 is operating based on the power usage information and, if it determines that the target device 500 is not operating, control the timing unit 290 to start timing. When the time counted by the timing unit 290 exceeds a preset time duration and the target device 500 is still not operating, the control unit 220 can control the single-pole single-throw switch 261 to open, thereby severing the electrical connection between the battery 240 and the control unit 220. It can be understood that the purpose of closing the single-pole single-throw switch 261 is to connect the battery 240 and the control unit 220, so that the control unit 220 can transmit the electric energy stored in the battery 240 to the bidirectional charging and discharging pile 300. At this time, the bidirectional charging and discharging pile 300 can be started based on the electric energy stored in the battery 240 in an off-grid state, and use the electric energy stored in the electric vehicle 400 to power the target device 500. However, when the target device 500 is not running and the time of not running exceeds the preset time, it means that the user does not need to use the target device 500 temporarily, which also means that it is temporarily not in use. It is necessary to use the electric energy stored in the battery 240 to power the bidirectional charging and discharging pile 300. In this case, the control unit 220 of the present application will control the single-pole single-throw switch 261 to disconnect, thereby cutting off the electrical connection between the battery 240 and the control unit 220, avoiding unnecessary consumption of electric energy in the battery 240. In the process of the control unit 220 controlling the single-pole single-throw switch 261 to disconnect, the handle of the single-pole single-throw switch 261 will push the button 262 to reset. Then, when the user needs to use the target device 500 in an off-grid state, he only needs to press the button 262 again.

[0022] Furthermore, the monitoring unit 2100 of this embodiment is also electrically connected to the storage battery 240, and the control unit 220 can be communicatively connected to an electronic terminal 600 (such as a mobile phone, a tablet computer, a smart wearable device, etc.) held by the user. During the actual power distribution process, when in the off-grid state, the monitoring unit 2100 can obtain the electrical parameters of the storage battery 240 (such as voltage, current, power, power consumption, etc.), and feedback the electrical parameters to the control unit 220. Subsequently, the control unit 220 can send the electrical parameters to the electronic terminal 600. The electronic terminal 600 can evaluate the health status of the storage battery 240 based on the electrical parameters and display the health status to the user. In this way, the user can clearly understand the health status of the storage battery 240. At the same time, the electronic terminal 600 can also judge whether to replace the storage battery 240 according to the health status. When it is judged that the storage battery 240 needs to be replaced, a third prompt message regarding the replacement of the storage battery 240 can be displayed to the user to remind the user to replace the storage battery 240 in time to avoid affecting subsequent use. In addition, the first prompt message regarding the off-grid state and the second prompt message regarding the grid-connected state described above are both sent by the control unit 220 to the electronic terminal 600 to be displayed to the user through the electronic terminal 600. When the user sees the first prompt message on the electronic terminal 600, they will know that they need to press the button 262 to close the single-pole single-throw switch 261 to connect the storage battery 240 and the control unit 220. When the user sees the second prompt message on the electronic terminal 600, they will know that they need to reset the button 262 to open the single-pole single-throw switch 261 to cut off the electrical connection between the storage battery 240 and the control unit 220.

[0023] As one of the embodiments, please refer to Figure 3 , in addition to the structures listed above, the distribution box 200 further includes a charging circuit 2110. The storage battery 240 is electrically connected to the charging circuit 2110, and the charging circuit 2110 is electrically connected between the voltage detection point 250 and the contactor 230. During the actual power distribution process, when in the grid-connected state, the charging circuit 2110 can perform floating charge on the storage battery 240 based on the electric energy provided by the power grid 100, so as to ensure that the storage battery 240 has sufficient electric energy to supply the bidirectional charging and discharging pile 300 in the off-grid state, so that the bidirectional charging and discharging pile 300 can be started in the off-grid state. It can be understood that the charging circuit 2110 performing floating charge on the storage battery 240 based on the electric energy provided by the power grid 100 can ensure that the storage battery 240 has a good health status, thereby extending the service life of the storage battery 240.

[0024] The above embodiments are only the preferred implementations of the present application, and they are not the only limitations on the power distribution system, the distribution box 200, etc.; in this regard, those skilled in the art can make flexible settings based on the above embodiments according to the actual application scenarios. It can be understood that through the implementation of the above embodiments of the present application, the transition between the grid-connected state and the off-grid state is determined by the control unit 220 in the distribution box 200 according to the detected voltage at the voltage detection point 250. When the grid-connected state changes to the off-grid state or the off-grid state changes to the grid-connected state, the control unit 220 can output corresponding prompt messages (i.e., the first prompt message or the second prompt message) to prompt the user to operate the switch unit 260 to connect the battery 240 and the control unit 220, or to cut off the electrical connection between the battery 240 and the control unit 220. At the same time, the control unit 220 will also control the grid switch 210, the contactor 230, etc. by itself, and finally achieve the purpose of supplying power to the bidirectional charging and discharging pile 300 based on the electric energy provided by the power grid 100 in the grid-connected state and supplying power to the bidirectional charging and discharging pile 300 based on the electric energy stored in the battery 240 in the off-grid state. That is to say, when the power grid 100 is powered off and enters the off-grid state accordingly, although the power grid 100 cannot supply power to the bidirectional charging and discharging pile 300 to start the bidirectional charging and discharging pile 300, the battery 240 in the distribution box 200 can still supply power to the bidirectional charging and discharging pile 300, which enables the bidirectional charging and discharging pile 300 to start normally in the off-grid state. In this way, the bidirectional charging and discharging pile 300 can supply power to the target device 500 based on the electric energy stored in the electric vehicle 400, thus ensuring the discharging function of the bidirectional charging and discharging pile 300 in the off-grid state and enabling the electric energy stored in the electric vehicle 400 to be fully utilized in the off-grid state.

[0025] It should be noted that several embodiments shown above in the present application are described in a progressive manner. Each embodiment focuses on the differences from other embodiments, and the same or similar parts between the embodiments can be referred to each other. It should also be noted that in the written description of the present application, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is such an actual relationship or order between these entities or operations. Further, the terms "include", "comprise" or any other corresponding variants are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes these elements, but may also include other elements not explicitly listed, or may also include elements inherent to this process, method, article or device; moreover, without more limitations, the element defined by the statement "including one..." does not exclude the existence of another identical element in the process, method, article or device including the said element.

[0026] In addition, by implementing the several embodiments shown above in the present application, those skilled in the art can implement or use the present application. For the several embodiments shown above in the present application, various modifications thereto will be obvious to those skilled in the art, and the general principles defined in the present application can be implemented in other embodiments not shown without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the several embodiments shown above, but rather to the broadest scope consistent with the principles and novel features disclosed in the present application.

Claims

1. A distribution box with off-grid power supply function, characterized in that, It includes a grid switch, a control unit, a switch unit, a contactor and a storage battery. The contactor is used for electrically connecting between a bi-directional charging and discharging pile and the grid switch. The grid switch is used for electrically connecting to the grid. A voltage detection point is provided between the contactor and the grid switch. The voltage detection point, the grid switch and the contactor are respectively electrically connected to the control unit. The storage battery is electrically connected to the control unit through the switch unit. The control unit is used for electrically connecting to the bi-directional charging and discharging pile. The bi-directional charging and discharging pile is used for electrically connecting to an electric vehicle and a target device. Wherein: In the grid-connected state, the control unit controls the grid switch to close so that the grid is connected to the voltage detection point. The control unit obtains the detected voltage of the voltage detection point and determines whether the detected voltage conforms to the corresponding grid-connected voltage rule. When the detected voltage conforms to the grid-connected voltage rule, the control unit controls the contactor to close to connect the bi-directional charging and discharging pile to the grid, and the bi-directional charging and discharging pile starts based on the electric energy provided by the grid. In the grid-connected state, when the control unit determines that the detected voltage conforms to a preset off-grid voltage rule, it determines to enter the off-grid state from the grid-connected state. The control unit controls the contactor to disconnect to cut off the electrical connection between the bi-directional charging and discharging pile and the grid, and outputs a first prompt message about the off-grid state to the user. The switch unit connects the storage battery and the control unit under the user's operation. The control unit delivers the electric energy stored in the storage battery to the bi-directional charging and discharging pile, and the bi-directional charging and discharging pile starts based on the electric energy stored in the storage battery. In the off-grid state, when the control unit determines that the detected voltage conforms to the grid-connected voltage rule, it determines to enter the grid-connected state from the off-grid state. The control unit outputs a second prompt message about the grid-connected state to the user. The switch unit cuts off the electrical connection between the storage battery and the control unit under the user's operation, so that the control unit stops delivering the electric energy stored in the storage battery to the bi-directional charging and discharging pile. And after cutting off the electrical connection between the storage battery and the control unit, the control unit controls the contactor to close to connect the bi-directional charging and discharging pile to the grid, and the bi-directional charging and discharging pile starts based on the electric energy provided by the grid.

2. The distribution box according to claim 1, characterized in that, The voltage detection point includes a bi-directional electricity meter and a lightning arrester. The contactor is electrically connected to the grid switch through the bi-directional electricity meter. One end of the lightning arrester is grounded, and the other end is electrically connected between the bi-directional electricity meter and the grid switch. The control unit is electrically connected to the bi-directional electricity meter.

3. The distribution box according to claim 1, characterized in that, It further includes a load switch which is used for electrically connecting between the bi-directional charging and discharging pile and the target device, and the load switch is electrically connected to the control unit; in the grid-connected state and the off-grid state, when the bi-directional charging and discharging pile supplies power to the target device by using the electric energy stored in the electric vehicle, the control unit controls the load switch to close so as to connect the bi-directional charging and discharging pile and the target device.

4. The distribution box according to claim 3, characterized in that, It further includes a maintenance switch, one end of the maintenance switch is electrically connected between the grid switch and the grid, and the other end is electrically connected between the load switch and the target device, and the maintenance switch is electrically connected to the control unit; when line maintenance is carried out between the grid switch and the load switch, the control unit controls both the grid switch and the load switch to be disconnected, and controls the maintenance switch to close, so that the target device is connected to the grid to supply power to the target device by using the electric energy provided by the grid.

5. The distribution box according to claim 1, characterized in that, The switch unit includes a button and a single-pole single-throw switch. The button is arranged on the outer wall of the distribution box, the single-pole single-throw switch is arranged inside the distribution box, the control unit is electrically connected to the storage battery through the single-pole single-throw switch, and the button is linked to the handle of the single-pole single-throw switch, where: In the off-grid state, the user presses the button in response to the first prompt message, the button pushes the handle and closes the single-pole single-throw switch to connect the storage battery and the control unit; when changing from the off-grid state to the grid-connected state, the user resets the button in response to the second prompt message, the button pulls the handle and disconnects the single-pole single-throw switch to cut off the electrical connection between the storage battery and the control unit.

6. The distribution box according to claim 5, characterized in that, It further includes a monitoring unit and a timing unit. The timing unit is electrically connected to the control unit, and the control unit is electrically connected to the target device through the monitoring unit, where: In the off-grid state, the monitoring unit obtains the power consumption information of the target device, the control unit judges whether the target device is running according to the power consumption information, and controls the timing unit to start timing when it is judged that the target device is not running. When the time counted by the timing unit is greater than the preset duration and the target device is not running, the single-pole single-throw switch is disconnected under the control of the control unit, and the handle pushes the button to reset.

7. The distribution box according to claim 6, characterized in that, The monitoring unit is electrically connected to the storage battery and is used for obtaining the electrical parameters of the storage battery in the off-grid state and feeding back the electrical parameters to the control unit; the distribution box further includes an electronic terminal held by the user, and the electronic terminal is communicatively connected to the control unit and is used for: Receive the first prompt message or the second prompt message sent by the control unit, and display the first prompt message or the second prompt message to the user; and, receive the electrical parameters sent by the control unit to evaluate the health status of the storage battery according to the electrical parameters, and determine whether to replace the storage battery according to the health status.

8. The distribution box according to claim 1, characterized in that, It further includes a charging circuit, the storage battery is electrically connected to the charging circuit, and the charging circuit is electrically connected between the voltage detection point and the contactor. The charging circuit is used to perform floating charge on the storage battery based on the electric energy provided by the power grid in the grid-connected state.

9. The distribution box according to claim 1, characterized in that There are two contactors, namely a first contactor and a second contactor, and the first contactor and the second contactor are connected in series.

10. A power distribution system, characterized in that, It includes a power grid, a bidirectional charging and discharging pile, at least one electric vehicle, at least one target device, and the distribution box according to any one of claims 1 to 9. The power grid is electrically connected to the bidirectional charging and discharging pile through the distribution box, and the bidirectional charging and discharging pile is electrically connected to at least one of the electric vehicles and at least one of the target devices.

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