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 electric vehicles 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 source 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 inability to start the bi-directional charging and discharging pile, and the electric vehicle cannot be used as a power source to supply power to other external devices through the bi-directional charging and discharging pile, severely limiting 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 limited 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. The distribution box includes a grid switch, a control unit, a contactor, and a 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, the contactor, and the battery are respectively electrically connected to the control 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 a target device and an electric vehicle. 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 bi-directional charging and discharging pile to the grid. The bi-directional charging and discharging pile starts based on the electric energy provided by the grid and delivers the electric energy provided by the grid to the electric vehicle, or feeds back the electric energy stored in the electric vehicle to the grid, or delivers the electric energy stored in the electric vehicle to the target device. 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 bi-directional charging and discharging pile and the grid, and delivers the electric energy stored in the battery to the bi-directional charging and discharging pile. The bi-directional charging and discharging pile starts based on the electric energy stored in the battery and delivers the electric energy stored in the electric vehicle to the target device. 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 stops delivering the electric energy stored in the battery to the bi-directional charging and discharging pile and controls the contactor to close to connect the bi-directional charging and discharging pile to the grid.

[0006] A second aspect of the present application provides a power distribution system, which includes a grid, a bi-directional 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 bi-directional charging and discharging pile through the distribution box. The bi-directional 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 energized (i.e., in the grid-connected state), the distribution box will connect the bi-directional charging and discharging pile to the power grid. The bi-directional charging and discharging pile is started based on the electric energy provided by the power grid, and the 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 the target device. When the power grid is powered off (i.e., in the off-grid state), the distribution box will cut off the electrical connection between the bi-directional charging and discharging pile and the power grid, and connect the bi-directional charging and discharging pile to the storage battery. The bi-directional charging and discharging pile is started based on the electric energy stored in the storage battery, and the electric energy stored in the electric vehicle is transmitted 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 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 the target device 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. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] In order to more clearly illustrate the related technologies or the technical solutions in the embodiments of the present application, the drawings required for use in the description of the related technologies 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, without creative efforts, other drawings can be obtained based on these drawings.

[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;

[0012] Figure 4 It is the third block diagram of the distribution box provided by the embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0013] 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, where the same or similar reference numerals represent the same or similar elements or elements with 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 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.

[0014] 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. Moreover, 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, severely limiting the discharging function of the bi-directional charging and discharging pile. For this reason, in the embodiments below, the present application proposes a distribution box with an off-grid power supply function and a power distribution system applying the distribution box. 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, thereby 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.

[0015] Figure 1It is a module block diagram of a power distribution system. In some embodiments, the power distribution system includes a power grid 100, a distribution box 200, a bi-directional 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 bi-directional charging and discharging pile 300 through the distribution box 200, and the bi-directional 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 devices such as refrigerators, air conditioners, televisions, and washing machines). Specifically, an auxiliary power supply is provided inside the distribution box 200. When the power grid 100 is powered on, that is, when it is in the grid-connected state, the distribution box 200 will connect the bi-directional charging and discharging pile 300 to the power grid 100. 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, or feeds back the electric energy stored on the electric vehicle 400 to the power grid 100, or delivers the electric energy stored on the electric vehicle 400 to the target device 500. When the power grid 100 is powered off, that is, when it is in the off-grid state, the distribution box 200 will cut off the electrical connection between the bi-directional charging and discharging pile 300 and the power grid 100, and connect the bi-directional charging and discharging pile 300 to the auxiliary power supply. The bi-directional charging and discharging pile 300 starts based on the electric energy provided by the auxiliary power supply, and delivers the electric energy stored on the electric vehicle 400 to the target device 500, thereby realizing 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 distribution box 200 can still supply power to the bi-directional charging and discharging pile 300, that is, the bi-directional charging and discharging pile 300 can still be normally started. In this way, the bi-directional 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 bi-directional 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.

[0016] 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 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, the contactor 230, and the storage battery 240 are respectively electrically connected to the control unit 220. 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, and various 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 of the storage battery 240 or the 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.

[0017] 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 rule (such as reaching a non-zero preset voltage threshold). When the detected voltage conforms to the grid-connected voltage rule, 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 feeds back the electric energy stored in the electric vehicle 400 to the power grid 100, or delivers the electric energy stored in 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 rule (such as the detected voltage is zero, indicating a power outage; or the detected voltage is much less than the preset voltage threshold, indicating under-voltage), 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 deliver the electric energy stored in the storage 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 storage battery 240 and delivers the electric energy stored in 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 rule, the control unit 220 determines to enter the grid-connected state from the off-grid state. Subsequently, the control unit 220 can stop delivering the electric energy stored in the storage battery 240 to the bi-directional charging and discharging pile 300 and 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 feeds back the electric energy stored in the electric vehicle 400 to the power grid 100, or delivers the electric energy stored in the electric vehicle 400 to the target device 500 to supply power to the target device 500.

[0018] As can be seen from the above, the transition between the grid-connected state and the off-grid state is determined by the control unit 220 in the distribution box 200 based on the detected voltage at the voltage detection point 250. When the grid-connected state changes to the off-grid state and vice versa, the control unit 220 can achieve the purpose of powering the bi-directional charging and discharging pile 300 with the electric energy provided by the power grid 100 in the grid-connected state and powering the bi-directional charging and discharging pile 300 with the electric energy stored in the storage battery 240 in the off-grid state by controlling different components such as the grid switch 210 and the contactor 230. This makes the distribution box 200 of the present application have a high level of intelligence and automation. Moreover, when the power grid 100 loses power and enters the off-grid state accordingly, although the power grid 100 cannot power the bi-directional charging and discharging pile 300 to start it, the storage battery 240 in the distribution box 200 can still power the bi-directional charging and discharging pile 300, enabling the bi-directional charging and discharging pile 300 to start normally in the off-grid state. In this way, the bi-directional charging and discharging pile 300 can power the target device 500 based on the electric energy stored in the electric vehicle 400, thus ensuring the discharging function of the bi-directional 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 or Figure 4 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 bi-directional charging and discharging pile 300 and the grid switch 210. The two contactors 230 can form a double insulation between the bi-directional charging and discharging pile 300 and the power grid 100, providing higher safety in the off-grid state.

[0019] As one of the embodiments, Figure 3 is the second module block diagram of the distribution box. The voltage detection point 250 of the present application includes a bi-directional electricity meter 251 and a lightning arrester 252. The contactor 230 is electrically connected to the grid switch 210 through the bi-directional electricity meter 251. One end of the lightning arrester 252 is grounded, and the other end is electrically connected between the bi-directional electricity meter 251 and the grid switch 210. The control unit 220 is electrically connected to the bi-directional electricity meter 251. During actual power distribution, the control unit 220 can obtain the voltage value displayed by the bi-directional electricity meter 251 and match the voltage value displayed by the bi-directional electricity meter 251 with the grid-connected voltage pattern or the off-grid voltage pattern to determine whether it is currently in the grid-connected state or the off-grid state. That is to say, the detected voltage described above is the voltage value displayed by the bi-directional 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.

[0020] 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 260. The load switch 260 is electrically connected between the bi-directional charging and discharging pile 300 and the target device 500, and the load switch 260 is also electrically connected to the control unit 220. During the actual power distribution process, whether in the grid-connected state or the off-grid state, as long as the electric energy stored in the electric vehicle 400 is used to supply power to the target device 500, the control unit 220 will control the load switch 260 to close, so as to connect the bi-directional charging and discharging pile 300 and the target device 500, enabling the bi-directional charging and discharging pile 300 to 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 270. One end of the maintenance switch 270 is electrically connected between the grid switch 210 and the power grid 100, the other end of the maintenance switch 270 is electrically connected between the load switch 260 and the target device 500, and the maintenance switch 270 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 260, that is, when performing line maintenance on the line between the grid switch 210 and the load switch 260, the control unit 220 can control both the grid switch 210 and the load switch 260 to disconnect, and control the maintenance switch 270 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 supply power to 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.

[0021] As one of the embodiments, the working states of the storage battery 240 include the starting state and the shutdown state. The storage battery 240 can only deliver the electric energy stored in itself when in the starting state, while in the shutdown state, the storage battery 240 will stop delivering the electric energy stored in itself. On this basis, during the actual power distribution process, when in the off-grid state, the control unit 220 can control the storage battery 240 to enter the starting state, so that the storage battery 240 delivers the electric energy stored in itself to the control unit 220. Subsequently, the control unit 220 can deliver the electric energy stored in the storage battery 240 to the bi-directional charging and discharging pile 300, enabling the bi-directional charging and discharging pile 300 to start based on the electric energy stored in the storage battery 240. When changing from the off-grid state to the grid-connected state, the control unit 220 can control the storage battery 240 to enter the shutdown state, so that the storage battery 240 stops delivering the electric energy stored in itself to the control unit 220. At the same time, the control unit 220 can control the contactor 230 to close, so as to connect the bi-directional charging and discharging pile 300 and the power grid 100, enabling the bi-directional charging and discharging pile 300 to start based on the electric energy provided by the power grid 100.

[0022] As one of the embodiments, please refer to Figure 3, in addition to the structures listed above, the distribution box 200 further includes a battery switch 280, and the storage battery 240 is electrically connected to the control unit 220 through the battery switch 280. During the actual power distribution process, when in the off-grid state, the control unit 220 can control the battery switch 280 to close, so as to connect the storage battery 240 and the control unit 220, enabling the storage battery 240 to deliver the electric energy stored in itself to the control unit 220. Subsequently, the control unit 220 can deliver the electric energy stored in the storage battery 240 to the bidirectional charging and discharging pile 300, enabling the bidirectional charging and discharging pile 300 to start based on the electric energy stored in the storage battery 240. When changing from the off-grid state to the grid-connected state, the control unit 220 can control the battery switch 280 to open, so as to cut off the electrical connection between the storage battery 240 and the control unit 220, causing the storage battery 240 to stop delivering the electric energy stored in itself to the control unit 220. At the same time, the control unit 220 can control the contactor 230 to close, so as to connect 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 electric energy provided by the power grid 100. It can be found that for the control of whether the storage battery 240 delivers the electric energy stored in itself outward, in the previous embodiment, it was achieved by controlling the working state of the storage battery 240 through the control unit 220, while in this embodiment, it is achieved by controlling the on-off of the battery switch 280 electrically connected to the storage battery 240 through the control unit 220. This is the difference between this embodiment and the previous embodiment.

[0023] As another embodiment, Figure 4It is the third module block diagram of the distribution box. Different from the previous embodiment, the storage battery 240 includes two, namely the first storage battery 241 and the second storage battery 242. The distribution box 200 further includes a monitoring unit 290 and two battery switches 280. The two battery switches 280 are respectively the first battery switch 281 and the second battery switch 282. The first storage battery 241 is electrically connected to the control unit 220 through the first battery switch 281, and the second storage battery 242 is electrically connected to the control unit 220 through the second battery switch 282. The two storage batteries 240 are respectively electrically connected to the monitoring unit 290, and the monitoring unit 290 is electrically connected to the control unit 220. During the actual power distribution process, when in the off-grid state, the monitoring unit 290 can obtain the electrical parameters (such as voltage, current, power, power consumption, etc.) of the two storage batteries 240, and the control unit 220 can control the closing and opening of each battery switch 280 according to the electrical parameters to adjust the storage battery 240 that supplies power to the bidirectional charging and discharging pile 300. Specifically, the control unit 220 can judge whether each storage battery 240 is faulty, out of power or has low power according to the electrical parameters. If the control unit 220 judges according to the electrical parameters that the storage battery 240 currently supplying power to the bidirectional charging and discharging pile 300 is out of power, has low power or is faulty, then the control unit 220 can control the closing and opening of each battery switch 280 to switch another storage battery 240 to supply power to the bidirectional charging and discharging pile 300. Preferably, the control unit 220 can switch another storage battery 240 to supply power to the bidirectional charging and discharging pile 300 before the storage battery 240 currently supplying power to the bidirectional charging and discharging pile 300 runs out of power, that is, when the storage battery 240 currently supplying power to the bidirectional charging and discharging pile 300 has low power, so as to ensure the continuity of power supply to the bidirectional charging and discharging pile 300, which is equivalent to ensuring the continuity of power supply to the target device 500. In addition, it should be noted that the number of the storage batteries 240 and the corresponding battery switches 280 in this embodiment is not limited. In other embodiments, the number of the storage batteries 240 and the corresponding battery switches 280 can be more than two, and can be specifically configured according to actual needs. In addition, it should be noted that for the control of whether the storage battery 240 delivers the electric energy stored in itself, if it is no longer achieved by controlling the on-off of the battery switch 280 electrically connected to the storage battery 240 through the control unit 220, but by controlling the working state of the storage battery 240 through the control unit 220, then the control unit 220 can adjust the storage battery 240 that supplies power to the bidirectional charging and discharging pile 300 by controlling the working state of each storage battery 240.

[0024] Further, both the monitoring unit 290 and the control unit 220 in this embodiment can be communicatively connected to the 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, the monitoring unit 290 can send the electrical parameters of the two storage batteries 240 detected by itself to the electronic terminal 600 in the off-grid state. The electronic terminal 600 can evaluate the health status of each storage battery 240 according to the electrical parameters and display the health status to the user. In this way, the user can clearly understand the health status of each storage battery 240, so as to facilitate the user to replace the storage battery 240 with poor health status in a timely manner. It can be understood that in the off-grid state, it is necessary to supply power to the bidirectional charging and discharging pile 300 based on the electric energy stored in the storage battery 240. Then, in order to ensure the discharging function of the bidirectional charging and discharging pile 300 in the off-grid state, the replacement of the storage battery 240 with poor health status by the user is preferably performed in the grid-connected state; of course, if the health status of each storage battery 240 in the off-grid state is not sufficient to support its power supply to the bidirectional charging and discharging pile 300, then the user can also replace the storage battery 240 in the off-grid state. In addition, it should be noted that regardless of whether the storage battery 240 is replaced in the grid-connected state or in the off-grid state, before replacing the storage battery 240, the user can send a cut-off command to the control unit 220 through the electronic terminal 600. Subsequently, the control unit 220 can respond to the cut-off command to control each battery switch 280 to disconnect, so as to cut off the electrical connection between each storage battery 240 and the control unit 220, thereby ensuring the safety of the user when replacing the storage battery 240.

[0025] 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 flexibly set according to the actual application scenarios on the basis of the above embodiments. 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 judged 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 and the off-grid state changes to the grid-connected state, the control unit 220 can achieve the purpose of powering the bidirectional charging and discharging pile 300 based on the electric energy provided by the power grid 100 in the grid-connected state and powering the bidirectional charging and discharging pile 300 based on the electric energy stored in the storage battery 240 in the off-grid state through different controls on the grid switch 210, the contactor 230, the battery switch 280, etc., which makes the distribution box 200 of the present application have higher intelligence and automation capabilities. Moreover, when the power grid 100 is powered off and enters the off-grid state accordingly, although the power grid 100 cannot power the bidirectional charging and discharging pile 300, the storage battery 240 in the distribution box 200 can still power 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 power 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.

[0026] 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 among 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 term "comprising", "including" or any other corresponding variant is 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 further limitation, 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.

[0027] 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 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 contactor and a battery, wherein the contactor is used to be electrically connected between the bidirectional charging and discharging pile and the grid switch, the grid switch is used to be electrically connected to the grid, a voltage detection point is provided between the contactor and the grid switch, the voltage detection point, the grid switch, the contactor and the battery are electrically connected to the control unit respectively, the control unit is used to be electrically connected to the bidirectional charging and discharging pile, the bidirectional charging and discharging pile is used to be electrically connected to the target device and the electric vehicle, 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 detection voltage of the voltage detection point, and determines whether the detection voltage conforms to the corresponding grid-connected voltage law. When the detection voltage conforms to the grid-connected voltage law, the control unit controls the contactor to close so as to connect the bidirectional charging and discharging pile with the grid. The bidirectional charging and discharging pile is started based on the electric energy provided by the grid, and transmits the electric energy provided by the grid to the electric vehicle, or feeds the electric energy stored in the electric vehicle back to the grid, or transmits the electric energy stored in the electric vehicle to the target device. In the grid-connected state, when the control unit determines that the detection voltage meets the preset off-grid voltage law, it is determined that the grid-connected state enters the off-grid state, and the control unit controls the contactor to disconnect to cut off the electrical connection between the bidirectional charging and discharging pile and the power grid, and transmits the electric energy stored in the battery to the bidirectional charging and discharging pile, and the bidirectional charging and discharging pile is started based on the electric energy stored in the battery, and transmits the electric energy stored in the electric vehicle to the target device; In the off-grid state, when the control unit determines that the detection voltage conforms to the grid-connected voltage law, it determines that the off-grid state enters the grid-connected state, and the control unit stops transmitting the electric energy stored in the battery to the bidirectional charging and discharging pile, and controls the contactor to close to connect the bidirectional charging and discharging pile with the grid.

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

3. The distribution box according to claim 1, characterized in that: It also includes a load switch, which is used to electrically connect between the bidirectional 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 target device is powered based on the electric energy stored in the electric vehicle, the control unit controls the load switch to close to connect the bidirectional charging and discharging pile and the target device.

4. The distribution box according to claim 3, characterized in that: It also includes a maintenance switch, one end of which 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 performed between the grid switch and the load switch, the control unit controls the grid switch and the load switch to be disconnected, and controls the maintenance switch to be closed, so that the target device is connected to the grid, so as to use the electric energy provided by the grid to power the target device.

5. The distribution box according to claim 1, characterized in that: The working state of the battery includes a start-up state and a stop state; in the off-grid state, the control unit controls the battery to enter the start-up state, and the battery transmits its own stored electric energy to the control unit, and the control unit transmits the electric energy stored in the battery to the bidirectional charging and discharging pile; when entering the grid-connected state from the off-grid state, the control unit controls the battery to enter the stop state, and the battery stops transmitting its own stored electric energy to the control unit.

6. The distribution box according to claim 1, characterized in that: It also includes a battery switch, and the battery is electrically connected to the control unit through the battery switch; in the off-grid state, the control unit controls the battery switch to close to connect the battery and the control unit, and the battery transmits its own stored electric energy to the control unit, and the control unit transmits the electric energy stored in the battery to the bidirectional charging and discharging pile, and the bidirectional charging and discharging pile is started based on the electric energy stored in the battery; when entering the grid-connected state from the off-grid state, the control unit controls the battery switch to open to disconnect the electrical connection between the control unit and the battery, so that the battery stops transmitting its own stored electric energy to the control unit.

7. The distribution box according to claim 1, characterized in that: The storage battery includes two, namely a first storage battery and a second storage battery. The distribution box also includes a monitoring unit and two battery switches. The two battery switches are respectively a first battery switch and a second battery switch. The first storage battery is electrically connected to the control unit through the first battery switch, and the second storage battery is electrically connected to the control unit through the second battery switch. The two storage batteries are electrically connected to the monitoring unit respectively, and the monitoring unit is electrically connected to the control unit; In the off-grid state, the monitoring unit obtains electrical parameters of the two batteries, and the control unit regulates the closing and opening of each battery switch according to the electrical parameters to adjust the battery that supplies power to the bidirectional charging and discharging pile.

8. The distribution box according to claim 7, characterized in that: It also includes an electronic terminal, which is held by a user and is communicatively connected to the monitoring unit for receiving the electrical parameters sent by the monitoring unit, evaluating the health status of each battery based on the electrical parameters, and displaying the health status to the user.

9. The distribution box according to claim 1, characterized in that: The contactors include two, 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 comprises a power grid, a bidirectional charging and discharging pile, at least one electric vehicle, at least one target device and a distribution box as described in any one of claims 1 to 9, wherein 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.

Images