Switching circuit and charging pile

Abstract

The embodiment of the utility model relates to the field of new energy, in particular to a switching circuit and a charging pile. The switching circuit comprises an input interface, an output interface, a first switching circuit, a second switching circuit and a controller, the input interface is electrically connected with a first-phase live wire, a second-phase live wire, a third-phase live wire and a zero line, and the output interface is electrically connected with an electric vehicle through a first output end and a second output end. The controller is electrically connected with the first switching circuit and the second switching circuit, and is used for controlling the first switching circuit to switch on or switch off the electrical connection between the first phase live wire or zero wire and the first output end, and controlling the second switching circuit to switch on or switch off the electrical connection between the second phase live wire or third phase live wire and the second output end. According to the embodiment of the invention, any two-phase live wires in the IT power system can be supported to perform two-phase charging on the electric vehicle, load balancing is realized, the total power of the output power of the charging station is improved, and the utilization rate of the commercial power is improved.

Description

Technical Field

[0001] The utility model embodiment relates to the field of new energy technology, and specifically to a switching circuit and a charging pile. Background Art

[0002] A charging pile is a device used to charge electric vehicles to replenish their power. There are three types of charging piles: DC charging piles, AC charging piles, and AC / DC integrated charging piles. DC charging piles are used to provide DC power to electric vehicles, AC charging piles are used to provide AC power to electric vehicles, and AC / DC integrated charging piles are used to provide DC power or AC power to electric vehicles.

[0003] Current AC charging piles are usually powered by three-phase AC power. Since electric vehicles usually support single-phase charging, in the actual charging process, AC charging piles generally use a fixed single-phase power to charge electric vehicles. This will cause the load on this phase to be too heavy, while the loads on the other two phases are lighter, resulting in the total power that the charging station can provide to electric vehicles being limited, thereby reducing the utilization rate of the AC power. Utility Model Content

[0004] One purpose of the embodiments of the utility model is to provide a switching circuit and a charging pile to solve the technical problem of low utility power utilization rate when the current AC charging pile charges electric vehicles.

[0005] In a first aspect, an embodiment of the present application provides a switching circuit, including:

[0006] An input interface, comprising a first input terminal, a second input terminal, a third input terminal and a fourth input terminal, wherein the first input terminal is electrically connected to the first-phase live wire, the second input terminal is electrically connected to the second-phase live wire, the third input terminal is electrically connected to the third-phase live wire, and the fourth input terminal is electrically connected to the neutral wire;

[0007] An output interface, comprising a first output end and a second output end, wherein the first output end and the second output end are electrically connected to the electric vehicle;

[0008] A first switch circuit is electrically connected to the first input terminal, the fourth input terminal and the second output terminal respectively;

[0009] A second switch circuit is electrically connected to the second input terminal, the third input terminal and the first output terminal respectively;

[0010] A controller is electrically connected to the first switch circuit and the second switch circuit, respectively, and is used to control the first switch circuit to turn on or off the electrical connection between the first input terminal or the fourth input terminal and the second output terminal, and to control the second switch circuit to turn on or off the electrical connection between the second input terminal or the third input terminal and the first output terminal.

[0011] Optionally, the first switch circuit includes:

[0012] a first single-pole single-throw relay, electrically connected to the controller, the first input terminal and the second output terminal respectively, and used for being controlled by the controller to switch on or off the electrical connection between the first input terminal and the second output terminal;

[0013] The second single-pole single-throw relay is electrically connected to the controller, the fourth input terminal and the second output terminal respectively, and is used for being controlled by the controller to switch on or off the electrical connection between the fourth input terminal and the second output terminal.

[0014] Optionally, the first switch circuit further includes a first interlock circuit;

[0015] The first interlock circuit is electrically connected to the controller, the first single-pole single-throw relay and the second single-pole single-throw relay respectively, and is used to be controlled by the controller to not turn on the first single-pole single-throw relay and the second single-pole single-throw relay at the same time.

[0016] Optionally, the second switch circuit includes:

[0017] a third single-pole single-throw relay, electrically connected to the controller, the second input terminal and the first output terminal respectively, and used for being controlled by the controller to switch on or off the electrical connection between the second input terminal and the first output terminal;

[0018] A fourth single-pole single-throw relay is electrically connected to the controller, the third input terminal and the first output terminal respectively, and is used to be controlled by the controller to switch on or off the electrical connection between the third input terminal and the first output terminal.

[0019] Optionally, the second switch circuit further includes a second interlock circuit;

[0020] The second interlock circuit is electrically connected to the controller, the third single-pole single-throw relay and the fourth single-pole single-throw relay respectively, and is used to be controlled by the controller to not turn on the third single-pole single-throw relay and the fourth single-pole single-throw relay at the same time.

[0021] Optionally, the switching circuit further includes a third switch circuit;

[0022] The third switch circuit is electrically connected to the controller, the first input terminal and the first output terminal respectively, and is used for being controlled by the controller to switch on or off the electrical connection between the first input terminal and the first output terminal.

[0023] Optionally, the output interface further includes a third output terminal and a fourth output terminal, and the switching circuit further includes a fourth switch circuit;

[0024] The fourth switch circuit is electrically connected to the controller, the second input terminal, the third input terminal, the fourth output terminal and the third output terminal, respectively, and is used to be controlled by the controller to turn on or off the electrical connection between the second input terminal and the third output terminal, and / or the electrical connection between the third input terminal and the fourth output terminal.

[0025] Optionally, the output interface further includes a third output terminal and a fourth output terminal, and the switching circuit further includes a fifth switch circuit;

[0026] The fifth switch circuit is electrically connected to the controller, the first switch circuit, the second switch circuit, the first output end and the second output end, respectively, and is used to be controlled by the controller to turn on or off the electrical connection between the first switch circuit and the second output end, and / or the electrical connection between the second switch circuit and the first output end.

[0027] Optionally, the switching circuit further includes a sampling module;

[0028] The sampling module is electrically connected to the controller, the first input terminal, the second input terminal, the third input terminal, the fourth input terminal, the first output terminal and the second output terminal, respectively, and is used to sample the voltage and phase angle of the first input terminal, the second input terminal, the third input terminal, the fourth input terminal, the first output terminal and the second output terminal.

[0029] In a second aspect, an embodiment of the utility model provides a charging pile, comprising a switching circuit as described in any one of the above items.

[0030] Compared with the prior art, the embodiment of the utility model provides a switching circuit and a charging pile, the switching circuit includes an input interface, an output interface, a first switch circuit, a second switch circuit and a controller, the input interface includes a first input end, a second input end, a third input end and a fourth input end, the first input end is electrically connected to the first phase live wire, the second input end is electrically connected to the second phase live wire, the third input end is electrically connected to the third phase live wire, and the fourth input end is electrically connected to the neutral wire, the output interface includes a first output end and a second output end, the first output end and the second output end are electrically connected to the electric vehicle, the first switch circuit is electrically connected to the first input end, the fourth input end and the second output end respectively, the second switch circuit is electrically connected to the second input end, the third input end and the first output end respectively, the controller is electrically connected to the first switch circuit and the second switch circuit respectively, and is used to control the first switch circuit to turn on or off the electrical connection between the first input end or the fourth input end and the second output end, and to control the second switch circuit to turn on or off the electrical connection between the second input end or the third input end and the first output end. This embodiment can support two-phase charging of electric vehicles using any two-phase live wires in an IT power system, thereby achieving load balancing and increasing the total power provided by the charging station to the electric vehicles, thereby improving the utilization rate of the mains electricity. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the description of the embodiments of the utility model will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0032] Figure 1 A schematic diagram of the structure of a charging system provided by an embodiment of the utility model;

[0033] Figure 2 A schematic diagram of the structure of a switching circuit provided by an embodiment of the utility model;

[0034] Figure 3 A schematic diagram of an application scenario of a switching circuit provided in an embodiment of the utility model;

[0035] Figure 4 A schematic diagram of another application scenario of the switching circuit provided in an embodiment of the utility model;

[0036] Figure 5 A schematic diagram of another application scenario of the switching circuit provided in an embodiment of the utility model;

[0037] Figure 6 A schematic diagram of the structure of a switching circuit provided in another embodiment of the utility model;

[0038] Figure 7 A schematic diagram of another application scenario of the switching circuit provided in an embodiment of the utility model;

[0039] Figure 8 A schematic diagram of another application scenario of the switching circuit provided in an embodiment of the utility model;

[0040] Fig. 9 A schematic diagram of another application scenario of the switching circuit provided in an embodiment of the utility model;

[0041] Fig.10 A schematic diagram of a switching circuit provided in another embodiment of the utility model;

[0042] Fig.11 A schematic diagram of another application scenario of the switching circuit provided in an embodiment of the utility model;

[0043] Fig.12 A schematic diagram of another application scenario of the switching circuit provided in an embodiment of the utility model;

[0044] Fig.13 A schematic diagram of a switching circuit provided in another embodiment of the utility model;

[0045] Fig.14 A schematic diagram of the structure of a first interlocking circuit provided in an embodiment of the utility model;

[0046] Fig.15 A schematic diagram of the structure of a second interlocking circuit provided in an embodiment of the utility model;

[0047] Fig.16 A schematic structural diagram of another first interlocking circuit provided in an embodiment of the utility model. DETAILED DESCRIPTION

[0048] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the utility model and are not used to limit the utility model. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the utility model.

[0049] It should be noted that, if there is no conflict, the various features in the embodiments of the present utility model can be combined with each other, all within the scope of protection of the present utility model. In addition, although the functional modules are divided in the device schematic diagram and the logical order is shown in the flow chart, in some cases, the steps shown or described can be performed in a different order than the module division in the device or the flow chart. Furthermore, the words "first", "second", "third", etc. used in the present utility model do not limit the data and execution order, but only distinguish the same items or similar items with basically the same functions and effects.

[0050] The present utility model provides a charging system. Figure 1 The charging system 100 includes a power grid 10 , a charging pile 20 and an electric vehicle 30 .

[0051] The power grid 10 is a power network that transmits city power to the charging pile 20 through a transmission line to supply power to the electric vehicle 30. The city power is industrial frequency alternating current, and the city power is characterized by three common quantities of alternating current, namely, voltage, current and frequency. Generally, the city power transmitted from the power grid 10 to the charging pile 20 is three-phase alternating current, such as Figure 1 As shown, the power grid 10 and the charging pile 20 are electrically connected through four power lines, and the four power lines are a first phase live line L1, a second phase live line L2, a third phase live line L3 and a neutral line N.

[0052] The charging pile 20 is a device used to charge the electric vehicle 30 to replenish the power of the electric vehicle 30. Its working principle is to receive electric energy from the power grid and then transmit the electric energy to the electric vehicle 30 through the charging line to charge the electric vehicle 30. The charging pile 20 can be any type of charging pile that can support AC charging, such as an AC charging pile, an AC / DC integrated charging pile, etc.

[0053] The AC charging pile is electrically connected to the external power grid and is used to use a single or multiple 220VAC / 380VAC AC output interface to provide power output to the electric vehicle 30, so that the electric vehicle 30 uses the on-board charger to charge the power battery of the electric vehicle 30. This charging method is also called "slow charging". The output power of the AC charging pile is generally 5kW (220VAC) / 20kW (380VAC), but the actual charging power is restricted by the on-board charger. Generally, the on-board charging power of a small electric vehicle 30 is between 2 and 3kW.

[0054] The input voltage of the AC / DC integrated charging pile generally adopts three-phase four-wire 380VAC±15%, frequency 50Hz, and the DC output port outputs adjustable DC power to charge the power battery of the electric vehicle 30. The general charging power is 10~40kW, and the AC output port outputs 220VAC (5kW) / 380VAC (20kW) AC power to provide charging power for the on-board charger of the electric vehicle 30. The AC / DC integrated charging pile can provide conventional charging through the AC output port and fast charging through the DC output port. When there are many charging services during the day, the fast charging method can be used for fast charging. At night, when there are few users at the charging station, the conventional charging method can be used for slow charging. The AC / DC integrated charging pile can realize both AC and DC charging at the same time, and interlocking charging. It adopts modular design for easy maintenance.

[0055] The electric vehicle 30 receives the AC power provided by the charging pile 20 through the on-board charger, filters and rectifies the AC power to obtain DC power, and then stores the DC power in the power battery of the electric vehicle 30, thereby charging the power battery of the electric vehicle 30. The electric vehicle 30 includes any vehicle that can be driven by electricity, including but not limited to pure electric vehicles, hybrid electric vehicles, fuel cell vehicles, etc.

[0056] In some embodiments, the charging pile 20 includes a switching circuit, which is used to select any one or more phases of the three-phase mains power according to actual needs to charge the electric vehicle 30. The switching circuit can support any type of grounding system, such as a TT power system, a TN power system, or an IT power system.

[0057] The grounding system is represented by two letter codes: TN, TT and IT. The first letter indicates the relationship between the power supply terminal and the ground: T means that there is a point directly grounded at the power supply terminal, and I means that all live parts at the power supply terminal are not grounded or one point is grounded through impedance. The second letter indicates the relationship between the exposed conductive part of the electrical device and the ground: T means that the exposed conductive part of the electrical device is directly grounded, and this grounding point is electrically independent of the grounding point at the power supply terminal, and N means that the exposed conductive part of the electrical device is directly electrically connected to the ground at the power supply terminal.

[0058] The TT power system refers to a protective grounding system that directly grounds the metal casing of electrical equipment. The first symbol T indicates that the neutral point of the power system is directly grounded, and the second symbol T indicates that the exposed metal conductive part of the load equipment that is not in contact with the live body is directly connected to the earth, regardless of how the system is grounded.

[0059] The TN power system is usually a three-phase power grid system with a grounded neutral point. Its characteristic is that the exposed conductive parts of the electrical equipment are directly connected to the system grounding point. When a shell short circuit occurs, the short-circuit current forms a closed loop through the metal wire, forming a metallic single-phase short circuit, thereby generating a sufficiently large short-circuit current so that the protection device can operate reliably and cut off the fault. In the TN power system, the exposed conductive parts of all electrical equipment are connected to the protection line and connected to the grounding point of the power supply, which is usually the neutral point of the distribution system. When the fault causes the metal shell of the electrical equipment to be energized, a short circuit is formed between the phase line and the ground line, the loop resistance is small, and the current is large, which can cause the fuse to melt quickly or the protection device to operate to cut off the power supply.

[0060] The IT power system is not directly connected to the earth, and the exposed conductive parts of the electrical device are connected to the grounding electrode through a protective grounding wire. In the IT power system, the live conductors of the electrical device are insulated from the ground or the neutral point of the power supply is grounded through a high impedance, and all exposed conductive parts and conductive parts outside the device are grounded through the grounding electrode of the electrical device. Since the fault current is small when the first fault occurs in the IT power system, the metal casing of the electrical equipment will not generate a dangerous contact voltage, so the power supply does not need to be cut off, the electrical equipment continues to operate, and the fault can be eliminated through the alarm device and inspection. When a second fault occurs in the IT power system, the power supply should be automatically cut off, that is, when a second fault occurs on another phase line or neutral line, the fault must be quickly removed.

[0061] In some embodiments, see Figure 2 The switching circuit 21 includes an input interface 211 , an output interface 212 , a first switch circuit 213 , a second switch circuit 214 and a controller 215 .

[0062] The input interface 211 is electrically connected to the power grid 10 , and includes a first input terminal 2111 , a second input terminal 2112 , a third input terminal 2113 , and a fourth input terminal 2114 .

[0063] The first input terminal 2111 is electrically connected to the first phase live wire L1 of the power grid 10 , the second input terminal 2112 is electrically connected to the second phase live wire L2 of the power grid 10 , the third input terminal 2113 is electrically connected to the third phase live wire L3 of the power grid 10 , and the fourth input terminal 2114 is electrically connected to the neutral line N of the power grid 10 .

[0064] The output interface 212 includes a first output terminal 2121 and a second output terminal 2122 .

[0065] The first output terminal 2121 and the second output terminal 2122 are both electrically connected to the electric vehicle 30 .

[0066] The first switch circuit 213 is electrically connected to the first input terminal 2111, the fourth input terminal 2114 and the second output terminal 2122 respectively. The first input terminal 2111, the first switch circuit 213 and the second output terminal 2122 can form a path, and the fourth input terminal 2114, the first switch circuit 213 and the second output terminal 2122 can form a path, but the two paths are not allowed to be formed at the same time.

[0067] The second switch circuit 214 is electrically connected to the second input terminal 2112, the third input terminal 2113 and the first output terminal 2121 respectively. The second input terminal 2112, the second switch circuit 214 and the first output terminal 2121 can form a path, and the third input terminal 2113, the second switch circuit 214 and the first output terminal 2121 can form a path, but the two paths are not allowed to be formed at the same time.

[0068] The controller 215 is electrically connected to the first switch circuit 213 and the second switch circuit 214 respectively, and is used to control the first switch circuit 213 to turn on or off the electrical connection between the first input terminal 2111 or the fourth input terminal 2114 and the second output terminal 2122, and to control the second switch circuit 214 to turn on or off the electrical connection between the second input terminal 2112 or the third input terminal 2113 and the first output terminal 2121.

[0069] This embodiment can support an IT power system. To support the IT power system, the first input terminal 2111, the second input terminal 2112 or the third input terminal 2113 can be short-circuited with the fourth input terminal 2114. For example, the first input terminal 2111 can be short-circuited with the fourth input terminal 2114, or the second input terminal 2112 can be short-circuited with the fourth input terminal 2114, or the third input terminal 2113 can be short-circuited with the fourth input terminal 2114.

[0070] For example, when the third input terminal 2113 and the fourth input terminal 2114 are short-circuited:

[0071] See also Figure 3 When the controller 215 controls the first switch circuit 213 to conduct the electrical connection between the first input terminal 2111 and the second output terminal 2122 and disconnect the electrical connection between the fourth input terminal 2114 and the second output terminal 2122, and controls the second switch circuit 214 to conduct the electrical connection between the second input terminal 2112 and the first output terminal 2121 and disconnect the electrical connection between the third input terminal 2113 and the first output terminal 2121, two-phase charging of the electric vehicle 30 can be achieved through the first phase live wire L1 and the second phase live wire L2 under the IT power system.

[0072] See also Figure 4When the controller 215 controls the first switch circuit 213 to conduct the electrical connection between the first input terminal 2111 and the second output terminal 2122 and disconnect the electrical connection between the fourth input terminal 2114 and the second output terminal 2122, and controls the second switch circuit 214 to conduct the electrical connection between the third input terminal 2113 and the first output terminal 2121 and disconnect the electrical connection between the second input terminal 2112 and the first output terminal 2121, two-phase charging of the electric vehicle 30 can be achieved through the first phase live wire L1 and the third phase live wire L3 under the IT power system.

[0073] See also Figure 5 When the controller 215 controls the first switch circuit 213 to conduct the electrical connection between the fourth input terminal 2114 and the second output terminal 2122 and disconnect the electrical connection between the first input terminal 2111 and the second output terminal 2122, and controls the second switch circuit 214 to conduct the electrical connection between the second input terminal 2112 and the first output terminal 2121 and disconnect the electrical connection between the third input terminal 2113 and the first output terminal 2121, two-phase charging of the electric vehicle 30 can be achieved through the second phase live wire L2 and the third phase live wire L3 under the IT power system.

[0074] Therefore, this embodiment can support two-phase charging of electric vehicles using any two-phase live wires in an IT power system, thereby achieving load balancing, increasing the total power provided by the charging station to the electric vehicles, and thus improving the utilization rate of the mains electricity.

[0075] In some embodiments, see Figure 6 The switching circuit 21 also includes a third switch circuit 216.

[0076] The third switch circuit 216 is electrically connected to the controller 215 , the first input terminal 2111 , and the first output terminal 2121 , respectively, and is used for being controlled by the controller 215 to switch on or off the electrical connection between the first input terminal 2111 and the first output terminal 2121 .

[0077] For example, when the first input terminal 2111, the second input terminal 2112 or the third input terminal 2113 does not need to be short-circuited with the fourth input terminal 2114:

[0078] See also Figure 7When the controller 215 controls the first switch circuit 213 to conduct the electrical connection between the fourth input terminal 2114 and the second output terminal 2122 and to disconnect the electrical connection between the first input terminal 2111 and the second output terminal 2122, controls the second switch circuit 214 to disconnect the electrical connection between the third input terminal 2113 and the first output terminal 2121 and between the second input terminal 2112 and the first output terminal 2121, and controls the third switch circuit 216 to conduct the electrical connection between the first input terminal 2111 and the first output terminal 2121, single-phase charging of the electric vehicle 30 can be achieved through the first phase live wire L1 under the TT power system / TN power system.

[0079] See also Figure 8 When the controller 215 controls the first switch circuit 213 to conduct the electrical connection between the fourth input terminal 2114 and the second output terminal 2122 and disconnect the electrical connection between the first input terminal 2111 and the second output terminal 2122, controls the second switch circuit 214 to conduct the electrical connection between the second input terminal 2112 and the first output terminal 2121 and disconnect the electrical connection between the third input terminal 2113 and the first output terminal 2121, and controls the third switch circuit 216 to disconnect the electrical connection between the first input terminal 2111 and the first output terminal 2121, single-phase charging of the electric vehicle 30 can be achieved through the second phase live wire L2 under the TT power system / TN power system.

[0080] See also Fig. 9 When the controller 215 controls the first switch circuit 213 to conduct the electrical connection between the fourth input terminal 2114 and the second output terminal 2122 and disconnect the electrical connection between the first input terminal 2111 and the second output terminal 2122, controls the second switch circuit 214 to conduct the electrical connection between the third input terminal 2113 and the first output terminal 2121 and disconnect the electrical connection between the second input terminal 2112 and the first output terminal 2121, and controls the third switch circuit 216 to disconnect the electrical connection between the first input terminal 2111 and the second output terminal 2122, single-phase charging of the electric vehicle 30 can be achieved through the third phase live wire L3 under the TT power system / TN power system.

[0081] This embodiment can support single-phase charging of electric vehicles using any live phase of the TT power system / TN power system, which is beneficial to improving charging flexibility.

[0082] In some embodiments, see Fig.10 The output interface 212 also includes a third output terminal 2123 and a fourth output terminal 2124 .

[0083] The third output terminal 2123 and the fourth output terminal 2124 are both electrically connected to the electric vehicle 30 .

[0084] like Fig.10 As shown, the switching circuit 21 further includes a fourth switch circuit 217 .

[0085] The fourth switch circuit 217 is electrically connected to the controller 215, the second input terminal 2112, the third input terminal 2113, the third output terminal 2123 and the fourth output terminal 2124 respectively, and is used to be controlled by the controller 215 to turn on or off the electrical connection between the second input terminal 2112 and the third output terminal 2123, and / or turn on or off the electrical connection between the third input terminal 2113 and the fourth output terminal 2124.

[0086] For example, when the third input terminal 2113 and the fourth input terminal 2114 are short-circuited:

[0087] See also Fig.11 When the controller 215 controls the first switch circuit 213 to disconnect the electrical connection between the first input terminal 2111 and the second output terminal 2122 and between the fourth input terminal 2114 and the second output terminal 2122, controls the second switch circuit 214 to disconnect the electrical connection between the second input terminal 2112 and the first output terminal 2121 and between the third input terminal 2113 and the first output terminal 2121, controls the third switch circuit 216 to conduct the electrical connection between the first input terminal 2111 and the first output terminal 2121, and controls the fourth switch circuit 217 to conduct the electrical connection between the second input terminal 2112 and the third output terminal 2123 and between the third input terminal 2113 and the fourth output terminal 2124, three-phase charging of the electric vehicle 30 can be achieved through the first phase live wire L1, the second phase live wire L2 and the third phase live wire L3 under the IT power system.

[0088] For another example, when the first input terminal 2111, the second input terminal 2112 or the third input terminal 2113 does not need to be short-circuited with the fourth input terminal 2114:

[0089] See also Fig.12 When the controller 215 controls the first switch circuit 213 to conduct the electrical connection between the fourth input terminal 2114 and the second output terminal 2122 and to disconnect the electrical connection between the first input terminal 2111 and the second output terminal 2122, controls the second switch circuit 214 to disconnect the electrical connection between the second input terminal 2112 and the first output terminal 2121 and the electrical connection between the third input terminal 2113 and the first output terminal 2121, controls the third switch circuit 216 to conduct the electrical connection between the first input terminal 2111 and the first output terminal 2121, and controls the fourth switch circuit 217 to conduct the electrical connection between the second input terminal 2112 and the third output terminal 2123 and between the third input terminal 2113 and the fourth output terminal 2124, the electric vehicle 30 can be charged in three phases through the first phase live wire L1, the second phase live wire L2 and the third phase live wire L3 under the TT power system / TN power system.

[0090] Therefore, this embodiment can not only support three-phase charging of electric vehicles using three-phase live wires under IT power systems, but also support three-phase charging of electric vehicles using three-phase live wires under TT power systems / TN power systems, which is beneficial to further improve charging flexibility.

[0091] In some embodiments, please refer to Fig.10 The switching circuit 21 also includes a fifth switching circuit 218.

[0092] The fifth switch circuit 218 is electrically connected to the controller 215, the first switch circuit 213, the second switch circuit 214, the first output terminal 2121 and the second output terminal 2122, respectively, and is used to be controlled by the controller 215 to turn on or off the electrical connection between the first switch circuit 213 and the second output terminal 2122, and / or turn on or off the electrical connection between the second switch circuit 214 and the first output terminal 2121.

[0093] For example, when the electric vehicle 30 is charged in two phases through the first phase live wire L1 and the second phase live wire L2 under the IT power system, if the controller determines that the current switching operation is correct, that is, the electrical connection between the first input terminal 2111 and the second output terminal 2122, and between the second input terminal 2112 and the first output terminal 2121 is normally connected, and the electrical connection between the fourth input terminal 2114 and the second output terminal 2122, and between the third input terminal 2113 and the first output terminal 2121 is normally disconnected, the fifth switch circuit 218 is controlled to connect the electrical connection between the first switch circuit 213 and the second output terminal 2122, and between the second switch circuit 214 and the first output terminal 2121, so as to improve the safety and reliability of the current switching operation; when the controller determines that the output interface 212 is not loaded, the fifth switch circuit 218 is controlled to disconnect the electrical connection between the first switch circuit 214 and the second output terminal 2122, and between the second switch circuit 214 and the second output terminal 2122, so as to safely and reliably end the current switching operation.

[0094] In some embodiments, Fig.10 As shown, the switching circuit 21 further includes a sampling module 219 .

[0095] The sampling module 219 is electrically connected to the controller 215 , the first input terminal 2111 , the second input terminal 2112 , the third input terminal 2113 , the fourth input terminal 2114 , the first output terminal 2121 , and the second output terminal 2122 , respectively.

[0096] The sampling module 219 is used to sample the voltages and phase angles of the first input terminal 2111, the second input terminal 2112, the third input terminal 2113, the fourth input terminal 2114, the first output terminal 2121 and the second output terminal 2122, so that the controller 215 can determine whether the current switching operation is correct based on these voltages and phase angles.

[0097] For example, as mentioned above, when the electric vehicle 30 is charged through the first phase live line L1 and the second phase live line L2 under the IT power system, the controller 215 determines whether there is voltage at the first output terminal 2121 and the second output terminal 2122. If there is no voltage, the controller 215 controls the first switch circuit 213 to conduct the electrical connection between the first input terminal 2111 and the second output terminal 2122, and disconnect the electrical connection between the fourth input terminal 2114 and the second output terminal 2122, and controls the second switch circuit 214 to conduct the electrical connection between the second input terminal 2112 and the first output terminal 2121, and disconnect the electrical connection between the third input terminal 2113 and the first output terminal 2121. If the voltage and phase angle of the first input terminal 2111 and the second output terminal 2122 are consistent, and the voltage and phase angle of the second input terminal 2112 and the first output terminal 2121 are also consistent, the controller 215 can determine that the current switching operation is correct, otherwise it is determined that the current switching operation is abnormal.

[0098] It can be understood that when the switching circuit 21 includes the fifth switching circuit 218, the sampling module 219 can also sample the voltage and phase angle of the connection node between the fifth switching circuit 218 and the first switching circuit 213, and the connection node between the fifth switching circuit 218 and the second switching circuit 214, without sampling the voltage and phase angle of the first output terminal 2121 and the second output terminal 2122. In this case, the controller can determine whether the current switching operation is correct through the voltage and phase angle of the corresponding port, and when it is determined that the current switching operation is correct, as described above, the controller can control the fifth switching circuit 218 to conduct the electrical connection between the second switching circuit 214 and the first output terminal 2121, and between the first switching circuit 213 and the second output terminal 2122. This method can improve the safety and reliability of the current switching operation.

[0099] In some embodiments, Fig.10 As shown, the switching circuit 21 also includes an alarm circuit 210 .

[0100] The alarm circuit 210 is electrically connected to the controller 215 and is used to be controlled by the controller 215 to give an alarm. As mentioned above, when the controller determines that the current switching operation is abnormal, it can output a control signal to the alarm circuit 210, so that the alarm circuit 210 generates an alarm signal according to the control signal, thereby giving an alarm. It is understood that the alarm signal includes but is not limited to text display, indicator light, sound, etc.

[0101] In some embodiments, see Fig.13 The first switch circuit 213 includes a first single-pole single-throw relay K1 and a second single-pole single-throw relay K2.

[0102] The first SPST relay K1 is electrically connected to the controller 215 , the first input terminal 2111 , and the first output terminal 2121 , respectively, and is used for being controlled by the controller 215 to switch on or off the electrical connection between the first input terminal 2111 and the first output terminal 2121 .

[0103] The second SPST relay K2 is electrically connected to the controller 215 , the fourth input terminal 2114 and the first output terminal 2121 respectively, and is used for being controlled by the controller 215 to switch on or off the electrical connection between the fourth input terminal 2114 and the first output terminal 2121 .

[0104] The first single-pole single-throw relay K1 and the second single-pole single-throw relay K2 can be complementary to each other and can also be non-conductive at the same time, but cannot be conductive at the same time.

[0105] For example, see Figure 3 When the electric vehicle 30 is charged through the first phase live wire L1 and the second phase live wire L2 under the IT power system, the controller 215 controls the first single-pole single-throw relay K1 to be turned on to conduct the electrical connection between the first input terminal 2111 and the second output terminal 2122, and controls the second single-pole single-throw relay K2 to be turned off to disconnect the electrical connection between the fourth input terminal 2114 and the second output terminal 2122. At this time, the first single-pole single-throw relay K1 and the second single-pole single-throw relay K2 are complementarily turned on.

[0106] Please continue reading Fig.11 When the electric vehicle 30 is charged through the first phase live wire L1, the second phase live wire L2 and the third phase live wire L3 under the IT power system, the controller 215 controls the first single-pole single-throw relay K1 and the second single-pole single-throw relay K2 to disconnect, so as to disconnect the electrical connection between the first input terminal 2111 and the second output terminal 2122, and the electrical connection between the fourth input terminal 2114 and the second output terminal 2122. At this time, the first single-pole single-throw relay K1 and the second single-pole single-throw relay K2 are not conductive at the same time.

[0107] It can be understood that although the first single-pole single-throw relay K1 and the second single-pole single-throw relay K2 are not allowed to be turned on at the same time in actual work, when a control abnormality occurs, there is a possibility that the first single-pole single-throw relay K1 and the second single-pole single-throw relay K2 are turned on at the same time. At this time, there is a risk of short-circuiting the first phase live wire L1 to the neutral wire N. Therefore, in order to ensure that the first single-pole single-throw relay K1 and the second single-pole single-throw relay K2 are not turned on at the same time to improve the circuit reliability, it is necessary to introduce an interlocking circuit.

[0108] In some embodiments, the first switch circuit 213 further includes a first interlock circuit.

[0109] The first interlock circuit is electrically connected to the controller 215 , the first SPST relay K1 and the second SPST relay K2 respectively, and is used to be controlled by the controller 215 to not turn on the first SPST relay K1 and the second SPST relay K2 at the same time.

[0110] In some embodiments, see Fig.14 The first interlocking circuit includes a first NAND gate circuit 2131 and a second NAND gate circuit 2132 .

[0111] The first NAND gate circuit 2131 is electrically connected to the controller 215 , the second NAND gate circuit 2132 and the first SPST relay K1 , respectively. The second NAND gate circuit 2132 is also electrically connected to the second SPST relay K2 .

[0112] The first NAND gate circuit 2131 and the second NAND gate circuit 2132 are used to receive two interlocking signals output by the controller 215 and output corresponding driving signals according to the two interlocking signals. The two interlocking signals can be the same signal, for example, both are low-level signals, or the two interlocking signals can be different signals, for example, one interlocking signal is a high-level signal and the other interlocking signal is a low-level signal.

[0113] In some embodiments, Fig.14 As shown, the first NAND gate circuit 2131 includes a first AND gate AND1 and a first NOT gate NOT1, and the second NAND gate circuit 2132 includes a second AND gate AND2 and a second NOT gate NOT2. The first AND gate AND1 and the second AND gate AND2 each include two input terminals, one input terminal of the first AND gate AND1 is electrically connected to the input terminals of the controller 215 and the second NOT gate NOT2, respectively, the other input terminal of the first AND gate AND1 is electrically connected to the output terminal of the first NOT gate NOT1, the output terminal of the first AND gate AND1 is electrically connected to the first single-pole single-throw relay K1, one input terminal of the second AND gate AND2 is electrically connected to the input terminals of the controller 215 and the first NOT gate NOT1, respectively, the other input terminal of the second AND gate AND2 is electrically connected to the output terminal of the second NOT gate NOT2, and the output terminal of the second AND gate AND2 is electrically connected to the second single-pole single-throw relay K2.

[0114] It can be understood that the working principle of the NOT gate is that the input signal is opposite to the output signal. For example, when the NOT gate is input with 1 (high level signal), the NOT gate will output 0 (low level signal), and when the NOT gate is input with 0, the NOT gate will output 1; the working principle of the AND gate is that when the input signals are all 1, it outputs 1, and when the input signals are not all 1, it outputs 0.

[0115] Combine the following Fig.14 The interlocking principle of the first interlocking circuit is explained.

[0116] When it is necessary to control the first single-pole single-throw relay K1 to be turned on and the second single-pole single-throw relay K2 to be turned off, the controller 215 can output a high-level signal to node A and a low-level signal to node B. The high-level signal is recorded as 1 and the low-level signal is recorded as 0. One input end of the first AND gate AND1 is 1. Since the input end of the first NOT gate NOT1 is input with 0, 1 will be output to the other input end of the first AND gate AND1. Since the input end signals of the first AND gate AND1 are all 1, the driving signal output by the first AND gate AND1 is 1, which will drive the first single-pole single-throw relay K1 to be turned on. At the same time, one input end of the second AND gate AND2 is 0. At this time, no matter whether the other input end of the second AND gate AND2 is input with 1 or 0, since the input end signals of the second AND gate AND2 are not all 1, the driving signal output by the second AND gate AND2 is 0, which will drive the second single-pole single-throw relay K2 to be turned off.

[0117] When it is necessary to control the first single-pole single-throw relay K1 to be turned on and the second single-pole single-throw relay K2 to be turned off, the controller 215 can output a low-level signal to node A and a high-level signal to node B. The specific working process is similar to the above case and will not be repeated here.

[0118] When the controller 215 abnormally inputs a high-level signal to node A and node B, although one input terminal of the first AND gate AND1 is 1, the input terminal of the first NOT gate NOT1 is also input with 1, so it will output 0 to the other input terminal of the first AND gate AND1, so that the input terminal signals of the first AND gate AND1 are not all 1, so the driving signal output by the first AND gate AND1 is 0, which will drive the first single-pole single-throw relay K1 to disconnect. Similarly, the second single-pole single-throw relay K2 will also disconnect.

[0119] In some embodiments, the first switch circuit 213 can also adopt any other suitable alternative method to achieve the same function. For example, the first switch circuit 213 includes a first single-pole double-throw relay, which is electrically connected to the controller 215. The first single-pole double-throw relay includes a first contact, a second contact and a first pole. The first contact is electrically connected to the first input terminal 2111, the second contact is electrically connected to the fourth input terminal 2114, and the first pole is electrically connected to the second output terminal 2122. When it is necessary to conduct the electrical connection between the first input terminal 2111 and the second output terminal 2122 and disconnect the electrical connection between the fourth input terminal 2114 and the second output terminal 2122, the controller 215 controls the first pole to contact the first contact.

[0120] It is understandable that, since the single-pole double-throw relay can only form one path at most and not two paths at any time, as mentioned above, when the controller controls the first knife to contact the first contact, the first input terminal 2111, the first single-pole double-throw relay and the second output terminal 2122 form a path, while the fourth input terminal 2114, the first single-pole double-throw relay and the second output terminal 2122 do not form a path; when the controller controls the first knife to contact the second contact, the fourth input terminal 2114, the first single-pole double-throw relay and the second output terminal 2122 form a path, while the first input terminal 2111, the first single-pole double-throw relay and the second output terminal 2122 do not form a path. Therefore, this embodiment can achieve hardware interlocking without the need to introduce an additional interlocking circuit.

[0121] In some embodiments, please refer to Fig.13 The second switch circuit 214 includes a third single-pole single-throw relay K3 and a fourth single-pole single-throw relay K4.

[0122] The third single-pole single-throw relay K3 is electrically connected to the controller 215 , the second input terminal 2112 , and the first output terminal 2121 , respectively, and is used for being controlled by the controller 215 to switch on or off the electrical connection between the second input terminal 2112 and the first output terminal 2121 .

[0123] The fourth SPST relay K4 is electrically connected to the controller 215 , the third input terminal 2113 and the first output terminal 2121 respectively, and is used for being controlled by the controller 215 to switch on or off the electrical connection between the third input terminal 2113 and the first output terminal 2121 .

[0124] It is understandable that, as mentioned above, the current switching operation is abnormal because the relay is stuck, the relay refuses to operate, or the relay that needs to operate does not operate normally.

[0125] As mentioned above, when the electric vehicle 30 is charged through the first phase live wire L1 and the second phase live wire L2 under the IT power system:

[0126] When the switching operation is not performed, if the controller 215 determines that there is voltage at the second output terminal 2122 and the voltage and phase of the second output terminal 2122 are consistent with the voltage and phase of the first input terminal 2111, it means that the first SPST relay K1 is stuck.

[0127] When the switching operation has been performed, if the controller 215 determines that the voltage and phase of the first output terminal 2121 are inconsistent with the voltage and phase of the second input terminal 2112, for example, there is no voltage at the first output terminal 2121 but there is voltage at the second input terminal 2112, it means that the third single-pole single-throw relay K3 refuses to operate.

[0128] The third single-pole single-throw relay K3 and the fourth single-pole single-throw relay K4 can be complementary to each other and can also be non-conductive at the same time, but cannot be conductive at the same time.

[0129] For example, see Figure 3 When the electric vehicle 30 is charged through the first phase live wire L1 and the second phase live wire L2 under the IT power system, the controller 215 controls the third single-pole single-throw relay K3 to be turned on to conduct the electrical connection between the second input terminal 2112 and the first output terminal 2121, and controls the fourth single-pole single-throw relay K4 to be turned off to disconnect the electrical connection between the third input terminal 2113 and the first output terminal 2121. At this time, the third single-pole single-throw relay K3 and the fourth single-pole single-throw relay K4 are complementarily turned on.

[0130] Please continue reading Fig.11 When the electric vehicle 30 is charged through the first phase live wire L1, the second phase live wire L2 and the third phase live wire L3 under the IT power system, the controller 215 controls the third single-pole single-throw relay K3 and the fourth single-pole single-throw relay K4 to disconnect, so as to disconnect the electrical connection between the second input terminal 2112 and the first output terminal 2121, and the electrical connection between the third input terminal 2113 and the first output terminal 2121. At this time, the third single-pole single-throw relay K3 and the fourth single-pole single-throw relay K4 are not conductive at the same time.

[0131] It can be understood that although the third single-pole single-throw relay K3 and the fourth single-pole single-throw relay K4 are not allowed to be turned on at the same time in actual work, when a control abnormality occurs, there is a possibility that the third single-pole single-throw relay K3 and the fourth single-pole single-throw relay K4 are turned on at the same time, and there is a risk of short-circuiting the live wire. Therefore, in order to ensure that the third single-pole single-throw relay K3 and the fourth single-pole single-throw relay K4 are not turned on at the same time to improve the circuit reliability, it is necessary to introduce an interlocking circuit.

[0132] In some embodiments, please refer to Fig.10 , the second switch circuit 214 also includes a second interlock circuit.

[0133] The second interlock circuit is electrically connected to the controller 215, the third SPST relay K3 and the fourth SPST relay K4 respectively, and is used to be controlled by the controller 215 to not turn on the third SPST relay K3 and the fourth SPST relay K4 at the same time.

[0134] In some embodiments, see Fig.15 The second interlocking circuit includes a third NAND gate circuit 2141 and a fourth NAND gate circuit 2142 .

[0135] The third NAND gate circuit 2141 is electrically connected to the controller 215, the fourth NAND gate circuit 2142 and the third SPST relay K3 respectively, and the fourth NAND gate circuit 2142 is also electrically connected to the fourth SPST relay K4.

[0136] In some embodiments, the third NAND gate circuit 2141 includes a third AND gate AND3 and a third NOT gate NOT3 , and the fourth NAND gate circuit 2142 includes a fourth AND gate AND4 and a fourth NOT gate NOT4 .

[0137] like Fig.15 As shown, the third AND gate AND3 and the fourth AND gate AND4 each include two input terminals, one input terminal of the third AND gate AND3 is electrically connected to the input terminals of the controller 215 and the fourth NOT gate NOT4, respectively, the other input terminal of the third AND gate AND3 is electrically connected to the output terminal of the third NOT gate NOT3, the output terminal of the third AND gate AND3 is electrically connected to the third single-pole single-throw relay K3, one input terminal of the fourth AND gate AND4 is electrically connected to the input terminals of the controller 215 and the third NOT gate NOT3, respectively, the other input terminal of the fourth AND gate AND4 is electrically connected to the output terminal of the fourth NOT gate NOT4, and the output terminal of the fourth AND gate AND4 is electrically connected to the fourth single-pole single-throw relay K4.

[0138] In this embodiment, the working principle of the second interlocking circuit is the same as Fig.14 The embodiment shown is similar, and the specific working process can be referred to Fig.14 The embodiments shown will not be described in detail here.

[0139] In some embodiments, the second switch circuit 214 can also adopt any other suitable alternative method to achieve the same function. For example, the second switch circuit 214 includes a second single-pole double-throw relay, which is electrically connected to the controller 215. The second single-pole double-throw relay includes a third contact, a fourth contact and a second pole. The third contact is electrically connected to the second input terminal 2112, the fourth contact is electrically connected to the third input terminal 2113, and the second pole is electrically connected to the first output terminal 2121. When it is necessary to conduct the electrical connection between the second input terminal 2112 and the first output terminal 2121 and disconnect the electrical connection between the third input terminal 2113 and the first output terminal 2121, the controller 215 controls the second pole to contact the third contact.

[0140] As mentioned above, since the single-pole double-throw relay can only form one path at most and cannot form two paths at any time, this embodiment can achieve hardware interlocking without the need to introduce an additional interlocking circuit.

[0141] In some embodiments, please refer to Fig.13 , the third switch circuit 216 includes a fifth single-pole single-throw relay K5.

[0142] The fifth single-pole single-throw relay K5 is electrically connected to the controller 215, the first input terminal 2111 and the second output terminal 2122, respectively. When the fifth single-pole single-throw relay K5 is controlled by the controller 215 and turned on, the electrical connection between the first input terminal 2111 and the second output terminal 2122 can be connected. When the fifth single-pole single-throw relay K5 is controlled by the controller 215 and turned off, the electrical connection between the first input terminal 2111 and the second output terminal 2122 can be disconnected.

[0143] It is understandable that Fig.13 In the embodiment shown, any two or three of the third single-pole single-throw relay K3, the fourth single-pole single-throw relay K4 and the fifth single-pole single-throw relay K5 are not allowed to be turned on at the same time, otherwise there will be a risk of short-circuiting the live wire. Therefore, in order to avoid this risk and improve circuit reliability, the second interlock circuit needs to be adaptively adjusted.

[0144] Therefore, in some embodiments, see Fig.16 , the second interlocking circuit also includes a fifth NAND gate circuit 2143.

[0145] The fifth NAND gate circuit 2143 is electrically connected to the controller 215 , the third NAND gate circuit 2141 , the fourth NAND gate circuit 2142 and the fifth single-pole single-throw relay K5 , respectively.

[0146] In some embodiments, the fifth NAND gate circuit 2143 includes a fifth AND gate AND5 and a fifth NOT gate NOT5.

[0147] like Fig.16 As shown, the third AND gate AND3, the fourth AND gate AND4 and the fifth AND gate AND5 all include three input terminals, the first input terminal of the third AND gate AND3 is electrically connected to the controller 215 and the input terminal of the third NOT gate NOT3 respectively, the output terminal of the third NOT gate NOT3 is electrically connected to the first input terminal of the fourth AND gate AND4 and the first input terminal of the fifth AND gate AND5 respectively, the second input terminal of the third AND gate AND3 is electrically connected to the output terminal of the fourth NOT gate NOT4 and the second input terminal of the fifth AND gate AND5 respectively, the second input terminal of the fourth AND gate AND4 is electrically connected to the output terminal of the fourth AND gate AND4 respectively. The controller 215 is electrically connected to the input end of the fourth NOT gate NOT4, the third input end of the fourth AND gate AND4 is electrically connected to the third input end of the third AND gate AND3 and the output end of the fifth NOT gate NOT5, the third input end of the fifth NOT gate NOT5 is electrically connected to the input ends of the controller 215 and the fifth NOT gate NOT5, the output end of the third AND gate AND3 is electrically connected to the third single-pole single-throw relay K3, the output end of the fourth AND gate AND4 is electrically connected to the second single-pole single-throw relay K2, and the output end of the fifth AND gate AND5 is electrically connected to the fifth single-pole single-throw relay K5.

[0148] In this embodiment, the working principle of the second interlocking circuit is the same as Fig.14 The embodiment shown is similar, and the specific working process can be referred to Fig.14 The embodiments shown will not be described in detail here.

[0149] In some embodiments, please refer to Fig.13 The fourth switch circuit 217 includes a first double-pole double-throw relay K6.

[0150] The first double-pole double-throw relay K6 is electrically connected to the controller 215. The first double-pole double-throw relay K6 includes a fifth contact, a sixth contact, a third knife and a fourth knife. The fifth contact is electrically connected to the third output terminal 2123, the sixth contact is electrically connected to the fourth output terminal 2124, the third knife is electrically connected to the second input terminal 2112, and the fourth knife is electrically connected to the third input terminal 2113. When the controller 215 controls the first double-pole double-throw relay K6 to be turned on, the fifth contact contacts the third knife, and the sixth contact contacts the fourth knife, thereby conducting the electrical connection between the second input terminal 2112 and the third output terminal 2123, and between the third input terminal 2113 and the fourth output terminal 2124.

[0151] In some embodiments, the fourth switch circuit 217 can also adopt any other suitable alternative method to achieve the same function. For example, the fourth switch circuit 217 includes a sixth single-pole double-throw relay and a seventh single-pole double-throw relay. The sixth single-pole double-throw relay is electrically connected to the controller 215, the second input terminal 2112 and the third output terminal 2123, respectively, and is used to be controlled by the controller 215 to turn on or off the electrical connection between the second input terminal 2112 and the third output terminal 2123. The seventh single-pole double-throw relay is electrically connected to the controller 215, the third input terminal 2113 and the fourth output terminal 2124, respectively, and is used to be controlled by the controller 215 to turn on or off the electrical connection between the third input terminal 2113 and the fourth output terminal 2124.

[0152] In some embodiments, Fig.13 As shown, the fifth switch circuit 218 includes a second double-pole double-throw relay K7.

[0153] The second double-pole double-throw relay K7 is electrically connected to the controller 215. The second double-pole double-throw relay K7 includes a seventh contact, an eighth contact, a fifth knife and a sixth knife. The seventh contact is electrically connected to the first output terminal 2121, the eighth contact is electrically connected to the second output terminal 2122, the fifth knife is electrically connected to the second switch circuit 214, and the sixth knife is electrically connected to the first switch circuit 213. When the controller 215 controls the second double-pole double-throw relay K7 to be turned on, the seventh contact contacts the fifth knife, and the eighth contact contacts the sixth knife, thereby conducting the electrical connection between the second switch circuit 214 and the first output terminal 2121, and between the first switch circuit 213 and the second output terminal 2122.

[0154] In some embodiments, the fifth switch circuit 218 can also adopt any other suitable alternative method to achieve the same function. For example, the fifth switch circuit 218 includes an eighth single-pole double-throw relay and a ninth single-pole double-throw relay. The eighth single-pole double-throw relay is electrically connected to the controller 215, the second switch circuit 214 and the first output terminal 2121, respectively, and is used to be controlled by the controller 215 to turn on or off the electrical connection between the second switch circuit 214 and the first output terminal 2121. The ninth single-pole double-throw relay is electrically connected to the controller 215, the first switch circuit 213 and the second output terminal 2122, respectively, and is used to be controlled by the controller 215 to turn on or off the electrical connection between the first switch circuit 213 and the second output terminal 2122.

[0155] Finally, it should be noted that the utility model can be implemented in many different forms and is not limited to the embodiments described in this specification. These embodiments cannot serve as additional limitations on the content of the utility model. The purpose of providing these implementation methods is to make the understanding of the disclosure of the utility model more thorough and comprehensive. And under the idea of ​​the utility model, the above-mentioned technical features continue to be combined with each other, and there are many other changes in different aspects of the utility model as described above, which are all regarded as the scope of the description of the utility model. Furthermore, for ordinary technicians in this field, improvements or changes can be made according to the above description, and all these improvements and changes should belong to the scope of protection of the claims attached to the utility model.

Claims

1. A switching circuit, characterized in that: include: An input interface, comprising a first input terminal, a second input terminal, a third input terminal and a fourth input terminal, wherein the first input terminal is electrically connected to the first-phase live wire, the second input terminal is electrically connected to the second-phase live wire, the third input terminal is electrically connected to the third-phase live wire, and the fourth input terminal is electrically connected to the neutral wire; An output interface, comprising a first output end and a second output end, wherein the first output end and the second output end are electrically connected to the electric vehicle; A first switch circuit is electrically connected to the first input terminal, the fourth input terminal and the second output terminal respectively; A second switch circuit is electrically connected to the second input terminal, the third input terminal and the first output terminal respectively; A controller is electrically connected to the first switch circuit and the second switch circuit, respectively, and is used to control the first switch circuit to turn on or off the electrical connection between the first input terminal or the fourth input terminal and the second output terminal, and to control the second switch circuit to turn on or off the electrical connection between the second input terminal or the third input terminal and the first output terminal.

2. The switching circuit according to claim 1, characterized in that: The first switch circuit comprises: a first single-pole single-throw relay, electrically connected to the controller, the first input terminal and the second output terminal respectively, and used for being controlled by the controller to switch on or off the electrical connection between the first input terminal and the second output terminal; The second single-pole single-throw relay is electrically connected to the controller, the fourth input terminal and the second output terminal respectively, and is used for being controlled by the controller to switch on or off the electrical connection between the fourth input terminal and the second output terminal.

3. The switching circuit according to claim 2, characterized in that: The first switch circuit further includes a first interlock circuit; The first interlock circuit is electrically connected to the controller, the first single-pole single-throw relay and the second single-pole single-throw relay respectively, and is used to be controlled by the controller to not turn on the first single-pole single-throw relay and the second single-pole single-throw relay at the same time.

4. The switching circuit according to claim 1, characterized in that: The second switch circuit comprises: a third single-pole single-throw relay, electrically connected to the controller, the second input terminal and the first output terminal respectively, and used for being controlled by the controller to switch on or off the electrical connection between the second input terminal and the first output terminal; A fourth single-pole single-throw relay is electrically connected to the controller, the third input terminal and the first output terminal respectively, and is used to be controlled by the controller to switch on or off the electrical connection between the third input terminal and the first output terminal.

5. The switching circuit according to claim 4, characterized in that: The second switch circuit further includes a second interlock circuit; The second interlock circuit is electrically connected to the controller, the third single-pole single-throw relay and the fourth single-pole single-throw relay respectively, and is used to be controlled by the controller to not turn on the third single-pole single-throw relay and the fourth single-pole single-throw relay at the same time.

6. The switching circuit according to claim 1, characterized in that: The switching circuit further includes a third switch circuit; The third switch circuit is electrically connected to the controller, the first input terminal and the first output terminal respectively, and is used for being controlled by the controller to switch on or off the electrical connection between the first input terminal and the first output terminal.

7. The switching circuit according to claim 6, characterized in that: The output interface further includes a third output terminal and a fourth output terminal, and the switching circuit further includes a fourth switch circuit; The fourth switch circuit is electrically connected to the controller, the second input terminal, the third input terminal, the fourth output terminal and the third output terminal, respectively, and is used to be controlled by the controller to turn on or off the electrical connection between the second input terminal and the third output terminal, and / or the electrical connection between the third input terminal and the fourth output terminal.

8. The switching circuit according to claim 6, characterized in that: The output interface further includes a third output terminal and a fourth output terminal, and the switching circuit further includes a fifth switch circuit; The fifth switch circuit is electrically connected to the controller, the first switch circuit, the second switch circuit, the first output end and the second output end, respectively, and is used to be controlled by the controller to turn on or off the electrical connection between the first switch circuit and the second output end, and / or the electrical connection between the second switch circuit and the first output end.

9. The switching circuit according to claim 1, characterized in that: The switching circuit also includes a sampling module; The sampling module is electrically connected to the controller, the first input terminal, the second input terminal, the third input terminal, the fourth input terminal, the first output terminal and the second output terminal, respectively, and is used to sample the voltage and phase angle of the first input terminal, the second input terminal, the third input terminal, the fourth input terminal, the first output terminal and the second output terminal.

10. A charging pile, characterized in that: Comprising the switching circuit as claimed in any one of claims 1 to 9.

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