Automatic power-off distribution box for charging electric automobile

Abstract

The utility model provides an automatic power-off distribution box for charging an electric automobile, which comprises a box body, a circuit breaker, a contactor, an intermediate relay and a current sensing switch, and is characterized in that the circuit breaker, the contactor, the intermediate relay and the current sensing switch are arranged on the inner side surface of the box body; the circuit breaker is electrically connected with the contactor, the contactor is electrically connected with the intermediate relay, and the intermediate relay is electrically connected with the current sensing switch. According to the automatic power-off distribution box for charging the electric automobile, through electrical mutual cooperation of the circuit breaker, the contactor, the intermediate relay, the current induction switch and the like, when the automatic power-off distribution box is used, a charging power supply is automatically cut off after the charging current is detected to be smaller than a set threshold value and lasts for one minute, and the automatic power-off distribution box is safe and reliable. And the battery is effectively prevented from being continuously charged after being fully charged, so that performance degradation and service life shortening caused by overcharge of the battery are prevented.

Description

Technical Field

[0001] This utility model relates to the field of electric vehicle charging equipment control technology, and in particular to an automatic power-off distribution box for electric vehicle charging. Background Technology

[0002] With the widespread use of electric vehicles, the safety and functionality of their charging equipment have become a major concern. Currently, most electric vehicle charging equipment relies on the BMS (Battery Management System) for power-off control. Once the battery is fully charged, only the current output stops, but the charging circuit remains connected. This method harbors a series of serious safety hazards.

[0003] In traditional charging mode, although the software cuts off the charging process after charging is completed, the power supply circuit of the charging gun remains physically closed, causing the gun head to remain energized for a long time. This can easily generate electric arcs when plugging and unplugging, threatening the personal safety of users. Moreover, the continuously energized interface is prone to leakage current in humid environments, which reduces insulation performance. The overheating of the contactor contacts also increases the risk of electrical fires. At the same time, float charging can damage the battery system, and devices that are not physically disconnected can also impact the power grid. The continuous energization of AC contactors can also accelerate mechanical wear.

[0004] Therefore, it is necessary to provide an automatic power-off distribution box for electric vehicle charging to solve the above-mentioned technical problems. Utility Model Content

[0005] This utility model provides an automatic power-off distribution box for electric vehicle charging, which solves the problem that existing electric vehicle charging equipment does not physically disconnect the charging circuit after charging is completed, which poses safety hazards, damages the battery system, impacts the power grid, and accelerates the wear and tear of electrical components.

[0006] To solve the above-mentioned technical problems, this utility model provides an automatic power-off distribution box for electric vehicle charging, comprising:

[0007] The enclosure includes a circuit breaker, a contactor, an intermediate relay, and a current sensing switch, all of which are located on the inner side of the enclosure.

[0008] The circuit breaker and the contactor are electrically connected, the contactor and the intermediate relay are electrically connected, and the intermediate relay and the current sensing switch are electrically connected.

[0009] Preferably, the current sensing switch is used for electrical connection with the car charging gun.

[0010] Preferably, the front of the housing is rotatably connected to a door.

[0011] Preferably, an installation frame is fixedly installed inside the top of the housing, ventilation slots are provided on both sides of the installation frame, air collection hoods are fixedly installed on both sides of the inner side of the installation frame, fans are fixedly installed at the output ends of the two air collection hoods, air blowing frames are fixedly installed at the output ends of the fans, the bottom of the air blowing frames is fixedly installed at the bottom of the inner side of the installation frame, and a filter screen is fixedly installed inside the bottom of the installation frame.

[0012] Preferably, a top plate is fixedly installed on the top of the mounting frame, a filter frame is fixedly installed on the bottom of the top plate, and the bottom of the filter frame is fixedly installed on the top of the housing.

[0013] Preferably, a shielding frame is fixedly installed at the bottom of the top plate, and the shielding frame is disposed on the inner side of the filter frame.

[0014] Preferably, the bottom of the shielding frame is located at the top of the box.

[0015] Compared with related technologies, the automatic power-off distribution box for electric vehicle charging provided by this utility model has the following beneficial effects:

[0016] This utility model provides an automatic power-off distribution box for electric vehicle charging. Through the coordinated operation of circuit breakers, contactors, intermediate relays, and current sensing switches, it automatically cuts off the charging power supply when the charging current is detected to be below a set threshold for one minute. This effectively prevents the battery from continuing to be charged after it is fully charged, thus preventing performance degradation and shortened lifespan due to overcharging. It also eliminates the risk of electric shock caused by arcing when plugging and unplugging the charging gun due to prolonged energization; avoids leakage current and insulation degradation caused by continuously energized charging interfaces in humid environments; and prevents contactor contacts from overheating due to prolonged energization, increasing the risk of electrical fires. Furthermore, it prevents the charging equipment, which is not physically disconnected, from impacting the power grid during voltage fluctuations, ensuring user safety and the safe operation of electrical equipment. Attached Figure Description

[0017] Figure 1 A schematic diagram of the structure of a first embodiment of an automatic power-off distribution box for electric vehicle charging provided by this utility model;

[0018] Figure 2 for Figure 1 The electrical schematic diagram shown;

[0019] Figure 3 A schematic diagram of the structure of a second embodiment of an automatic power-off distribution box for electric vehicle charging provided by this utility model;

[0020] Figure 4 for Figure 3 The diagram shows a three-dimensional structure of the mounting frame.

[0021] Figure 5 for Figure 4 The diagram shows a side cross-sectional view of the mounting frame.

[0022] The following are the labels in the diagram: 1. Box body, 11. Door body, 2. Circuit breaker, 3. Contactor, 4. Intermediate relay, 5. Current sensing switch, 6. Mounting frame, 61. Ventilation slot, 62. Filter screen, 63. Top plate, 64. Filter frame, 65. Shielding frame, 66. Fan, 67. Air blowing frame, 68. Gas collection hood. Detailed Implementation

[0023] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0024] First Embodiment

[0025] Please refer to the following: Figure 1 , Figure 2 ,in, Figure 1 A schematic diagram of the structure of a first embodiment of an automatic power-off distribution box for electric vehicle charging provided by this utility model; Figure 2 for Figure 1 The electrical schematic diagram is shown. An automatic power-off distribution box for electric vehicle charging includes: a box body 1, a circuit breaker 2, a contactor 3, an intermediate relay 4, and a current sensing switch 5, wherein the circuit breaker 2, the contactor 3, the intermediate relay 4, and the current sensing switch 5 are all disposed on the inner side of the box body 1;

[0026] The circuit breaker 2 is electrically connected to the contactor 3, the contactor 3 is electrically connected to the intermediate relay 4, and the intermediate relay 4 is electrically connected to the current sensing switch 5.

[0027] The current sensing switch 5 is used for electrical connection with the car charging gun.

[0028] The front of the box 1 is rotatably connected to a door 11.

[0029] As an important component of the main circuit, circuit breaker 2 plays a role in controlling the circuit on and off and providing overload and short circuit protection, ensuring the safe operation of the entire distribution box and charging circuit. When an abnormal current occurs in the circuit, circuit breaker 2 will automatically disconnect the circuit to prevent the fault from escalating further.

[0030] The main contacts of contactor 3 carry the charging current. Its coil voltage is AC220V, which is the same as the mains power. During the charging process, the main contacts of contactor 3 are closed, allowing the charging current to pass smoothly and charge the electric vehicle. When it is necessary to disconnect the power, the main contacts are open, cutting off the charging circuit.

[0031] Intermediate relay 4, model MY4NJ-AC220V, has a coil controlled by a current switch and a contact capacity of 10A. In the circuit, it is mainly used to isolate the coil of contactor 3, and plays the role of signal amplification and isolation, thereby enhancing the stability and reliability of the control circuit.

[0032] The current sensing switch 5 is a model M3050 current sensing switch with an adjustable range of 1-5A and a normally open contact characteristic (closing when the current is greater than the threshold). It is used to detect the charging current in real time and is a key component for realizing the automatic power-off function. When the detected charging current is greater than the set threshold (such as 1.5A), its internal normally open contact closes; when the current is less than the threshold, the contact resets and opens.

[0033] The enclosure 1 provides physical protection and installation space for the internal electrical components, preventing damage from the external environment. The design of the door 11 facilitates the inspection, maintenance and operation of the internal components by the operators, while also enhancing the safety of the distribution box and preventing personnel from accidentally touching live parts.

[0034] The working principle of the automatic power-off distribution box for electric vehicle charging provided by this utility model is as follows:

[0035] After the user inserts the charging gun, presses the start button (the start button is connected in series with the coil circuit of intermediate relay 4 and in parallel with the current sensing switch 5). At this time, the start button temporarily short-circuites the normally open contact of the current sensing switch, the coil of intermediate relay 4 is energized, the normally open contact closes, the coil of contactor 3 is energized, the main contact closes, the charging gun is powered on, and charging begins. When the charging current is greater than 1.5A (adjustable), the current sensing switch 5 automatically keeps the normally open contact closed. When the start button is released, the system enters the self-holding state.

[0036] When the battery is nearly fully charged, the charging current drops to less than 1.5A (adjustable threshold), the normally open contact of the current sensing switch 5 is reset and opened, the coil of the intermediate relay 4 is de-energized and its normally open contact is reset, the coil of the contactor 3 is de-energized and the main contacts are opened, the charging gun is de-energized, and the charging operation stops.

[0037] In case of an emergency during the entire charging process, the user can press the red emergency stop button to physically cut off the contactor coil circuit, causing the charging gun to be powered off immediately. It can only be restarted after being rotated to reset.

[0038] Compared with related technologies, the automatic power-off distribution box for electric vehicle charging provided by this utility model has the following beneficial effects:

[0039] Through the coordinated operation of circuit breaker 2, contactor 3, intermediate relay 4, and current sensing switch 5, the system automatically cuts off the charging power when the charging current is detected to be less than a set threshold for one minute. This effectively prevents the battery from continuing to be charged after it is fully charged, thus preventing performance degradation and shortened lifespan due to overcharging. It also eliminates the risk of electric shock caused by arcing when plugging and unplugging the charging gun due to prolonged energization; avoids leakage current and insulation degradation caused by continuously energized charging interfaces in humid environments; and prevents contactor contacts from overheating due to prolonged energization, which increases the risk of electrical fires. Furthermore, it prevents the charging equipment that is not physically disconnected from impacting the power grid during voltage fluctuations, ensuring the safety of users and the safe operation of electrical equipment.

[0040] Second Embodiment

[0041] Please refer to the following: Figure 3 , Figure 4 and Figure 5 Based on the first embodiment of this application which provides an automatic power-off distribution box for electric vehicle charging, the second embodiment of this application proposes another automatic power-off distribution box for electric vehicle charging. The second embodiment is merely a preferred embodiment of the first embodiment, and the implementation of the second embodiment will not affect the separate implementation of the first embodiment.

[0042] Specifically, the second embodiment of this application provides an automatic power-off distribution box for electric vehicle charging, which differs in that the automatic power-off distribution box for electric vehicle charging has an installation frame 6 fixedly installed inside the top of the box body 1. Ventilation slots 61 are provided on both sides of the installation frame 6. Air collection hoods 68 are fixedly installed on both sides of the inner side of the installation frame 6. Fans 66 are fixedly installed at the output ends of the two air collection hoods 68. Air blowing frames 67 are fixedly installed at the output ends of the fans 66. The bottom of the air blowing frames 67 is fixedly installed at the bottom of the inner side of the installation frame 6. A filter screen 62 is fixedly installed inside the bottom of the installation frame 6.

[0043] A top plate 63 is fixedly installed on the top of the mounting frame 6, and a filter frame 64 is fixedly installed on the bottom of the top plate 63. The bottom of the filter frame 64 is fixedly installed on the top of the housing 1.

[0044] A shielding frame 65 is fixedly installed at the bottom of the top plate 63, and the shielding frame 65 is disposed on the inner side of the filter frame 64.

[0045] The bottom of the shielding frame 65 is located at the top of the box 1.

[0046] The filter frame 64 filters the outside air, blocking dust and impurities from entering the enclosure 1 and preventing them from adhering to the electrical components and affecting heat dissipation and normal operation. The design of the shielding frame 65 effectively prevents rainwater from entering the enclosure 1, providing a relatively dry and clean operating environment for the electrical components, reducing the risk of electrical failures caused by dust and rainwater, and improving the applicability and safety of the distribution box in complex outdoor environments.

[0047] A through slot for venting air and a mounting slot for extending the charging gun wiring harness are provided at the bottom of the housing 1.

[0048] The working principle of the automatic power-off distribution box for electric vehicle charging provided by this utility model is as follows:

[0049] When used outdoors for extended periods, the electrical components inside the enclosure 1 continuously generate heat, causing the internal temperature of the enclosure 1 to gradually rise. At this time, the temperature sensor installed at the bottom of the mounting frame 6, located on the inner side of the enclosure 1, comes into play, monitoring the internal temperature of the enclosure 1 in real time. When the temperature reaches a preset value, the temperature sensor sends an electrical signal to the fan 66.

[0050] Upon receiving the electrical signal, the fan 66 starts to operate. The operation of the fan 66 generates suction, drawing external air in from the outer side of the filter frame 64. The filter frame 64 is a frame shape formed by bending a metal filter mesh, which can filter dust and impurities in the external air, ensuring that the air entering the housing 1 is relatively clean, and preventing dust and impurities from entering the housing 1 and affecting the normal operation and service life of electrical components.

[0051] After being filtered by the filter frame 64, the air then enters the inner side of the air collection hood 68 through the bottom of the shield frame 65 and the ventilation slot 61. The shield frame 65 is located on the inner side of the filter frame 64, and its bottom is located at the top of the housing 1, which effectively prevents external rainwater from entering the inner side of the housing 1 through the ventilation slot 61, and prevents short circuits and other malfunctions caused by rainwater entering.

[0052] After the air enters the air collection hood 68, it enters the fan 66. Then the fan 66 blows the air through the air blowing frame 67 and the filter screen 62 to the inner side of the housing 1. Through this series of air circulation processes, the electrical components inside the housing 1 are cooled and dissipated, so that the electrical components can operate stably in a suitable temperature environment and reduce the probability of failure caused by high temperature.

[0053] Compared with related technologies, the automatic power-off distribution box for electric vehicle charging provided by this utility model has the following beneficial effects:

[0054] By cooperating with each other, the mounting frame 6, ventilation slot 61, fan 66, air blowing frame 67 and air collection hood 68 can actively introduce external cold air into the enclosure 1 and form an air circulation inside, which can quickly and effectively reduce the temperature inside the enclosure 1, ensure that the internal electrical components maintain good heat dissipation during long-term operation, improve the stability and reliability of the electrical components, and extend the service life of the electrical components.

[0055] The above description is merely an embodiment of this utility model and does not limit the patent scope of this utility model. Any equivalent structural or procedural transformations made based on the content of this utility model specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. An automatic power-off distribution box for electric vehicle charging, characterized in that, include: The enclosure includes a circuit breaker, a contactor, an intermediate relay, and a current sensing switch, all of which are located on the inner side of the enclosure. The circuit breaker and the contactor are electrically connected, the contactor and the intermediate relay are electrically connected, and the intermediate relay and the current sensing switch are electrically connected.

2. The automatic power-off distribution box for electric vehicle charging according to claim 1, characterized in that, The current sensing switch is used for electrical connection with the car charging gun.

3. The automatic power-off distribution box for electric vehicle charging according to claim 1, characterized in that, The front of the box is rotatably connected to a door.

4. The automatic power-off distribution box for electric vehicle charging according to claim 1, characterized in that, An installation frame is fixedly installed inside the top of the housing. Ventilation slots are provided on both sides of the installation frame. Air collection hoods are fixedly installed on both sides of the inner side of the installation frame. Fans are fixedly installed at the output ends of the two air collection hoods. A blower frame is fixedly installed at the output end of the fan. The bottom of the blower frame is fixedly installed at the bottom of the inner side of the installation frame. A filter screen is fixedly installed inside the bottom of the installation frame.

5. The automatic power-off distribution box for electric vehicle charging according to claim 4, characterized in that, A top plate is fixedly installed on the top of the mounting frame, a filter frame is fixedly installed on the bottom of the top plate, and the bottom of the filter frame is fixedly installed on the top of the box.

6. The automatic power-off distribution box for electric vehicle charging according to claim 5, characterized in that, A shielding frame is fixedly installed at the bottom of the top plate, and the shielding frame is located on the inner side of the filter frame.

7. An automatic power-off distribution box for electric vehicle charging according to claim 6, characterized in that, The bottom of the shielding frame is located at the top of the box.

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