External test interface safety protection method

Abstract

The invention relates to the technical field of charging facility detection, and discloses an external test interface safety protection method, which comprises the steps of S1, safety grounding design; s2, designing surge protection; s3, strong and weak current isolation design; s4, designing a residual electric quantity discharge function; s5, equipping a leakage protection switch in the equipment; s6, a multi-protection mechanism is designed, the multi-protection mechanism is designed in the load module, and when it is detected that the working state of the load module is abnormal, input is automatically cut off, specifically, a, a temperature sensor is arranged in the load module; b, arranging a voltage monitoring circuit at the input end of the load module; and c, a current sensor is connected in series in a current path of the load module, by implementing safe grounding, surge voltage protection, strong and weak current isolation and load multiple protection, the safety and electromagnetic compatibility of an interface are remarkably improved, the electromagnetic interference and equipment damage risks are reduced, and meanwhile, the optimal protection effect under the abnormal condition is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of charging facility detection, and in particular to a safety protection method for an external test interface. Background Art

[0002] The external test interface refers to the interface between the detection equipment and the device under test (such as the charging pile), which is used to transmit test signals, data and control instructions. It is a key component for realizing the detection function of charging facilities. With the rapid development of the electric vehicle industry, charging piles are important supporting facilities for electric vehicles. The stability and safety of their performance are crucial to ensure the normal use of electric vehicles. Therefore, regular and efficient detection of charging piles has become a key link to ensure the operation quality of charging facilities. The external test interface, as an important bridge in the detection process, not only affects the accuracy and reliability of the detection data, but also directly relates to the safety of the detection personnel and the stability of the equipment. Through the external test interface, the detection equipment can obtain the working status parameters of the charging pile in real time, such as voltage, current, power, etc., and perform various performance tests on the charging pile, so as to ensure the safe and efficient operation of the charging pile. Therefore, the design and optimization of the external test interface is of great significance to improving the detection level of charging facilities and ensuring the safety of electric vehicle charging.

[0003] Although external test interfaces play an important role in the detection of charging facilities, existing external test interfaces often have deficiencies in the isolation of strong and weak electricity. There is a lack of effective isolation measures between the strong and weak electricity parts, which can easily cause equipment damage or personal injury due to excessive current or short circuit. Secondly, for the processing of residual power, the existing technology may not be able to discharge the voltage to a safe level in a short time, increasing the risk of electric shock for operators. For this reason, we propose a safety protection method for an external test interface. Summary of the invention

[0004] 1. Technical issues to be solved

[0005] In view of the deficiencies in the prior art, the present invention provides a safety protection method for an external test interface, which solves the above-mentioned problems.

[0006] (II) Technical solution

[0007] To achieve the above-mentioned purpose, the present invention provides the following technical solution: a method for protecting the safety of an external test interface, characterized in that it comprises the following steps:

[0008] S1: Safety grounding design, use a dedicated grounding wire to connect the metal casing of the equipment and the grounding contact to the grounding body.

[0009] S2: Surge protection design, solder a parallel TVS diode on the AC input side of the device. If the device is AC input, use two TVS diodes, one connected between the live wire and the ground, and the other connected between the neutral wire and the ground.

[0010] S3: Strong and weak current isolation design, use insulating sleeves to connect the strong and weak current circuits. For circuits that are difficult to connect, fix an insulating plate or apply an insulating coating between the two.

[0011] S4: Residual power discharge function design, a residual power discharge circuit is set in the power output module, when the output connection device is disconnected, the voltage is discharged to below the safe voltage.

[0012] S5: Equip the device with a leakage protection switch to cut off the power supply immediately once leakage is detected.

[0013] S6: Multiple protection mechanisms are designed in the load module. When the working state of the load module is detected to be abnormal, such as over-temperature, voltage or current exceeding the set range, the input is automatically cut off. Specifically:

[0014] a. A temperature sensor is set in the load module. When it is detected that the operating temperature of the load module exceeds the preset safety threshold, the input power is automatically cut off.

[0015] b. Set up a voltage monitoring circuit at the input end of the load module. When it is detected that the input voltage exceeds or falls below the set safety range, the input power is immediately cut off.

[0016] c. Connect a current sensor in series in the current path of the load module. When it is detected that the current exceeds the maximum current of the load module, the input power is quickly cut off.

[0017] Preferably, in S1, the resistance value of the grounding resistor needs to be checked regularly to ensure that the resistance value of the grounding wire does not exceed 4 ohms.

[0018] Preferably, the breakdown voltage of the TVS diode in S2 should be no less than 1.2 times the operating voltage of the device, and its maximum operating current should be able to meet the protection requirements of the device in surge conditions.

[0019] Preferably, the thickness of the S3 insulating board should be no less than 1 mm, and the thickness of the insulating coating should be no less than 0.5 mm to ensure sufficient insulation distance and insulation strength.

[0020] Preferably, in S4, when the output connection device is disconnected, the discharge circuit should discharge the voltage to a safe voltage range below 60V within 1 second to prevent the operator from getting an electric shock due to contact with residual electricity.

[0021] Preferably, the leakage action current of the leakage protection switch in S5 should be no more than 30 mA.

[0022] Preferably, the temperature sensor in S6 automatically cuts off the input power when it detects that the operating temperature of the load module exceeds 85°C.

[0023] Preferably, in the voltage monitoring circuit in S6, when it is detected that the input voltage exceeds 110% of the rated voltage of the load module or when it is detected that the input voltage is lower than 90% of the rated voltage of the load module, the input power is immediately cut off.

[0024] Preferably, the current sensor in S6 sets the maximum current bearing capacity of the load module to 120%, and when the current sensor detects that the current exceeds the threshold, the input power is quickly cut off.

[0025] (III) Beneficial effects

[0026] Compared with the prior art, the present invention provides a safety protection method for an external test interface, which has the following beneficial effects:

[0027] 1. This external test interface safety protection method significantly improves the safety of the external test interface by implementing a safe grounding design. A dedicated grounding wire is used to connect the metal casing of the equipment and the grounding contact to the grounding body. It not only effectively prevents electric shock accidents caused by leakage or static electricity accumulation, but also enhances the electromagnetic compatibility of the equipment and reduces the impact of external electromagnetic interference on equipment performance. In addition, it also stipulates the requirement for regular inspection of the grounding resistance value, further ensuring the reliability and safety of the grounding.

[0028] 2. This external test interface safety protection method provides a strong surge voltage protection capability for the device by welding a TVS diode in parallel on the AC input side of the device. The TVS diode has the characteristics of high breakdown voltage and fast response speed. It can absorb surge voltage in an instant to prevent it from damaging the internal electronic components of the device. At the same time, the design also takes into account the selection and use environment of the TVS diode to ensure that its protection effect in surge conditions is optimal.

[0029] 3. This external test interface safety protection method uses an insulating sleeve to sleeve on the high-voltage circuit and the low-voltage circuit, and fixes an insulating plate or applies an insulating coating between circuits that are difficult to sleeve. This not only prevents the high-voltage circuit from interfering with the low-voltage circuit and ensures the accurate transmission of the low-voltage signal, but also reduces the risk of electric shock and improves the safety performance of the equipment.

[0030] 4. This external test interface safety protection method realizes real-time monitoring and abnormal protection of the working status of the load module by designing multiple protection mechanisms in the load module, such as temperature sensors, voltage monitoring circuits and current sensors. When it is detected that the working temperature, voltage or current of the load module exceeds the set range, the invention can automatically cut off the input power to prevent the equipment from being damaged or causing safety accidents due to abnormal working conditions, ensuring that its protection effect under abnormal conditions is optimal. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a schematic diagram of the process flow of the external test interface safety protection method of the present invention;

[0032] Figure 2 This is a schematic diagram of the safety grounding process of the present invention;

[0033] Figure 3 This is a schematic diagram of the surge protection process of the present invention;

[0034] Figure 4 This is a schematic diagram of the strong and weak electricity isolation process of the present invention;

[0035] Figure 5 This is a schematic diagram of the residual power discharge function flow of the present invention;

[0036] Figure 6 A schematic diagram of the flow chart of the leakage protection switch provided for the present invention;

[0037] Figure 7 It is a schematic diagram of the multiple protection mechanism flow of the present invention. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] See also Figure 1-7 , a safety protection method for an external test interface, comprising the following steps:

[0040] S1: Safety grounding design, use a dedicated grounding wire to connect the metal shell of the equipment and the grounding contact to the grounding body. Through the safety grounding design, it can effectively prevent electric shock accidents caused by leakage or static electricity accumulation of the equipment and protect the safety of operators. At the same time, good grounding can also improve the electromagnetic compatibility of the equipment and reduce the impact of external electromagnetic interference on the equipment.

[0041] S2: Surge protection design, weld a TVS diode in parallel on the AC input side of the device. If the device is AC input, use two TVS diodes, one connected between the live wire and the ground, and the other connected between the neutral wire and the ground, to form a complete surge protection circuit. At the same time, when using the TVS diode, verify whether the rated voltage and current of the TVS diode meet the equipment requirements to ensure that it can work normally without damage under surge voltage shock. The surge protection design can effectively prevent the surge voltage in the power grid from damaging the equipment and extend the service life of the equipment. At the same time, it can also protect the electronic components inside the equipment from overvoltage shock and improve the reliability and stability of the equipment.

[0042] S3: Strong and weak current isolation design, use insulating sleeves to connect strong and weak current circuits. The insulating sleeves should have good insulation and high temperature resistance. For circuits that are difficult to connect, fix insulating plates or apply insulating coatings between the two to ensure good electrical isolation between strong and weak current. The strong and weak current isolation design can effectively prevent the strong current circuit from interfering with the weak current circuit and ensure the accurate transmission of weak current signals. At the same time, it can also reduce the risk of electric shock and improve the safety performance of the equipment. Through regular inspection and maintenance, it can ensure that the insulation isolation measures are always effective.

[0043] S4: Residual power discharge function design. A residual power discharge circuit is set in the power output module. The discharge circuit should include components such as resistors and capacitors to form a discharge loop. When the output connection device is disconnected, the voltage is discharged to below the safe voltage. The discharge circuit can quickly discharge the voltage to below the safe voltage. Generally, the discharge time is required not to exceed 1 second. The residual power discharge function design can prevent the risk of electric shock to the operator caused by the accumulated power inside the device after the output connection is disconnected. By quickly discharging the residual power, it can ensure that the device is in a safe state after disconnection, thereby improving the safety performance of the equipment.

[0044] S5: Equip the equipment with a leakage protection switch, which should have the characteristics of high sensitivity and reliable operation. Configure the parameters of the leakage protection switch, such as leakage action current and action time. Generally, the leakage action current is required to be no more than 30mA and the action time is required to be no more than 0.1 second.

[0045] Once leakage is detected, the power supply will be cut off immediately. The leakage protection switch can quickly cut off the power supply when leakage is detected, effectively preventing electric shock accidents. By reasonably configuring parameters and regular inspection and maintenance, it can be ensured that the leakage protection switch is always in good working condition and improve the safety performance of the equipment.

[0046] S6: Multiple protection mechanisms are designed in the load module. When the working state of the load module is detected to be abnormal, such as over-temperature, voltage or current exceeding the set range, the input is automatically cut off. Specifically:

[0047] a. A temperature sensor is set in the load module. When it is detected that the operating temperature of the load module exceeds the preset safety threshold, the input power is automatically cut off.

[0048] b. Set up a voltage monitoring circuit at the input end of the load module. When it is detected that the input voltage exceeds or falls below the set safety range, the input power is immediately cut off.

[0049] c. Connect a current sensor in series in the current path of the load module. When it is detected that the current exceeds the maximum current of the load module, the input power supply is quickly cut off;

[0050] The multiple protection mechanism design can effectively prevent the load module from being damaged or causing safety accidents under abnormal working conditions. By real-time monitoring of the working status of the load module and timely cutting off the input power when abnormal conditions are detected, the safe operation of the load module and the entire equipment can be protected. At the same time, this design can also improve the reliability and stability of the equipment and extend the service life of the equipment.

[0051] In S1, the grounding resistance value needs to be checked regularly to ensure that the resistance value of the grounding wire does not exceed 4 ohms. For the selection of grounding body, corrosion-resistant and conductive materials such as copper or galvanized steel should be selected to ensure that the grounding resistance meets the standards;

[0052] Use a dedicated grounding wire to connect the metal casing of the equipment and the grounding contact to the grounding body, ensure that the buried depth of the grounding body is not less than 0.8 meters, and check whether the grounding connection is firm and reliable, without looseness or corrosion, to ensure a good grounding effect. The dedicated grounding wire should be a multi-strand copper core wire with a cross-sectional area of ​​not less than 2.5 square millimeters to ensure sufficient current passing capacity;

[0053] In addition to checking the grounding resistance, you should also regularly check whether the connection between the grounding wire and the grounding body is firm and whether there is any corrosion or damage.

[0054] The breakdown voltage of the TVS diode in S2 should not be less than 1.2 times the operating voltage of the equipment, and its maximum operating current should be able to meet the protection requirements of the equipment under surge conditions. The breakdown voltage should not be too high to avoid affecting the protection effect. At the same time, the TVS diode should be installed close to the input end of the equipment to reduce the impact of line inductance and resistance on the protection effect, and ensure that there is enough space between the diode and surrounding components to facilitate heat dissipation.

[0055] The thickness of S3 insulation board shall not be less than 1 mm, and the thickness of insulation coating shall not be less than 0.5 mm to ensure sufficient insulation distance and insulation strength. Insulation sleeve shall be made of polyvinyl chloride material with high temperature resistance, wear resistance and good insulation performance. Insulation board shall be made of halogen-free flame retardant material with low dielectric constant, epoxy resin board. Insulation coating shall be made of coating with strong adhesion and good insulation performance, polyurethane coating. At the same time, insulation sleeve, insulation board and insulation coating shall be regularly checked for damage, aging or falling off, and replaced or repaired in time.

[0056] S4 When the output connection device is disconnected, the discharge circuit should discharge the voltage to a safe voltage range below 60V within 1 second to prevent the operator from getting an electric shock due to contact with residual electricity. The discharge circuit is composed of components such as resistors, capacitors or diodes to ensure that the voltage can be quickly discharged to a safe range after the output connection device is disconnected, that is, the discharge circuit should discharge the voltage to below 60V within 1 second.

[0057] The leakage action current of the leakage protection switch in S5 should not be greater than 30 mA. The leakage protection switch is installed at the main power input terminal of the equipment, and the leakage protection switch needs to be a highly sensitive and reliable model. The leakage action current should not be greater than 30 mA to ensure that the power supply can be cut off in time when leakage occurs, so as to protect the entire equipment.

[0058] The temperature sensor in S6, as part of the multiple protection mechanism, should be of high precision and fast response speed. Its measurement range is 0℃ to 100℃, and the accuracy is maintained at ±1℃, and the response time is <1 second;

[0059] When the operating temperature of the load module is detected to be over 75°C, an early warning signal is issued. When the operating temperature of the load module is detected to be over 85°C, the input power is automatically cut off to protect the equipment from high temperature damage.

[0060] The temperature sensor needs to be installed near the heating element in the load module. At the same time, in order to ensure the safe and reliable operation of the equipment, the temperature safety threshold can be appropriately lowered according to factors such as the equipment's operating environment and heat dissipation conditions to increase the safety margin.

[0061] In the voltage monitoring circuit in S6, the measurement range of the voltage monitoring circuit is ±10% of the rated range of the input voltage, the accuracy is ±1V, and the overvoltage alarm threshold is set to 105% of the input voltage rating, the overvoltage cutoff threshold is set to 110% of the input voltage rating, the undervoltage alarm threshold is: 95% of the input voltage rating, the undervoltage cutoff threshold is set to 90% of the input voltage rating, and the response time is <50 milliseconds;

[0062] When the input voltage is detected to exceed 105% of the rated voltage of the load module or when the input voltage is detected to be lower than 95% of the rated voltage of the load module, an alarm is issued; when the input voltage is detected to exceed 110% of the rated voltage of the load module or when the input voltage is detected to be lower than 90% of the rated voltage of the load module, the input power is immediately cut off.

[0063] The maximum current-bearing current of the current sensor in S6 is set to 120%, the measurement range should be 0% to 150% of the rated current of the load module, the measurement accuracy is ±1%, the response time is <20 milliseconds (i.e. the time from detecting overcurrent to cutting off the power supply), and the overcurrent alarm threshold is set to 110% of the rated current of the load module, and the overcurrent cut-off threshold is set to 120% of the rated current of the load module.

[0064] When the current sensor detects that the current exceeds the threshold, the input power is quickly cut off to prevent the equipment from being damaged due to overcurrent. The current sensor is connected in series in the current path of the load module to monitor the current changes in real time.

[0065] Reasonable protection logic should be designed through multiple protection mechanisms to ensure that the input power can be quickly cut off when any abnormal situation is detected, and an alarm signal can be issued at the same time so that the operator can deal with it in time.

[0066] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A safety protection method for an external test interface, characterized in that: The following steps are involved: S1: Safety grounding design, use a dedicated grounding wire to connect the metal casing of the equipment and the grounding contact to the grounding body. S2: Surge protection design, solder a parallel TVS diode on the AC input side of the device. If the device is AC input, use two TVS diodes, one connected between the live wire and the ground, and the other connected between the neutral wire and the ground. S3: Strong and weak current isolation design, use insulating sleeves to connect the strong and weak current circuits. For circuits that are difficult to connect, fix an insulating plate or apply an insulating coating between the two. S4: Residual power discharge function design, a residual power discharge circuit is set in the power output module, when the output connection device is disconnected, the voltage is discharged to below the safe voltage. S5: Equip the device with a leakage protection switch to cut off the power supply immediately once leakage is detected. S6: Multiple protection mechanisms are designed in the load module. When the working state of the load module is detected to be abnormal, such as over-temperature, voltage or current exceeding the set range, the input is automatically cut off. Specifically: a. A temperature sensor is set in the load module. When it is detected that the operating temperature of the load module exceeds the preset safety threshold, the input power is automatically cut off. b. Set up a voltage monitoring circuit at the input end of the load module. When it is detected that the input voltage exceeds or falls below the set safety range, the input power is immediately cut off. c. Connect a current sensor in series in the current path of the load module. When it is detected that the current exceeds the maximum current of the load module, the input power is quickly cut off.

2. The external test interface safety protection method according to claim 1, characterized in that: In the S1, the resistance value of the grounding resistor needs to be checked regularly to ensure that the resistance value of the grounding wire does not exceed 4 ohms.

3. The external test interface safety protection method according to claim 1, characterized in that: The breakdown voltage of the TVS diode in S2 should be no less than 1.2 times the operating voltage of the device, and its maximum operating current should be able to meet the protection requirements of the device under surge conditions.

4. The external test interface safety protection method according to claim 1, characterized in that: The thickness of the S3 insulating board should be no less than 1 mm, and the coating thickness of the insulating coating should be no less than 0.5 mm to ensure sufficient insulation distance and insulation strength.

5. The external test interface safety protection method according to claim 1, characterized in that: When the output connection device of S4 is disconnected, the discharge circuit should discharge the voltage to a safe voltage range below 60V within 1 second to prevent the operator from getting an electric shock due to contact with residual electricity.

6. The external test interface safety protection method according to claim 1, characterized in that: The leakage action current of the leakage protection switch in S5 should not be greater than 30 mA.

7. The external test interface safety protection method according to claim 1, characterized in that: The temperature sensor in S6 automatically cuts off the input power when it detects that the operating temperature of the load module exceeds 85°C.

8. The external test interface safety protection method according to claim 1, characterized in that: In the voltage monitoring circuit in S6, when it is detected that the input voltage exceeds 110% of the rated voltage of the load module or when it is detected that the input voltage is lower than 90% of the rated voltage of the load module, the input power is immediately cut off.

9. The external test interface safety protection method according to claim 1, characterized in that: The current sensor in S6 sets the maximum current of the load module to 120%. When the current sensor detects that the current exceeds the threshold, the input power is quickly cut off.

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