High-voltage injection attack detection system for intelligent electric energy meter

Abstract

The invention provides a high-voltage injection attack detection system for an intelligent electric energy meter, and relates to the technical field of high-voltage attack detection. The system comprises a receiving circuit and a detection circuit, the receiving circuit and the detection circuit are connected in sequence, and the receiving circuit and the detection circuit are packaged in an intelligent electric energy meter; the receiving circuit is used for receiving a high-voltage signal and transmitting the high-voltage signal to the detection circuit through an air gap, and the high-voltage signal is a voltage signal generated by natural factors or human factors; and the detection circuit is used for clamping the high-voltage signal and transmitting the clamped high-voltage signal to the MCU port of the intelligent electric energy meter so as to detect the high-voltage signal. The high-voltage signal identification precision of the detection circuit can be improved.

Description

Technical Field

[0001] This application relates to the technical field of high-voltage attack detection, and particularly to an intelligent electricity meter high-voltage injection attack detection system. Background Art

[0002] With the development of the new power system, the operating environment of intelligent electricity meters is becoming increasingly complex. High-voltage injection attacks caused by natural factors or human interference are easily coupled into the internal circuit through the communication interface (such as RS485 or HPLC) of the intelligent electricity meter, which may lead to damage to the electricity meter, data distortion, or system collapse. High-voltage injection attack incidents occur frequently at the scene, but currently, intelligent electricity meters do not have effective detection means. In order to promote metering fairness and ensure the safe operation of the smart grid, it is urgent to carry out research on the high-voltage injection attack detection technology for intelligent electricity meters. Summary of the Invention

[0003] This application provides an intelligent electricity meter high-voltage injection attack detection system to solve the problem that existing intelligent electricity meters do not have the detection ability for high-voltage injection attacks.

[0004] In a first aspect, this application provides an intelligent electricity meter high-voltage injection attack detection system, which includes:

[0005] A receiving circuit and a detection circuit, the receiving circuit and the detection circuit are connected in sequence, and the receiving circuit and the detection circuit are encapsulated in the intelligent electricity meter;

[0006] The receiving circuit is configured to receive a high-voltage signal and transmit the high-voltage signal to the detection circuit through an air gap, where the high-voltage signal is a voltage signal generated by natural factors or human factors;

[0007] The detection circuit is configured to clamp the high-voltage signal and transmit the clamped high-voltage signal to the MCU port of the intelligent electricity meter for detecting the high-voltage signal.

[0008] In a possible implementation, the receiving circuit includes a 485 communication line;

[0009] The A end of the 485 communication line is connected to the input end of the receiving circuit, and the reference ground of the 485 communication line is connected to the output end of the receiving circuit through the air gap.

[0010] In a possible implementation, the gap distance of the air gap is 1 mm.

[0011] In a possible implementation, the detection circuit includes a transient voltage suppression diode, a voltage dividing circuit, and an integrating capacitor;

[0012] The anode of the transient voltage suppression diode is respectively connected to the input end of the detection circuit and the first input end of the voltage dividing circuit, and the cathode of the transient voltage suppression diode is respectively connected to the second input end of the voltage dividing circuit, the second output end of the voltage dividing circuit, and the first end of the integrating capacitor;

[0013] The first output end of the voltage dividing circuit is respectively connected to the second end of the integrating capacitor and the output end of the detection circuit, and the output end of the detection circuit is connected to the smart energy meter through the MCU port.

[0014] In a possible implementation manner, the voltage dividing circuit includes a first resistor and a second resistor;

[0015] The first end of the first resistor is respectively connected to the first input end of the voltage dividing circuit and the first end of the second resistor, and the second end of the first resistor is connected to the first output end of the voltage dividing circuit;

[0016] The second end of the second resistor is respectively connected to the second input end of the voltage dividing circuit and the second output end of the voltage dividing circuit.

[0017] In a possible implementation manner, the detection circuit is specifically configured to:

[0018] Clamp the high-voltage signal through the transient voltage suppression diode;

[0019] Use the voltage dividing circuit to charge the clamped high-voltage signal to the integrating circuit, and use the integrating capacitor to transfer the stored clamped high-voltage signal to the smart energy meter through the MCU port for detecting the high-voltage signal.

[0020] In a possible implementation manner, the clamped high-voltage signal is the withstand voltage signal of the MCU port.

[0021] In a possible implementation manner, the receiving circuit is further configured to:

[0022] During analog verification, receive the high-voltage signal generated by the interference device through simulation and transfer the high-voltage signal to the detection circuit through the air gap.

[0023] In a possible implementation manner, the interference device includes a DC power supply, a step-up transformer, a third resistor, a fourth resistor, a first capacitor, a first switch, a diode, and a discharge head;

[0024] The first end of the primary side of the step-up transformer is connected to the first end of the first switch, the second end of the primary side of the step-up transformer is connected to the negative pole of the DC power supply, the first end of the secondary side of the step-up transformer is connected to the positive pole of the diode, the second end of the secondary side of the step-up transformer is respectively connected to the first end of the first capacitor and the ground, and the positive pole of the DC power supply is connected to the second end of the first switch;

[0025] The first end of the third resistor is connected to the negative pole of the diode, and the second end of the third resistor is respectively connected to the first end of the fourth resistor and the second end of the first capacitor;

[0026] The second end of the fourth resistor is connected to the first end of the discharge head, and the second end of the discharge head is connected to the output end of the interference device.

[0027] In a possible implementation manner, the detection system further includes a second capacitor and a third capacitor;

[0028] The first end of the second capacitor is connected to the grounding end of the interference device, and the second end of the second capacitor is grounded;

[0029] The first end of the third capacitor is connected to the grounding end of the detection circuit, and the second end of the third capacitor is grounded.

[0030] This application provides an intelligent electricity meter high-voltage injection attack detection system. The detection system includes a receiving circuit and a detection circuit, which are connected in sequence, and the receiving circuit and the detection circuit are encapsulated in the intelligent electricity meter; the receiving circuit is used to receive a high-voltage signal and transmit the high-voltage signal to the detection circuit through an air gap. The high-voltage signal is a voltage signal generated by natural factors or human factors; the detection circuit is used to clamp the high-voltage signal and transmit the clamped high-voltage signal to the MCU port of the intelligent electricity meter for detecting the high-voltage signal. Through this system, this application can effectively simulate a high-voltage injection attack on the intelligent electricity meter. This active defense mechanism can timely discover potential security threats, thereby enhancing the security of the intelligent electricity meter and the power network where it is located. And using the air gap can make the transmission of the high-voltage signal more reliable, thereby improving the recognition accuracy of the detection circuit for the high-voltage signal. At the same time, the detection circuit clamps the high-voltage signal, which can effectively limit the magnitude of the signal and prevent the high-voltage signal from damaging the intelligent electricity meter. In addition, the detection system has the advantages of simple circuit form, low device cost, and remarkable detection effect, improving the early warning ability of the intelligent electricity meter and providing guarantee for the safe operation of the intelligent electricity meter. Description of the Drawings

[0031] To more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0032] Figure 1 is a schematic structural diagram of the high-voltage injection attack detection system for an intelligent electric energy meter provided by an embodiment of the present application;

[0033] Figure 2 is a schematic structural diagram of the voltage dividing circuit provided by an embodiment of the present application;

[0034] Figure 3 is a schematic structural diagram of the high-voltage injection attack detection system for an intelligent electric energy meter after adding an interference device provided by an embodiment of the present application;

[0035] Figure 4 is a schematic structural diagram of the interference device provided by an embodiment of the present application. Detailed implementation manners

[0036] In the following description, for the purpose of illustration rather than limitation, specific details such as specific system structures and technologies are presented to thoroughly understand the embodiments of the present application. However, those skilled in the art should clearly understand that the present application can also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to avoid unnecessary details from interfering with the description of the present application.

[0037] To make the objectives, technical solutions, and advantages of the present application clearer, the following will be described through specific embodiments in conjunction with the drawings.

[0038] Figure 1 is a schematic structural diagram of the high-voltage injection attack detection system for an intelligent electric energy meter provided by an embodiment of the present application. As Figure 1 shown, the high-voltage injection attack detection system for an intelligent electric energy meter includes a receiving circuit 1 and a detection circuit 2. The receiving circuit 1 and the detection circuit 2 are connected in sequence, and the receiving circuit 1 and the detection circuit 2 are encapsulated in the intelligent electric energy meter.

[0039] The receiving circuit 1 is used to receive a high-voltage signal and transmit the high-voltage signal to the detection circuit 2 through an air gap. The high-voltage signal is a voltage signal generated due to natural factors or human factors.

[0040] The detection circuit 2 is used to clamp the high-voltage signal and transmit the clamped high-voltage signal to the MCU port of the intelligent electric energy meter for detecting the high-voltage signal.

[0041] To solve the problem that smart electricity meters do not have the ability to detect high-voltage injection attacks, this application proposes a high-voltage injection attack detection system for smart electricity meters, and its detection principle is based on the air breakdown theory. Among them, air breakdown refers to the phenomenon that under the action of an electric field, air molecules are ionized to form electrons and ions, thereby converting air from an insulator into a conductor. If a discharge point with a certain distance of air gap is designed between the detection circuit and the 485 communication line, the high-voltage injection attack can convert the air from an insulator into a conductor, and then transmit the signal to the MCU port for detection. The embodiments of this application aim to improve the detection ability of high-voltage injection attacks on smart electricity meters and ensure the accurate metering of smart electricity meters.

[0042] Among them, when the system is under high-voltage attacks caused by natural factors or human factors, the high-voltage injection attack detection system for smart electricity meters will be used, which can ensure the safety of smart electricity meters.

[0043] The embodiments of this application utilize the high-voltage injection attack detection system for smart electricity meters to provide a theoretical basis for high-voltage injection attack behaviors, which helps to promote metering fairness and reduce metering disputes.

[0044] Moreover, the high-voltage injection attack detection system for smart electricity meters provided by the embodiments of this application has the advantages of simple structure, low device cost, and remarkable detection effect, improving the early warning ability of smart electricity meters and providing guarantee for the safe operation of smart electricity meters.

[0045] The embodiments of this application can specifically detect high-voltage signal injection attacks caused by external factors such as nature and human, effectively prevent these high-voltage signals from damaging the internal circuit of the smart electricity meter, thereby protecting the normal operation of the smart electricity meter. And through the cooperation of the receiving circuit and the detection circuit, the system can accurately identify and process high-voltage signals, avoid interfering with the metering and communication functions of the electricity meter, and ensure the accuracy and reliability of the data.

[0046] In addition, through special receiving and detection circuits, high-voltage injection attacks can be effectively identified and responded to, which is crucial for smart electricity meters. Therefore, it can prevent malicious attackers from destroying or tampering with the metering data of the electricity meter through high-voltage injection means, thereby ensuring the accuracy and fairness of metering and maintaining the safety and stability of power supply and use.

[0047] Then, the embodiments of this application connect the detection circuit to the MCU port of the smart electricity meter to achieve real-time monitoring and data analysis of high-voltage signals. And through the processing of the MCU, the system can timely detect and respond to high-voltage injection attacks, take necessary protection measures, and improve the self-protection ability of the electricity meter.

[0048] Furthermore, in the embodiments of the present application, the high-voltage injection attack detection system is encapsulated inside the smart electricity meter, enabling it to be conveniently integrated into existing electricity meter products. This design not only simplifies the installation and debugging processes but also reduces additional hardware costs, facilitating the wide application and popularization of the system. Meanwhile, through the collaborative operation of the receiving circuit and the detection circuit, the embodiments of the present application can effectively isolate and process high-voltage signals, preventing them from directly acting on other circuit parts of the smart electricity meter. This not only protects the circuit from high-voltage damage but also extends the service life of the electricity meter.

[0049] In a possible implementation, referring to Figure 1 , the receiving circuit 1 may include a 485 communication line, namely 485GND.

[0050] The A end of the 485 communication line is connected to the input end of the receiving circuit 1, and the reference ground of the 485 communication line is connected to the output end of the receiving circuit 1 through an air gap.

[0051] In the prior art, when the smart electricity meter performs ordinary voltage detection, ordinary voltage signals do not enter the smart electricity meter through the 485GND terminal, and 485GND is only used for data copying. However, in the embodiments of the present application, the receiving circuit plays a role in transmitting high-voltage signals and can transfer the high-voltage signals to the subsequent detection circuit 2 through the provided air gap.

[0052] Among them, the gap distance of the air gap is 1 mm.

[0053] In the embodiments of the present application, this gap distance is determined through actual on-site measurement.

[0054] The embodiments of the present application utilize the air gap to transfer high-voltage signals, avoiding potential safety hazards that may be brought by direct electrical connection and improving the anti-interference performance at the same time.

[0055] In a possible implementation, referring to Figure 1 , the detection circuit 2 may include a transient voltage suppression diode TVS1, a voltage dividing circuit 21, and an integrating capacitor C1.

[0056] The anode of the transient voltage suppression diode TVS1 is respectively connected to the input end of the detection circuit 2 and the first input end a1 of the voltage dividing circuit 21, and the cathode of the transient voltage suppression diode TVS1 is respectively connected to the second input end a2 of the voltage dividing circuit 21, the second output end b2 of the voltage dividing circuit 21, and the first end of the integrating capacitor C1;

[0057] The first output end b1 of the voltage dividing circuit 21 is respectively connected to the second end of the integrating capacitor C1 and the output end of the detection circuit 2, and the output end of the detection circuit 2 is connected to the smart electricity meter through the MCU port.

[0058] Among them, a Transient Voltage Suppressor (TVS) is an overvoltage protection device with bidirectional voltage regulation characteristics and bidirectional negative resistance characteristics, similar to a varistor. It is applied to various AC and DC power supply circuits to suppress instantaneous overvoltage. When a surge pulse voltage appears instantaneously in the protected circuit, the bidirectional breakdown diode can quickly break down in a Zener manner, changing from a high-resistance state to a low-resistance state, shunting and clamping the surge voltage, thereby protecting the components in the circuit from being damaged by the instantaneous surge pulse voltage.

[0059] Optionally, the detection circuit in this embodiment plays a role in signal clamping and signal maintenance. The transient voltage suppression diode TVS1 can clamp the high-voltage signal transmitted by the receiving circuit to protect the MCU port. Then, a charge-discharge circuit is formed by using the voltage-dividing circuit 21 and the integrating capacitor C1, which can play a role in maintaining the signal output to the MCU port and improve the detection success rate of the MCU port.

[0060] Among them, the structure of the voltage-dividing circuit refers to Figure 2 As shown, the voltage-dividing circuit 21 may include a first resistor R1 and a second resistor R2.

[0061] The first end of the first resistor R1 is respectively connected to the first input terminal a1 of the voltage-dividing circuit 21 and the first end of the second resistor R2, and the second end of the first resistor R1 is connected to the first output terminal b1 of the voltage-dividing circuit 21;

[0062] The second end of the second resistor R2 is respectively connected to the second input terminal a2 of the voltage-dividing circuit 21 and the second output terminal b2 of the voltage-dividing circuit 21.

[0063] In a possible implementation manner, the detection circuit can specifically be used for:

[0064] Clamping the high-voltage signal through the transient voltage suppression diode;

[0065] Using the voltage-dividing circuit to charge the clamped high-voltage signal to the integrating circuit, and using the integrating capacitor to transfer the stored clamped high-voltage signal to the smart energy meter through the MCU port for detecting the high-voltage signal.

[0066] Optionally, based on Figure 1 and Figure 2 the detection circuit structure in, the process executed by the detection circuit is as follows:

[0067] First, use the transient voltage suppression diode TVS1 to clamp the high-voltage signal transmitted by the receiving circuit.

[0068] Then, charge the clamped high-voltage signal to the integrating capacitor C1 through the voltage-dividing circuit 21.

[0069] Finally, the stored and clamped high-voltage signal is sent to the MCU port of the smart energy meter by using the integrating capacitor C1 to detect the high-voltage signal.

[0070] Among them, since the smart energy meter needs to be protected from breakdown, it is required that the high-voltage signal after clamping is the withstand voltage signal of the MCU port.

[0071] The detection circuit in the embodiment of the present application can clamp the received high-voltage signal and transmit it to the MCU port of the smart energy meter for further detection, which means that this embodiment can monitor the change of the high-voltage signal in real time and respond quickly when an abnormality is found, thus effectively preventing potential security threats. Moreover, the detection circuit clamps the high-voltage signal, which can also limit the amplitude and duration of the high-voltage signal, thereby reducing its impact and influence on the internal circuit of the energy meter.

[0072] In a possible implementation manner, the receiving circuit can also be used for:

[0073] During analog verification, the receiving circuit receives the high-voltage signal generated by the interference device simulation and transmits the high-voltage signal to the detection circuit through the air gap.

[0074] Optionally, when verifying the high-voltage injection attack detection system of the smart energy meter, the high-voltage signal simulated by the interference device can be sent to the receiving circuit, and the simulated high-voltage signal is transmitted to the detection circuit through the receiving circuit.

[0075] Among them, the connection relationship between the interference device and the high-voltage injection attack detection system of the smart energy meter refers to Figure 3 As shown, the interference device 3 transmits the simulated high-voltage signal from 485GND to the receiving circuit.

[0076] In a possible implementation manner, referring to Figure 4 , the interference device 3 may include a DC power supply 31, a step-up transformer 32, a third resistor R3, a fourth resistor R4, a first capacitor C2, a first switch K1, a diode D1, and a discharge head;

[0077] The first end of the primary side of the step-up transformer 32 is connected to the first end of the first switch K1, the second end of the primary side of the step-up transformer 32 is connected to the negative pole of the DC power supply 31, the first end of the secondary side of the step-up transformer 32 is connected to the positive pole of the diode D1, the second end of the secondary side of the step-up transformer 32 is respectively connected to the first end of the first capacitor C2 and the ground, and the positive pole of the DC power supply 31 is connected to the second end of the first switch K1;

[0078] The first end of the third resistor R3 is connected to the negative pole of the diode D1, and the second end of the third resistor R3 is respectively connected to the first end of the fourth resistor R4 and the second end of the first capacitor C2;

[0079] The second end of the fourth resistor R4 is connected to the first end of the discharge head, and the second end of the discharge head is connected to the output end of the interference device 3.

[0080] Optionally, after the first switch K1 is closed, the DC power supply 31 in the interference device 3 is converted into a high-voltage signal through the step-up transformer 32. The high-voltage signal continuously charges the first capacitor C2 through the third resistor R3, and the first capacitor C2 continuously releases the transient high-voltage signal stored therein to the receiving circuit through the fourth resistor R4 and the discharge head.

[0081] Wherein, a diode is arranged in the interference device. The purpose is that since the electric energy stored in the second capacitor has two flowing directions, in order to avoid the backflow of electric energy and the flow to the discharge head side, a diode is arranged between the step-up transformer and the third resistor.

[0082] In a possible implementation manner, with reference to Figure 3 , the detection system may further include a second capacitor C3 and a third capacitor C4;

[0083] The first end of the second capacitor C3 is connected to the grounding end of the interference device 3, and the second end of the second capacitor C3 is grounded;

[0084] The first end of the third capacitor C4 is connected to the grounding end of the detection circuit 2, and the second end of the third capacitor C4 is grounded.

[0085] Since the detection principle is based on the air breakdown theory, a loop needs to be formed among the interference device, the receiving circuit, the detection circuit and the ground. Therefore, in the embodiments of the present application, in order to meet the requirements of the air breakdown theory, a second capacitor C3 and a third capacitor C4 are respectively arranged between the ground and the interference device and the detection circuit to form a closed path.

[0086] The high-voltage injection attack detection system for the smart electricity meter in the embodiments of the present application further enhances the electrical stability and reliability of the smart electricity meter by introducing components such as the second capacitor and the third capacitor. These capacitor components can absorb and release electric energy, balance the voltage fluctuations in the circuit, thereby protecting the smart electricity meter from the interference of external factors such as voltage instability.

[0087] Exemplarily, in actual engineering applications, a continuous DC power supply is used to simulate the on-site high-voltage injection attack scenario to test and verify the high-voltage injection detection circuit. The test mode selects the continuous discharge mode, the test level is 10 kV, a high-voltage injection signal is continuously applied to 485GND, 10 times are collected in one cycle, and the corresponding event records are read through 485 after the test. The results show that there are 10 high-voltage injection attack events, and the detection success rate is 100%.

[0088] The present application provides an intelligent electric energy meter high-voltage injection attack detection system. The detection system includes a receiving circuit and a detection circuit, which are connected in sequence, and the receiving circuit and the detection circuit are encapsulated in the intelligent electric energy meter; the receiving circuit is used to receive a high-voltage signal and transmit the high-voltage signal to the detection circuit through an air gap. The high-voltage signal is a voltage signal generated due to natural factors or human factors; the detection circuit is used to clamp the high-voltage signal and transmit the clamped high-voltage signal to the MCU port of the intelligent electric energy meter for detecting the high-voltage signal. Through this system, the present application can effectively simulate a high-voltage injection attack on the intelligent electric energy meter. This active defense mechanism can timely discover potential security threats, thereby enhancing the security of the intelligent electric energy meter and the power network where it is located. Moreover, the use of an air gap can make the transmission of the high-voltage signal more reliable, thereby improving the recognition accuracy of the detection circuit for the high-voltage signal. At the same time, the detection circuit clamps the high-voltage signal, which can effectively limit the magnitude of the signal and prevent the high-voltage signal from damaging the intelligent electric energy meter. In addition, the detection system has the advantages of simple circuit form, low device cost, and remarkable detection effect, improving the early warning ability of the intelligent electric energy meter and providing guarantee for the safe operation of the intelligent electric energy meter.

[0089] It should be understood that the magnitudes of the sequence numbers of the steps in the above embodiments do not mean the order of execution. The order of execution of each process should be determined according to its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

[0090] In the above embodiments, the descriptions of the respective embodiments have their own emphases. For the parts not detailed or recorded in a certain embodiment, reference may be made to the relevant descriptions of other embodiments.

[0091] Those of ordinary skill in the art can realize that the templates, units, and algorithm steps of the examples described in combination with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present invention.

[0092] If the module / unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, to implement all or part of the processes in the above-described embodiment methods of the present invention, it can also be completed by a computer program instructing relevant hardware. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by a processor, the steps of the above-described various embodiments of the network measurement method based on a two-stage and three-level sketch can be implemented. Among them, the computer program includes computer program code, and the computer program code can be in the form of source code, object code, executable file, or some intermediate form, etc. The computer-readable medium can include: any entity or device capable of carrying the computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disc, computer memory, read-only memory, random access memory, electrical carrier signal, telecommunication signal, and software distribution medium, etc.

[0093] The above-described embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A smart energy meter high voltage injection attack detection system, characterized in that: include: A receiving circuit and a detecting circuit, wherein the receiving circuit and the detecting circuit are connected in sequence, and the receiving circuit and the detecting circuit are packaged in a smart electric energy meter; The receiving circuit is used to receive a high-voltage signal and transmit the high-voltage signal to the detection circuit through an air gap, wherein the high-voltage signal is a voltage signal generated by natural factors or human factors; The detection circuit is used to clamp the high-voltage signal and transmit the clamped high-voltage signal to the MCU port of the smart electric energy meter to detect the high-voltage signal.

2. The intelligent electric energy meter high voltage injection attack detection system according to claim 1 is characterized in that: The receiving circuit includes a 485 communication line; The A end of the 485 communication line is connected to the input end of the receiving circuit, and the reference ground of the 485 communication line is connected to the output end of the receiving circuit through the air gap.

3. The intelligent electric energy meter high voltage injection attack detection system according to claim 1 is characterized in that: The gap distance of the air gap is 1 mm.

4. The intelligent electric energy meter high voltage injection attack detection system according to claim 1 is characterized in that: The detection circuit includes a transient voltage suppression diode, a voltage divider circuit and an integral capacitor; The anode of the transient voltage suppression diode is respectively connected to the input end of the detection circuit and the first input end of the voltage divider circuit, and the cathode of the transient voltage suppression diode is respectively connected to the second input end of the voltage divider circuit, the second output end of the voltage divider circuit and the first end of the integration capacitor; The first output end of the voltage divider circuit is connected to the second end of the integral capacitor and the output end of the detection circuit respectively, and the output end of the detection circuit is connected to the smart electric energy meter through the MCU port.

5. The intelligent electric energy meter high voltage injection attack detection system according to claim 4 is characterized in that: The voltage divider circuit includes a first resistor and a second resistor; The first end of the first resistor is connected to the first input end of the voltage divider circuit and the first end of the second resistor respectively, and the second end of the first resistor is connected to the first output end of the voltage divider circuit; The second end of the second resistor is connected to the second input end of the voltage divider circuit and the second output end of the voltage divider circuit respectively.

6. The intelligent electric energy meter high voltage injection attack detection system according to claim 4 is characterized in that: The detection circuit is specifically used for: Clamping the high voltage signal by the transient voltage suppression diode; The voltage divider circuit is used to charge the clamped high-voltage signal to the integration circuit, and the integration capacitor is used to transfer the stored clamped high-voltage signal to the smart electric energy meter through the MCU port to detect the high-voltage signal.

7. The intelligent electric energy meter high voltage injection attack detection system according to claim 6 is characterized in that: The clamped high voltage signal is a withstand voltage signal of the MCU port.

8. The intelligent electric energy meter high voltage injection attack detection system according to claim 1 is characterized in that: The receiving circuit is also used for: During the simulation verification, a high voltage signal simulated by the interference device is received, and the high voltage signal is transmitted to the detection circuit through the air gap.

9. The intelligent electric energy meter high voltage injection attack detection system according to claim 8, characterized in that: The interference device includes a DC power supply, a step-up transformer, a third resistor, a fourth resistor, a first capacitor, a first switch, a diode and a discharge head; The first end of the primary side of the step-up transformer is connected to the first end of the first switch, the second end of the primary side of the step-up transformer is connected to the negative electrode of the DC power supply, the first end of the secondary side of the step-up transformer is connected to the positive electrode of the diode, the second end of the secondary side of the step-up transformer is connected to the first end of the first capacitor and the ground respectively, and the positive electrode of the DC power supply is connected to the second end of the first switch; The first end of the third resistor is connected to the cathode of the diode, and the second end of the third resistor is connected to the first end of the fourth resistor and the second end of the first capacitor respectively; The second end of the fourth resistor is connected to the first end of the discharge head, and the second end of the discharge head is connected to the output end of the interference device.

10. The intelligent electric energy meter high voltage injection attack detection system according to claim 8, characterized in that: The detection system also includes a second capacitor and a third capacitor; A first end of the second capacitor is connected to a ground terminal of the interference device, and a second end of the second capacitor is grounded; A first end of the third capacitor is connected to the ground end of the detection circuit, and a second end of the third capacitor is grounded.

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