Method for safely connecting photovoltaic inverter to power grid information system and secure communication connector

Abstract

The present invention proposes a method and a secure communication connector for securely connecting a photovoltaic inverter to a power grid information system. The method includes: when sensing that a first interface is connected to a photovoltaic inverter via a plug-in operation switch, determining whether a first connection event or a reconnection event is triggered; the plug-in operation switch and the first interface are arranged on a secure communication connector, and the secure communication connector is also provided with a second interface; when the first connection event is triggered, a unique identity for the photovoltaic inverter connected for the first time is constructed, the constructed unique identity is stored in an ESAM security unit, and the photovoltaic inverter connected for the first time is controlled to communicate with the power grid information system; when the reconnection event is triggered, the unique identity stored in the ESAM security unit is used to authenticate the photovoltaic inverter connected again; after the photovoltaic inverter connected again is authenticated, the photovoltaic inverter connected again is controlled to communicate with the power grid information system. This is beneficial to reducing the information security risk when the photovoltaic inverter is connected to the power grid.

Description

Technical Field

[0001] The present invention relates to the technical field of inverter grid connection, and in particular to a method for safely connecting a photovoltaic inverter to a power grid information system and a safety communication connector. Background Art

[0002] Low-voltage distributed photovoltaic inverters are mostly user assets and are the power supply for the inverter side. Similar to self-provided power plants, distributed photovoltaics have the characteristics of small capacity, large number, large load fluctuation, many grid connection points, and difficulty in adjustment.

[0003] In order to give full play to the flexible and adjustable characteristics of new energy loads, the grid-connected management and control of distributed photovoltaic inverters have been carried out. During the adjustment and control process, there are currently information security risks such as maliciously changing the identity of the inverter and forging grid-connected information through the inverter communication stick.

[0004] In order to reduce information security risks, it is urgent to propose a technical solution that can enable the inverter to be safely connected to the power grid information system without modifying the user's photovoltaic inverter. Summary of the invention

[0005] In view of this, the present invention proposes a method for safely connecting a photovoltaic inverter to a power grid information system and a secure communication connector, aiming to solve the problem of insufficient security of connecting an inverter to a power grid information system in the prior art.

[0006] In a first aspect, the present invention provides a method for safely connecting a photovoltaic inverter to a power grid information system, comprising:

[0007] When it is sensed that the first interface is connected to the photovoltaic inverter via the plug-in operation switch, it is determined whether a first connection event or a reconnection event is triggered; wherein the plug-in operation switch and the first interface are arranged on a safety communication connector, and the safety communication connector is further provided with a second interface, and the second interface is connected to the power grid information system;

[0008] When the first connection event is triggered, a unique identity for the photovoltaic inverter connected for the first time is constructed, the constructed unique identity is stored in the ESAM security unit, and the photovoltaic inverter connected for the first time is controlled to communicate with the power grid information system; wherein the ESAM security unit is arranged at the security communication connector;

[0009] When a reconnection event is triggered, the reconnected photovoltaic inverter is authenticated using the unique identity stored in the ESAM security unit; after the reconnected photovoltaic inverter passes the authentication, the reconnected photovoltaic inverter is controlled to communicate with the power grid information system.

[0010] Further, the determining whether a first connection event or a reconnection event is triggered includes:

[0011] Acquire an access status flag, wherein the access status flag is stored in the ESAM security unit. When the ESAM security unit is initialized, the access status flag is set to an initial value, and the initial value is used to indicate that the ESAM security unit is not bound to the photovoltaic inverter;

[0012] When the access state flag value is the same as the initial value, determining to trigger a first connection event; after the first connection event is triggered, updating the access state flag value to the unique identity constructed for the photovoltaic inverter connected for the first time;

[0013] When the access status flag value is different from the initial value, it is determined to trigger a reconnection event.

[0014] Furthermore, the step of constructing a unique identity of the photovoltaic inverter connected for the first time includes:

[0015] Sending a first basic information request message to the photovoltaic inverter connected for the first time;

[0016] Receiving a first basic information response message sent by a photovoltaic inverter connected for the first time; the first basic information response message records basic information of the photovoltaic inverter connected for the first time;

[0017] Extracting basic information of the photovoltaic inverter from the first basic information response message, processing the extracted basic information of the photovoltaic inverter using the encryption and decryption algorithm built into the ESAM security unit, generating a first hash value as a unique identity for the photovoltaic inverter connected for the first time;

[0018] The extracted basic information of the photovoltaic inverter includes at least one of the following: photovoltaic inverter device type, photovoltaic inverter hardware serial number, photovoltaic inverter model, photovoltaic inverter software version number, and photovoltaic inverter MAC address.

[0019] Further, the authenticating the reconnected photovoltaic inverter using the unique identity stored in the ESAM security unit includes:

[0020] Sending a second basic information request message to the photovoltaic inverter that is connected again;

[0021] Receive a second basic information response message sent by the reconnected photovoltaic inverter; the second basic information response message records the basic information of the reconnected photovoltaic inverter:

[0022] Extracting the photovoltaic inverter basic information from the second basic information response message, processing the extracted photovoltaic inverter basic information using the encryption and decryption algorithm built into the ESAM security unit, and generating a second hash value;

[0023] When the second hash value is consistent with the first hash value, it is determined that the reconnected photovoltaic inverter has passed the authentication.

[0024] Furthermore, the step of constructing a unique identity of the photovoltaic inverter connected for the first time includes:

[0025] Obtaining initial network traffic between a photovoltaic inverter connected for the first time and the power grid information system in a specified scenario;

[0026] Extracting the time intervals of arrival of multiple data packets in the initial network traffic, using the time intervals of arrival of multiple data packets to train a probability distribution model of the time intervals of arrival of data packets using a machine learning algorithm, and determining a standard mean of the time intervals of arrival of data packets;

[0027] The determined standard mean value of the data packet arrival time interval is used as a unique identification mark for the photovoltaic inverter connected for the first time.

[0028] Further, the authenticating the reconnected photovoltaic inverter using the unique identity stored in the ESAM security unit includes:

[0029] Acquire the detection network traffic of the reconnected photovoltaic inverter and the power grid information system in the specified scenario;

[0030] Extracting the arrival time intervals of multiple data packets in the detected network traffic, using a machine learning algorithm to train a probability distribution model of the data packet arrival time interval using the arrival time intervals of multiple data packets, and determining a detection mean of the data packet arrival time interval;

[0031] When the detected mean value is consistent with the standard mean value, it is determined that the reconnected photovoltaic inverter has passed the authentication.

[0032] Furthermore, the step of constructing a unique identity of the photovoltaic inverter connected for the first time includes:

[0033] Sending a first hardware serial number request message to the photovoltaic inverter connected for the first time;

[0034] Receiving a first hardware serial number response message sent by a photovoltaic inverter connected for the first time;

[0035] Extracting the photovoltaic inverter hardware serial number from the received first hardware serial number response message, processing the photovoltaic inverter hardware serial number using the encryption and decryption algorithm built into the ESAM security unit, and generating a data write-back tag;

[0036] The data write-back tag is used as a unique identification of the photovoltaic inverter that is connected for the first time, and is sent to the photovoltaic inverter that is connected for the first time, so that the photovoltaic inverter that is connected for the first time embeds the data write-back tag in the tag bit of the data format when sending electrical data.

[0037] Further, the authenticating the reconnected photovoltaic inverter using the unique identity stored in the ESAM security unit includes:

[0038] Get the electrical data sent by the reconnected PV inverter;

[0039] Extracting the data source tag recorded in the tag bit from the data format of the electrical data sent by the reconnected PV inverter;

[0040] When the data source tag is compared and consistent with the data write-back tag, it is determined that the reconnected photovoltaic inverter has passed the authentication.

[0041] Further, controlling the photovoltaic inverter connected for the first time to communicate with the power grid information system includes:

[0042] Acquiring electrical data sent by the photovoltaic inverter connected for the first time through a photovoltaic upstream channel;

[0043] Verifying the electrical data, encrypting and / or converting the verified electrical data into a protocol, and sending the data to the power grid information system;

[0044] Controlling the reconnected photovoltaic inverter to communicate with the grid information system includes:

[0045] Acquiring electrical data sent by the reconnected photovoltaic inverter through a photovoltaic uplink channel;

[0046] The electrical data is verified, the verified electrical data is encrypted and / or protocol converted, and sent to the power grid information system.

[0047] In a second aspect, the present invention provides a secure communication connector for connecting a photovoltaic inverter to a power grid information system;

[0048] The secure communication connector comprises:

[0049] A first interface, used for connecting to a photovoltaic inverter;

[0050] A second interface, used for connecting to the power grid information system;

[0051] A cable body, wherein the first interface and the second interface are respectively arranged at two ends of the cable body;

[0052] A plug-in operation switch, the plug-in operation switch is close to the first interface or far away from the second interface, and is used to control the first interface to maintain connection with the photovoltaic inverter or control the first interface to disconnect from the photovoltaic inverter;

[0053] ESAM security unit, the ESAM security unit has at least one of the following encryption and decryption algorithms built in: SM1 encryption and decryption algorithm, SM2 encryption and decryption algorithm, SM3 encryption and decryption algorithm, SM4 encryption and decryption algorithm;

[0054] A state quantity sensing element is connected to the plug-in operation switch, and generates a connection maintaining message when the first interface is connected to the photovoltaic inverter; and generates a connection disconnection message when the first interface is disconnected from the photovoltaic inverter;

[0055] The processing unit is connected to the ESAM security unit and the state quantity sensing element, and is used to obtain the connection maintenance message, sense that the first interface is connected to the photovoltaic inverter through the plug-in operation switch, and use the method described in the first aspect to connect the photovoltaic inverter connected to the first interface to the power grid information system.

[0056] In a third aspect, the present invention provides a terminal, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the method described in the first aspect.

[0057] In a fourth aspect, the present invention provides a computer storage medium storing computer controllable instructions, wherein the computer controllable instructions are used to execute the method described in the first aspect.

[0058] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0060] Figure 1A A schematic diagram of a photovoltaic inverter securely connected to a power grid information system and a photovoltaic control scenario according to an embodiment of the present invention;

[0061] Figure 1B A schematic diagram of the deployment of distributed photovoltaic inverters to securely access the grid information system;

[0062] Figure 2A schematic diagram of the composition of a secure communication connector according to an embodiment of the present invention;

[0063] Figure 3A It is a schematic diagram of a side view of a safety communication connector according to an embodiment of the present invention when the plug-in operation switch is in a disconnected or free state;

[0064] Figure 3B It is a schematic diagram of a top view of a safety communication connector according to an embodiment of the present invention when the plug-in operation switch is in a disconnected or free state;

[0065] Figure 3C It is a partial enlarged view of the safety communication connector of the embodiment of the present invention when the plug-in operation switch is in a disconnected or free state from a top view;

[0066] Figure 4A It is a schematic diagram of a safety communication connector according to an embodiment of the present invention in a side view when the plugging and unplugging operation switch is in a connection holding or locking state;

[0067] Figure 4B It is a schematic diagram of a safety communication connector according to an embodiment of the present invention in a top view when the plugging and unplugging operation switch is in a connection holding or locking state;

[0068] Figure 4C A partial cross-sectional schematic diagram of a safety communication connector according to an embodiment of the present invention in a side view when the plugging and unplugging operation switch is in a connection holding or locking state;

[0069] Figure 5 A schematic flow chart of a method for safely connecting a photovoltaic inverter to a power grid information system according to an embodiment of the present invention;

[0070] Figure 6 A schematic diagram of a flow chart of determining when a first connection event or a reconnection event is triggered in a method for safely connecting a photovoltaic inverter to a power grid information system according to an embodiment of the present invention;

[0071] Figure 7 A schematic diagram of a process of binding a secure communication connector to an inverter in a method for securely connecting a photovoltaic inverter to a power grid information system according to an embodiment of the present invention;

[0072] Figure 8 A schematic diagram of a flow chart of a method for securely connecting a photovoltaic inverter to a power grid information system according to an embodiment of the present invention, in which a secure communication connector controls the inverter to communicate with a power grid information system;

[0073] Fig.9A A schematic diagram of a process when a secure communication connector is connected for the first time or again in a method for securely connecting a photovoltaic inverter to a power grid information system according to an embodiment of the present invention;

[0074] Fig. 9BIt is a schematic diagram of the process of connecting and communicating between a secure communication connector and a photovoltaic inverter in a method for securely connecting a photovoltaic inverter to a power grid information system according to an embodiment of the present invention;

[0075] Fig. 9C It is a schematic diagram of the process of identity authentication when the secure communication connector is connected to the photovoltaic inverter again in the method for securely connecting the photovoltaic inverter to the power grid information system according to an embodiment of the present invention;

[0076] Fig.10 The present invention is a schematic diagram of the composition of a terminal for applying the method for securely connecting a photovoltaic inverter to a power grid information system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0077] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0078] The Embedded Secure Access Module (ESAM) security unit, ESAM security unit or national secret security chip can be a variety of commercially available security chips certified by the National Cryptography Administration.

[0079] For example, a certain type of high-speed, high-performance 32-bit information security high-speed stream encryption chip integrates security algorithms and communication interfaces, which greatly improves the speed of data stream encryption and decryption, and is suitable for high-speed data stream encryption. This information security high-speed stream encryption chip has the following four features: 1). High-speed data stream encryption, the encrypted transmission speed can be as high as 20MByte / s; 2) It has a USB host interface and two USB-OTG interfaces, which can be set as Host or Device according to application requirements; up to 6 endpoints, which can be set as multiple composite devices; 3) Rich interfaces, in addition to the keyboard controller interface and 2-way USB-OTG interface, it also supports 2 SPI high-speed master / slave interfaces, 32 I / O interfaces (including 8 interrupt I / O interfaces), Nand Flash interface with ECC check, I 2 C interface and UART interface can meet the board-level communication needs; 4) The algorithm is comprehensive, integrating various information security algorithms such as SM1, SM2, SM3, SM4, DES and RSA.

[0080] For example, a certain type of ESAM security unit has sensors, independent internal clocks, SFI detection mechanisms, passive and active shields, glue logic, handshake circuits, high-density multi-layer technology, metal shielding protection layer, internal data self-destruction after detecting external attacks, bus and memory encryption, virtual address, chip anti-tampering design, unique serial number, hardware error detection, random number generator, predictive power analysis and other security structures, and also has hardware security features such as anti-detection, anti-attack, and self-destruction. And this type of ESAM security unit has secure file key storage, perfect security mechanism, standard encryption algorithm, and can realize multiple functions such as identity two-way authentication, data encryption and decryption, decentralized key derivation, internal decentralized key, digital signature, electronic wallet, transmission line protection, and data security storage.

[0081] The SM3 algorithm was released by the State Cryptography Administration on December 17, 2010. It is a cryptographic hash function standard. Related standards include GM / T0004-2012 SM3 Cryptographic Hash Algorithm. Hash value, also known as hash value or hash value, is a fixed-length output value obtained by converting input data of any length through a specific hash algorithm. Since the output hash value or hash value space is usually much smaller than the input space, this conversion is a compression mapping. Therefore, different inputs may hash to the same output, which also means that it is impossible to uniquely determine the corresponding input value from the hash value. Therefore, hash values ​​are widely used in information security, data encryption, file verification and other fields.

[0082] Message Authentication Code (MAC) technology is used to verify the origin and nature of a message. MACs use authenticated encryption to verify the legitimacy of data sent over a network. In this way, MAC ensures that the message comes from the correct sender and has not been tampered with along the way.

[0083] Low-voltage (380V or 220V) distributed photovoltaics (such as household distributed photovoltaics, which include photovoltaic panels and photovoltaic inverters) are mostly user assets, installed inside the user, and are the inverter-side power supply. They have the characteristics of small capacity, large number, large load fluctuation, many grid connection points, and difficulty in adjustment.

[0084] In order to solve the problems of deteriorating power quality and increased difficulty in regulation caused by large-scale access of low-voltage distributed photovoltaics, give full play to the flexible and adjustable characteristics of distributed photovoltaics, ensure the safe and stable operation of the power grid, and improve the collection and monitoring capabilities of low-voltage distributed photovoltaics, the low-voltage distributed photovoltaic layered and graded regulation technology implementation plan specifies the equipment selection and master station function requirements, and proposes data collection configuration, communication networking solutions and layered and graded regulation strategies to guide the construction of low-voltage distributed photovoltaic group regulation and control capabilities, and to help the healthy development of new power systems.

[0085] On the other hand, with the access of a large number of distributed photovoltaic devices to the power grid information system, the interaction between the grid side and the inverter side becomes more frequent and the content of the interaction becomes richer. For example, flexible regulation of photovoltaic power generation active power, reactive power and voltage output can be achieved through extended acquisition and control of photovoltaic inverters.

[0086] The power grid information system includes the power consumption information collection system, the collection master station, and the concentrator. Figure 1B As shown, the photovoltaic inverter 10 is connected to the concentrator 20 via a cable 30. Figure 1A , Figure 1B As shown, P concentrators are connected to the power grid information system through the network. There are upstream channels A and downstream channels A between Q photovoltaic inverters and the concentrator to transmit Modbus protocol messages. There are upstream channels B and downstream channels B between the concentrator and the power grid information system to transmit DL / T698 series protocol messages. Where P and Q are natural numbers, and P is not less than Q.

[0087] The photovoltaic inverter collects data and sends the collected electrical data to the concentrator through the upstream channel A. The concentrator processes the received data and sends the processed data to the power grid information system through the upstream channel B. The power grid information system receives, generates or sends control instructions for the photovoltaic inverter and sends the control instructions to the concentrator through the downstream channel B. The concentrator processes the received control instructions and sends the processed control instructions to the photovoltaic inverter through the downstream channel A.

[0088] like Figure 1B As shown, the photovoltaic inverter and the concentrator are connected via a cable 30, and the body of the cable 30 and the connectors on both sides (including the inverter side connector and the concentrator side connector) are exposed to the outside of the inverter or the external natural environment. Figure 1A Under the communication architecture design shown, the existing distributed photovoltaic field deployment technology has the following problems that affect the security of the power grid information system:

[0089] a) It is difficult for the grid information system to remotely detect the plugging and unplugging operations on the inverter side, such as replacing the PV inverter connected to the concentrator with another inverter, such as replacing the concentrator connected to the PV inverter. If an attacker maliciously connects a legitimate cable connected to the concentrator authorized by the grid to an uncertified PV inverter, it will cause chaos in the grid asset management, economic losses, and even disrupt the normal and safe operation of the grid.

[0090] b) Some PV inverters have system vulnerabilities. Attackers can exploit these system vulnerabilities to establish a connection with the data acquisition stick of the PV inverter (the PV inverter is usually bundled with a data acquisition stick when it leaves the factory), forge the PV inverter status information, and send the forged PV inverter status information to the power grid information system through the PV inverter's uplink channel A and the concentrator, causing the power grid information system to obtain false electrical data or status information, resulting in the power grid information system making erroneous group dispatching and group control decisions, and even causing economic losses.

[0091] c) When controlling distributed photovoltaic inverters, the electrical data uploaded by the photovoltaic inverters and the control instructions issued by the power grid information system are mostly transmitted in plain text, which poses a great security risk, such as key data being leaked and then stolen and / or data being tampered with. There are many low-voltage distributed photovoltaic inverters and many grid-connected points. Once large-scale theft and tampering are formed, it will endanger the safe and stable operation of the regional power grid.

[0092] With reference to the above description, in order to address the problems of cables being exposed, plugging and unplugging operations being difficult to detect, malicious access being difficult to detect, inverter identities lacking authentication, and difficulty in effectively ensuring data security that exist during the hierarchical and graded regulation (or group regulation and control) of a large number of photovoltaic inverters connected to the grid, the present invention proposes a technical solution for securely connecting photovoltaic inverters to a power grid information system, including a secure communication connector with an embedded ESAM security unit, a method for securely connecting photovoltaic inverters to a power grid information system, a terminal, and a computer storage medium.

[0093] The method for securely accessing a photovoltaic inverter to a power grid information system according to an embodiment of the present invention is used in conjunction with a secure communication connector. When the secure communication connector is detected to be connected to the photovoltaic inverter, a unique identity of the photovoltaic inverter is constructed, and the constructed unique identity of the photovoltaic inverter is stored in the ESAM security unit of the secure communication connector. The secure communication connector is bound to the photovoltaic inverter using the unique identity of the photovoltaic inverter. For the photovoltaic inverter that is connected again, the unique identity of the photovoltaic inverter is used to perform legality authentication. When the electrical data collected by the photovoltaic inverter that has passed the legal authentication is received, the electrical data collected by the photovoltaic inverter is verified, encrypted, and / or protocol converted. In this way, photovoltaic inverter plug-in detection (indirectly by detecting the connection status of the secure communication connector and the photovoltaic inverter), authentication, data isolation, and encrypted transmission are realized, which is conducive to reducing the security communication risks that exist when the photovoltaic inverter is connected to the power grid and solving the security management and control issues.

[0094] By using the secure communication connector and the method for securely connecting a photovoltaic inverter to a power grid information system, a method for securely connecting a distributed photovoltaic inverter to a power grid information system can also be realized, such as using multiple secure communication connectors to securely connect the same number of photovoltaic inverters to the power grid information system in a distributed manner, wherein each secure communication connector is used to securely connect a photovoltaic inverter to the power grid information system. In this way, by making use of the secure communication connectors in large quantities and through a hierarchical and graded architecture design, a large number of photovoltaic inverters can be securely connected to the grid in a distributed manner.

[0095] like Figure 2 As shown, the safety communication connector 40 of the embodiment of the present invention is used to connect the photovoltaic inverter to the power grid information system;

[0096] The safety communication connector 40 comprises:

[0097] A first interface 41, used for connecting to a photovoltaic inverter;

[0098] A second interface 45, used for connecting to the power grid information system;

[0099] A cable body 44, with the first interface 41 and the second interface 45 respectively disposed at two ends of the cable body;

[0100] A plug-in operation switch 420, the plug-in operation switch is close to the first interface or far away from the second interface, and is used to control the first interface to maintain connection with the photovoltaic inverter or control the first interface to disconnect from the photovoltaic inverter;

[0101] ESAM security unit 43, the ESAM security unit has at least one of the following encryption and decryption algorithms built in: SM1 encryption and decryption algorithm, SM2 encryption and decryption algorithm, SM3 encryption and decryption algorithm, SM4 encryption and decryption algorithm;

[0102] The state quantity sensing element 48 is connected to the plug-in operation switch, and generates a connection maintaining message when the first interface is connected to the photovoltaic inverter; and generates a connection disconnection message when the first interface is disconnected from the photovoltaic inverter;

[0103] The processing unit 47 is connected to the ESAM security unit and the state quantity sensing element, and is used to obtain the connection maintenance message, sense that the first interface is connected to the photovoltaic inverter through the plug-in operation switch, and use the method described later to connect the photovoltaic inverter connected to the first interface to the power grid information system.

[0104] As described below, the encryption and decryption algorithm built into the ESAM security unit is used to encrypt the plain text output by the PV inverter into cipher text, and to decrypt the cipher text output by the concentrator (such as the control instructions sent by the power grid information system) into plain text.

[0105] In this way, the secure communication connector processes the plain text sent by the photovoltaic inverter into ciphertext and then securely transmits it to the concentrator through the cable body, and the concentrator further sends it to the power grid information system; the secure communication connector processes the ciphertext transmitted by the concentrator through the cable into plaintext (processes the control instructions sent by the power grid information system into plaintext) and transmits it to the photovoltaic inverter, thereby securely transmitting the control instructions sent by the power grid information system to the photovoltaic inverter to the photovoltaic inverter.

[0106] In some embodiments, Figure 3A , Figure 3B , Figure 3C , Figure 4A , Figure 4B and Figure 4C As shown, the plug-in operation switch 420 includes at least two relatively arranged buckles 42, an elastic arm and a switch element (used to output a 5V low-level trigger pulse or a 5V high-level trigger pulse); when the safety communication connector is inserted into the photovoltaic inverter via the first interface, the buckle pops up and the elastic arm is retracted to a locked state, triggering an insertion signal; the state quantity sensing element receives the insertion signal and generates a connection maintenance message; when the safety communication connector is separated from the photovoltaic inverter via the first interface, the buckle retracts and the elastic arm pops up to a free state, triggering a disconnection signal; the state quantity sensing element receives the disconnection signal and generates a connection disconnection message.

[0107] In this way, the plug-in operation switch acts as a mechanical and electronic composite switch. When the safety communication connector is connected to the photovoltaic inverter, the plug-in operation switch is in a connection lock state; when the safety communication connector is disconnected from the photovoltaic inverter or loses connection, the plug-in operation switch is in a connection open state. In this way, the plug-in operation switch controls the first interface to maintain connection with the photovoltaic inverter or controls the first interface to disconnect from the photovoltaic inverter, which is safe and reliable, and is conducive to improving the information security of the power grid information system.

[0108] Specifically, the state quantity sensing element 48 includes a digital input signal (Digital Input, DI) interface, which is used to connect the switch quantity element in the plug-in operation switch and receive the unplug signal or the plug-in signal. Specifically, the unplug signal is a 5V low-level trigger pulse or a 5V high-level trigger pulse, and the plug-in signal is a 5V high-level trigger pulse or a 5V low-level trigger pulse. In this way, the processing unit 47 senses the connection state between the first interface and the inverter via the state quantity sensing element 48.

[0109] In this way, the plug-in operation switch 420 uses the buckle and the elastic arm to work together, which is easy to disassemble and assemble, stable and durable, and quick to operate.

[0110] Specifically, the state quantity sensing element 48 may be a DI channel set from a single-chip microcomputer; the processing unit 47 may be a single-chip microcomputer or an ARM processor chip.

[0111] In some embodiments, the safety communication connector actively reports the connection status and disconnection status of the plug-in operation switch to the power grid information system, and generates a log locally on the safety communication connector to record the status changes of the plug-in operation switch.

[0112] In some embodiments, the first interface for connecting to the photovoltaic inverter is based on a Type-C male connector design. To achieve compatibility and improve interoperability, the secure communication connector can also be configured with a Type-C female connector to USB3.0 device, a Type-C female connector to a 4-pin aviation plug, and a Type-C female connector to an RJ45 device, which can be easily connected to photovoltaic inverters from different manufacturers, thereby improving flexibility and scalability.

[0113] like Figure 2 As shown, the processing unit 47 of the secure communication connector 40 of the embodiment of the present invention includes a plug-in detection module, an identity authentication module 471, a data isolation module 472, a protocol conversion module 473, a data encryption and decryption module 474, and an alarm module 475;

[0114] Specifically, the identity authentication module 471 is used to execute the steps S100, S200 and S300 described later. In this way, the identity authentication module 471 performs identity authentication on external devices, such as between the photovoltaic inverter and the concentrator, such as between the photovoltaic inverter and the power grid master station, to receive downlink data sent by the power grid.

[0115] Specifically, the data isolation module 472 is used to execute the following steps 200 and 300, to analyze and judge the data sent by the photovoltaic inverter to the target concentrator, to block and isolate non-compliant and illegal data, and to prevent malicious attackers from using the photovoltaic inverter uplink channel to attack the power grid information system.

[0116] Specifically, the protocol conversion module 473 is used to execute the steps 200 and 300 described later, and realize the conversion between the Modbus protocol message and the DL / T698 series protocol message.

[0117] Specifically, the data encryption and decryption module 474 is used to execute the steps 200 and 300 described later, to encrypt and decrypt the transmitted and stored data, and to support national encryption algorithms such as SM1 / 4 and SM2 / 3.

[0118] Specifically, the alarm module 745 is used to execute the steps 200 and 300 described later, including actively reporting abnormal conditions of the communication link with the photovoltaic inverter, so that the collection master station can promptly notify the operation and maintenance personnel to handle the situation.

[0119] Specifically, the processing unit 47 is used to execute steps S100, S200 and S300 described later, and call other modules to perform corresponding operations.

[0120] like Figure 5 As shown, the method for safely connecting a photovoltaic inverter to a power grid information system according to an embodiment of the present invention includes the following steps S100, S200 and S300.

[0121] S100: When sensing that the first interface is connected to the photovoltaic inverter via the plug-in operation switch, determining whether a first connection event or a reconnection event is triggered; wherein the plug-in operation switch and the first interface are arranged on a safety communication connector, the safety communication connector is further provided with a second interface, and the second interface is connected to the power grid information system;

[0122] S200: when a first connection event is triggered, construct a unique identity for the photovoltaic inverter that is connected for the first time, store the constructed unique identity in an ESAM security unit, and control the photovoltaic inverter that is connected for the first time to communicate with the power grid information system; wherein the ESAM security unit is set at the security communication connector;

[0123] S300: When a reconnection event is triggered, the reconnected photovoltaic inverter is authenticated using the unique identity stored in the ESAM security unit; after the reconnected photovoltaic inverter passes the authentication, the reconnected photovoltaic inverter is controlled to communicate with the power grid information system.

[0124] In this way, when the security communication connector is connected to the photovoltaic inverter again, the security communication connector compares and authenticates the photovoltaic inverter. If the comparison is consistent, the photovoltaic inverter is controlled to communicate normally with the power grid information system. If the comparison is inconsistent, the security communication connector generates abnormal event alarm information to the power grid information system, and the power grid information system marks the data uploaded by the photovoltaic inverter as a security risk or generates a security log for analysis and processing, thereby blocking the communication between the photovoltaic inverter and the power grid information system.

[0125] In some embodiments, Figure 6 As shown, the determination of triggering the first connection event or the reconnection event in step S100 includes the following steps S110, S120 and S130.

[0126] S110: acquiring an access status flag value, wherein the access status flag value is stored in the ESAM security unit, and when the ESAM security unit is initialized, the access status flag value is set to an initial value, and the initial value is used to indicate that the ESAM security unit is not bound to the photovoltaic inverter;

[0127] S120: When the access state flag value is the same as the initial value, determine to trigger a first connection event; after the first connection event is triggered, update the access state flag value to the unique identity constructed for the photovoltaic inverter connected for the first time;

[0128] S130: When the access status flag value is different from the initial value, determine to trigger a reconnection event.

[0129] In the above, when the ESAM security unit is initialized, the access status flag is set to the initial value; when the photovoltaic inverter is connected for the first time, the security communication connector updates the access status flag from the initial value to the unique identity constructed for the photovoltaic inverter connected for the first time. When it is sensed that the first interface is connected to the photovoltaic inverter through the plug-in operation switch, the access status flag is obtained, and when the access status flag is the same as the initial value, it is determined that the first connection event is triggered; after the first connection event is triggered, the access status flag is updated to the unique identity constructed for the photovoltaic inverter connected for the first time; when the access status flag is different from the initial value, it is determined that the reconnection event is triggered.

[0130] In this way, the first update operation is triggered when the safety communication connector is connected to the inverter for the first time. After the first update operation is executed, other update operation attempts triggered when the safety communication connector is unplugged and then connected to the inverter again will be locked, and the access status flag will remain unchanged after being updated from the initial value to the unique identity constructed for the photovoltaic inverter connected for the first time, unless it is returned to the factory or initialized again by the organization that issued the ESAM safety unit. In this way, the ESAM safety unit is bound to the photovoltaic inverter connected for the first time, and the safety communication connector is then bound to the photovoltaic inverter connected for the first time.

[0131] It should be understood that when the manufacturer or the factory or the institution that issues the ESAM security unit initializes the ESAM security unit, the access status flag is set to an initial value, and the initial value is used to indicate that the ESAM security unit is not bound to the photovoltaic inverter. After the ESAM security unit is issued, it can only be returned to the factory or initialized by the institution that issues the ESAM security unit. The initialization operation for the ESAM security unit is locked to the security communication connector. The security communication connector can only perform a status update operation on the initialized ESAM security unit, that is, the security communication connector can only perform an update operation triggered by the inverter plug-in operation and cannot perform an initialization operation on the ESAM security unit.

[0132] Given that the safety communication connector does not have the ability to actively disconnect from the photovoltaic inverter, nor does it have the ability to force the photovoltaic inverter to exit the grid, and when a large number of distributed photovoltaic inverters are connected to the grid through safety communication connectors, it is necessary to remotely monitor the connection status between the safety communication connector and the photovoltaic inverter to reduce the cost of manual inspections.

[0133] The above-mentioned steps of judging whether to trigger the first connection event or the reconnection event are conducive to realizing the plug-in and unplug detection of the photovoltaic inverter, so that the power grid information system can timely and remotely grasp the access status of the photovoltaic inverter, which is conducive to discovering abnormal situations and quickly handling them.

[0134] In some embodiments, in step S200, the step of constructing a unique identity of a photovoltaic inverter connected for the first time includes:

[0135] Sending a first basic information request message to the photovoltaic inverter connected for the first time;

[0136] Receiving a first basic information response message sent by a photovoltaic inverter connected for the first time; the first basic information response message records basic information of the photovoltaic inverter connected for the first time;

[0137] Extracting basic information of the photovoltaic inverter from the first basic information response message, processing the extracted basic information of the photovoltaic inverter using the encryption and decryption algorithm built into the ESAM security unit, generating a first hash value as a unique identity for the photovoltaic inverter connected for the first time;

[0138] The extracted basic information of the photovoltaic inverter includes at least one of the following: photovoltaic inverter device type, photovoltaic inverter hardware serial number, photovoltaic inverter model, photovoltaic inverter software version number, and photovoltaic inverter MAC address.

[0139] As described above, when the secure communication connector is connected to the photovoltaic inverter for the first time, an active device fingerprint is generated for the photovoltaic inverter that is connected for the first time, and is used as a unique identity for the photovoltaic inverter that is connected for the first time. The active device fingerprint refers to the secure communication connector actively sending a first basic information request message to the photovoltaic inverter, and generating a unique identity for the photovoltaic inverter that is connected for the first time based on the first basic information response message received from the photovoltaic inverter that is connected for the first time.

[0140] In some embodiments, the basic information of the photovoltaic inverter connected for the first time recorded in the first basic information response message includes the hardware characteristics and software characteristics of the photovoltaic inverter; based on the acquired hardware characteristics and software characteristics of the first photovoltaic inverter, a first hash value is generated using the hash operation function recorded in the SM3 built into the ESAM security unit and used as a unique identity for the photovoltaic inverter connected for the first time.

[0141] In some embodiments, the hardware features and software features include the following items: device type, hardware serial number, device model (including series name, power level, topology identification, product code, etc.), software version number, the inverter's location in the acquisition master station or network address (such as a 12-bit MAC code).

[0142] In some embodiments, a basic information request message is sent to the photovoltaic inverter, and the basic information includes the photovoltaic inverter device type C t , Hardware serial number D t 、Model E t , Software version number F t 、MAC address G t ; After receiving the basic information request message, the photovoltaic inverter sends the basic information response message to the security communication connector; after receiving the basic information response message, the security communication connector extracts the basic information of the photovoltaic inverter and calculates the hash value using the SM3 algorithm built into the ESAM security unit And use it as an active device fingerprint, where “||” is a connection operation.

[0143] So, like Figure 7 As shown, an active device fingerprint is generated and used as a unique identity for the photovoltaic inverter connected for the first time to establish a binding relationship between the secure communication connector and the photovoltaic inverter. In addition, it is used as identity authentication in the reconnection authentication process described later, which is conducive to improving the information security when the photovoltaic inverter is connected to the power grid information system.

[0144] Accordingly, in step S300, the authenticating the reconnected photovoltaic inverter using the unique identity stored in the ESAM security unit includes:

[0145] Sending a second basic information request message to the photovoltaic inverter that is connected again;

[0146] Receive a second basic information response message sent by the reconnected photovoltaic inverter; the second basic information response message records the basic information of the reconnected photovoltaic inverter:

[0147] Extracting the photovoltaic inverter basic information from the second basic information response message, processing the extracted photovoltaic inverter basic information using the encryption and decryption algorithm built into the ESAM security unit, and generating a second hash value;

[0148] When the second hash value is consistent with the first hash value, it is determined that the reconnected photovoltaic inverter has passed the authentication.

[0149] In some embodiments, verifying the unique identity of the photovoltaic inverter based on the active device fingerprint and authenticating the photovoltaic inverter that is connected again includes:

[0150] Send a basic information request message to the PV inverter connected to it. The basic information includes the type of PV inverter device. , Hardware serial number ,model , Software version number 、MAC address ; After receiving the basic information request message, the photovoltaic inverter connected to the safety communication connector sends the basic information response message to the safety communication connector connected to it;

[0151] After receiving the basic information response message (the request message and the response message can be one-to-one correspondence based on the serial number, etc.), the secure communication connector extracts the basic information of the photovoltaic inverter and calculates the active device fingerprint of the photovoltaic inverter connected to it through the ESAM security unit using the SM3 algorithm. ;

[0152] The secure communication connector stores the active device fingerprint, or hash value, when it first connects to the PV inverter. The active device fingerprint generated when the PV inverter is connected again, that is, the hash value Make a comparison;

[0153] If they are consistent, it is determined that the identity of the photovoltaic inverter connected this time is authentic and it is the photovoltaic inverter connected for the first time before. The reconnection operation this time is a normal plug-in and unplug operation. Then the safety communication connector controls the photovoltaic inverter to communicate normally with the power grid information system;

[0154] If they are inconsistent, it is determined that the PV inverter that is reconnected to the safety communication connector is a device that has not passed the authentication and is not the PV inverter that was connected for the first time. If the inverter is improperly replaced or impersonated by another inverter, this reconnection operation is an abnormal plug-in and unplug operation.

[0155] In some embodiments, for an inverter whose reconnection operation is an abnormal plug-in and unplug operation, the safety communication connector blocks the communication between the reconnected photovoltaic inverter and the power grid information system; or generates abnormal event alarm information and sends it to the power grid information system, and the power grid information system marks the data uploaded by the photovoltaic inverter as a security risk.

[0156] In this way, the above photovoltaic inverter unique identity generation and identity authentication steps can authenticate the photovoltaic inverter each time it is connected to the power grid information system, verify whether the reconnection operation is an abnormal plug-in operation or a normal plug-in operation, and automatically block the communication link between the power grid information system and the photovoltaic inverter for photovoltaic inverters that have not passed the identity authentication, which can reduce the risk of photovoltaic inverters with abnormal identities accessing by forging legitimate identities, and is conducive to improving the information security of photovoltaic inverters when they are connected to the power grid information system.

[0157] In some embodiments, in step S200, the step of constructing a unique identity of a photovoltaic inverter connected for the first time includes:

[0158] Obtaining initial network traffic between a photovoltaic inverter connected for the first time and the power grid information system in a specified scenario;

[0159] Extracting the time intervals of arrival of multiple data packets in the initial network traffic, using the time intervals of arrival of multiple data packets to train a probability distribution model of the time intervals of arrival of data packets using a machine learning algorithm, and determining a standard mean of the time intervals of arrival of data packets;

[0160] The determined standard mean value of the data packet arrival time interval is used as a unique identification mark for the photovoltaic inverter connected for the first time.

[0161] Specifically, the specified scenario includes a configuration phase or a normal communication phase.

[0162] Specifically, the probability distribution model of the data packet arrival time interval includes a value range of the data packet arrival time interval, and its distribution is geometric distribution, exponential distribution or Poisson distribution.

[0163] In the above, when the secure communication connector is connected to the photovoltaic inverter for the first time, a passive device fingerprint is generated for the photovoltaic inverter connected for the first time, and used as a unique identity for the photovoltaic inverter connected for the first time. The passive device fingerprint refers to the secure communication connector using the initial network traffic obtained when the photovoltaic inverter connected for the first time communicates with the power grid information system in a specified scenario to generate a unique identity for the photovoltaic inverter connected for the first time.

[0164] In some embodiments, the generating a unique identity of the photovoltaic inverter based on the passive device fingerprint includes: obtaining network traffic during the photovoltaic inverter configuration phase;

[0165] The arrival time intervals of multiple data packets in the network traffic are extracted, and the arrival time intervals of multiple data packets are trained using a machine learning algorithm to obtain a probability distribution model of the data packet arrival time intervals, and the mean of the arrival time intervals is used as the passive device fingerprint of the photovoltaic inverter.

[0166] So, like Figure 7 As shown, a passive device fingerprint is generated and used as a unique identity for the photovoltaic inverter connected for the first time to establish a binding relationship between the secure communication connector and the photovoltaic inverter. The passive device fingerprint is used as identity authentication in the reconnection authentication process described later, which is conducive to improving the information security of the photovoltaic inverter when it is connected to the power grid information system.

[0167] Accordingly, in step S300, the authenticating the reconnected photovoltaic inverter using the unique identity stored in the ESAM security unit includes:

[0168] Acquire the detection network traffic of the reconnected photovoltaic inverter and the power grid information system in the specified scenario;

[0169] Extracting the arrival time intervals of multiple data packets in the detected network traffic, using a machine learning algorithm to train a probability distribution model of the data packet arrival time interval using the arrival time intervals of multiple data packets, and determining a detection mean of the data packet arrival time interval;

[0170] When the detected mean value is consistent with the standard mean value, it is determined that the reconnected photovoltaic inverter has passed the authentication.

[0171] Specifically, the detected mean is consistent with the standard mean, including: the probability distribution model of the data packet arrival time interval and / or the value range of the data packet arrival time interval are consistent.

[0172] In some embodiments, verifying the unique identity of the photovoltaic inverter based on the passive device fingerprint and authenticating the photovoltaic inverter that is connected again includes:

[0173] During the configuration phase of the reconnected photovoltaic inverter, the secure communication connector obtains the network traffic during the configuration phase of the reconnected photovoltaic inverter (e.g., until the reconnected photovoltaic inverter can communicate normally with the grid information system, such as sending control instructions uplink and receiving control instructions downlink);

[0174] After the secure communication connector obtains the network traffic, it extracts the time intervals of arrival of multiple data packets, trains the time intervals of arrival of multiple data packets using a machine learning algorithm, obtains a probability distribution model of the time intervals of arrival of data packets, and determines the mean of the time intervals of arrival of data packets;

[0175] Comparing the mean value of the arrival time interval stored when the photovoltaic inverter is first connected with the mean value of the arrival time interval stored when the photovoltaic inverter is connected again;

[0176] If they are consistent, the identity of the photovoltaic inverter is determined to be authentic, and this operation is a normal plug-in and unplug operation. It is the photovoltaic inverter that was connected for the first time before, and this reconnection operation is a normal plug-in and unplug operation. Before the next unplugging is detected, the safety communication connector controls the photovoltaic inverter to communicate normally with the power grid information system;

[0177] If they are inconsistent, it is determined that the PV inverter that is reconnected to the safety communication connector is a device that has not passed the authentication and is not the PV inverter that was connected for the first time. If the inverter is improperly replaced or impersonated by another inverter, this reconnection operation is an abnormal plug-in and unplug operation.

[0178] In some embodiments, for an inverter whose reconnection operation is an abnormal plug-in and unplug operation, the safety communication connector blocks the communication between the reconnected photovoltaic inverter and the power grid information system; or generates abnormal event alarm information and sends it to the power grid information system, and the power grid information system marks the data uploaded by the photovoltaic inverter as a security risk.

[0179] In this way, the above photovoltaic inverter unique identity generation and identity authentication steps can authenticate the photovoltaic inverter each time it is connected to the power grid information system, verify whether the reconnection operation is an abnormal plug-in operation or a normal plug-in operation, and automatically block the communication link between the power grid information system and the photovoltaic inverter for photovoltaic inverters that have not passed the identity authentication, which can reduce the risk of photovoltaic inverters with abnormal identities accessing by forging legitimate identities, and is conducive to improving the information security of photovoltaic inverters when they are connected to the power grid information system.

[0180] In some embodiments, in step S200, the step of constructing a unique identity of a photovoltaic inverter connected for the first time includes:

[0181] Sending a first hardware serial number request message to the photovoltaic inverter connected for the first time;

[0182] Receiving a first hardware serial number response message sent by a photovoltaic inverter connected for the first time;

[0183] Extracting the photovoltaic inverter hardware serial number from the received first hardware serial number response message, processing the photovoltaic inverter hardware serial number using the encryption and decryption algorithm built into the ESAM security unit, and generating a data write-back tag;

[0184] The data write-back tag is used as a unique identification of the photovoltaic inverter that is connected for the first time, and is sent to the photovoltaic inverter that is connected for the first time, so that the photovoltaic inverter that is connected for the first time embeds the data write-back tag in the tag bit of the data format when sending electrical data.

[0185] In some embodiments, generating a unique identification of a photovoltaic inverter connected for the first time based on data writeback includes:

[0186] The secure communication connector sends a hardware serial number request message to the photovoltaic inverter;

[0187] After receiving the hardware serial number request message, the photovoltaic inverter sends the hardware serial number response message to the safety communication connector;

[0188] After receiving the hardware serial number message, the secure communication connector obtains the hardware serial number D of the photovoltaic inverter t , the third hash value is calculated by the ESAM security unit using the hash operation function recorded in SM3 As a data write-back tag.

[0189] In some embodiments, the third hash value The data format written to the photovoltaic inverter includes:

[0190] The data write-back tag is used as a unique identification of the photovoltaic inverter that is connected for the first time, and is sent to the photovoltaic inverter that is connected for the first time, so that the photovoltaic inverter that is connected for the first time embeds the data write-back tag in the tag bit of the data format when sending electrical data.

[0191] So, like Figure 7 As shown, a unique identity of the photovoltaic inverter connected for the first time is generated based on data writeback, and a binding relationship between the secure communication connector and the photovoltaic inverter is established. The unique identity based on data writeback is used as identity authentication in the reconnection authentication process described later, which is conducive to improving the information security of the photovoltaic inverter when it is connected to the power grid information system.

[0192] Accordingly, in step S300, the authenticating the reconnected photovoltaic inverter using the unique identity stored in the ESAM security unit includes:

[0193] Get the electrical data sent by the reconnected PV inverter;

[0194] Extracting the data source tag recorded in the tag bit from the data format of the electrical data sent by the reconnected PV inverter;

[0195] When the data source tag is compared and consistent with the data write-back tag, it is determined that the reconnected photovoltaic inverter has passed the authentication.

[0196] Specifically, the data source tag is compared and consistent with the data write-back tag, including:

[0197] In some embodiments, verifying the unique identity of the photovoltaic inverter based on data writeback and authenticating the photovoltaic inverter that is connected again includes:

[0198] The secure communication connector sends a hardware serial number request message to the photovoltaic inverter that is connected again;

[0199] After receiving the hardware serial number request message, the reconnected PV inverter sends the hardware serial number response message to the safety communication connector;

[0200] After receiving the hardware serial number message, the secure communication connector obtains the hardware serial number of the PV inverter that is connected again , the fourth hash value is calculated by the SM3 algorithm built into the ESAM security unit ;

[0201] The secure communication connector writes back the fourth hash value based on the data Write into the data format of the photovoltaic inverter that is connected again;

[0202] The secure communication connector receives the data and extracts the fourth hash value recorded in the data format, and compares it with the fourth hash value in the data format stored when the photovoltaic inverter is first connected;

[0203] If they are consistent, it is determined that the identity of the photovoltaic inverter is authentic, this operation is a normal plug-in and pull-out operation, and the photovoltaic inverter communicates normally with the power grid information system;

[0204] If there is any inconsistency, it is determined that the photovoltaic inverter connected to the security communication connector has been replaced with a device that has not passed the authentication. The security communication connector generates an abnormal event alarm message to the power grid information system. The power grid information system marks the data uploaded by the photovoltaic inverter as a security risk or generates a security log for analysis and processing, thereby blocking communication with the photovoltaic inverter.

[0205] In the above, the unique identity of the photovoltaic inverter is generated by the active device fingerprint, the passive device fingerprint or the data write-back method, and the unique identity of the photovoltaic inverter is verified by the ESAM security unit using the national secret SM3 algorithm to authenticate the identity of the reconnected photovoltaic inverter, and determine whether the reconnected photovoltaic inverter belongs to an abnormal plug-in operation or a normal plug-in operation, which is conducive to improving the information security of the photovoltaic inverter when it is connected to the power grid information system.

[0206] In some embodiments, in step S200, controlling the photovoltaic inverter connected for the first time to communicate with the power grid information system includes:

[0207] Acquiring electrical data sent by the photovoltaic inverter connected for the first time through a photovoltaic upstream channel;

[0208] The electrical data is verified, the verified electrical data is encrypted and / or protocol converted, and sent to the power grid information system.

[0209] In some embodiments, in step S300, controlling the reconnected photovoltaic inverter to communicate with the power grid information system includes:

[0210] Acquiring electrical data sent by the reconnected photovoltaic inverter through a photovoltaic uplink channel;

[0211] The electrical data is verified, the verified electrical data is encrypted and / or protocol converted, and sent to the power grid information system.

[0212] In some embodiments, Figure 8 As shown, after the photovoltaic inverter is connected to the power grid information system through the secure communication connector, the secure communication connector verifies, encrypts and / or performs protocol conversion on the electrical data collected by the photovoltaic inverter through the ESAM security unit, and sends it to the power grid information system through the power grid uplink channel.

[0213] In some embodiments, the verification of the electrical data includes: soft isolation of data and hard isolation of data; the hard isolation includes: performing data detection based on the Modus protocol to determine whether the data domain is legal and harmless; or excluding non-electrical data such as non-voltage and non-current data, and only retaining electrical data such as voltage and current data; or blocking and isolating non-compliant and illegal data to prevent malicious visitors from using the upstream channel of the photovoltaic inverter to attack the power grid system.

[0214] In this way, the secure communication connector blocks and isolates non-compliant and illegal electrical data, preventing the use of the photovoltaic inverter upstream channel to attack the power grid system, and has a secure isolation capability.

[0215] In some embodiments, the verification of the electrical data includes: data content identification; the data content identification includes: parsing the message format of the data packet through deep packet inspection technology, and identifying whether the protocol and data type therein comply with the communication protocol; verifying the received electrical data, and if the verification is successful, it is determined that the data is complete and has not been tampered with, thereby completing the data integrity verification, wherein before transmitting the data, the photovoltaic inverter processes the electrical data to be transmitted based on the message authentication code (MAC); based on the data content monitored by the power grid information system and the predetermined electrical data of the photovoltaic inverter such as the rated output voltage, rated output frequency, and maximum output current, it is determined whether the electrical data complies with the specifications of the photovoltaic inverter to determine whether the photovoltaic inverter has been counterfeited, thereby completing the data content analysis.

[0216] In some embodiments, the electrical data includes: the output voltage (ABCN), output frequency, output current, and output power of the photovoltaic inverter. In the technical specifications of the photovoltaic inverter, according to the rated power of the photovoltaic inverter, the rated output voltage when connected to the grid includes multiple levels such as 220V / 380V, 230V / 400V, 480V, and 500V, among which the allowable deviation of the 220V voltage is -15% to +10% of the rated voltage, and the allowable deviation of the 380V voltage is -10% to +10% of the rated voltage. The output frequency is generally 50Hz, and the deviation is within +1% under normal working conditions. The maximum output current of photovoltaic inverters of different specifications or models is different. Usually, when the photovoltaic inverter is working normally (the output voltage is within the allowable deviation of the voltage), the current that can be continuously output does not exceed 110% of the nominal maximum output current.

[0217] Taking a certain manufacturer's photovoltaic inverter as an example, in its household rooftop grid-connected system and small ground photovoltaic power station grid-connected system, the rated output voltage of the photovoltaic inverter includes 220V / 380V, 230V / 400V, etc., the rated output power is 20kW, and the maximum output current is 33.5A; in its large power station grid-connected system and commercial distributed grid-connected system, the rated output voltage of the photovoltaic inverter is 500V, the rated output power is 125kW, and the maximum output current is 160.4A.

[0218] This electrical data verification step can isolate non-compliant and illegal data during the process of uploading the electrical data of the photovoltaic inverter, thereby improving the reliability of the transmitted data.

[0219] In some embodiments, the verified electrical data protocol conversion includes: converting the Modbus protocol message of the inverter upstream channel into the DL / T698 series protocol message; converting the DL / T698 series protocol message of the concentrator downstream channel into the Modbus protocol message.

[0220] In some embodiments, the verified electrical data protocol conversion includes: the safety communication connector converts the Modbus protocol message into a DL / T698 series protocol message for communication.

[0221] Specifically, the data transmission protocol supported by the photovoltaic inverter is usually the Modbus protocol, and the data transmission protocol supported by the power grid information system is the DL / T698 series protocol. The communication message definitions and requirements involved in these two protocols are different. In order to achieve smooth communication between the photovoltaic inverter and the power grid, protocol conversion is required. When the photovoltaic inverter uploads electrical data such as voltage, current, active power, reactive power, and frequency to the power grid information system, the safety communication connector converts the Modbus protocol message into a DL / T698 series protocol message for communication. When the power grid information system issues a control instruction to the photovoltaic inverter, the safety communication connector identifies the Modbus protocol supported by the photovoltaic inverter, and converts the DL / T698 series protocol message received from the power grid information system into a Modbus protocol message supported by the photovoltaic inverter for communication.

[0222] In some embodiments, encrypting the verified electrical data includes:

[0223] The ESAM security unit uses a symmetric encryption algorithm or an asymmetric encryption algorithm to encrypt the electrical data such as voltage, current, active power, reactive power, frequency, etc. collected by the photovoltaic inverter, and uploads it to the power grid collection system.

[0224] In this way, data can be prevented from being eavesdropped, forged, and tampered with.

[0225] In some embodiments, the encryption of verified electrical data includes: the secure communication connector encrypts the message converted into the DL / T698 series protocol based on a symmetric encryption algorithm, and uploads the encrypted data to the power grid information system to prevent the data uploaded by the photovoltaic inverter from being eavesdropped and tampered with in the upstream channel B.

[0226] In some embodiments, determining the connection status between the photovoltaic inverter and the power grid information system based on the communication content between the power grid information system and the photovoltaic inverter includes:

[0227] When the PV inverter is not generating power on a cloudy day or at night, the grid information system sends a basic information request message to the PV inverter bound to the safety communication connector every 5 minutes;

[0228] After receiving the basic information request message, the photovoltaic inverter sends the basic information response message to the safety communication connector;

[0229] After receiving the basic information response message, the safety communication connector extracts the basic information and sends the extracted basic information to the power grid information system. The power grid information system determines that the safety communication connector and the photovoltaic inverter are in a connection-maintaining state based on the received basic information of the inverter.

[0230] If the above steps are performed multiple times in succession and the grid information system does not receive the basic information of the photovoltaic inverter, it is determined that the safety communication connector is disconnected from the photovoltaic inverter.

[0231] In some embodiments, the grid information system can also determine the connection status between the photovoltaic inverter and the grid information system by remotely monitoring the current and voltage values ​​output by the photovoltaic inverter in real time. When the photovoltaic inverter is operating normally, the output voltage / current is within a preset range; after the photovoltaic inverter is disconnected from the safety communication connector, the grid information system remotely monitors in real time that the output current / voltage of the photovoltaic inverter drops to 0.

[0232] In some embodiments, the power grid information system sends a request message for normal and abnormal plugging and unplugging records of photovoltaic inverters at a fixed time every day. After the security communication connector receives the request message, it uses the SM3 algorithm to calculate the hash value of the normal and abnormal plugging and unplugging records of the photovoltaic inverter, and combines the normal and abnormal plugging and unplugging records of the photovoltaic inverter and the hash value into a response message, which is sent to the power grid information system for storage.

[0233] In some embodiments, the grid information system remotely monitors the communication status between the grid information system and the photovoltaic inverter to determine the connection status between the photovoltaic inverter and the safety communication connector.

[0234] In some embodiments, when the inverter works normally during the day, the inverter communicates with the power grid information system on a regular basis; if the inverter communicates with the power grid information system successfully, the power grid information system determines that the inverter is normally connected to the safety communication connector; if the communication fails for multiple consecutive times, the power grid information system determines that the inverter is disconnected from the safety communication connector.

[0235] In some embodiments, the power grid information system remotely monitors the current and voltage values ​​output by the photovoltaic inverter to determine the plug-in and unplug-out status of the photovoltaic inverter.

[0236] In summary, the method for securely accessing a distributed photovoltaic inverter to a power grid information system provided by the present invention utilizes a security communication connector with an embedded ESAM security unit and a plug-in operation switch to connect to a photovoltaic inverter. When the security communication connector is connected to the photovoltaic inverter for the first time, a unique identity identifier of the photovoltaic inverter is constructed and stored in the ESAM security unit, and the security communication connector is bound to the photovoltaic inverter; when the distributed photovoltaic inverter communicates with the power grid information system, data verification (including analysis, isolation), protocol conversion and encrypted transmission are performed on the collected data sent by the photovoltaic inverter; when the security communication connector is connected to the photovoltaic inverter again, identity authentication is performed on the connected photovoltaic inverter; plug-in detection and perception of the security communication connector is realized by using a plug-in operation switch; plug-in detection, authentication, data isolation and encrypted transmission of the photovoltaic inverter are realized, which is beneficial to reducing the security communication risks existing when the photovoltaic inverter is connected to the power grid. In this way, the information security problem when the photovoltaic inverter is connected to the grid is solved or partially solved.

[0237] The following combination Fig.9A , specifically describing the steps of using the safety communication connector S provided by the present invention to safely connect a household photovoltaic inverter V of a certain manufacturer to the power grid information system.

[0238] First, when the initialized safety communication connector S is connected to the photovoltaic inverter V for the first time, it includes:

[0239] (g1) connecting the first interface to the household photovoltaic inverter, closing the buckle near the first interface, and changing the output level; connecting the second interface to the concentrator; and the state quantity sensing element generating a connection maintenance message;

[0240] (g2) when the processing unit senses that the first interface is connected to the photovoltaic inverter through the plug-in operation switch, it determines that the first connection event is triggered;

[0241] (g3) Sending a basic information request message to the photovoltaic inverter V connected for the first time;

[0242] (g4) After receiving the basic information request message, the photovoltaic inverter V sends the basic information response message to the safety communication connector;

[0243] (g5) After receiving the basic information response message, the secure communication connector extracts the basic information of the photovoltaic inverter and calculates the active device fingerprint of the photovoltaic inverter using the SM3 algorithm through the ESAM security unit. , and store it in the ESAM security unit, update the access status flag, bind the ESAM security unit to the photovoltaic inverter V, and then bind the safety communication connector S to the photovoltaic inverter V connected for the first time;

[0244] (g6) Active device fingerprint The storage in the ESAM security unit may further include: using the SM4 algorithm to detect active devices Encryption is performed and the encryption result is stored in the ESAM security unit;

[0245] (g7) After updating the access status flag to the unique identity tag constructed for the photovoltaic inverter connected for the first time, controlling the photovoltaic inverter V connected for the first time to communicate with the power grid information system.

[0246] After the photovoltaic inverter is successfully connected to the power grid information system, the photovoltaic inverter communicates with the power grid information system and sends data packets to the power grid information system regularly or irregularly. In response to the data packets, the secure communication connector performs at least one of the following operations:

[0247] (h1) Inverter V sends a data packet using the Modbus protocol. Using deep packet inspection technology, the message format of the received data packet is analyzed to be consistent with the Modbus protocol, and the data integrity verification is successful;

[0248] (h2) The deep packet inspection technology is used to analyze the electrical data such as voltage, current, and power in the data packet. The detection finds that the output current is 50A, which exceeds the 33.5A specified for this type of photovoltaic inverter. The data is determined to be non-compliant, discarded and reported to the power grid information system. The photovoltaic inverter V is operating abnormally or the data is abnormal.

[0249] (h3) Use deep packet inspection technology to analyze the voltage, current, power and other information in the data. If the output data is found to be compliant, convert the compliant data into DL / T698.45 protocol data, encrypt it using the SM1 / 4 algorithm, and upload it to the power grid information system through a secure communication connector; the power grid information system analyzes, processes, and stores the collected electrical data of the photovoltaic inverter.

[0250] Furthermore, after the photovoltaic inverter V is successfully connected to the power grid information system, the safety communication connector S uses the aforementioned plug-in operation switch or remote monitoring of the communication status, voltage or current. After detecting that the safety communication connector is unplugged from the photovoltaic inverter or loses connection with the photovoltaic inverter, the plug-in operation time is recorded and reported to the power grid information system.

[0251] refer to Fig.9A As shown, when the safety communication connector S detects that it is connected to the photovoltaic inverter W again, naturally, W is different from V, and the identity authentication of the photovoltaic inverter W includes the following steps:

[0252] (j1) The plug-in and pull-out operation switch changes the output level, the state quantity sensing element senses the buckle closure, and generates a connection maintenance message; the processing unit triggers a reconnection event, and in response to the reconnection event,

[0253] (j2) Send a basic information request message to the PV inverter W connected to it. The basic information includes the type of PV inverter equipment. , Hardware serial number ,model , Software version number 、MAC address ;

[0254] (j3) After receiving the basic information request message, the photovoltaic inverter W sends the basic information response message to the safety communication connector;

[0255] (j4) After receiving the basic information response message, the basic information of the photovoltaic inverter W is extracted, and the active device fingerprint of the photovoltaic inverter W is calculated by the ESAM security unit using the SM3 algorithm: ;

[0256] (j5) The hash value stored when the photovoltaic inverter V is first connected and If the comparison is inconsistent, it is determined that the photovoltaic inverter W to which the safety communication connector S is connected again is replaced with a device that has not passed the certification, and the photovoltaic inverter is blocked from communicating with the power grid information system to improve the information security of the power grid information system.

[0257] refer to Fig.9A As shown, when the safety communication connector S detects that it is connected to the photovoltaic inverter V again, the identity authentication of the photovoltaic inverter V includes the following steps:

[0258] (l1) The plug-in operation switch changes the output level, the state quantity sensing element senses the buckle closure, and generates a connection maintenance message; the processing unit triggers a reconnection event, and in response to the reconnection event,

[0259] (l2) Send a basic information request message to the photovoltaic inverter V connected to it. The basic information includes the type of photovoltaic inverter equipment. , Hardware serial number ,model , Software version number 、MAC address ;

[0260] (l3) After receiving the basic information request message, the photovoltaic inverter V sends the basic information response message to the safety communication connector;

[0261] (l4) After receiving the basic information response message, extract the basic information of the photovoltaic inverter V, and calculate the active device fingerprint of the photovoltaic inverter V using the SM3 algorithm through the ESAM security unit: ;

[0262] (l5) The hash value stored when the photovoltaic inverter V is first connected and A comparison is performed; if the comparison is consistent, the photovoltaic inverter V connected again by the safety communication connector S is determined to be a legally authenticated device, and the photovoltaic inverter is controlled to communicate with the power grid information system.

[0263] After the photovoltaic inverter V is successfully connected to the grid information system, communication begins. Please refer to the above steps (h1) to (h3) and will not be repeated here.

[0264] In summary, the method for securely connecting the photovoltaic inverter to the power grid information system realizes the connection status and electrical data collection of the photovoltaic inverter based on the secure communication connector without modifying the photovoltaic inverter, thereby improving the reliability and authenticity of the photovoltaic inverter connecting to the power grid, and is conducive to preventing malicious attackers from accessing the power grid through the upstream channel of the photovoltaic inverter.

[0265] like Fig. 9B As shown, physical detection can be performed when the photovoltaic inverter is safely connected to the power grid information system using the aforementioned safety communication interface. Referring to the aforementioned description, the mechanical and electronic composite switch configured by the safety communication interface includes a plug-in operation switch. During physical detection, when the first interface is inserted into the photovoltaic inverter, the plug-in operation switch remains closed and is in a closed state; when the first interface is disconnected from the photovoltaic inverter, the plug-in operation switch remains open and is in an open state; the plug-in operation switch changes the port voltage, the state quantity sensing element generates a connection maintenance message or a connection disconnection message, the processing unit triggers and processes the first connection event or the reconnection event, and actively reports to the power grid information system for record.

[0266] like Fig. 9B As shown, when the photovoltaic inverter is safely connected to the power grid information system using the aforementioned secure communication interface, communication detection can be performed. During communication detection, the power grid information system regularly communicates with the photovoltaic inverter through the secure communication connector. Successful communication is a normal connection state, and multiple consecutive communication failures are disconnected; or the power grid information system remotely monitors the current and voltage values ​​output by the photovoltaic inverter in real time; the processing unit triggers and processes the first connection event or the reconnection event, and actively reports it to the power grid information system for record.

[0267] like Fig. 9C As shown, when the photovoltaic inverter is connected to the power grid information system again using the aforementioned safety communication interface, the safety communication connector detects the status of the first interface and the photovoltaic inverter connected again, and records the insertion time; the safety communication connector verifies whether the current connection operation is a normal plug and unplug operation;

[0268] Specifically, the processing unit reads information such as the hardware serial number of the photovoltaic inverter and calculates a hash value for comparison; or the processing unit captures network traffic to obtain the arrival time intervals of multiple data packets, obtains the average of the arrival time intervals through machine learning training, and performs comparison.

[0269] When the comparison is consistent, the processing unit controls the photovoltaic inverter to communicate normally with the grid side; when the comparison is inconsistent, the processing unit generates abnormal event alarm information to the grid information system to block the communication between the photovoltaic inverter and the grid information system.

[0270] The present invention also provides a method for safely connecting distributed photovoltaic inverters to a power grid information system, using a plurality of the aforementioned safety communication connectors to safely connect the same number of photovoltaic inverters to the power grid information system in a distributed manner, wherein each of the safety communication connectors is used to safely connect a photovoltaic inverter to the power grid information system.

[0271] The method for safely connecting distributed photovoltaic inverters to a power grid information system can be used for Figure 1A In the distributed grid-connected scenario shown, the connected equipment is authenticated, the data transmission channel protocol is converted and encrypted, the authenticity of the identities of both communicating parties of the photovoltaic inverter on the concentrator side is verified, the incoming and outgoing data flows of the photovoltaic inverter are actively controlled, and the information security level of the photovoltaic inverter connected to the power grid is improved; the application prospects are relatively broad, and the benefits of the transformation of results are relatively considerable, which plays an important supporting role in maintaining the safe and stable operation of the system after the distributed power source is connected to the grid.

[0272] As the only data export manager of the distributed photovoltaic inverter, the secure communication connector performs protocol conversion and isolation at the data link layer, effectively preventing attackers from reversely attacking power grid equipment through the photovoltaic inverter.

[0273] This secure communication connector has a variety of extended usage scenarios and is not limited to the grid-connected access of photovoltaic inverters. It can be widely used in the secure communication of various interface converters and protocol converters, which is conducive to the secure access management and control of other distributed new energy sources in the future.

[0274] The embodiment of the present invention also provides a terminal to execute the method. Fig.10 It shows a schematic diagram of a terminal provided by some embodiments of the present invention. Fig.10As shown, the terminal 8 includes: a processor 800, a memory 801, a bus 802 and a communication interface 803, wherein the processor 800, the communication interface 803 and the memory 801 are connected via the bus 802; the memory 801 stores a computer program that can be run on the processor 800, and the processor 800 executes the method provided by any of the aforementioned embodiments of the present invention when running the computer program.

[0275] The memory 801 may include a high-speed random access memory (RAM), and may also include a non-volatile memory (Non-volatile Memory), such as at least one disk storage. The communication connection between the device network element and at least one other network element is realized through at least one communication interface 803 (which may be wired or wireless), and the Internet, wide area network, local area network, metropolitan area network, etc. may be used.

[0276] The bus 802 may be an ISA bus, a PCI bus, or an EISA bus, etc. The bus may be divided into an address bus, a data bus, a control bus, etc. The memory 801 is used to store programs, and the processor 800 executes the programs after receiving the control instructions. The method disclosed in any implementation of the above embodiments of the present invention may be applied to the processor 800, or implemented by the processor 800.

[0277] The processor 800 may be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the method can be completed by the hardware integrated logic circuit in the processor 800 or the instruction in the form of software. The processor 800 may be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it may also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components. The methods, steps and logic block diagrams disclosed in the embodiments of the present invention can be implemented or executed. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc. The steps of the method disclosed in the embodiments of the present invention may be directly embodied as being executed by a hardware decoding processor, or executed by a combination of hardware and software modules in the decoding processor. The software module may be located in a mature storage medium in the field such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory or an electrically erasable programmable memory, a register, etc. The storage medium is located in the memory 801, and the processor 800 reads the information in the memory 801 and completes the steps of the method in combination with its hardware.

[0278] The terminal and the method are based on the same inventive concept and have the same beneficial effects as the method adopted, operated or implemented by them.

[0279] An embodiment of the present invention further provides a computer-readable storage medium corresponding to the method provided in the aforementioned embodiment, wherein the computer-readable storage medium is a CD on which a computer program (i.e., a program product) is stored. When the computer program is run by a processor, it will execute the method provided in any of the aforementioned embodiments.

[0280] It should be noted that examples of the computer-readable storage medium may also include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other optical or magnetic storage media, which are not listed here one by one.

[0281] The computer-readable storage medium provided by the embodiment of the present invention is based on the same inventive concept as the present method and has the same beneficial effects as the method adopted, run or implemented by the application program stored therein.

[0282] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these adjustments and modifications of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these changes and modifications.

Claims

1. A method for safely connecting a photovoltaic inverter to a power grid information system, characterized in that: include: When it is sensed that the first interface is connected to the photovoltaic inverter via the plug-in operation switch, it is determined whether a first connection event or a reconnection event is triggered; wherein the plug-in operation switch and the first interface are arranged on a safety communication connector, and the safety communication connector is further provided with a second interface, and the second interface is connected to the power grid information system; When the first connection event is triggered, a unique identity for the photovoltaic inverter connected for the first time is constructed, the constructed unique identity is stored in the ESAM security unit, and the photovoltaic inverter connected for the first time is controlled to communicate with the power grid information system; wherein the ESAM security unit is arranged at the security communication connector; When a reconnection event is triggered, the reconnected photovoltaic inverter is authenticated using the unique identity stored in the ESAM security unit; after the reconnected photovoltaic inverter passes the authentication, the reconnected photovoltaic inverter is controlled to communicate with the power grid information system; The construction of a unique identification for a photovoltaic inverter connected for the first time includes: Sending a first basic information request message to the photovoltaic inverter connected for the first time; Receiving a first basic information response message sent by a photovoltaic inverter connected for the first time; the first basic information response message records basic information of the photovoltaic inverter connected for the first time; Extracting basic information of the photovoltaic inverter from the first basic information response message, processing the extracted basic information of the photovoltaic inverter using the encryption and decryption algorithm built into the ESAM security unit, generating a first hash value as a unique identity for the photovoltaic inverter connected for the first time; The extracted basic information of the photovoltaic inverter includes at least one of the following: photovoltaic inverter device type, photovoltaic inverter hardware serial number, photovoltaic inverter model, photovoltaic inverter software version number, photovoltaic inverter MAC address; The method of authenticating the reconnected photovoltaic inverter using the unique identity stored in the ESAM security unit includes: Sending a second basic information request message to the photovoltaic inverter that is connected again; A second basic information response message sent by the reconnected photovoltaic inverter is received; the second basic information response message records the basic information of the reconnected photovoltaic inverter: Extracting the photovoltaic inverter basic information from the second basic information response message, processing the extracted photovoltaic inverter basic information using the encryption and decryption algorithm built into the ESAM security unit, and generating a second hash value; When the second hash value is consistent with the first hash value, it is determined that the reconnected photovoltaic inverter has passed the authentication.

2. The method for safely connecting a photovoltaic inverter to a power grid information system according to claim 1, characterized in that: The determining of triggering a first connection event or a reconnection event includes: Acquire an access status flag, wherein the access status flag is stored in the ESAM security unit. When the ESAM security unit is initialized, the access status flag is set to an initial value, and the initial value is used to indicate that the ESAM security unit is not bound to the photovoltaic inverter; When the access state flag value is the same as the initial value, determining to trigger a first connection event; after the first connection event is triggered, updating the access state flag value to the unique identity constructed for the photovoltaic inverter connected for the first time; When the access status flag value is different from the initial value, it is determined to trigger a reconnection event.

3. The method for safely connecting a photovoltaic inverter to a power grid information system according to claim 1, characterized in that: Controlling the photovoltaic inverter connected for the first time to communicate with the power grid information system includes: Acquiring electrical data sent by the photovoltaic inverter connected for the first time through a photovoltaic upstream channel; Verifying the electrical data, encrypting and / or converting the verified electrical data into a protocol, and sending the data to the power grid information system; Controlling the reconnected photovoltaic inverter to communicate with the grid information system includes: Acquiring electrical data sent by the reconnected photovoltaic inverter through a photovoltaic uplink channel; The electrical data is verified, the verified electrical data is encrypted and / or protocol converted, and sent to the power grid information system.

4. A method for safely connecting a photovoltaic inverter to a power grid information system, characterized in that: include: When it is sensed that the first interface is connected to the photovoltaic inverter via the plug-in operation switch, it is determined whether a first connection event or a reconnection event is triggered; wherein the plug-in operation switch and the first interface are arranged on a safety communication connector, and the safety communication connector is further provided with a second interface, and the second interface is connected to the power grid information system; When the first connection event is triggered, a unique identity for the photovoltaic inverter connected for the first time is constructed, the constructed unique identity is stored in the ESAM security unit, and the photovoltaic inverter connected for the first time is controlled to communicate with the power grid information system; wherein the ESAM security unit is arranged at the security communication connector; When a reconnection event is triggered, the reconnected photovoltaic inverter is authenticated using the unique identity stored in the ESAM security unit; after the reconnected photovoltaic inverter passes the authentication, the reconnected photovoltaic inverter is controlled to communicate with the power grid information system; The construction of a unique identification for a photovoltaic inverter connected for the first time includes: Obtaining initial network traffic between a photovoltaic inverter connected for the first time and the power grid information system in a specified scenario; Extracting the time intervals of arrival of multiple data packets in the initial network traffic, using a machine learning algorithm to train a probability distribution model of the time intervals of arrival of data packets using the time intervals of arrival of multiple data packets, and determining a standard mean of the time intervals of arrival of data packets; Using the determined standard mean value of the time interval between arrival of the data packets as a unique identification mark for the photovoltaic inverter connected for the first time; The method of authenticating the reconnected photovoltaic inverter using the unique identity stored in the ESAM security unit includes: Acquire the detection network traffic of the reconnected photovoltaic inverter and the power grid information system in the specified scenario; Extracting the arrival time intervals of multiple data packets in the detected network traffic, using a machine learning algorithm to train a probability distribution model of the data packet arrival time interval using the arrival time intervals of multiple data packets, and determining a detection mean of the data packet arrival time interval; When the detected mean value is consistent with the standard mean value, it is determined that the reconnected photovoltaic inverter has passed the authentication.

5. The method for safely connecting a photovoltaic inverter to a power grid information system according to claim 4, characterized in that: The determining of triggering a first connection event or a reconnection event includes: Acquire an access status flag, wherein the access status flag is stored in the ESAM security unit. When the ESAM security unit is initialized, the access status flag is set to an initial value, and the initial value is used to indicate that the ESAM security unit is not bound to the photovoltaic inverter; When the access state flag value is the same as the initial value, determining to trigger a first connection event; after the first connection event is triggered, updating the access state flag value to the unique identity constructed for the photovoltaic inverter connected for the first time; When the access status flag value is different from the initial value, it is determined to trigger a reconnection event.

6. The method for safely connecting a photovoltaic inverter to a power grid information system according to claim 4, characterized in that: Controlling the photovoltaic inverter connected for the first time to communicate with the power grid information system includes: Acquiring electrical data sent by the photovoltaic inverter connected for the first time through a photovoltaic upstream channel; Verifying the electrical data, encrypting and / or converting the verified electrical data into a protocol, and sending the data to the power grid information system; Controlling the reconnected photovoltaic inverter to communicate with the grid information system includes: Acquiring electrical data sent by the reconnected photovoltaic inverter through a photovoltaic uplink channel; The electrical data is verified, the verified electrical data is encrypted and / or protocol converted, and sent to the power grid information system.

7. A method for safely connecting a photovoltaic inverter to a power grid information system, characterized in that: include: When it is sensed that the first interface is connected to the photovoltaic inverter via the plug-in operation switch, it is determined whether a first connection event or a reconnection event is triggered; wherein the plug-in operation switch and the first interface are arranged on a safety communication connector, and the safety communication connector is further provided with a second interface, and the second interface is connected to the power grid information system; When the first connection event is triggered, a unique identity for the photovoltaic inverter connected for the first time is constructed, the constructed unique identity is stored in the ESAM security unit, and the photovoltaic inverter connected for the first time is controlled to communicate with the power grid information system; wherein the ESAM security unit is arranged at the security communication connector; When a reconnection event is triggered, the reconnected photovoltaic inverter is authenticated using the unique identity stored in the ESAM security unit; after the reconnected photovoltaic inverter passes the authentication, the reconnected photovoltaic inverter is controlled to communicate with the power grid information system; The construction of a unique identification for a photovoltaic inverter connected for the first time includes: Sending a first hardware serial number request message to the photovoltaic inverter connected for the first time; Receiving a first hardware serial number response message sent by a photovoltaic inverter connected for the first time; Extracting the photovoltaic inverter hardware serial number from the received first hardware serial number response message, processing the photovoltaic inverter hardware serial number using the encryption and decryption algorithm built into the ESAM security unit, and generating a data write-back tag; The data write-back tag is used as a unique identification mark of the photovoltaic inverter that is connected for the first time, and is sent to the photovoltaic inverter that is connected for the first time, so that the photovoltaic inverter that is connected for the first time embeds the data write-back tag in the tag position of the data format when sending electrical data; The method of authenticating the reconnected photovoltaic inverter using the unique identity stored in the ESAM security unit includes: Get the electrical data sent by the reconnected PV inverter; Extracting the data source tag recorded in the tag bit from the data format of the electrical data sent by the reconnected PV inverter; When the data source tag is compared and consistent with the data write-back tag, it is determined that the reconnected photovoltaic inverter has passed the authentication.

8. The method for safely connecting a photovoltaic inverter to a power grid information system according to claim 7, characterized in that: The determining of triggering a first connection event or a reconnection event includes: Acquire an access status flag, wherein the access status flag is stored in the ESAM security unit. When the ESAM security unit is initialized, the access status flag is set to an initial value, and the initial value is used to indicate that the ESAM security unit is not bound to the photovoltaic inverter; When the access state flag value is the same as the initial value, determining to trigger a first connection event; after the first connection event is triggered, updating the access state flag value to the unique identity constructed for the photovoltaic inverter connected for the first time; When the access status flag value is different from the initial value, it is determined to trigger a reconnection event.

9. The method for safely connecting a photovoltaic inverter to a power grid information system according to claim 7, characterized in that: Controlling the photovoltaic inverter connected for the first time to communicate with the power grid information system includes: Acquiring electrical data sent by the photovoltaic inverter connected for the first time through a photovoltaic upstream channel; Verifying the electrical data, encrypting and / or converting the verified electrical data into a protocol, and sending the data to the power grid information system; Controlling the reconnected photovoltaic inverter to communicate with the grid information system includes: Acquiring electrical data sent by the reconnected photovoltaic inverter through a photovoltaic uplink channel; The electrical data is verified, the verified electrical data is encrypted and / or protocol converted, and sent to the power grid information system.

10. A secure communication connector, characterized in that: Used to connect photovoltaic inverters to the grid information system; The secure communication connector comprises: A first interface, used for connecting to a photovoltaic inverter; A second interface, used for connecting to the power grid information system; A cable body, wherein the first interface and the second interface are respectively arranged at two ends of the cable body; A plug-in operation switch, the plug-in operation switch is close to the first interface or far away from the second interface, and is used to control the first interface to maintain connection with the photovoltaic inverter or control the first interface to disconnect from the photovoltaic inverter; ESAM security unit, the ESAM security unit has at least one of the following encryption and decryption algorithms built in: SM1 encryption and decryption algorithm, SM2 encryption and decryption algorithm, SM3 encryption and decryption algorithm, SM4 encryption and decryption algorithm; A state quantity sensing element is connected to the plug-in operation switch, and generates a connection maintaining message when the first interface is connected to the photovoltaic inverter; and generates a connection disconnection message when the first interface is disconnected from the photovoltaic inverter; A processing unit is connected to the ESAM security unit and the state quantity sensing element, and is used to obtain the connection maintenance message, sense that the first interface is connected to the photovoltaic inverter through the plug-in operation switch, and use the method described in any one of claims 1, 4 or 7 to connect the photovoltaic inverter connected to the first interface to the power grid information system.

11. A terminal, comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the method described in any one of claims 1 to 9.

12. A computer storage medium, characterized in that: Computer controllable instructions are stored, and the computer controllable instructions are used to execute the method according to any one of claims 1 to 9.

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