An intelligent operation and maintenance communication method based on JSON format

Abstract

The present invention discloses an intelligent operation and maintenance communication method based on the JSON format, which aims to solve the problems of high complexity, low security and difficulty in scalability of existing protocols, thereby improving the reliability, speed and security of smart grid operation and maintenance. Its characteristics are as follows: the communication protocol between the master and substation of the intelligent operation and maintenance system is based on the publish / subscribe mechanism of the MQTT protocol, and adopts the lightweight JSON format for data exchange, which is suitable for data communication between the intelligent operation and maintenance master station and the intelligent operation and maintenance substation; the identity between the master and substation is verified by SSL / TLS digital signature to ensure communication security; the protocol design includes management channels and business channels, which are used to transmit management data and business data of model services and asset services respectively, thereby improving the flexibility of data management; the master and substation integrated design concept is adopted to realize configuration management and data synchronization, so that the master station can monitor and manage substations distributed in different locations in real time, thereby improving the operation and maintenance efficiency and response speed of the entire system.

Description

Technical Field

[0001] The present invention relates to the field of intelligent operation and maintenance of substations, and in particular to an intelligent operation and maintenance communication method based on the JSON format. Background Art

[0002] With the rapid development of smart grids and automation systems, the requirements for communication protocols are becoming increasingly stringent. Smart grids must offer high reliability, real-time performance, security, interoperability, and scalability to support the integration of large-scale devices, the transmission of massive amounts of data, and complex control functions. DNP3 and Modbus protocols are primarily used in traditional power systems. Their relatively fixed data formats make it difficult to express complex device status, alarm information, and control commands. Furthermore, the real-time and security requirements of these protocols fall short of meeting the demands of modern power systems. Scenarios such as fault detection and isolation require millisecond-level response times, but DNP3 and Modbus, due to their polling mechanisms and limited bandwidth, may not be able to achieve this performance. Furthermore, the security mechanisms of DNP3 and Modbus are relatively weak, making them vulnerable to cyberattacks and data tampering. This is unacceptable for the security-critical smart grid.

[0003] CN 117808449 A describes a secondary operation and maintenance system interactive communication method that uses VSS data types to model substations and transmit intelligent operation and maintenance alarm information to improve the efficiency and accuracy of information transmission. When an alarm occurs at a substation, this method generates an intelligent operation and maintenance file and sends the file path and name to the main station via a VSS signal, allowing the main station to retrieve the file. However, this method uses a static communication strategy that cannot adapt to dynamic changes in network status, particularly under high load or fluctuating network conditions.

[0004] CN 109379219 A discloses a method for sharing and interacting between a TMS and a mobile operation and maintenance terminal for power communication sites. The TMS's data interconnection interface communicates with the intelligent operation and maintenance platform and the intelligent operation and maintenance terminal in the terminal system, enabling resource information exchange. However, optimizing the data sharing service features and implementing efficient data sharing and interaction between the intelligent operation and maintenance platform and the TMS to ensure the stability and real-time performance of data interaction remain challenges. Summary of the Invention

[0005] The present invention provides an intelligent operation and maintenance communication method based on the JSON format, aiming to solve the technical problems of insufficient flexibility and poor scalability of traditional communication protocols in the intelligent operation and maintenance of existing power systems, especially the problem that existing protocols are difficult to simultaneously take into account lightweight and efficient, safe and reliable, and flexible expansion.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] S1: Establish a secure communication connection based on the MQTT protocol. The secure communication connection uses SSL / TLS encryption and digital signature verification for identity authentication, supports the MQTT QoS mechanism and will message function, and uses the predefined JSON Schema to define device status, commands, and metadata information.

[0008] S2: The key exchange of the SSL / TLS encrypted communication adopts the Elliptic Curve Diffie-Hellman Ephemeral (ECDHE) algorithm, and the encryption suite adopts TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256. The master station updates the key regularly, and the client verifies the server certificate issued by a trusted third-party CA organization and uses the root certificate trust chain for verification to ensure the server identity is credible and prevent man-in-the-middle attacks.

[0009] S3: Use at least one management channel and at least one business channel to transmit management data and business data of model services and asset services respectively. The management channel is used to transmit device registration, configuration update and status monitoring management data, and the business channel is used to transmit real-time data and alarm information business data. The management channel and business channel are distinguished by different MQTT topics.

[0010] S4: The intelligent operation and maintenance master station communicates with the intelligent operation and maintenance substation through the MQTT protocol, and realizes real-time monitoring and management of substations distributed in different locations by the master station through configuration management and data synchronization. The configuration management includes parameter distribution, version control and configuration readback, and the data synchronization includes real-time data collection, historical data query and data reporting frequency control.

[0011] Furthermore, the identity authentication process between the intelligent operation and maintenance master station and the intelligent operation and maintenance substation in step S1 includes:

[0012] (1) The intelligent operation and maintenance substation sends a connection request to the master station. The request carries the substation identification information, which includes the station identification and service name. The station identification is assigned by the master station and is defined by the combination of the region identification, voltage level, and station name in hexadecimal.

[0013] (2) The intelligent operation and maintenance master verifies the identity information of the slave station. After the verification is passed, an MQTT connection is established and a unique client ID is assigned to the slave station. If the client is disconnected abnormally, the server will automatically publish the will message to the specified topic so that other clients can know the client's offline status;

[0014] (3) Using JSON as the data exchange format, the message header contains three fields: message type, message ID, and timestamp. The message type field is used to identify the function of the message, the message ID field is used to distinguish different messages, and the timestamp field is used to record the creation time of the message.

[0015] Further, the step 2 includes:

[0016] (1) When the SSL / TLS digital signature verifies identity, the client verifies the server's digital certificate, which is issued by a trusted third-party CA organization, and checks the signature, validity period, and revocation status of the certificate to ensure the server's identity is credible. The root certificate trust chain is used for verification to prevent man-in-the-middle attacks. The server's digital certificate contains the server's public key.

[0017] (2) Key exchange uses the Elliptic Curve Diffie-Hellman Ephemeral (ECDHE) key exchange algorithm. The master station updates the key regularly and uses the new shared key to encrypt subsequent MQTT messages after each key update. The key update cycle is every 24 hours.

[0018] (3) The encryption suite adopts TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA 256 to ensure the security and confidentiality of MQTT message transmission.

[0019] Further, the step 3 includes:

[0020] (1) The MQTT topic of the management channel is / MGR / REQ / {station identifier} / {service name} / {message type}, and the MQTT topic of the service channel is / DATA / RSP / {station identifier} / {service name} / {message type}, where {message type} is used to distinguish different types of JSON messages;

[0021] (2) In the management channel, the device registration message contains the device ID, device type, and device description information; the configuration update message contains the parameter name and parameter value to be updated; and the status monitoring message contains information such as the device's operating status, CPU usage, and memory occupancy;

[0022] (3) In the service channel, the real-time data message includes the collection time and data value, and the alarm information message includes the alarm level, alarm content and alarm time information;

[0023] (4) All MQTT messages are transmitted using QoS level 1.

[0024] Further, the step 4 includes:

[0025] (1) The configuration management parameters are distributed through file services and model services, where the file service is used to distribute configuration files and the model service is used to update the device model; the version control function is implemented through the file service, and after each configuration update, the file service records the new version number and modified content;

[0026] (2) The configuration readback is implemented through file services and model services to obtain the current configuration files and device models of the substation; the real-time data collection function of the data synchronization is implemented through data services, supporting data collection at a preset frequency;

[0027] (3) The historical data query function is implemented through data services, supporting the query of historical data according to the time range; the data reporting frequency control function is implemented through data services, and the master station dynamically adjusts the data reporting frequency of the slave station.

[0028] The beneficial effects of the present invention are as follows:

[0029] The present invention proposes an intelligent operation and maintenance communication method based on the JSON format, which adopts the lightweight and efficient MQTT protocol and flexible JSON data format, significantly improving the communication efficiency and data processing efficiency. Through the MQTT QoS mechanism, the reliable transmission of messages can be guaranteed even in the case of unstable network, ensuring the delivery of key data and improving the reliability of the system. At the same time, the publish / subscribe mechanism and flexible topic definition of MQTT, as well as the flexible data format of JSON, facilitate access to various devices and systems, support flexible message routing, enhance the scalability of the system, and better adapt to the development needs of smart grids. In addition, the use of SSL / TLS digital signature verification effectively resists security threats such as man-in-the-middle attacks and replay attacks, ensuring the security of smart grid operation and maintenance. The master-substation integrated design concept allows the master station to perform configuration management and data synchronization on the substation through the management channel, which simplifies the system configuration and maintenance work, reduces operation and maintenance costs, and improves operation and maintenance efficiency. The proposed intelligent operation and maintenance communication method is suitable for use in intelligent operation and maintenance master stations and intelligent operation and maintenance substations, improving the operation and maintenance efficiency and response speed of the entire system. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a diagram of the communication architecture of the main station established in the present invention;

[0031] Figure 2 It is a communication flow chart between the master and slave stations in the present invention. DETAILED DESCRIPTION

[0032] The present invention is described in detail below based on the accompanying drawings, and the technical solutions in the present invention are clearly described so that the features of the present invention can be more clearly understood. The present invention proposes an intelligent operation and maintenance communication method based on JSON format, such as Figure 1As shown, the method includes the following steps:

[0033] S1: Establish a communication connection based on the MQTT protocol and perform authentication between the intelligent operation and maintenance master station and the intelligent operation and maintenance substation. The authentication uses SSL / TLS digital signature verification and supports the MQTT QoS mechanism and will message function. The predefined JSON Schema is used to define device status, commands, and metadata information.

[0034] S2: The MQTT protocol verifies identity through SSL / TLS digital signatures, where the SSL / TLS key exchange uses the ECDHE algorithm and the cipher suite uses TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256;

[0035] S3: Use at least one management channel and at least one business channel to transmit management data and business data of model services and asset services respectively. The management channel is used to transmit device registration, configuration update, and status monitoring management data, and the business channel is used to transmit real-time data and alarm information business data. The management channel and business channel are distinguished by different MQTT topics.

[0036] S4: The intelligent operation and maintenance master station communicates with the intelligent operation and maintenance substation through the MQTT protocol to achieve configuration management and data synchronization, wherein the configuration management includes parameter distribution, version control and configuration readback functions, and the data synchronization includes real-time data collection, historical data query and data reporting frequency control.

[0037] Furthermore, the intelligent operation and maintenance communication protocol adopts a master-substation architecture and combines it with the MQTT protocol for communication. The core components include the operation and maintenance master station, operation and maintenance substation, MQTT client, proxy server and other virtual units. The master station is responsible for the control and management of the entire system, and the substation executes control commands and sends information. Figure 1 As shown;

[0038] Furthermore, at the master site layer, the Broker proxy server is responsible for the transfer and routing of messages, and the MQTT client is responsible for the generation and processing of operation and maintenance business information.

[0039] Furthermore, at the substation level, local operation and maintenance services send information through the proxy server, other automation equipment connects to the proxy server through access modules of other protocols, and the virtual unit establishes a secure connection with Broke through SSL / TLS for digital signature authentication.

[0040] Furthermore, after the intelligent operation and maintenance substation is online, a secure connection with the MQTT Broker is established through SSL / TLS, and digital signature authentication is performed. The authentication information includes the station identifier and service name (SRVNAME). After sending a registration request and waiting for the platform to return a registration response, the mutation data is allowed to be uploaded; at the same time, after the platform detects that the substation is online, it reads the substation model configuration and updates the configuration between the master and substation. The design concept is an integrated design of the master and substation. The master station can read and modify the substation configuration. At the same time, after the substation is modified, the master station can synchronize the substation configuration. The communication process is as shown in the attached figure. Figure 2 As shown;

[0041] Furthermore, the communication identifier between the master and substations is assigned by the master station, and the definition rule is CN_XX_XX_220kV_XJ_TEXT, region_220Kv voltage level_station name in hexadecimal;

[0042] Furthermore, the master subscribes to the relevant topics of the management channel and business channel to receive messages from the slave. The slave encapsulates the data and request in JSON format and publishes it to the corresponding MQTT topic. The slave publishes registration requests and configuration update requests to the topic / MGR / REQ / {station ID} / {service name} / , and publishes real-time data and alarm information to the topic / DATA / RSP / {station ID} / {service name} / .

[0043] Furthermore, the device status, command, and metadata information are defined in JSON format. The JSON format header definition is shown in Table 1. The message header contains UUID, SubID, SrvName, DstAddr, SrcAddr, and Para fields, which are used to describe message attributes and contextual key information, making the content more structured and improving the efficiency and accuracy of message processing.

[0044] Table 1

[0045]

[0046] Furthermore, the MQTT Broker receives messages published by the slave station and forwards them to the master station that has subscribed to the corresponding topic. After receiving the message, the master station parses the JSON data and performs corresponding operations, such as updating configuration, storing data, and triggering alarms.

[0047] Furthermore, the master and slave stations communicate bidirectionally via the MQTT protocol. The master station manages configuration and synchronizes data with the slave stations through management channels. The master station sends configuration parameters to the slave stations, which then return the configuration results to the master station. The slave stations can also periodically report status information and real-time data to the master station.

[0048] Furthermore, a JSON service encapsulation extensible service framework is defined. This service framework covers the key functions of intelligent operation and maintenance, including data collection, equipment control, configuration management, and fault diagnosis. It is customized for intelligent operation and maintenance requirements and supports the use of extensible service codes (SC) for model services (ModelServer) and asset services (GetAsserts, SetAsserts) for power equipment. This facilitates the addition of new service types to adapt to the ever-changing needs of future operation and maintenance, enhancing the flexibility and scalability of the system. The list of extensible services for intelligent operation and maintenance is shown in Table 2:

[0049] Table 2

[0050]

[0051] Compared with the existing technology, the beneficial effects of the present invention include at least the following: the intelligent operation and maintenance communication method based on the JSON format proposed by the present invention has certain advantages in communication efficiency and security, as well as scalability and configuration maintenance. The present invention adopts the lightweight JSON format and the efficient MQTT protocol to reduce data transmission volume and parsing time, thereby reducing device resource usage; adopts SSL / TLS and encryption algorithms to ensure communication security; utilizes the MQTT QoS mechanism to ensure reliable message transmission; based on the publish / subscribe mechanism and flexible topic definition, it facilitates access to various devices and systems and supports flexible expansion; the integrated design of the master and substation simplifies system configuration and maintenance, reducing operation and maintenance costs; and through an extensible service framework, supports a rich range of service types to meet the diverse operation and maintenance needs of the smart grid.

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or replaced. Any modification or replacement that does not depart from the spirit and scope of the present invention should be covered by the scope of protection of the claims of the present invention.

Claims

1. An intelligent operation and maintenance communication method based on JSON format, characterized in that: include: S1: Establish a communication connection based on the MQTT protocol and perform authentication between the intelligent operation and maintenance master station and the intelligent operation and maintenance substation. The authentication uses SSL / TLS digital signature verification and supports the MQTT QoS mechanism and will message function. The predefined JSON Schema is used to define device status, commands, and metadata information. S2: The MQTT protocol verifies identity through SSL / TLS digital signatures. SSL / TLS uses the ECDHE algorithm for key exchange and TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 for the cipher suite. The master station regularly updates the key, and the client verifies the server certificate issued by a trusted third-party CA to prevent man-in-the-middle attacks. S3: Use at least one management channel and at least one business channel to transmit management data and business data of model services and asset services respectively. The management channel is used to transmit device registration, configuration update, and status monitoring management data, and the business channel is used to transmit real-time data and alarm information business data. The management channel and business channel are distinguished by different MQTT topics. S4: The intelligent operation and maintenance master station communicates with the intelligent operation and maintenance substation through the MQTT protocol, and realizes real-time monitoring and management of substations distributed in different locations by the master station through configuration management and data synchronization. The configuration management includes parameter distribution, version control and configuration readback, and the data synchronization includes real-time data collection, historical data query and data reporting frequency control.

2. The intelligent operation and maintenance communication method based on JSON format according to claim 1 is characterized in that The identity authentication process between the intelligent operation and maintenance master station and the intelligent operation and maintenance substation in step S1 includes: (1) The intelligent operation and maintenance substation sends a connection request to the master station, which carries the substation identification information. This information includes the station identification and service name. The station identification is assigned by the master station and is defined by the combination of the region identification, voltage level, and station name in hexadecimal. (2) The intelligent operation and maintenance master verifies the identity information of the substation, establishes an MQTT connection after the verification is passed, and assigns a unique client ID to the substation. If the client disconnects abnormally, the server will automatically publish the will message to the specified topic so that other clients can know the client's offline status; (3) Using JSON as the data exchange format, the message header contains three fields: message type, message ID, and timestamp. The message type field is used to identify the function of the message, the message ID field is used to distinguish different messages, and the timestamp field is used to record the creation time of the message.

3. The intelligent operation and maintenance communication method based on JSON format according to claim 1 is characterized in that The step S2 comprises: (1) When the SSL / TLS digital signature verifies the identity, the client verifies the server digital certificate issued by a trusted third-party CA organization and checks the signature, validity period and revocation status of the certificate to ensure the server's identity is credible. The root certificate trust chain is used for verification to prevent man-in-the-middle attacks. The server digital certificate contains the server's public key. (2) The key exchange uses the Elliptic Curve Diffie-Hellman Ephemeral (ECDHE) key exchange algorithm. The master station updates the key regularly and uses the new shared key to encrypt subsequent MQTT messages after each key update. The key update cycle is once every 24 hours. (3) The encryption suite uses TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA 256, used to ensure the security and confidentiality of MQTT message transmission.

4. The intelligent operation and maintenance communication method based on JSON format according to claim 1, characterized in that The step S3 comprises: (1) The MQTT topic of the management channel is / MGR / REQ / {station identifier} / {service name} / {message type}, and the MQTT topic of the service channel is / DATA / RSP / {station identifier} / {service name} / {message type}, where {message type} is used to distinguish different types of JSON messages; (2) In the management channel, the device registration message contains the device ID, device type and device description information, the configuration update message contains the parameter name and parameter value to be updated, and the status monitoring message contains the device's operating status, CPU usage and memory occupancy information; (3) In the business channel, the real-time data message includes the collection time and data value, and the alarm information message includes the alarm level, alarm content and alarm time information; (4) All MQTT messages are transmitted using QoS level 1.

5. The intelligent operation and maintenance communication method based on JSON format according to claim 1 is characterized in that The step S4 comprises: (1) The configuration management parameters are distributed through file services and model services, where the file service is used to distribute configuration files and the model service is used to update the device model; the version control function is implemented through the file service, and after each configuration update, the file service records the new version number and modified content; (2) The configuration readback is implemented through file services and model services to obtain the current configuration files and device models of the substation; the real-time data collection function of the data synchronization is implemented through data services, supporting data collection at a preset frequency; (3) The historical data query function is implemented through data services, supporting the query of historical data according to the time range; the data reporting frequency control function is implemented through data services, and the master station dynamically adjusts the data reporting frequency of the substation.

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