Intelligent operation and maintenance communication method based on JSON format

Abstract

The invention discloses an intelligent operation and maintenance communication method based on a JSON (JavaScript Object Notation) format, and aims to solve the problems of high complexity, low security and difficulty in extension of the existing protocol, so as to improve the reliability, speed and security of operation and maintenance of an intelligent power grid. The method is characterized in that an intelligent operation and maintenance system master-slave station communication protocol is based on a publishing / subscribing mechanism of an MQTT protocol, performs data exchange in a lightweight JSON format, and is suitable for data communication between an intelligent operation and maintenance master station and an intelligent operation and maintenance slave station; the identity between the master station and the slave station is verified through an SSL / TLS digital signature, so that the communication security is ensured; the protocol design comprises a management channel and a business channel which are respectively used for transmitting management data and business data of the model service and the asset service, so that the flexibility of data management is improved; by adopting the design concept of integration of the master station and the substation, configuration management and data synchronization are realized, so that the master station can monitor and manage the substations distributed at different places in real time, and the operation and maintenance efficiency and the response speed of the whole system are improved.

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 JSON format. Background Art

[0002] With the rapid development of smart grids and automation systems, the requirements for communication protocols are becoming increasingly higher. Smart grids need to have high reliability, real-time performance, security, interoperability, and scalability to support the access of large-scale devices, the transmission of massive data, and complex control functions. DNP3 and Modbus protocols are mainly used in traditional power systems. Their data formats are relatively fixed, making it difficult to express complex equipment status, alarm information, and control instructions. In addition, the real-time and security of these protocols are also difficult to meet the needs of new power systems. In scenarios such as fault detection and isolation, millisecond-level response speeds are required, but DNP3 and Modbus may not be able to achieve such performance due to their polling mechanisms and limited bandwidth. At the same time, the security mechanisms of DNP3 and Modbus are relatively weak and vulnerable to network attacks and data tampering, which is unacceptable for smart grids with extremely high security requirements.

[0003] CN 117808449 A describes a secondary operation and maintenance system interactive communication method, which uses VSS data types to model substations and transmit intelligent operation and maintenance alarm information to improve the efficiency and accuracy of information transmission. The method generates an intelligent operation and maintenance file when an alarm occurs in the substation, and sends the file path and name to the main station through a VSS signal so that the main station can call the file. However, the method adopts a static communication strategy and cannot adapt to dynamic changes in network status, especially 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 a power communication site. The data interconnection interface of the TMS is connected with the data interconnection interface of the intelligent operation and maintenance platform and the intelligent operation and maintenance terminal in the terminal system to realize the interaction of resource information. However, there are still problems in how to optimize the data sharing service characteristics and how to specifically realize the efficient data sharing interaction between the intelligent operation and maintenance platform and the TMS to ensure the stability and real-time performance of the data interaction. 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 process 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 QoS mechanism and will message function of MQTT, and uses the predefined JSONSchema 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, the encryption suite adopts TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256, the master station updates the key regularly, 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 that 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, wherein 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 the 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 the substations distributed in different locations by the master station through configuration management and data synchronization. The configuration management includes parameter issuance, 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 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;

[0014] (3) JSON is used 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 comprises:

[0016] (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 that the server's identity is credible, and uses the root certificate trust chain for verification to prevent man-in-the-middle attacks. The server 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 performed 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 comprises:

[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 includes the device ID, device type and device description information, the configuration update message includes the parameter name and parameter value to be updated, and the status monitoring message includes the device's operating status, CPU usage and memory occupancy rate;

[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 comprises:

[0025] (1) The configuration management parameters are sent through file services and model services, where the file service is used to send configuration files and the model service is used to update the device model; the version control function is implemented through file services, 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 service and model service to obtain the current configuration file and device model of the substation; the real-time data collection function of the data synchronization is implemented through data service to support data collection according to a preset frequency;

[0027] (3) The historical data query function is implemented through data services, supporting historical data query according to 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 JSON format, which adopts lightweight and efficient MQTT protocol and flexible JSON data format, and significantly improves communication efficiency and data processing efficiency. Through the QoS mechanism of MQTT, the reliable transmission of messages can be guaranteed even in the case of unstable network, ensuring the delivery of key data and improving system reliability. 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 system scalability, and better adapt to the development needs of smart grids. In addition, SSL / TLS digital signature verification is adopted to effectively resist security threats such as man-in-the-middle attacks and replay attacks, and ensure the safety of smart grid operation and maintenance. The master-substation integrated design concept, the master station configures and manages the substation and synchronizes the data through the management channel, simplifies the system configuration and maintenance work, reduces the operation and maintenance cost, and improves the operation and maintenance efficiency. The proposed intelligent operation and maintenance communication method is suitable for the use of intelligent operation and maintenance master station and intelligent operation and maintenance substation, and improves the operation and maintenance efficiency and response speed of the entire system. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a main station communication architecture diagram 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 solution in the present invention is clearly described so that the inventive 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 comprises the following steps:

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

[0034] S2: The MQTT protocol verifies identity through SSL / TLS digital signature, where the key exchange of SSL / TLS adopts ECDHE algorithm and the encryption suite adopts 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, wherein 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, and the management channel and the business channel are distinguished by different MQTT topics;

[0036] S4: The intelligent operation and maintenance main station communicates with the intelligent operation and maintenance substation through the MQTT protocol to realize configuration management and data synchronization, wherein the configuration management includes parameter issuance, 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 the master-substation architecture and combines 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 the control command and sends the 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 proxy servers, other automation equipment connects to the proxy servers through access modules of other protocols, and the virtual unit establishes a secure connection with Broke through SSL / TLS for digital signature identity 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 identification and service name (SRVNAME). After sending a registration request and waiting for the platform to return a registration response, 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 allocated 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 station subscribes to the relevant topics of the management channel and the business channel to receive messages from the slave station. The slave station encapsulates the data and request in JSON format and publishes it to the corresponding MQTT topic. The slave station publishes registration requests and configuration update requests to the topic / MGR / REQ / {station identifier} / {service name} / , and publishes real-time data and alarm information to the topic / DATA / RSP / {station identifier} / {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 station and the substation communicate bidirectionally through the MQTT protocol. The master station performs configuration management and data synchronization on the substation through the management channel. The master station sends configuration parameters to the substation, and the substation returns the configuration results to the master station. The substation can also regularly 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 data collection, equipment control, configuration management, fault diagnosis and intelligent operation and maintenance, and is customized for the needs of intelligent operation and maintenance. It supports the use of extensible service code (SC) design for model services (ModelServer) and asset services (GetAsserts, SetAsserts) for power equipment, which facilitates the addition of new service types to adapt to the changing needs of future operation and maintenance and enhance the flexibility and scalability of the system. The content of the extensible service list for intelligent operation and maintenance is shown in Table 2:

[0049] Table 2

[0050]

[0051] Compared with the prior art, the beneficial effects of the present invention include at least: the intelligent operation and maintenance communication method based on 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 lightweight JSON format and efficient MQTT protocol, which reduces the data transmission volume and parsing time, and reduces the device resource occupation; adopts SSL / TLS and encryption algorithm to ensure communication security; utilizes MQTT's QoS mechanism to ensure reliable message transmission; based on the publish / subscribe mechanism and flexible topic definition, it is convenient to access various devices and systems, and supports flexible expansion; the integrated design of the master and substation simplifies system configuration and maintenance, and reduces operation and maintenance costs; through an extensible service framework, it supports a variety of service types to meet the diverse smart grid operation and maintenance needs.

[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 relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced, and any modification or replacement that does not depart from the spirit and scope of the present invention should be covered within 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 identity authentication between the intelligent operation and maintenance master station and the intelligent operation and maintenance substation. The identity authentication adopts SSL / TLS digital signature verification, supports the QoS mechanism and will message function of MQTT, and uses the predefined JSON Schema to define device status, command and metadata information; S2: The MQTT protocol verifies identity through SSL / TLS digital signatures, where the key exchange of SSL / TLS uses the ECDHE algorithm and the encryption suite uses TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256; the master station regularly updates the key, and the client verifies the server certificate issued by a trusted third-party CA organization 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, wherein 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, and the management channel and the 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 the substations distributed in different locations by the master station through configuration management and data synchronization. The configuration management includes parameter issuance, version control and configuration readback, and the data synchronization includes real-time data collection, historical data query and data reporting frequency control.

2. According to claim 1, a JSON-based intelligent operation and maintenance communication method 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. 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. (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 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) JSON is used 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. According to claim 1, a JSON-based intelligent operation and maintenance communication method is characterized in that The step 2 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 that the server's identity is credible, and uses the root certificate trust chain for verification to prevent man-in-the-middle attacks. The server digital certificate contains the server's public key. (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 performed every 24 hours. (3) The encryption suite adopts TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA 256 to ensure the security and confidentiality of MQTT message transmission.

4. According to claim 1, a JSON-based intelligent operation and maintenance communication method is characterized in that The step 3 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 includes the device ID, device type and device description information, the configuration update message includes the parameter name and parameter value to be updated, and the status monitoring message includes the device's operating status, CPU usage and memory occupancy rate; (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; (4) All MQTT messages are transmitted using QoS level 1.

5. According to claim 1, a JSON-based intelligent operation and maintenance communication method is characterized in that The step 4 comprises: (1) The configuration management parameters are sent through file services and model services, where the file service is used to send configuration files and the model service is used to update the device model; the version control function is implemented through file services, and after each configuration update, the file service records the new version number and modified content; (2) The configuration readback is implemented through file service and model service to obtain the current configuration file and device model of the substation; the real-time data collection function of the data synchronization is implemented through data service to support data collection according to a preset frequency; (3) The historical data query function is implemented through data services, supporting historical data query according to 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.

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