In active response to the initiative of the State Grid Dispatching and Control Center on promoting the application of auxiliary monitoring technology for hard press plates of relay protection devices, the dispatching and control center of a certain province is accelerating the intelligentization process of power grid safety protection. It has put forward the overall principle for the upgrading of hard press plate monitoring technology: for all newly-built, renovated and in-service relay protection and safety automatic devices in the future (including protection devices, security and control devices, automatic bus transfer equipment, under-frequency load shedding devices, intelligent terminals, integrated intelligent devices, etc.), real-time online monitoring shall be implemented for their key outlet hard press plates (such as trip, close, reclosing, failure initiation, etc.). For new construction and renovation projects, the embedded dual-link press plate technical solution shall be prioritized; for in-service devices, the external embedded magnetic induction technical solution is recommended for intelligent transformation.

Wuhan Haomai has an early layout in the field of online monitoring of press plates, actively carrying out cooperation with power supply companies on the renovation of press plate online monitoring. It has innovatively launched a hard press plate online monitoring solution, which has been successfully applied in multiple substations and accumulated rich practical experience.

Mature Sensing System for Hard Press Plates

Press Plate Sensor: It innovatively adopts high-precision magnetic induction technology to accurately detect the switching status of press plates. The dual-reed switch collaborative verification architecture is adopted, and dual safety confirmation is realized through a dynamic voting mechanism, effectively improving the fault tolerance and reliability of the sensor.

Convergence Unit: Based on multi-channel edge computing, it efficiently acquires press plate status in real time and supports rapid response.

Intelligent Press Plate Management System: Composed of an intelligent press plate management system platform, an intelligent management host, a press plate controller, a press plate detector and accessories. In substation renovation projects, it realizes comprehensive online monitoring of key press plates on the protection panels, measurement and control panels and switch cabinet panels in the 10kV high-voltage room of the substation.

Early Warning Mechanism: The system is configured with a three-level early warning mechanism (early warning/alarm/emergency disposal) in synchronization, supports automatic generation of fault root cause analysis, and provides quantitative decision-making basis for preventive maintenance. Based on real-time section preservation technology, it completely records the switching status information of all press plates in the substation.

Efficient Deployment: Modular Design and Standardized Construction Adopted in Project Implementation

Power Supply: Power is taken from the UPS in the protection room, uniformly distributed by the convergence unit, and a multi-channel power supply design is adopted to ensure the reliable operation of the system.

Acquisition Layer: Each panel equipped with press plates is configured with a press plate detector to collect their status, and the convergence and transmission of data of the panel are completed through the press plate controller.

Transmission Layer: Based on distributed transmission technology, the distributed convergence unit realizes efficient and real-time transmission of press plate status data to the management host.

Management Layer: An intelligent management host is deployed in the protection room to collect data of the entire substation, and upload the processed data to the substation control layer network through a security isolation device.

Security Architecture: Strictly complying with network security specifications, the press plate monitoring system is deployed in Zone I/II, and the press plate inspection and verification system is deployed in Zone IV, with data transmitted through a one-way isolation device. (Support for third-party IEC61850/IEC104 access to monitoring/telecontrol/protection information sub-stations)

The renovation project was completed ahead of schedule and passed the acceptance inspection. It has significantly reduced the cost of manual verification, avoided maloperation of relay protection devices caused by incorrect or missing switching of press plates, remarkably improved the operation and maintenance efficiency and safety of the substation, and won unanimous praise from the user unit.

In the future, Wuhan Haomai will give full play to its technical expertise and practical experience in the field of intelligent monitoring of hard press plates, continue to focus on technological innovation and solution optimization, actively cooperate with users to promote the comprehensive implementation of intelligent monitoring of hard press plates, and ensure the safe, stable and efficient operation of the power grid.