Abstract: With the rapid development of the social economy, China's substation is continuously advancing towards modernization. Automation equipment and relay protection devices have gained widespread application due to their excellent performance. This article introduces the AM5SE series of micro-computer protection devices, which can provide corresponding protection functions for different protected objects in the intelligent energy distribution project of the Central Plains Technology City. Moreover, by collecting relevant remote measurement and remote signal data through the power monitoring system, it can greatly enhance the reliability, safety, and power supply quality of substation operations, contributing to the realization of comprehensive automation in substation and the achievement of unattended or minimally attended operation.
Keywords: Safety; Reliability; Microcomputer Protective Device; Power Monitoring System
1. Overview
Zhongyuan Technology City, located in the northern Longhu District of Zhengdong New District, Zhengzhou City, extends north to the Lianhao Expressway, south to Longhu Lake, east to Longzi Lake, and west to Zhongzhou Avenue. The core land area is approximately 16.4 square kilometers. This is a "city technology belt" that Henan Province and Zhengzhou City have focused on building collectively during the 14th Five-Year Plan period, encompassing core areas such as digital culture and creativity, information technology, cutting-edge science and technology, life sciences, and talent education. The core starting area of the Zhongyuan Technology City covers approximately 453 acres with a total floor area of 1.142 million square meters.
This project is for the 10kV Comprehensive Smart Energy Stations A1 and A4, located within the core starting area of the Zhongyuan Science and Technology City. Each incoming line source is from an industrial innovation switchgear. The incoming and outgoing line cabinets use cable feeding and outgoing methods, respectively, and are equipped with KYN28-12 type metal-enclosed switchgear. Both energy stations have a power supply system with two incoming lines and one bus tie, along with multiple transformer, motor, and capacitor outgoing circuitries.
Product Requirements
2.1 Protection Function Requirements
In the distribution engineering of the intelligent energy station in the Zhongyuan Technology City, different micro-computer protection devices are configured for different objects. Specifically, the incoming line cabinet is equipped with an AM5SE-F line protection device, the PT cabinet is fitted with an AM5SE-UB PT monitoring and parallel protection device, the distribution transformer cabinet is equipped with an AM5SE-T transformer protection device, the bus tie cabinet is fitted with an AM5SE-B backup protection device, the capacitor outlet cabinet is equipped with an AM5SE-C capacitor protection device, and the motor outlet cabinet is fitted with an AM5SE-M motor protection device. These micro-computer protection devices primarily implement real-time monitoring and protection of the equipment operation status of the high-voltage cabinets through the following protection functions:
2.2 Signal Export Demand
The distribution engineering of the intelligent energy station in the Central Plains Technology City requires the separation of multiple signal outlets, delivering these signals to signal boxes for easier implementation of different indicator lights triggered by various faults, as shown in Figure 1. The AM5SE series microcomputer protection devices feature the signal separation function, meeting this requirement. Additionally, real-time monitoring of the microcomputer protection data through the power monitoring system is necessary.
Figure 1: Signal Box Schematic Diagram
Product Solutions
This project's power distribution engineering includes two energy stations, A1 and A4, with two 10kV sub-substation transformer rooms. Each transformer room has two busbars and employs a single-busbar system, including 37 high-voltage switchgear panels. The entire transformer room is equipped with a total of 31 protective devices. As an example, the system of Energy Station A1 is illustrated in the diagram above:
Figure 2: A1 Energy Station 10kV Primary System Diagram
The 10kV distribution engineering of the A1 and A4 Energy Stations is equipped with the following types and quantities of micro-computer protection:
4 System Requirements
To monitor the operation of the entire power distribution room and collect data in real-time, this project is equipped with an electric power monitoring system, primarily for the monitoring and management of power consumption at various sub-stations. The monitoring scope includes the micro-computer protection devices and instruments of the sub-stations. The system consists of three parts: the user management layer, the network communication layer, and the field equipment layer. It is connected to the local area network switch via Ethernet cables and uploaded to the host of the electric power monitoring system, thereby achieving power monitoring functions.
The following functions can be achieved with the power monitoring system:
Real-Time Monitoring: Visually displays the operation status of power distribution lines in the form of a single-phase distribution diagram, enabling real-time monitoring of electrical parameters such as voltage, current, power, and power factor for each circuit. It also dynamically supervises the closing and opening states of circuit breakers, disconnect switches, and ground switches for each power distribution loop.
Electrical Parameter Inquiry: In the primary distribution diagram, you can directly view detailed electrical parameters of the circuit, including three-phase current, three-phase voltage, total active power, total reactive power, total power factor, and active energy in the forward direction.
Operation Reports: Query operational parameters of specific circuits or equipment for designated time periods. The report should display electrical parameter information including: phase currents, three-phase voltages, total power factor, total active power, total reactive power, and positive active energy. Report formats include daily, monthly, and annual reports.
Real-time Alerts: Capable of issuing alerts for remote signal changes in distribution circuit circuit breakers, disconnect switches, earthing blades, and their opening and closing actions, as well as protection operations and accident tripping events.
Historical Event Query: Stores and manages records of events such as remote signal changes, protective actions, tripped circuit breakers, and limits on voltage, current, power, and power factor, facilitating users to trace historical system events and alarm information, as well as for query statistics and accident analysis.
Fault Recording: Capable of automatically and accurately recording the changes in various electrical quantities before and after a system failure. The analysis and comparison of these electrical quantities play a crucial role in analyzing accidents, determining if protective actions are correctly triggered, and enhancing the safety and stable operation of the power system.
7) Incident Memoir: Automatically records all real-time steady-state information around the time of an incident, including switch positions, protective action states, remote measurements, etc., to form the data foundation for incident analysis.
8) Curve Query: Enables real-time and historical curve searches, including all remote measurements such as three-phase current, three-phase voltage, active power, reactive power, and power factor.
9) User Permission Management: We have implemented a user permission management feature that prevents unauthorized operations (such as remote control actions, database modifications, etc.). The system can define permission groups with different operational privileges (e.g., admin group, engineer group, operator group, etc.), and allocate different users within each group, ensuring reliable security for system operation, maintenance, and management.
10) Network Topology: Supports real-time monitoring of communication status for all devices connected to the system, fully displaying the entire system's network structure; enables online diagnosis of device communication status, and can automatically display faulty devices or components and their malfunctioning areas on the interface during network anomalies.
11) Remote Control Function: In compliance with electrical regulations, remote control operations can be performed on equipment throughout the entire distribution system range.
12) Communication Management: Allows for the management, control, and real-time monitoring of equipment communication across the entire distribution system.
5 On-site Installation Photos
This project features local and decentralized microcomputer protection installations on various high-voltage switchgear cabinets. The power monitoring system's main unit and display are arranged on the control panel, as shown in the image below. The project was energized for use in 2023 and is operating normally.
Figure 3: Installation view of microcomputer protection at the power distribution engineering site in Zhongyuan Science and Technology City
Figure 4: Power Monitoring System Interface at the Distribution Engineering Site in Central Plains Science City
6 Conclusion
Micro-computer protective devices hold a crucial position in the power system, capable of detecting equipment failures and abnormal operating conditions, and automatically and selectively actuating circuit breakers to remove faulty equipment from the system. This ensures that non-faulty equipment continues to operate normally, containing the scope of accidents to the smallest extent possible, and improving the reliability of system operation. It also maximizes the safety and continuity of power supply to customers. The AM5SE series micro-computer protective devices introduced in this article provide corresponding protection functions for different protection objects in the comprehensive intelligent energy distribution project of the core starting area of Zhongyuan Science and Technology City. Moreover, through the power system monitoring system, the collection of relevant remote measurement and remote signal data for monitoring can significantly enhance the reliability and safety of substation operations, improve power quality, and facilitate the realization of substation comprehensive automation, and achieve unattended or minimally attended operation.
Reference
Ankorri Enterprise Microgrid Design and Application Manual. June 2020 Edition
[2] Ankerui 35KV and Below Substation Intelligent Distribution System Design and Product Second Principle Diagram Collection. October 2020 Edition
[3] Ankerui User Substation Integrated Automation and Operation & Maintenance Solution. November 2021 Edition
