Abstract: With the rapid development of the social economy, China's substation is continuously advancing towards modernization, with automation equipment and relay protection devices widely used due to their excellent performance. This article introduces the AM5SE series of microcomputer protection devices, which can provide corresponding protection functions for different protection objects in the intelligent energy distribution project of the Central Plains Science and Technology City. Moreover, by collecting relevant remote measurement and remote signal data through the power monitoring system, it can significantly enhance the reliability, safety, and power supply quality of substation operations, benefiting the realization of comprehensive automation in substation and the achievement of unattended or minimally attended operation.
Keywords: Safety; Reliability; Microcomputer Protection Device; Power Monitoring System
1. Overview
Zhongyuan Technology City, located in the northern Longhu area 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 covers approximately 16.4 square kilometers. It is a "city technology belt" that focuses on digital culture and creativity, information technology, cutting-edge science and technology, life sciences, and talent education, which the Henan Province and Zhengzhou City are committed to building during the 14th Five-Year Plan period. 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 incoming and outgoing lines, respectively, and are equipped with KYN28-12 type metal-enclosed handcart-type vacuum switchgear. Both energy stations have a two-line-to-one-mother-line power supply system, with multiple transformer, motor, and capacitor outgoing circuitries.
Product Requirements
2.1 Protection Function Requirements
In the distribution engineering of the smart energy station at the Central Plains Technology City, different micro-computer protection devices are configured for various objects. Specifically, the incoming line cabinet is equipped with the AM5SE-F line protection device, the PT cabinet with the AM5SE-UB PT monitoring and parallel protection device, the distribution transformer cabinet with the AM5SE-T transformer protection device, the bus tie cabinet with the AM5SE-B backup and self-throw protection device, the capacitor outgoing line cabinet with the AM5SE-C capacitor protection device, and the motor outgoing line cabinet with the AM5SE-M motor protection device. These micro-computer protection devices primarily achieve real-time monitoring and protection of the equipment operation in 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, routing 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 signal separation functionality, meeting this requirement. Additionally, real-time monitoring of the microcomputer protection data is necessary through the power monitoring system.
Figure 1: Signal Box Schematic
Product Solutions
This project's power distribution system consists of two energy stations, A1 and A4, including two 10kV substation-transformers, each with two busbars, employing a single-busbar system. This includes 37 high-voltage switchgears, with a total of 31 protective devices in the entire distribution room. Taking the system of Energy Station A1 as an example, the proposed scheme is as shown in the above diagram:
Figure 2: A1 Energy Station's 10kV Primary System Diagram
The micro-computer protection models and quantities for the 10kV power distribution project at Energy Stations A1 and A4 are as follows:
4 System Requirements
To monitor the operation of the entire power distribution room and collect data in real-time, the project is equipped with an electric power monitoring system, primarily for the monitoring and management of power consumption at various transformer substations. The monitoring scope includes the microcomputer protection devices and instruments in the transformer substations. The system is composed 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 realizing the power monitoring function.
The power monitoring system can achieve the following functions:
Real-Time Monitoring: Displayed in the form of a primary distribution diagram, this system provides a clear visual representation of the operational status of distribution lines. It enables real-time monitoring of electrical parameters such as voltage, current, power, and power factor for each circuit. Additionally, it dynamically supervises the closing and opening states of circuit breakers, disconnect switches, and earthing switches for each distribution loop.
Power Parameter Inquiry: In the primary distribution diagram, detailed power parameters of the circuit can be directly viewed, including three-phase current, three-phase voltage, total active power, total reactive power, total power factor, and forward active energy.
Operation Report: The report queries operating parameters for each loop or equipment's time, displaying electrical parameter information such as phase currents, three-phase voltages, total power factor, total active power, total reactive power, and forward active energy. The report formats include daily, monthly, and annual reports, etc.
Real-time Alerts: Capable of issuing alerts for remote signal changes in distribution circuit circuit breakers, disconnectors, earthing switches, and their opening and closing actions, as well as for protective operations and accident-induced tripping events.
Historical Event Inquiry: Capable of storing and managing records of events such as remote signal changes, protective actions, accidental tripping, and over-limit conditions for voltage, current, power, and power factor, facilitating users in tracing historical system events and alarm information, conducting query and statistics, and accident analysis.
Fault Recording: Capable of automatically and accurately recording the changes in various electrical quantities before and after a system failure, this function plays a crucial role in analyzing and comparing these electrical quantities, which is essential for accident analysis, determining whether protective actions are correctly executed, and enhancing the safety and operational level of the power system.
7) Incident Retrospective: Automatically records all real-time stable information around the incident, including switch positions, protective action states, remote measurements, etc., to form a data foundation for incident analysis.
8) Curve Query: Enables real-time and historical curve queries, including all remote measurements such as three-phase current, three-phase voltage, active power, reactive power, and power factor.
9) User Permission Management: The user permission management feature has been set up to prevent unauthorized operations (such as remote operations, database modifications, etc.). The system can define permission groups with different operational permissions (such as the Admin group, Engineer group, Operator group, etc.), allocate different users within each group, and provide reliable security guarantees for the system's operation, maintenance, and management.
10) Network Topology: Supports real-time monitoring of communication status among devices connected to the system, fully displaying the entire system's network structure; allows for online diagnosis of device communication status, and can automatically display faulty devices or components and their respective fault locations on the interface in the event of network anomalies.
11) Remote Control Function: In accordance with electrical regulations, remote control operations can be performed on equipment within the entire distribution system range.
12) Communication Management: Manages, controls, and monitors real-time data for communication among equipment within the entire distribution system range.
5 On-site Installation Photos
This project features local, decentralized installation of micro-computer protection systems on each high-voltage switchgear cabinet, with the power monitoring system's host and display units placed on the control console, as shown in the diagram below. The project was energized and put into operation in 2023 and is running smoothly.
Figure 3: Installation of Microcomputer Protection at the Power Distribution Engineering Site in Zhongyuan Technology City
Figure 4: Power Monitoring System Interface at the Distribution Engineering Site in Zhongyuan Science and Technology City
6 Conclusion
Microcomputer protective devices play a crucial role in the power system, capable of detecting equipment faults and abnormal operating conditions, and automatically and selectively actuating circuit breakers to isolate faulty equipment from the system. This ensures the continued normal operation of the equipment, confines the scope of accidents to a certain small range, enhances the reliability of system operation, and maximizes the safety and continuity of power supply to users. This article introduces the AM5SE series of microcomputer protective devices, which provide corresponding protection functions for different protected objects in the comprehensive intelligent energy distribution project of the core starting area of the Zhongyuan Science and Technology City. Moreover, through the power system monitoring and control system, the collection of relevant remote measurement and remote signal data for monitoring can significantly improve the reliability, safety, and power supply quality of substation operations, facilitating the realization of substation comprehensive automation and achieving unmanned or minimally staffed operations.
Reference
Ankorri Corporation Microgrid Design and Application Manual, June 2020 Edition
[2] Ankerui's 35KV and Substation Intelligent Power Distribution System Design and Product Secondary Schematic Collection, October 2020 Edition
[3] Ankerui User Substation Integrated Automation and Operation & Maintenance Solution. November 2021 Edition
