Abstract: With the rapid development of social economy, mainland substations are developing in the direction of modernization, and automation equipment and relay protection devices have been widely used with their excellent performance. The AM5SE series microcomputer protection device introduced in this paper can provide corresponding protection functions for different protection objects in the smart energy distribution project of Zhongyuan Science and Technology City. And through the Acrel-2000 power monitoring system to collect relevant telemetry, remote signal data for monitoring, can greatly improve the reliability and safety of substation operation, improve the quality of power supply, is conducive to the realization of comprehensive automation of substation, to achieve unmanned or less people on duty.
Keywords: security; Reliability; Microcomputer protection device; Acrel-2000。
Zhongyuan Science and Technology City, located in Longhu Area in the north of Zhengdong New District, Zhengzhou City, is bordered by Lianhuo Expressway in the north, Longhu Lake in the south, Longzi Lake in the east, and Zhongzhou Avenue in the west, with a core land area of about 16.4 square kilometers. This is an "urban science and technology belt" built by Henan Province and Zhengzhou City during the "14th Five-Year Plan" period, which integrates the core of digital cultural creativity, information technology, cutting-edge science and technology, life sciences, and talent education. Among them, the core start-up area of Zhongyuan Science and Technology City has a total land area of about 453 mu and a construction area of 1.142 million square meters.
This project is a comprehensive smart energy A1 and A4 energy station 10kV project, the project site is located in the core starting area of Zhongyuan Science and Technology City, and each incoming source is an industrial innovation opening and closing place. The inlet and outlet cabinets adopt the methods of cable inlet and outlet respectively, and adopt KYN28-12 metal armored handcart type vacuum switchgear. Both energy stations are two-inlet and one-bus power supply systems, with multiple transformers, motors, capacitors outlet circuits.
2.1 Protection Function Requirements
For different objects in the distribution project of smart energy station in Zhongyuan Science and Technology City, different microcomputer protection devices are configured, among which, the incoming cabinet is equipped with AM5SE-F line protection device, the PT cabinet is equipped with AM5SE-UB PT monitoring and parallel protection device, the distribution transformer cabinet is equipped with AM5SE-T transformer protection device, the bus union cabinet is equipped with AM5SE-B standby self-investment protection device, the capacitor outlet cabinet is equipped with AM5SE-C capacitor protection device, and the motor outlet cabinet is equipped with AM5SE-M motor protection device. These microcomputer protection devices mainly realize real-time monitoring and protection of the equipment operation of the high-voltage cabinet through the following protection functions:
2.2 Signal export demand
The power distribution project of the smart energy station of Zhongyuan Science and Technology City needs to separate multiple signal outlets and send these signals to the signal box to facilitate different faults to trigger different indicator lights, as shown in Figure 1. The AM5SE series microcomputer protection device has the function of signal separation to meet this need. At the same time, it is necessary to monitor the data protected by the microcomputer in real time through the power monitoring system.
Figure 1 Signal box schematic
The power distribution project of this project has two energy stations A1 and A4, including two 10kV substation and distribution rooms, the distribution room has two sections of busbars, both adopt a single bus system, including 37 high-voltage switchgear, the entire distribution room is equipped with a total of 31 protection devices, taking the system of A1 energy station as an example, the above scheme is as follows:
Figure 2 Figure of the 10kV primary system of A1 energy station
The microcomputer protection models and quantities of the 10kV power distribution project of A1 and A4 energy stations are as follows:
In order to monitor the operation and data collection of the entire distribution room in real time, the project is equipped with an Acrel-2000 power monitoring system, which mainly realizes the power monitoring and management of each substation. The monitoring scope is the microcomputer protection device and instrument of the substation. The system is composed of three parts: user management layer, network communication layer and field device layer, which are connected to the LAN switch and uploaded to the power monitoring system host through the network cable to realize the power monitoring function.
The functions that can be achieved by the power monitoring system are as follows:
1) Real-time monitoring: Intuitively display the operation status of the distribution line in the form of a distribution map, which can monitor the voltage, current, power, power factor and other electrical parameter information of each circuit in real time, and dynamically monitor the circuit breaker, isolation switch, ground knife and other closing and opening status of each distribution circuit.
2) Electrical parameter query: In the distribution diagram, you can directly view the detailed electrical parameters of the circuit, including three-phase current, three-phase voltage, total active power, total reactive power, total power factor, positive active energy, etc.
3) Operation report: query the operating parameters of each circuit or equipment at a specified time, the report shows electrical parameter information should include: each phase current, three-phase voltage, total power factor, total active power, total reactive power, positive active energy, etc., the report format includes daily report, monthly report, annual report, etc.
4) Real-time alarm: It can issue alarms for remote signal displacement such as distribution circuit breakers, isolation switches, grounding knife divisions, and combined actions, protection actions, accident tripping and other events.
5) Historical event query: It can store and manage event records such as remote signal shifting, protection action, accident tripping, and voltage, current, power, power factor translimit, etc., which is convenient for users to trace the history of system events and alarm information, query statistics, and accident analysis.
6) Fault recording: It can automatically and accurately record the changes of various electrical quantities in the process before and after the failure when the system fails, and through the analysis and comparison of these electrical quantities, it plays an important role in analyzing and handling accidents, judging whether the protection is correct, and improving the safe operation level of the power system.
7) Accident recall: It can automatically record all real-time steady-state information before and after the accident moment, including switch position, protection action state, remote measurement, etc., forming the data basis for accident analysis.
8) Curve query: can query real-time curve and historical curve, including three-phase current, three-phase voltage, active power, reactive power, power factor and other remote measurements.
9) User rights management: The user rights management function is set up, and unauthorized operations (such as remote control operations, database modifications, etc.) can be prevented through user rights management. The system can define permission groups with different operation permissions (such as administrator group, engineer group, operator group, etc.), and assign different users in each permission group to provide reliable security for system operation, maintenance and management.
10) Network topology diagram: support real-time monitoring of the communication status of each device connected to the system, and can completely display the entire system network structure; It can diagnose the communication status of the device online, and automatically display the faulty equipment or components and their fault parts on the interface when a network abnormality occurs.
11) Remote control function: According to the requirements of power regulations, remote control operation can be carried out on the equipment within the scope of the entire power distribution system.
12) Communication management: It can manage, control and monitor the real-time monitoring of equipment communication within the scope of the entire power distribution system.
Microcomputer protection device in the power system is in a vital position, it can reflect the failure and abnormal state of the equipment and automatically and quickly and selectively act on the circuit breaker to cut the faulty equipment from the system, ensure that the fault-free equipment continues to operate normally, reduce the scope of the accident, improve the reliability of the system operation, and ensure the safe and continuous power supply to users. The AM5SE series microcomputer protection device introduced in this paper can provide corresponding protection functions for different protection objects in the comprehensive smart energy power distribution project in the core starting area of Zhongyuan Science and Technology City. And through the Acrel-2000 power monitoring system to collect relevant telemetry, remote signal data for monitoring, can greatly improve the reliability and safety of substation operation, improve the quality of power supply, is conducive to the realization of comprehensive automation of substation, to achieve unmanned or less people on duty.