With the automation upgrade of substations, the update of substation monitoring information, and the continuous increase in daily maintenance and repair work of relay protection, the data-related work for the relay protection specialty in smart substations has become increasingly cumbersome and complex. For the point-to-point commissioning and acceptance in the implementation of smart substation projects, modularization, proceduralization and traceability of data operations such as configuration file compilation in master station joint commissioning can be adopted to improve on-site data supervision and management, and realize closed-loop automatic protection tests featuring full-link verification, full-channel check and full-information calibration of secondary equipment.

At present, the point-to-point work in the joint commissioning of the main power grid is mainly based on device simulators, which conduct simulated point-to-point tests at the front and rear ends of the telecontrol gateway device. This method only verifies the configuration information of the telecontrol gateway device, fails to perform a real verification from the overall perspective of the entire substation, and lacks a comprehensive detection tool to support the daily operation, maintenance and repair of point-to-point work for the whole substation. In response to this, aiming at the joint commissioning and acceptance work of the substation main power grid, Wuhan Haomai Electric Power has developed the DMA-1000 Substation Monitoring Information Full-Link Acceptance System, which changes the on-site point-to-point detection that only stays at the test of telecontrol devices and truly restores the working mode and operation and maintenance method in the actual point-to-point work.

△ DMA-1000 Substation Monitoring Information Full-Link Acceptance System

1 Overall System Architecture

The point-to-point and automatic closed-loop test system mainly consists of a point-to-point automatic acceptance platform and an automatic test platform.

△ Architecture of Point-to-Point and Automatic Closed-Loop Test System

1) Point-to-Point Automatic Acceptance Platform

The point-to-point device issues test tasks to the automatic test PC terminal device via network cables, and simultaneously connects to the telecontrol device to receive SOE signals in the substation, completing the verification of the point list. Its main modules include point list loading, SCD loading, RCD loading, wireless task distribution, DLT104 communication and automatic result judgment.

Point List Loading: Parse the Excel-format point list and display the point list information on the interface.

SCD Loading: Parse the substation configuration file (SCD), extract relevant IEDs in the substation, perform fuzzy matching with the point list content by description name, realize the association between the point list and IEDs without RCD files, and support manual association.

RCD Loading: Parse the telecontrol device configuration file (RCD) to achieve accurate matching and association between the point list and IEDs.

Wireless Task Distribution: Establish communication with the automatic test platform via wireless WIFI and issue test tasks to the automatic test platform.

DLT104 Communication: Establish a master station, build communication with the telecontrol device, and complete the reception of SOE, remote signal, remote measurement and other signals.

Automatic Result Judgment: Automatically compare the received telecontrol signals with the issued tasks and judge whether the results are correct automatically.

△ Point-to-Point Automatic Acceptance Platform

2) Automatic Test Platform

Core Function: A fully automatic one-click test system applicable to both conventional and smart substations, supporting the automatic test of protection devices complying with the IEC61850 protocol.

△ Schematic Diagram of the Automatic Test Platform System

With the automatic test platform as the core, it establishes network communication with the point-to-point device, relay protection tester and protection device via wired or wireless network connection.

The point-to-point device communicates through a wireless WIFI module to issue test tasks, and automatically uploads the results to the point-to-point device after task completion.

The protection device communicates via network cables; the station control layer MMS protocol is mainly used to transmit MMS messages, including reading of protection models, reading and modification of setting values, press plates and control words, and alarm information.

The relay protection tester communicates through a wireless WIFI module, and applies analog quantities to the protection device via cables to conduct protection tests.

2 Automatic Test Process

1) Equipment Connection

Connect the voltage input and output terminals of the relay protection tester to the protection device, and interconnect the network port of the automatic test platform with the protection device.

2. Software Setting

Import the SCD file and parse it through a full-substation scan; select the substation type (conventional/smart) and protection device type, and configure the local IP, the wireless network IP for controlling the relay protection tester and the IP of the protection device.

3. Model Summoning

Acquire the current system parameters, setting values, press plates and control words of the protection device (supporting modification), compare and verify with the imported scheme model, and automatically calculate the state quantities of the current scheme according to the setting values.

4) Automatic Test

Automatically match the corresponding scheme template according to the IED name issued by the point-to-point device; automatically match the corresponding test item according to the issued test item name and calculate the state quantities. When a start command is received, it automatically controls the relay protection tester to apply test quantities, and returns a completion command to the point-to-point device after the test is finished.

3 Field Application

 

Before the substation was put into operation, 203 remote signal points including dispatch information point list remote signals and protection outlet remote signals were collected, and the automatic acceptance of 4 line protection devices and 4 main transformer protection devices was completed with a total time consumption of 3 hours. This ensures the efficiency of the joint commissioning and acceptance of the main power grid, greatly improves the degree of automation, and enhances the reliability and authenticity of the acceptance work.