The CSC2000 Integrated Automation System is a comprehensive automation system developed and applied to substation protection and control by Sifang Co., Ltd. since 1994. The company further refined and developed the system in 1998, and it was first put into operation at the Xintang Substation in Zengcheng, Guangzhou. 1. System Overview of Xintang Substation The Xintang 220 kV substation has two 220 kV incoming lines, planned as a double busbar with bypass connection. The first phase of operation includes two busbar sections and a bypass busbar. The plan includes three 180 MW main transformers, with one four-winding main transformer in the first phase. The low-voltage side is supplied to the two busbar sections via reactors. There are seven 110 kV outgoing lines, with double busbars and bypass connections; and twelve 10 kV outgoing lines, divided into two busbar sections. The protection and monitoring system mainly uses Sifang's CSC2000 integrated automation system, with a small number of protection devices from other manufacturers connected to the system via CSN020A protocol converters. The station is equipped with a local monitoring station and provides communication with the provincial, municipal, and county dispatch centers. [b]2 Protection and Monitoring Front-End Equipment[/b] In the improved CSC2000 integrated automation system, the design principles for protection and monitoring front-end equipment are further clarified. 2.1 All protection and monitoring front-end equipment is distributed in bays. The 10 kV bays are equipped with CSL200B line protection, CSP200A capacitor protection, CST302A grounding transformer protection, CSB21A automatic transfer switch, etc. These devices can be installed separately on low-voltage switchgear or centrally in panels. In the Xintang substation, a centralized panel configuration is used. The 110 kV bays are also equipped with CSL164B line protection and CSI200B monitoring and control units, using a centralized panel configuration. The 220 kV bays use a three-panel "four-unified" configuration. In addition, each line is equipped with one CSI200B monitoring and control unit. The main transformer bay adopts a dual configuration, consisting of CST140A, CST130A, CST141A, and CST131A main transformer protection devices, as well as CSI101A and CSI301A trip control units, totaling three panels. 2.2 The 10 kV line and components adopt an integrated protection, measurement, and control scheme. To fully utilize the performance of the 10 kV equipment, an integrated protection, measurement, and control scheme is adopted. To address the accuracy issues caused by the different requirements of the acquisition range for protection and measurement currents, the protection and measurement current loops of the line protection device each employ two sets of converters. The full-scale value of the protection current converter is 20In, while the full-scale value of the measurement current converter is 1.1In. In this way, the 10 kV line protection device can operate rapidly in the event of a three-phase circuit break at the outlet, while ensuring that the measurement accuracy of a single device is not lower than 0.5 class, thus guaranteeing the practical acceptance index of a comprehensive accuracy of 1.5 class. The tripping and closing control circuits of the protection device and the tripping and closing circuits of the protection system use different outputs at the front end of the operating box. Simultaneously, a simplified operating circuit is designed within the device to ensure the integrity of the protection device's functions. The 10 kV line protection device also undertakes the acquisition functions of 30 and 30 phase quantities in the distributed low-frequency load shedding function and grounding line selection function, thus ensuring minimal cable connections during distributed installation. The commissioning of the 10 kV protection device is very simple, with automatic zero drift and scale self-calibration functions. 2.3 110 kV and above lines and components adopt the principle of independent protection, measurement, and control functions. For voltage levels of 110 kV and above, the principle of independent configuration of protection and measurement/control functions is adopted. Therefore, the CSI200B device suitable for high-voltage line measurement and control was designed. This device has passed the remote terminal product network access certification of the Power Equipment and Instrumentation Quality Inspection Center of the Ministry of Electric Power. This device not only boasts high measurement accuracy but also features unique control capabilities. It can implement anti-misoperation interlocking for this interval through logic programming and can also cooperate with the five-prevention monitoring backend of the CSC2000 system to perform functions similar to the 8TK in the LSA678 system. Furthermore, the CSI200B also includes a function for acquiring energy metering pulses. 2.4 Adopting Fieldbus Communication Connection The CSC2000 system consistently adheres to the design principles of fieldbus. In years of using serial communication, we found that simply relying on summation checks and acknowledgments is insufficient to guarantee high-volume data communication; additionally, prioritizing information reporting is very difficult. Mature fieldbus developers, such as ECHLON, have already done extensive work in perfecting communication mechanisms, making the direct utilization of these achievements a very reasonable choice. In the improved system, the new system's screen response speed, telemetry refresh rate, and remote signaling refresh rate all meet and exceed the standards set by the Ministry. 2.5 Computer-Aided Debugging Interface and Network Debugging Methods Computerized and networked human-machine interaction is one of the characteristics of integrated automation systems and an important feature that distinguishes them from conventional "four-remote" systems. All microcomputer devices in the CSC2000 integrated automation system have good computer debugging interfaces, and all protection devices support online debugging. As operators' habits change, this feature will be increasingly recognized by users. [b]3 System Components[/b] 3.1 Network Architecture The network of the Xintang Substation Integrated Automation System is divided into two layers: the bay layer and the master station communication layer. The bay layer uses ECHLON's LonWorks network, which is the real-time data exchange channel for the entire station. The 220 kV and main transformer sections use a dual-network configuration to increase communication reliability, while the 110 kV and 10 kV sections use a single network. Since all master station equipment is centrally located, shielded twisted-pair cable, which is easy to wire, is chosen as the network medium. All front-end protection units and measurement and control units have independent network chips providing complete communication support. At the master station, a parallel network communication card PCLTA based on the ISA bus is used. In this network structure, there is no network communication "bottleneck" similar to a front-end server, thus maximizing communication reliability and significantly improving network processing capacity and response speed. At the substation level, the system has three types of master stations: local monitoring master station, remote control master station, and functional master station, which respectively perform functions such as local monitoring, RTU simulation and network debugging, grounding line selection, and VQC. The master stations are connected via Ethernet to achieve information sharing. 3.2 Local Monitoring The local monitoring master station of Xintang Substation was developed based on the WIZCON monitoring platform introduced from PC SOFT, and secondary development of the WIZCON software platform was carried out, completing the improved design of the communication driver, historical data management, report generation system, and real-time alarm system on the WIZCON software platform. The local monitoring master station of Xintang Substation is equipped with two PII-266 industrial control computers. Each computer is equipped with a color monitor, one dual-channel PCLTA card, one single-channel PCLTA-10 card, and one Ethernet card. The two computers are connected via Ethernet to achieve hot standby functionality between the two machines. If centralized control is required, one computer can be remotely located via fiber optic channel. An LQ1600KⅡ dot matrix printer serves as the output device for real-time information and reports. The local monitoring master station operates on a Windows NT system, employing a multi-threaded architecture, ensuring stable and reliable operation and convenient maintenance. The system boasts powerful design tools for its graphical interface, alarm classification, and operation hierarchy, allowing for flexible customization of alarm prompt window styles and report formats according to operator requirements. 3.3 Remote Control Master Station The remote control master station transmits local LonWorks network information to the dispatch terminal using standard protocols such as CDT, N4F, DNP3.0, 1801, 870-5, and 8890. The remote control master station uses an industrial-grade PC as its hardware platform, significantly expanding resources and providing rapid information processing capabilities. Furthermore, this master station is equipped with a large-capacity front-end database and remote control database, effectively buffering upstream data to ensure information integrity. According to user requirements, the Xintang Substation is equipped with four P200 industrial control computers, one dual-channel PCLTA network card, and one single-channel PCLTA network card. The four P200 industrial control computers share a single monitor and keyboard via a shared device. 3.4 The engineering station and waveform recording backend are equipped with a dedicated PII-266 industrial control computer as the waveform recording and engineering station, configured with one dual-channel PCLTA network card and one waveform recording data receiving network card. On this computer, fault waveform recording receiving software is run normally to receive fault waveform recording information sent by all distributed waveform recording plug-ins. All 110 kV line protection devices, 220 kV line protection devices, and main transformer protection devices are equipped with distributed waveform recording units, each with its own independent LonWorks network interface. These units are connected to the waveform recording backend data receiving network card via a bus through the LonWorks network, and the data is received by the computer through the network card. Simultaneously, fault waveform recording analysis software is also provided for analyzing the recorded data after an accident. The fault data of this distributed waveform recording system is stored in the IEEE standard format, which can be analyzed by other analysis software that conforms to this format or used for fault reproduction. When protection engineers are on-site for commissioning, they can run the engineer station background software to complete tasks such as accessing historical protection reports, sampling data, verifying protection version numbers, and verifying protection settings. When equipped with a modem and corresponding support software, the master station supports remote operation. 3.5 After achieving the goal of integrated automation information sharing, some functions that originally required a lot of cable wiring can be easily implemented on the network, such as voltage and reactive power integrated control and grounding selection functions. This station is equipped with one PII-266 integrated industrial control computer to act as the network function master station. This computer is equipped with one dual-channel PCLTA network card. The entire grounding selection system consists of three parts: a 3V0 measurement unit, a 10 kV line protection device, and a functional master station, which are constructed according to the principle of "measurement and control acquisition, master station discrimination", without adding any special cable wiring. The implementation of VQC (Voltage Quality Control) function is more complex than ground fault location. It consists of the CSD22A analog measurement device on all four sides of the main transformer, the CSI301A control unit for the main transformer's circuit breaker, the CSP215A capacitor protection device, and the main station. The entire control process is as follows: a. The CSD22A transmits the real-time collected current and voltage, active and reactive power, and medium-voltage side voltage values ​​of the main transformer to the network; b. The VQC main station calculates the high-voltage side power factor based on the received information and determines the current operating area (using the nine-zone diagram criterion) by combining the medium-voltage side voltage value; c. If the operating area is not in the normal zone, it sends an adjustment tap command to the CSI301A or a switching command to the capacitor protection device. The ground fault location and VQC function main station is equipped with an LCD display and a user-friendly human-machine interface, which can be used for monitoring during operation and for performing a series of preset tests, thus facilitating commissioning. 3.6 Database Definition and Maintenance Tool For a long time, the database maintenance of the CSC2000 integrated automation system relied on a professional maintenance interface, making system expansion complex for users. Therefore, a dedicated database maintenance tool was designed in the improved CSC2000 integrated automation system. Using this software, users can independently perform database maintenance for local monitoring, remote control master stations, and VQC master stations. This database maintenance software adopts a bay-oriented design method. The manufacturer pre-inputs all device information into the software, and users only need to determine the quantity names and addresses based on the panel design drawings and cable construction drawings to automatically generate the required database definitions for each master station. After a period of learning, users can completely build the CSC2000 integrated automation system independently. Currently, this maintenance tool has been successfully applied to the local monitoring backend; the local monitoring system of Xintang Substation was automatically generated using this tool. 3.7 System Time Synchronization The CSC2000 integrated automation system offers two time synchronization solutions: one is dispatch terminal time synchronization; the other is in-station GPS time synchronization. After comprehensive comparison, the GPS in-station time synchronization solution was recommended and adopted by Xintang Substation. [b]4 Conclusion[/b] After the redevelopment of the CSC2000 system, the developers tested the system in the factory and on-site. All indicators of the system met and exceeded the national standards "General Technical Conditions for Regional Power Grid Data Acquisition and Monitoring Systems GB/T 13730-92" and "General Technical Conditions for Remote Terminals GB/T 13729-92". All indicators met the internal standards of Sifang Company. The indicators in terms of measurement accuracy, screen response time, status update time, and telemetry update time were greatly improved compared with the ministerial standards. On December 27, 1998, the system was successfully put into operation at Xintang Substation. [b]References[/b] ［1］Yang Qixun. Development Trend of Substation Integrated Automation Technology. Automation of Electric Power Systems, 1995, 19(10).