[Abstract] This article begins with an overview of my country's water resources, elaborates on the role and content of hydropower station automation, further explores the development direction of hydropower station automation technology, and discusses the composition, characteristics, and functions of hydropower station integrated monitoring systems and their application in water resource development and utilization, as well as in the construction of water conservancy projects. [Keywords] Programmable Logic Controller (PLC); Intelligent I/O; Integrated Monitoring System; SOE Point; Automatic Generation Control (AGC); Automatic Voltage Control (AVC) my country possesses abundant hydropower resources, with a theoretical total potential of 676 million kW and a technically exploitable potential of 378 million kW, generating 1.92 trillion kWh annually, accounting for 13.22% of the world's total, ranking first globally. Statistics show that in 2000, my country's installed hydropower capacity was 75 million kW, with a development rate of only 19.8%. Compared with other developed countries, my country's hydropower resource development and utilization level is still very low, and the automation level of hydropower stations is still lagging behind. How to gradually increase development efforts and make good use of abundant hydropower resources is of great significance to my country's modernization and the implementation of its sustainable development strategy. (I) Overview of Hydropower Station Automation 1. Role of Hydropower Station Automation Hydropower station automation aims to enable the operation, control, and monitoring of the hydropower station's production process to proceed automatically according to a predetermined plan or procedure without direct human (or minimal) involvement. The degree of automation in hydropower stations is an important indicator of their modernization level. At the same time, automation technology is an indispensable technical means for the safe and economical operation of hydropower stations. The role of hydropower station automation is mainly reflected in the following aspects: (1) Improving the reliability of operations: After the hydropower station achieves automation, on the one hand, various automatic devices can quickly, accurately, and promptly detect, record, and alarm, which can prevent abnormal working conditions from developing into accidents and prevent equipment that has experienced accidents from suffering more serious damage, thereby improving the reliability of power supply. On the other hand, by using various automatic devices to complete various operations and controls of the hydropower station (such as start-up and shutdown operations and parallel operation), not only can the possibility of operator misoperation be greatly reduced, thus reducing the chance of accidents; but also the operation or control process can be greatly accelerated. Especially in emergency situations where accidents occur, ensuring the safe operation of the system and the normal power supply to users is of great significance. (2) Improve the economic efficiency of operation: After the hydropower station is automated, it can be rationally scheduled according to the load allocated to the station by the system and the specific conditions of the station, maintain high head operation, and rationally select the number of units to be started so that the units can operate in the high efficiency zone to obtain better economic benefits. How to achieve the rational and optimal scheduling of each station, avoid unnecessary water wastage, and make full use of water resources is particularly important for cascade power stations. In addition, hydropower stations are usually part of the comprehensive utilization of water resources, and need to take into account multiple requirements such as power system, navigation, irrigation, and flood control. The economic operation conditions are complex and difficult to achieve by manual control alone. After automation, it will help to achieve the economic operation tasks of the station. In particular, for hydropower stations with regulation capabilities, the application of electronic computers can not only predict and calculate the water inflow of the reservoir, but also integrate parameters such as water level, flow rate, system load and parameters of each unit, and automatically control according to the economic operation program, which greatly improves the economic efficiency of operation. (3) Ensure power quality: We know that voltage and frequency are two basic indicators for measuring the quality of power. The normal voltage deviation shall not exceed ±5% of the rated value, and the normal frequency deviation shall not exceed ±0.2 to 0.5 Hz of the rated value. The stability of voltage or frequency mainly depends on the balance of reactive power and active power in the power system. Therefore, to maintain the system voltage and frequency within the specified range, it is necessary to quickly and accurately adjust the active and reactive power generated by the relevant generator sets. Especially in the event of an accident, rapid adjustment or control is of decisive significance for the rapid restoration of power quality. This process is difficult to achieve by manual operation alone, both in terms of speed and accuracy. It can only be accomplished with the help of automatic devices. It can be seen that improving the automation level of hydropower stations is one of the important measures to ensure the power quality of the power system. (4) Improve labor productivity and working conditions: Most hydropower stations are located in remote mountainous areas, far from towns, and employees have long lived in poor environments. After the hydropower station is automated, many tasks are automatically completed by various automatic devices according to certain programs. Computer monitoring systems replace manual operation and timed inspections and recording, which greatly improves the working and living environment of the operators, reduces labor intensity, and improves the level of operation and management. At the same time, it can also reduce the number of operators, realize unmanned operation (or less manned operation), improve labor productivity, and reduce operating costs and electricity costs. 2. Content of hydropower station automation The content of hydropower station automation is related to the scale of the hydropower station and its status and importance in the power system, the type and operation mode of the hydropower station, the type and layout of the main electrical wiring and the main electromechanical equipment. In general, hydropower station automation includes the following aspects: (1) Complete the automatic control of the operation mode of the turbine generator unit: On the one hand, realize the automation of start-up and shutdown and parallel operation, generation to phase adjustment and phase adjustment to power generation, so that the above operations are completed automatically according to the set program; on the other hand, automatically maintain the economic operation of the turbine generator unit, automatically select the optimal number of operating units according to the system requirements and the specific conditions of the power station, realize the economic distribution of load among the units, and automatically adjust the active and reactive power of the units according to the changes in system load. In addition, when the working unit has an accident or the power system frequency decreases, the standby unit can be automatically started and put into operation; when the system frequency is too high, some units can be automatically disconnected. (2) Monitor the operating conditions of the hydro-generator unit and its auxiliary equipment: such as monitoring the electrical quantities of the generator stator and rotor circuits, monitoring the temperature of the engine stator windings and cores and bearings, monitoring the operation of the unit's lubrication and cooling systems, and monitoring the operation of the unit's speed control system. When abnormal operating conditions occur or accidents happen, take corresponding protective measures quickly and automatically, such as issuing signals or emergency shutdown. (3) Automatically control the auxiliary equipment: including the control of various oil pumps, water pumps and air compressors, and automatically put the backup auxiliary equipment into operation when an accident occurs. (4) Control, monitor and protect the main electrical equipment (such as transformers, busbars and transmission lines). (5) Control and monitor the operating conditions of hydraulic structures: such as controlling and monitoring the working status of gates, monitoring whether trash racks are blocked, measuring and monitoring upstream and downstream water levels, and protecting the water intake pressure pipe (for hydroelectric power stations). (II) Development of Hydropower Station Automation Technology With the rapid development of science and technology, electronic computers have been widely used in various fields. A modular hydropower station computer monitoring system based on fieldbus has emerged, gradually replacing the traditional control mode based on conventional control and manual operation, greatly improving the automation level of hydropower stations and realizing "unmanned operation and reduced manpower" in hydropower stations. 1. System Composition: The system adopts computers, programmable logic controllers (PLCs) or intelligent I/O, microcomputer relay protection devices and dedicated intelligent measurement and control devices. The main control unit is organically connected with various local control stations and intelligent devices through standard Ethernet and fieldbus, forming a hierarchical distributed integrated monitoring system with functional division of labor and cooperation. 2. Main Features of the System: (1) Open architecture with clear hierarchy and good scalability. (2) Hierarchical distributed system, which can be configured according to the monitoring object and function, with good decentralization, openness and flexibility. (3) Redundant configuration is adopted, which has high reliability. (4) Advanced technologies such as Chinese Windows operating system and intelligent communication are used to facilitate system upgrades. (5) Flexible configuration interface, strong human-machine interface capability, user-friendly interface, easy to master, convenient for design, debugging and on-site operation. 3. Main functions of the system: (1) Automatic monitoring and recording of power station equipment: The computer monitoring system automatically completes the collection and processing of power station equipment data and the automatic monitoring and recording of equipment operation status, including monitoring of switch quantity information, monitoring of analog quantity information, fault/accident alarm, recording and display, SOE point recording and display. (2) Automatic control of the power station: According to the requirements of the superior dispatch and the specific situation of the power station itself, the power station equipment is operated or adjusted, including the automatic start and stop of the unit and parallel operation, automatic conversion of operating conditions, automatic adjustment of active and reactive loads of the unit, automatic generation control AGC, automatic voltage control AVC, circuit breaker operation, etc. (3) Protection and monitoring of main equipment and auxiliary equipment such as generators, main transformers, and lines. (4) Automation of power station operation management: Automatic generation of operation reports, automatic recording of operation operations, recording and saving of power station equipment parameters or setting values, automatic or call printing of all reports, and simulation training of operation personnel, etc. (5) System Communication: Enables communication with computer systems such as the superior dispatching system, hydrological monitoring system, and office automation network to achieve information resource sharing and fully leverage the comprehensive benefits of the entire system. (III) Application of Hydropower Station Automation Technology The Zhao'an Longtan Hydropower Project in Zhangzhou City, Fujian Province, is a key construction project of Fujian Province's "15th Five-Year Plan" with a total investment of 116 million yuan. The survey and design were carried out by our institute. The total installed capacity of the power station is 12,600 kW, consisting of two 6,300 kW units. The computer monitoring system of the hydropower station adopts the MTC-3S microcomputer integrated automation system produced by Changsha Huaneng Automation Group Co., Ltd. 1. System Composition: It consists of workstation 1, workstation 2, LCU of unit 1, LCU of unit 2, common LCU synchronization panel, unit protection panel, main transformer line protection panel, fault filtering system panel, and GPS (satellite clock), etc., and is constructed through standard Ethernet. The system diagram is as follows: 2. Main System Configuration: See system diagram. 3. System Communication: The system adopts the international standard TCP/IP protocol, using a contention-based communication mode. The interface is RS485, conforming to the IEEE 802.3 standard. The transmission medium is network coaxial cable/twisted pair, with a node count greater than or equal to 255. The data transmission rate is 10/100Mbps, and the communication interface and channel error rate is less than 10⁻⁶. 4. System Features: The system integrates five major functions: protection, remote control, telemetry, remote signaling, and remote adjustment. It boasts advantages such as reliable protection, high automation, fast grid connection, and high precision. After its completion and commissioning, this project alleviated the tight power supply situation in Fujian Province, improved drinking water conditions for urban and rural residents and livestock in the county, and the computer monitoring system fully meets the comprehensive automation requirements of the hydropower station, achieving significant economic benefits. (IV) Conclusion In summary, the adoption of integrated automation systems in hydropower stations not only improves the economic efficiency and reliability of hydropower station operation and ensures power quality, but also increases labor productivity, improves working conditions, and reduces the number of operating personnel, thereby increasing the efficiency of power station operation. For example, using computer systems to monitor reservoir inflow and medium- to long-term forecasts for optimized operation, curve plotting, and scientific scheduling, as well as peak power generation, can increase power generation by about 2% annually. Simultaneously, by using computers to monitor various parameters and operating conditions of the power station, potential hazards can be detected and eliminated in a timely manner, and accidents can be handled promptly to prevent escalation and restore power supply as quickly as possible, thus reducing the system's accident rate and shortening the time required to handle accidents, thereby increasing power generation by about 1% annually. Furthermore, computer monitoring reduces personnel and corresponding living and office equipment and wage expenditures, thus generating significant economic benefits. It is evident that integrated automation systems in hydropower stations are closely related to the production and efficiency of hydropower stations. With the adjustment of the national energy structure and the increasing development and utilization of water resources, integrated automation systems in hydropower stations are being more widely applied in more and more water conservancy projects, playing a greater role. 【References】 [1] Lou Chengren, Huang Shengxian, Li Zhixin. Automation of Hydropower Stations. China Water Resources and Hydropower Press, 1995, 10, 1. [2] Liu Zhongyuan. Automation of Hydropower Stations. China Water Resources and Hydropower Press, 1998, 5, 1 (Second Edition). [3] Cui Ming. Integrated Automation of Substations and Hydropower Stations. China Water Resources and Hydropower Press, 2005, 5, 1