GWSC-HS Hydropower Station Computerized Monitoring and Control System

System Architecture

• The system adopts a standard layered and distributed architecture, consisting of six core parts: Station Level, Local Control Level, Panel Level (Protection, Control & Synchronizing), AC/DC Power Supply System, Bay-level Measurement & Control Units, and Communication Network Layer. Each functional unit is independent in operation with clear hierarchical division, fully conforming to international hydropower automation design specifications. All system components realize stable bidirectional data interaction through an independent redundant industrial Ethernet network.

Station Level

• The Station Level is the core centralized management layer of the entire power plant. It is equipped with complete GWSC-HS upper monitoring equipment, including operator workstations, engineer workstations, redundant data servers, network security devices, UPS uninterruptible power supply systems, and printing terminals. It undertakes human-machine interface monitoring, remote operation control, online parameter setting, historical data storage, event and alarm processing, automatic report generation, and data interaction with superior dispatching centers, serving as the core hub for plant-wide monitoring, operation maintenance and dispatching docking.

Local Control Level (GWPC-LCU Local Control Unit)

• This layer consists of unit LCU, switchyard LCU, common service LCU, and gate LCU. Each LCU is equipped with industrial PLC integrated with high-speed counting and frequency measurement modules, analog and digital signal acquisition modules, temperature acquisition units, signal conditioning modules and lightning protection components. The LCU can operate independently. Even when disconnected from the upper monitoring system, it can complete on-site data acquisition, local sequence control, operating condition regulation and safety interlock protection, acting as the core field acquisition and control hub.

Panel Level (Protection, Control & Synchronizing)

• This layer covers core control, protection and synchronizing functional panels of the power plant, undertaking key functions such as unit regulation, electrical protection and grid synchronizing. The detailed configuration is as follows:

GWPC-GOV Governor Control Panel

• Equipped with turbine governing control units, responsible for unit speed sampling, guide vane regulation and oil pressure device status monitoring. It receives active power regulation commands issued by the station-level system, realizes automatic unit start-up, shutdown and stable speed maintenance, and supports independent regulation and fault protection functions.

GWPC-EXC Excitation Control Panel

• Configured with generator excitation regulators, de-excitation and power converter units to realize real-time regulation of generator terminal voltage and reactive power. It interacts with the station-level system to receive reactive power adjustment commands, and collects excitation voltage, excitation current, channel operating status and various fault alarm signals.

GWPC-SYN Synchronization Panel

• Integrated with intelligent automatic synchronizers. It collects voltage signals of the generator side and grid side, calculates frequency difference, phase difference and voltage difference in real time to complete unit paralleling and line synchronous closing. Equipped with complete synchronous interlock logic to prevent non-synchronous closing risks. It receives synchronizing start commands from the upper system and feeds back real-time paralleling status.

GWPC300-GP Generator Protection Panel

• Equipped with dedicated generator protection relays, covering generator differential protection, inter-turn protection, loss-of-excitation protection, overload protection, overvoltage protection, negative-sequence overcurrent protection and stator earth fault protection. Rapid tripping logic is triggered under fault conditions. All protection action records, measured values, status variations and alarm information are uploaded to the station-level monitoring system.

GWPC300-TP Transformer Protection Panel

• Dedicated main transformer protection panel equipped with professional transformer protection relays. It realizes main transformer differential protection, gas protection, backup overcurrent protection, zero-sequence protection and cooling system monitoring. It continuously monitors transformer operating conditions, executes fast tripping during faults, and uploads all protection events, measured data, status changes and abnormal signals to the monitoring system.

GWPC300-LP Line Protection Panel

• Integrated protection and measurement-control panel for outgoing lines. It is configured with line protection relays to implement line current and voltage protection, distance protection, zero-sequence protection, fault recording, status acquisition and analog measurement. It accurately identifies line faults and executes tripping control to ensure safe and stable operation of power transmission lines.

 GWPS Series AC/DC Power Supply System

• The system is composed of AC distribution units, high-frequency rectifier chargers, battery banks and DC insulation monitoring devices. It provides stable and reliable control power, operating power and signal power for all on-site LCUs, protection relays, governing systems, excitation systems, synchronizing devices, telecontrol equipment and switchgear local devices. The system monitors busbar voltage, charger operating status, battery charge-discharge current and DC insulation status in real time, and uploads all abnormal signals to the station-level monitoring platform uniformly.

Bay-level Measurement & Control Units

• Distributed units installed inside high-voltage switchgear and auxiliary power switchgears, equipped with decentralized protection relays and multi-functional intelligent power meters. It realizes auxiliary feeder protection, busbar status monitoring, switch position collection, electric parameter metering and local/remote circuit breaker control. It completes on-site analog and digital signal acquisition, fault judgment and over-limit alarming, and transmits all operating data to the station-level monitoring system through the communication network, realizing full digital coverage of switchyard and auxiliary power monitoring.

 Communication Network Layer

• Composed of the GWPC-RTU Telecontrol Panel and plant-wide network transmission equipment, including gigabit industrial switches, optical-electrical converters and network isolation devices. A dual-redundant hot-standby industrial Ethernet architecture is adopted to completely eliminate single points of failure in the communication links.
• The GWPC-RTU Telecontrol Panel is equipped with telecontrol devices and communication managers, complying with international power protocols including IEC 60870-5-101, IEC 60870-5-104 and IEC 61850 (GOOSE/SV). It undertakes plant-wide protocol conversion and data processing, realizes bidirectional data interaction between the monitoring system, superior dispatching centers and cascade hydropower centralized control platforms, uploads telemetry and telesignalling data, and receives remote control and setpoint commands from dispatch. It supports IEC 61850 peer-to-peer GOOSE fast interlock tripping and SV sampling value transmission. Network equipment distributes data and commands by priority to ensure real-time performance, stability and security of plant-wide communication, supporting full-layer data interaction, command delivery and signal uploading.

System Functions

Full-scope Real-time Data Acquisition and Operation Monitoring

• The system continuously collects operating parameters of generating units, main transformers and high-voltage switchgear, covering all data from governing panels, excitation panels, synchronization panels, protection panels, on-site LCUs, AC/DC power supply systems, switchgear relays and intelligent meters. It displays real-time power, voltage, current, water head, guide vane opening, unit speed, excitation parameters, DC bus voltage, switch status and protection action signals, and dynamically presents electrical single-line diagrams and unit operating condition diagrams. All data are centrally processed and displayed at the station level.

Automatic Unit Sequence Control and Condition Regulation

• The system executes automatic unit start-up and shutdown sequences. It receives dispatching commands to realize closed-loop regulation of active and reactive power, coordinates with the governing system for speed and active power adjustment, and cooperates with the excitation system for terminal voltage and reactive power optimization, ensuring stable unit operation.

Automatic Synchronizing Control

• The station-level system issues synchronizing instructions to the synchronization panel. The system calculates frequency difference, phase difference and voltage difference between the generator side and grid side to complete safe paralleling. Built-in synchronous interlock and fault judgment logic effectively avoid non-synchronous paralleling risks.

Cooperative Monitoring of Governing and Excitation Systems

• Real-time monitoring of governor oil pressure, guide vane position, operating status and fault alarms; real-time collection of excitation regulator operating conditions, limit actions, channel switching status and fault information. The station-level system can issue regulation commands to realize coordinated joint control of governing and excitation systems.

Unified Management of Relay Protection Information

• The system centrally collects measured data, status changes, protection events and fault alarms from generator, transformer and line protection panels, as well as distributed switchgear protection relays. It identifies main protection action signals, distinguishes fault alarms and warning alarms, supports rapid fault location and chronological sequence tracing of protection events. Based on the IEC 61850 standard, all protection data adopt standardized logical node modeling and support SCL configuration file import for seamless interconnection with substation automation systems.

On-line Monitoring of GWPS AC/DC Power Supply System

• It continuously monitors AC/DC bus voltage, charger operating status, battery charge-discharge state and DC insulation performance. It timely reports faults such as insulation deterioration, power loss and charger abnormality, ensuring reliable power supply for all secondary equipment of the power plant.

Switchgear Circuit Monitoring and Remote Operation

• Based on decentralized protection relays and intelligent meters, the system realizes energy metering and real-time condition monitoring of high-voltage and auxiliary power feeders, supports remote circuit breaker opening and closing and circuit fault alarming, achieving full coverage of plant-wide power distribution monitoring.

Safety Interlock and Misoperation Prevention

• Complete electrical interlock and sequence control interlock logic is configured via LCUs. The system supports emergency shutdown and fault tripping linkage, and automatically locks invalid remote control commands under abnormal working conditions to prevent manual misoperation.

SOE Recording and Hierarchical Alarm Management

• The system fully records status changes, protection actions, remote operations, parameter overruns, communication interruptions and equipment faults. It supports pop-up window and audible-visual multi-level alarms, with functions of alarm filtering, playback, statistics and export.

Historical Data Storage, Query and Automatic Reporting

• Long-term archiving of operating data, operation logs and fault records is realized. The system automatically generates reports of power generation statistics, unit operation duration, load curves and dispatching data, supporting custom templates, data export and online printing.

Telecontrol Communication and Remote O&M

• The system communicates with superior dispatching platforms through RTU equipment in the communication network layer in accordance with international standard protocols. It supports remote parameter modification, program debugging and fault diagnosis, and can be connected to cascade hydropower cluster centralized control platforms.

Auxiliary System and Gate Monitoring

• The LCU realizes remote gate opening and closing and water level linkage control, monitors auxiliary power standby switching status, and completes status monitoring and linkage control of plant-wide oil, water and gas auxiliary equipment.

System Features

• The integrated GWSC300 + GWPC/GWPC300 series equipment adopts international industrial-grade hardware standards, adapting to harsh hydropower plant environments with high humidity, dust and strong electromagnetic interference. The system adopts a scientific layered architecture, strictly distinguishing functional equipment and network transmission equipment, fully complying with international hydropower automation design specifications.
• It supports dual deployment modes of centralized panel installation and switchgear decentralized installation, covering all electrical loops of units, main transformers, outgoing lines and auxiliary power systems. The software adopts a modular architecture, with flexible equipment configuration according to plant installed capacity, and reserves sufficient expansion interfaces for later system upgrading, functional expansion and cascade hydropower cluster access. Native IEC 61850 compatibility ensures good interoperability with digital substation equipment and lays a foundation for smart grid and condition-based maintenance applications.