Implementation Of SCADA In Power Plant Presented by Muhammad Usman tee-307-206 What Is SCADA? SCADA stands for supervisory control and data acquisition. It generally refers to a computer system monitoring and controlling a process. Why SCADA is Needed Reduce the needs for field travel Faster indication on field problems Higher reliability of supply Lower cost maintenance Higher customer satisfaction Reduce risk 1950’s – 1970’s Control room 1970’s : Improved Control manual systems 1970’s Onward : Mixed auto/manual systems 1980’s : SCADA systems appear Present SCADA system Basic SCADA System Structure SCADA •HMI SCADA Modem PLC Versatile Interface Comm.- Progr. Tool Comm. •Interface Progr. Tool RTU • Local Control Data Terminal •Local Display RTU • Local Control SCADA system has three layers 1. 2. 3. SCADA master communication media local control system SCADA Master SCADA master consists of three main parts SCADA console The console is HMI SCADA server The server contains database for historical trends of relevant data. MTU (Master Terminal Unit). MTU is a terminal that communicates with RTU’s at local site. Human Machine Interface (HMI) This is the Heart of the System Operator receives information via the HMI System functions are initiated via the HMI Architecture of the HMI Single PC up to Hierarchical PC Network Standby to assure reliability Services of HMI Layer Wise Higher Management Information and Finance Planning and Engineering Mid Control Systems Real time network management Low Control System Remote monitoring and Control Alarm management Human Machine Interface SCADA HMI Provides: Monitoring of Parameters and Status Pressures Flow Levels Pump Operation status Power consumption Control of remote sites Pump operation Dynamic pressure control Historical data collection and analysis Trending on past demand and parameters Fault events Communication Media Communication media For the data communication between MTU and RTU, communication media will be chosen from leased line microwave radio fiber optic transmission satellite communication Redundant Source for back-up What is protocol? A protocol is a set of rules that governs how message containing data and control information are assembled at a source for their transmission across the network and then dissembled when they reach their destination. IEC 60850-5-101 IEC 60850-5-103 DNP3 Elcom-90 TCP/IP and SLIP ABB - RP570/571 ABB - INDACTIC 2033 GI74 TG709/E & TG809 Data Communication Network RTU RTU RTU Site 2 RTU Site 1 Remote Programming SCADA Local Control System Remote Terminal Units An RTU converts the electrical signals from the equipment to digital values such as the open/closed status for a switch, Valve or pump etc. By sending and receiving these electrical signal RTU can control equipment. Reliable and Secure Very Low Failure rate Secure and Reliable messages Expandable and Upgradeable Provides platform for growth and enhancement Modular concept allows simple modifications Friendly to Operate and Maintain What to Look for in a SCADA-RTU Sufficient capacity to support the equipment at your site Rugged construction Secure, redundant power supply. Redundant communication ports. NVRAM Watchdog timer Intelligent control. Remote Terminal Units Housing & Chassis Power Supply CPU Frames I/O Modules Radios Software Dynamic Pressure Control Antenna Optional Solar Panel RTU Monitor and Control Q Flow Power Consumption Reduction 1/2 Pressure / flow Sensors Pump Power Main valve Start/Stop Controls Interface between HMI and RTU Different RTU’s Case Study CRITICAL CONTROL Of BOILER Manual Control Human Errors Hard Wired Logic Control (Contactors & relay's together with timers and counters) Bulky and complex wiring The work can be started only when the task is fully defined and this leads to longer project time. Scada Environment Advantages Reduced Space Higher productivity Superior quality of end product Efficient usage of raw materials and Energy Easy trouble shooting Improved safety in working condition Reduce Human Error CRITICAL CONTROL PARAMETERS IN BOILER Level Control Steam Drum level De-aerator level Pressure Control Steam pressure drum pressure De-aerator pressure Turbine inlet pressure Flow Control Air flow Steam flow Water flow Temperature Control De-aerator temperature Steam drum temperature Turbine inlet steam temperature Flue gas temperature Flow Chart Of PLC-Scada Purpose of PLC works ? Basics of a PLC function are continual scanning of a program. The scanning process involves three basic steps. 1. 2. 3. Testing input status Programming execution Checking and Correcting of output status Scanning time = Time for performing step 1+ Time for performing step 2+ Time for performing step 3. PLC Working At the beginning of each cycle the CPU brings in all the field input signals from the input signals and store into internal memory of CPU is called as process input image (PII). User program will be available in CPU program memory. Once PII is read, CPU pointer moves in ladder program from left to right and from top to bottom. CPU takes status of input from PII and user program. The result of scan is stored in the internal memory of CPU called process output image or POI and Is sent to the field control. I/O driver (SCADA) picks up PII and POI and transfers the image to database and this image is called driver image. This driver image available in SCADA database is used for graphical view of process monitoring from operator station (OS) in the central control room. PID Controller-SCADA Flow chart of Boiler Operation Any Questions?