67 Energy management 67.2 Power System Data Acquisition and Control 67.3 Automatic Generation Control Load Frequency Control. Economic Dispatch.Reserve Neil n y 67.5 Energy Management Cegelec ESCA Corporation 67.6 Security Control Anjan Bose 67.7 Operator Training Simulator Energy Control System. Power System Dynami Washington State University Simulation. Instructional System 67.1 Introduction Energy management is the process of monitoring, coordinating, and controlling the generation, transmission and distribution of electrical energy. The physical plant to be managed includes generating plants that produce energy fed through transformers to the high-voltage transmission network(grid), interconnecting generating plants and load centers. Transmission lines terminate at substations that perform switching, voltage transfor mation, measurement, and control. Substations at load centers transform to subtransmission and distribution levels. These lower-voltage circuits typically operate radially, i.e., no normally closed paths between substations through subtransmission or distribution circuits (Underground cable networks in large cities are an exception. Since transmission systems provide negligible energy storage, supply and demand must be balanced by either generation or load. Production is controlled by turbine governors at generating plants, and automatic generation control is performed by control center computers remote from generating plants. Load management, sometimes called demand-side management, extends remote supervision and control to subtransmission and distribution circuits, including control of residential, commercial, and industrial load Events such as lightning strikes, short circuits, equipment failure, or accidents may cause a system fault Protective relays actuate rapid, local control through operation of circuit breakers before operators can respond The goal is to maximize safety, minimize damage, and continue to supply load with the least inconvenience to customers. Data acquisition provides operators and computer control systems with status and measurement information needed to supervise overall operations. Security control analyzes the consequences of faults to establish operating conditions that are both robust and economical. Energy management is performed at control centers(see Fig. 67.1), typically called system control centers, by computer systems called energy management systems(EMS). Data acquisition and remote control is per- formed by computer systems called supervisory control and data acquisition(SCADA) systems. These latter systems may be installed at a variety of sites including system control centers. An EMS typically includes a SCADA"front-end"through which it communicates with generating plants, substations, and other remote Ices. Figure 67. 2 illustrates the applications layer of modern EMS as well as the underlying layers on which it is built: the operating system, a database manager, and a utilities/services laye c 2000 by CRC Press LLC© 2000 by CRC Press LLC 67 Energy Management 67.1 Introduction 67.2 Power System Data Acquisition and Control 67.3 Automatic Generation Control Load Frequency Control • Economic Dispatch • Reserve Monitoring • Interchange Transaction Scheduling 67.4 Load Management 67.5 Energy Management 67.6 Security Control 67.7 Operator Training Simulator Energy Control System • Power System Dynamic Simulation • Instructional System 67.1 Introduction Energy management is the process of monitoring, coordinating, and controlling the generation, transmission, and distribution of electrical energy. The physical plant to be managed includes generating plants that produce energy fed through transformers to the high-voltage transmission network (grid), interconnecting generating plants and load centers. Transmission lines terminate at substations that perform switching, voltage transfor￾mation, measurement, and control. Substations at load centers transform to subtransmission and distribution levels. These lower-voltage circuits typically operate radially, i.e., no normally closed paths between substations through subtransmission or distribution circuits. (Underground cable networks in large cities are an exception.) Since transmission systems provide negligible energy storage, supply and demand must be balanced by either generation or load. Production is controlled by turbine governors at generating plants, and automatic generation control is performed by control center computers remote from generating plants. Load management, sometimes called demand-side management, extends remote supervision and control to subtransmission and distribution circuits, including control of residential, commercial, and industrial loads. Events such as lightning strikes, short circuits, equipment failure, or accidents may cause a system fault. Protective relays actuate rapid, local control through operation of circuit breakers before operators can respond. The goal is to maximize safety, minimize damage, and continue to supply load with the least inconvenience to customers. Data acquisition provides operators and computer control systems with status and measurement information needed to supervise overall operations. Security control analyzes the consequences of faults to establish operating conditions that are both robust and economical. Energy management is performed at control centers (see Fig. 67.1), typically called system control centers, by computer systems called energy management systems (EMS). Data acquisition and remote control is per￾formed by computer systems called supervisory control and data acquisition (SCADA) systems. These latter systems may be installed at a variety of sites including system control centers. An EMS typically includes a SCADA “front-end” through which it communicates with generating plants, substations, and other remote devices. Figure 67.2 illustrates the applications layer of modern EMS as well as the underlying layers on which it is built: the operating system, a database manager, and a utilities/services layer. K. Neil Stanton Stanton Associates Jay C. Giri Cegelec ESCA Corporation Anjan Bose Washington State University