EE2401 POWER SYSTEM OPERATION AND CONTROL
AIM:
To understand the day to day operation of power system and the control actions to be implemented on the system to meet the minute-to-minute variation of system load demand.
OBJECTIVES:
i. To have an overview of power system operation and control.
ii. To model power-frequency dynamics and to design power-frequency controller.
iii. To model reactive power-voltage interaction and the control actions to be implemented for maintaining the voltage profile against varying system load.
UNIT I INTRODUCTION
System load – variation - load characteristics - load curves and load-duration curve (daily, weekly and annual) - load factor - diversity factor. Importance of load forecasting and simple techniques of forecasting. An overview of power system operation and control and the role of computers in the implementation. (Qualitative treatment with block diagram).
UNIT II REAL POWER - FREQUENCY CONTROL
Basics of speed governing mechanism and modeling - speed-load characteristics – load sharing between two synchronous machines in parallel. Control area concept LFC control of a singlearea system. Static and dynamic analysis of uncontrolled and controlled cases. Integration of economic dispatch control with LFC. Two-area system – modeling - static analysis of uncontrolled case - tie line with frequency bias control of two-area system - state variable model.
UNIT III REACTIVE POWER–VOLTAGE CONTROL
Basics of reactive power control. Excitation systems – modeling. Static and dynamic analysis stability compensation - generation and absorption of reactive power. Relation between voltage, power and reactive power at a node - method of voltage control - tap-changing transformer. System level control using generator voltage magnitude setting, tap setting of OLTC transformer and
MVAR injection of switched capacitors to maintain acceptable voltage profile and to minimize transmission loss.
UNIT IV UNIT COMMITMENT AND ECONOMIC DISPATCH 9
Statement of economic dispatch problem – cost of generation – incremental cost curve co-ordination equations without loss and with loss, solution by direct method and λ-iteration method. (No derivation of loss coefficients). Statement of Unit Commitment problem – constraints; spinning reserve, thermal unit constraints, hydro constraints, fuel constraints and other constraints. Solution
methods - Priority-list methods - forward dynamic programming approach. Numerical problems only in priority-list method using full-load average production cost.
UNIT V COMPUTER CONTROL OF POWER SYSTEMS
Need of computer control of power systems. Concept of energy control centre (or) load dispatchcentre and the functions - system monitoring - data acquisition and control. System hardware configuration – SCADA and EMS functions. Network topology - state estimation - security analysis and control. Various operating states (Normal, alert, emergency, in-extremis and restorative). State
transition diagram showing various state transitions and control strategies.
TEXT BOOKS
1. Allen. J. Wood and Bruce F. Wollenberg, ‘Power Generation, Operation and Control’, John Wiley& Sons, Inc., 2003.
2. Chakrabarti & Halder, “Power System Analysis: Operation and Control”, Prentice Hall of India, 2004 Edition.
REFERENCES
1. D.P. Kothari and I.J. Nagrath, ‘Modern Power System Analysis’, Third Edition, Tata McGraw Hill Publishing Company Limited, New Delhi, 2003. (For Chapters 1, 2 & 3)
2. L.L. Grigsby, ‘The Electric Power Engineering, Hand Book’, CRC Press & IEEE Press, 2001.
3. Hadi Saadat, “Power System Analysis”, (For the chapters 1, 2, 3 and 4)11th Reprint 2007.
4. P.Kundur, ‘Power System Stability and Control’ MC Craw Hill Publisher, USA, 1994.
5. Olle.I.Elgerd, ‘Electric Energy Systems theory An introduction’ Tata McGraw Hill Publishing Company Ltd. New Delhi, Second Edition 2003.