Optimization of Power System Operation

by Zhu, Jizhong

• ISBN13: 9780470298886
• ISBN10: 047029888X
• Format: Hardcover
• Copyright: 2009-08-17
• Publisher: Wiley-IEEE Press

Summary

Power System Optimal Operation is intended to apply the advanced methods and optimization technologies to power system operation, covering power flow analysis, steady-state security region analysis, security constrained economic dispatch, multi-area system economic dispatch, unit commitment, optimal power flow, reactive power (VAR) optimization, optimal load shed, optimal reconfiguration of distribution network, power system uncertainty analysis, as well as power system sensitivity analysis. The advanced methods and optimization technologies include genetic algorithm, fuzzy theory, neural network, analytic hierarchy process, network flow program, interior point method, and cost benefit analysis, etc. Power system engineers, operators and planners benefit from the book. It is also of great interest to postgraduate and advanced undergraduate students in electrical and power engineering.The book provides the latest application of new technologies to power system operation and analysis. It has several new and important content areas that the existing books do not cover, such as Chapter 2 "Uncertainty Analysis in Power Systems," Chapter 9 "Steady State Security Regions," Chapter 11 "Optimal Load Shedding," and Chapter 12 "Optimal Reconfiguration of Electric Distribution Networks."

Author Biography

Jizhong Zhu is Principal Power Systems Engineer in the Power Systems Application Group with AREVA T&D SA. In addition to his industry experience, Dr. Zhu has also worked at Howard University in Washington, D.C., the National University of Singapore, Brunel University in England, and Chongqing University in China. A Senior Member of the IEEE and an honorable advisory professor of Chongqing University, he has published more than sixty papers in international journals as well as three books. His research interest is in the analysis, operation, planning, and control of power systems.

Table of Contents

Preface	p. xvii
Introduction	p. 1
Conventional Methods	p. 2
Unconstrained Optimization Approaches	p. 2
Linear Programming	p. 3
Nonlinear Programming	p. 3
Quadratic Programming	p. 3
Newton's Method	p. 4
Interior Point Methods	p. 4
Mixed-Integer Programming	p. 4
Network Flow Programming	p. 5
Intelligent Search Methods	p. 5
Optimization Neural Network	p. 5
Evolutionary Algorithms	p. 5
Tabu Search	p. 6
Particle Swarm Optimization	p. 6
Application of Fuzzy Set Theory	p. 6
References	p. 7
Power Flow Analysis	p. 9
Mathematical Model of Power Flow	p. 9
Newton-Raphson Method	p. 12
Principle of Newton-Raphson Method	p. 12
Power Flow Solution with Polar Coordinate System	p. 14
Power Flow Solution with Rectangular Coordinate System	p. 19
Gauss-Seidel Method	p. 27
P-Q decoupling Method	p. 29
Fast Decoupled Power Flow	p. 29
Decoupled Power Flow Without Major Approximation	p. 37
DC Power Flow	p. 39
References	p. 41
Sensitivity Calculation	p. 43
Introduction	p. 43
Loss Sensitivity Calculation	p. 45
Calculation of Constrained Shift Sensitivity Factors	p. 49
Definition of Constraint Shift Factors	p. 49
Computation of Constraint Shift Factors	p. 51
Constraint Shift Factors with Different References	p. 59
Sensitivities for the Transfer Path	p. 60
Perturbation Method for Sensitivity Analysis	p. 62
Loss Sensitivity	p. 62
Generator Shift Factor Sensitivity	p. 62
Shift Factor Sensitivity for the Phase Shifter	p. 63
Line Outage Distribution Factor	p. 63
Outage Transfer Distribution Factor	p. 64
Voltage Sensitivity Analysis	p. 65
Real-Time Application of Sensitivity Factors	p. 67
Simulation Results	p. 68
Sample Computation for Loss Sensitivity Factors	p. 68
Sample Computation for Constrained Shift Factors	p. 77
Sample Computation for Voltage Sensitivity Analysis	p. 80
Conclusion	p. 80
References	p. 83
Classic Economic Dispatch	p. 85
Introduction	p. 85
Input-Output Characteristic of Generator Units	p. 85
Input-Output Characteristic of Thermal Units	p. 85
Calculation of Input-Output Characteristic Parameters	p. 87
Input-Output Characteristic of Hydroelectric Units	p. 90
Thermal System Economic Dispatch Neglecting Network Losses	p. 91
Principle of Equal Incremental Rate	p. 91
Economic Dispatch without Network Losses	p. 94
Calculation of Incremental Power Losses	p. 100
Thermal System Economic Dispatch with Network Losses	p. 103
Hydrothermal System Economic Dispatch	p. 104
Neglect Network Losses	p. 104
Consider Network Losses	p. 110
Economic Dispatch by Gradient Method	p. 112
Introduction	p. 112
Gradient Search in Economic Dispatch	p. 112
Classic Economic Dispatch by Genetic Algorithm	p. 120
Introduction	p. 120
GA-Based ED Solution	p. 121
Classic Economic Dispatch by Hopfield Neural Network	p. 124
Hopfield Neural Network Model	p. 124
Mapping of Economic Dispatch to HNN	p. 126
Simulation Results	p. 129
Appendix: Optimization Methods used in Economic Operation	p. 130
References	p. 139
Security-Constrained Economic Dispatch	p. 141
Introduction	p. 141
Linear Programming Method	p. 141
Mathematical Model of Economic Dispatch with Security	p. 141
Linearization of ED Model	p. 142
Linear Programming Model	p. 146
Implementation	p. 146
Piecewise Linear Approach	p. 149
Quadratic Programming Method	p. 152
QP Model of Economic Dispatch	p. 152
QP Algorithm	p. 153
Implementation	p. 156
Network Flow Programming Method	p. 159
Introduction	p. 159
Out-of-Kilter Algorithm	p. 159
N Security Economic Dispatch Model	p. 167
Calculation of N-1 Security Constraints	p. 171
N-1 Security Economic Dispatch	p. 172
Implementation	p. 174
Nonlinear Convex Network Flow Programming Method	p. 180
Introduction	p. 180
NLCNFP Model of EDC	p. 180
Solution Method	p. 185
Implementation	p. 191
Two-Stage Economic Dispatch Approach	p. 194
Introduction	p. 194
Economic Power Dispatch-Stage One	p. 194
Economic Power Dispatch-Stage Two	p. 195
Evaluation of System Total Fuel Consumption	p. 197
Security-Constrained ED by Genetic Algorithms	p. 199
Appendix: Network Flow Programming	p. 201
References	p. 209
Multiarea System Economic Dispatch	p. 211
Introduction	p. 211
Economy of Multiarea Interconnection	p. 212
Wheeling	p. 217
Concept of Wheeling	p. 217
Cost Models of Wheeling	p. 220
Multiarea Wheeling	p. 223
MAED Solved by Nonlinear Convex Network Flow Programming	p. 224
Introduction	p. 224
NLCNFP Model of MAED	p. 224
Solution Method	p. 229
Test Results	p. 230
Nonlinear Optimization Neural Network Approach	p. 233
Introduction	p. 233
The Problem of MAED	p. 233
Nonlinear Optimization Neural Network Algorithm	p. 235
Test Results	p. 239
Total Transfer Capacity Computation in Multiareas	p. 242
Continuation Power Flow Method	p. 243
Multiarea TTC Computation	p. 245
Appendix: Comparison of Two Optimization Neural Network Models	p. 246
References	p. 248
Unit Commitment	p. 251
Introduction	p. 251
Priority Method	p. 252
Dynamic Programming Method	p. 254
Lagrange Relaxation Method	p. 258
Evolutionary Programming-Based Tabu Search Method	p. 264
Introduction	p. 264
Tabu Search Method	p. 264
Evolutionary Programming	p. 265
EP-Based TS for Unit Commitment	p. 268
Particle Swarm Optimization for Unit Commitment	p. 268
Algorithm	p. 268
Implementation	p. 271
Analytic Hierarchy Process	p. 273
Explanation of Proposed Scheme	p. 273
Formulation of Optimal Generation Scheduling	p. 275
Application of AHP to Unit Commitment	p. 278
References	p. 293
Optimal Power Flow	p. 297
Introduction	p. 297
Newton Method	p. 298
Neglect Line Security Constraints	p. 298
Consider Line Security Constraints	p. 304
Gradient Method	p. 307
OPF Problem without Inequality Constraints	p. 307
Consider Inequality Constraints	p. 311
Linear Programming OPF	p. 313
Modified Interior Point OPF	p. 315
Introduction	p. 315
OPF Formulation	p. 316
IP OPF Algorithms	p. 318
OPF with Phase Shifter	p. 330
Phase Shifter Model	p. 331
Rule-Based OPF with Phase Shifter Scheme	p. 332
Multiple-Objectives OPF	p. 339
Formulation of Combined Active and Reactive Dispatch	p. 339
Solution Algorithm	p. 345
Particle Swarm Optimization for OPF	p. 347
Mathematical Model	p. 347
PSO Methods	p. 349
OPF Considering Valve Loading Effects	p. 355
References	p. 360
Steady-State Security Regions	p. 365
Introduction	p. 365
Security Corridors	p. 366
Concept of Security Corridor	p. 366
Construction of Security Corridor	p. 369
Traditional Expansion Method	p. 372
Power Flow Model	p. 372
Security Constraints	p. 373
Definition of Steady-State Security Regions	p. 373
Illustration of Calculation of Steady-State Security Region	p. 374
Numerical Examples	p. 375
Enhanced Expansion Method	p. 375
Introduction	p. 375
Extended Steady-State Security Region	p. 376
Steady-State Security Regions with N-1 Security	p. 378
Consideration of Failure Probability of Branch Temporary Overload	p. 378
Implementation	p. 379
Test Results and Analysis	p. 381
Fuzzy Set and Linear Programming	p. 386
Introduction	p. 386
Steady-State Security Regions Solved by LP	p. 387
Numerical Examples	p. 390
Appendix: Linear Programming	p. 393
References	p. 405
Reactive Power Optimization	p. 409
Introduction	p. 409
Classic Method for Reactive Power Dispatch	p. 410
Reactive Power Balance	p. 410
Reactive Power Economic Dispatch	p. 411
Linear Programming Method of VAR Optimization	p. 415
VAR Optimization Model	p. 416
Linear Programming Method Based on Sensitivity	p. 418
Interior Point Method for VAR Optimization Problem	p. 420
Introduction	p. 420
Optimal VAR Control Model	p. 420
Calculation of Weighting Factors by AHP	p. 420
Homogeneous Self-Dual Interior Point Method	p. 421
NLONN Approach	p. 426
Placement of VAR Compensation	p. 426
VAR Control Optimization	p. 429
Solution Method	p. 430
Numerical Simulations	p. 431
VAR Optimization by Evolutionary Algorithm	p. 433
Mathematical Model	p. 433
Evolutionary Algorithm of Multiobjective Optimization	p. 434
VAR Optimization by Particle Swarm Optimization Algorithm	p. 438
Reactive Power Pricing Calculation	p. 440
Introduction	p. 440
Reactive Power Pricing	p. 442
Multiarea VAR Pricing Problem	p. 444
References	p. 452
Optimal Load Shedding	p. 455
Introduction	p. 455
Conventional Load Shedding	p. 456
Intelligent Load Shedding	p. 459
Description of Intelligent Load Shedding	p. 459
Function Block Diagram of the ILS	p. 461
Formulation of Optimal Load Shedding	p. 461
Objective Function-Maximization of Benefit Function	p. 462
Constraints of Load Curtailment	p. 462
Optimal Load Shedding with Network Constraints	p. 463
Calculation of Weighting Factors by AHP	p. 463
Network Flow Model	p. 464
Implementation and Simulation	p. 465
Optimal Load Shedding without Network Constraints	p. 471
Everett Method	p. 471
Calculation of Independent Load Values	p. 473
Distributed Interruptible Load Shedding	p. 479
Introduction	p. 479
DILS Methods	p. 480
Undervoltage Load Shedding	p. 486
Introduction	p. 486
Undervoltage Load Shedding using Distributed Controllers	p. 487
Optimal Location of Installing Controller	p. 490
Congestion Management	p. 492
Introduction	p. 492
Congestion Management in U.S. Power Industry	p. 493
Congestion Management Method	p. 495
References	p. 500
Optimal Reconfiguration of Electrical Distribution Network	p. 503
Introduction	p. 503
Mathematical Model of DNRC	p. 505
Heuristic Methods	p. 507
Simple Branch Exchange Method	p. 507
Optimal Flow Pattern	p. 507
Enhanced Optimal Flow Pattern	p. 508
Rule-Based Comprehensive Approach	p. 509
Radial Distribution Network Load Flow	p. 509
Description of Rule-Based Comprehensive Method	p. 510
Numerical Examples	p. 511
Mixed-Integer Linear Programming Approach	p. 513
Selection of Candidate Subnetworks	p. 514
Simplified Mathematical Model	p. 521
Mixed-Integer Linear Model	p. 522
Application of GA to DNRC	p. 524
Introduction	p. 524
Refined GA Approach to DNRC Problem	p. 526
Numerical Examples	p. 528
Multiobjective Evolution Programming to DNRC	p. 530
Multiobjective Optimization Model	p. 530
EP-Based Multiobjective Optimization Approach	p. 531
Genetic Algorithm Based on Matroid Theory	p. 535
Network Topology Coding Method	p. 535
GA with Matroid Theory	p. 537
References	p. 541
Uncertainty Analysis in Power Systems	p. 545
Introduction	p. 545
Definition of Uncertainty	p. 546
Uncertainty Load Analysis	p. 547
Probability Representation of Uncertainty Load	p. 547
Fuzzy Set Representation of Uncertainty Load	p. 554
Uncertainty Power Flow Analysis	p. 559
Probabilistic Power Flow	p. 559
Fuzzy Power Flow	p. 560
Economic Dispatch with Uncertainties	p. 562
Min-Max Optimal Method	p. 562
Stochastic Model Method	p. 564
Fuzzy ED Algorithm	p. 566
Hydrothermal System Operation with Uncertainty	p. 573
Unit Commitment with Uncertainties	p. 573
Introduction	p. 573
Chance-Constrained Optimization Model	p. 574
Chance-Constrained Optimization Algorithms	p. 577
VAR Optimization with Uncertain Reactive Load	p. 579
Linearized VAR Optimization Model	p. 579
Formulation of Fuzzy VAR Optimization Problem	p. 581
Probabilistic Optimal Power Flow	p. 581
Introduction	p. 581
Two-Point Estimate Methods for OPF	p. 582
Cumulant-Based Probabilistic Optimal Power Flow	p. 588
Comparison of Deterministic and Probabilistic Methods	p. 593
References	p. 594
Author Biography	p. 597
Index	p. 599
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