Transmission Expansion Planning: The Network Challenges of the Energy Transition

Preface
Acknowledgments
Contents
1 Introduction: The Key Role of the Transmission Network
	1.1 Motivation
	1.2 General Formulation of a TEP Problem
		1.2.1 General Formulation for a TEP Problem
		1.2.2 Objective Function
		1.2.3 Constraints
	1.3 Modeling Options
	1.4 Solution Methods
		1.4.1 Classical Optimization
		1.4.2 Nonclassical Techniques
		1.4.3 Iterative Methods with Human Interaction
	References
2 Metaheuristics for Transmission Network Expansion Planning
	2.1 Introduction
	2.2 Decision Variables and Metaheuristic Principles
		2.2.1 Decision Variables
		2.2.2 Metaheuristic Principles Applied to the TNEP Problem
		2.2.3 Scheme of the Population-Based Metaheuristics
	2.3 Metaheuristics for the Single-Objective TNEP
		2.3.1 Metaheuristics List
		2.3.2 Initial Population
		2.3.3 Objective Functions and Customisation for TNEP
		2.3.4 Stop Criterion
		2.3.5 Test Systems for Case Study Applications
		2.3.6 Comparisons Among the Solution Algorithms
		2.3.7 Hybridisation of Metaheuristic Solvers and Other Solutions
	2.4 Metaheuristics for the Multi-objective TNEP
		2.4.1 Relevance of Metaheuristics and Objective Functions for Multi-objective TNEP
		2.4.2 Conflicting Objectives and Pareto Front Construction
		2.4.3 Concepts Referring to the Pareto Front for Multi-objective Metaheuristics
		2.4.4 Initial Population
		2.4.5 Solution Methods and Customisation on the TNEP
		2.4.6 Stop Criterion
		2.4.7 Final Decision from Solution Ranking
		2.4.8 Test Systems for Case Study Applications
		2.4.9 Comparisons Among the Solution Algorithms
	2.5 Conclusions
	References
3 Transmission Network Expansion Planning of a Large Power System
	3.1 Transmission Network Planning at the National Level
		3.1.1 Introduction – Historical Approach
		3.1.2 Key Drivers for Network Development
		3.1.3 Scenario as a Basis for the System Planner
		3.1.4 Methodology for Network Expanding
	3.2 Transmission Expansion Planning for Large Systems
		3.2.1 Introduction
		3.2.2 European Experience of Transmission Expansion Planning for a Large System
		3.2.3 Motivation for e-Highway2050 Project
		3.2.4 Scenario Building Process
		3.2.5 Approach of e-Highway2050
		3.2.6 Grid Reduction
		3.2.7 Quantification of Scenarios
		3.2.8 System Simulations and Grid Development
		3.2.9 Application of the Methodology to One Scenario of the e-Highway2050 Project
	3.3 Conclusion
	References
4 Reduction Techniques for TEP Problems
	4.1 Temporal Representation
		4.1.1 Relaxed TEP Problem and Related Optimal Investments
		4.1.2 Computation of Line Benefits for Each Snapshot
		4.1.3 Dimension Reduction of the Line Benefit Space
		4.1.4 Clustering Algorithm
	4.2 Spatial Representation
		4.2.1 Identification of the Critical Pairs of Buses
		4.2.2 Network Partition
			4.2.2.1 Minimum Multicut Problem and Appropriate Weight
			4.2.2.2 Relaxation of the Multicut Problem and a Rounding Algorithm
		4.2.3 Bus Elimination
		4.2.4 Equivalencing and Candidate Lines in the Reduced Network
	4.3 Candidate Grid Elements to Consider
		4.3.1 Relaxed TEP Problem with an Unbounded Number of Candidate Lines per Corridor
		4.3.2 Relaxed TEP Problem with Bounded Number of Candidate Lines per Corridor
		4.3.3 Convergence of the Method
	4.4 Conclusion
		4.4.1 Summary of the Presented Techniques
		4.4.2 Combination and Order of the Reduction Techniques
	References
5 Offshore Grid Development as a Particular Case of TEP
	5.1 The Emergence of Offshore Grids
		5.1.1 Drivers of Offshore Transmission Expansion
		5.1.2 Integrated Offshore Grids
		5.1.3 Risk of Suboptimal Offshore Expansion
		5.1.4 Current Research and Practice for Offshore Grids
	5.2 Challenges for Offshore Grids
		5.2.1 Governance
		5.2.2 Planning
		5.2.3 Ownership
		5.2.4 Pricing and Finance
		5.2.5 Operation
	5.3 Conclusions
	References
6 HVDC in the Future Power Systems
	6.1 Introduction
		6.1.1 A Brief History of HVDC Systems
		6.1.2 HVDC Versus HVAC systems
	6.2 HVDC Technology
		6.2.1 LCC-HVDC Technology
		6.2.2 VSC-HVDC Technology
		6.2.3 HVDC Configurations
		6.2.4 Multiterminal VSC-HVDC Systems
	6.3 Concept of Supergrid
	6.4 Challenges of Future HVDC Systems
		6.4.1 Technical Operation
		6.4.2 HVDC in TEP
		6.4.3 Need of Tools for Cost-Benefit Analysis
	6.5 Optimal Operation of a Hybrid VSC-Based AC/DC Network
		6.5.1 OPF of a Hybrid VSC-Based AC/DC System
		6.5.2 Modelling of VSC Stations and Their Losses
		6.5.3 VSC Operation Limits
		6.5.4 Modelling of Network Technical Constraints
		6.5.5 Modelling of AC Network Flows
		6.5.6 Modelling of DC Network Flows
		6.5.7 Power Balance at Every Bus
		6.5.8 Phase Current Sign
		6.5.9 Generation Limits
		6.5.10 Objective Function/Optimization Criterion
	6.6 Solution Techniques
		6.6.1 Nonlinear OPF
		6.6.2 Linearized OPF
		6.6.3 Linearization of Quadratic Terms
	6.7 Case Study
	6.8 Conclusions
	References
7 Transmission Expansion Planning Outside the Box: A Bilevel Approach
	Nomenclature
		Indices and Sets
		Parameters
		Primal Variables
		Lagrange Multipliers (Dual Variables)
		Auxiliary Binary Variables
	7.1 Introduction
	7.2 Basics of Bilevel Programming
	7.3 Literature Review on Bilevel Transmission Expansion Planning
		7.3.1 Proactive Transmission Expansion Planning
		7.3.2 Reactive Transmission Expansion Planning
		7.3.3 Overview of Solution Methods for Bilevel Problems in Energy
		7.3.4 Challenges of Bilevel Programming in TEP
	7.4 Proactive Transmission Expansion Model Formulation
		7.4.1 Lower-Level Equilibrium
			7.4.1.1 GENCOS' Profit Maximization
			7.4.1.2 Consumer Surplus Maximization
			7.4.1.3 System Operator's Congestion Rent Maximization
			7.4.1.4 Demand Balance and Market-Clearing
			7.4.1.5 Formulation of Lower-Level Equilibrium
		7.4.2 Upper Level and Complete Bilevel TEP Problem
		7.4.3 Linearization of TEP MPEC
	7.5 Illustrative Case Study
		7.5.1 Centralized Planning Model
		7.5.2 Comparison Framework
		7.5.3 Data
		7.5.4 Results
	7.6 Conclusions
	References
8 The Impact of Distributed Energy Resources on the Networks
	8.1 Introduction
	8.2 Impact in the Operation and Planning of the Networks
		8.2.1 Operation
			8.2.1.1 Congestion Management and Voltage Control
			8.2.1.2 Contingencies
		8.2.2 Planning
		8.2.3 Crosscutting Topics
			8.2.3.1 Resiliency
			8.2.3.2 Cybersecurity
	8.3 Impact Assessment
		8.3.1 Network Model
		8.3.2 Traditional Approach
		8.3.3 Impact of Distributed Energy Resources
			8.3.3.1 Distributed Generation
			8.3.3.2 Electric Vehicles
	8.4 Conclusions
	Bibliography
9 Stability Considerations for Transmission System Planning
	9.1 Introduction
	9.2 Power System Stability
		9.2.1 Angle Stability
			9.2.1.1 Small-Signal Stability
			9.2.1.2 Large Disturbance Stability
		9.2.2 Frequency Stability
		9.2.3 Voltage Stability
			9.2.3.1 Concept and Definition of Voltage Collapse Margin
			9.2.3.2 Margin to Voltage Collapse Computation Techniques
			9.2.3.3 Other Voltage Stability Indices
	9.3 Guidelines for Stability Studies During Planning Stage
		9.3.1 Procedure
		9.3.2 Dynamic Analyses Considered
	9.4 Case Studies
		9.4.1 Impact of HVDC on Transient Stability
			9.4.1.1 Small-Scale Power System
			9.4.1.2 French-Iberian Power System
		9.4.2 Impact of HVDC on Small-Signal Stability
		9.4.3 Impact of Transmission Lines on Voltage Stability
	9.5 Conclusions
	References
10 Energy Storage Systems in Transmission Expansion Planning
	10.1 Introduction
	10.2 Modelling and Formulation
	10.3 Test Network and Data
	10.4 Numerical Results and Discussions
		10.4.1 TEP Without ESS
		10.4.2 TEP with ESS
		10.4.3 Sensitivity Analysis
	10.5 Conclusions
	References
11 Regulation of the Expansion of Electricity Transmission
	11.1 Some Preliminary Considerations on the Organization of the Electricity Transmission Activity
		11.1.1 On the Relationship Between the System Operation and Transmission Activities
	11.2 Regulatory Schemes for the Expansion of the Transmission Grid
		11.2.1 Centralized Network Expansion
			11.2.1.1 Passive System Operator
			11.2.1.2 Active System Operator
		11.2.2 Investments by Coalitions of Network Users
		11.2.3 Merchant Lines
		11.2.4 Defining an Efficient Scheme for the Expansion of the Grid
	11.3 Driving the Proposal of Regulated Investments and their Assessment by the Authorities: The Regulatory Test
	11.4 Allocating the Cost of Regulated Network Investment Projects
	11.5 Regulation of the Expansion of the Grid in a Regional Context
	11.6 Conclusions
	References
Index