AC/DC Hybrid Large-Scale Power Grid System Protection

Foreword by Zhou Xiaoxin
Foreword by Sun Guanghui
Preface
Contents
1 Overview
	1.1 Analysis of Typical Chain Failures in Domestic and International Power Grids
		1.1.1 2012 Southern Grid AC Failure Triggers Phase Change Failure [1]
		1.1.2 Power Outage in Brazil
	1.2 Interlocking Faults in AC-DC Hybrid Grids
		1.2.1 Current Status and Development Trend of Domestic and International Power Grids
		1.2.2 Key Features of the AC-DC Hybrid Grid
		1.2.3 Interlocking Faults in AC-DC Hybrid Grids
	1.3 System Protection Against Interlocking Faults in Mixed AC-DC Grids
		1.3.1 Defined Functions and Components of System Protection
		1.3.2 Our Three Lines of Defense [44]
		1.3.3 Special Protection Systems [48]
2 Distance Protection Against Overload
	2.1 Analysis of the Action Behavior of the Distance III Section Under Accidental Overload
		2.1.1 Triggering Events for Accidental Overload
		2.1.2 Action Behavior of Distance III Segments During Dynamics
	2.2 Network Analysis of Accidental Overload
		2.2.1 Station Domain Accidental Overload Versus Nonstation Domain Accidental Overload
		2.2.2 Network Analysis of Nonstation Domain Accidental Overload
	2.3 Analysis of the Conditions for the Operation of the Distance III Section Under Accidental Overload
		2.3.1 Operating Condition 1: The Line is Heavily Loaded, and the Equivalent System Power Angle is Stable at Both Ends
		2.3.2 Operating Condition 2: The Line is Heavily Loaded, and the Equivalent System Voltage at Both Ends is Stable
		2.3.3 Adjustment Conditions: Protection Installed on Long Lines and Large Fixed Values
		2.3.4 Summary
	2.4 Identification Methods for Accidental Overload
		2.4.1 Division of the Incident Overload Action Domain and Protection Action Domain
		2.4.2 Identification of Dynamic Processes of Accidental Overload
	2.5 Distance III Accidental Overload Blocking Scheme
		2.5.1 Description of the Lockout Program
		2.5.2 Lockout Logic
	2.6 Solving for the Davinan Equivalent Impedance
	2.7 Adaptive Adjustment of Distance Protection Based on Shared Information in the Station Domain
		2.7.1 Factors Affecting Distance III Segment Adjustment and Performance
		2.7.2 Adaptive Tuning Scheme
		2.7.3 Simulation Analysis of Overload Blocking Performance
		2.7.4 Simulation Analysis of Intra-Zone Faults and Complex Fault Opening
		2.7.5 Summary
3 Immunityin Distance Protection of Oscillations
	3.1 Multiphase Compensated Distance Relays
	3.2 Multiphase Compensated Distance Relay Performance Analysis
		3.2.1 Oscillation Without Fault Condition
		3.2.2 Fault Conditions Without Oscillation
		3.2.3 Oscillation Accompanied by Fault Conditions
		3.2.4 Effect of Transition Resistors on Multiphase Compensated Distance Relays
	3.3 Distance Protection from Power System Oscillations
		3.3.1 Improved Multiphase Compensated Distance Protection
		3.3.2 Distance Protection Based on Information from Both Ends
	3.4 EMTP Simulation Experiments
		3.4.1 Simulation System
		3.4.2 Power System Oscillations Without Fault Conditions
		3.4.3 Power System Oscillation with a Single-Phase Ground Fault in the Zone
		3.4.4 Power System Oscillation with Out-Of-Area Single-Phase Ground Fault Conditions
		3.4.5 Transition Resistance Test
	3.5 Summary
4 Commutation Failure Prevention and Control
	4.1 Analysis of the DC Commutation Failure Mechanism
		4.1.1 First Commutation Failure
		4.1.2 Continuous Commutation Failure
		4.1.3 Multifed DC Commutation Failure
	4.2 Early Warning Measures for Commutation Failure in a Hybrid AC/DC Grid
		4.2.1 Early Warning Measures for the First Commutation Failure
		4.2.2 Early Warning Measures for Continuous Commutation Failure
		4.2.3 Early Warning Measures for Multifeeder DC Commutation Failure
	4.3 Commutation Failure Suppression for the AC/DC Hybrid Grid
		4.3.1 Suppression Measures for the First Commutation Failure
		4.3.2 Suppression Measures Against Successive Commutation Failures
		4.3.3 Suppression Measures for Multifeed DC Successive Commutation Failures
	4.4 Summary
5 DC Participation in Emergency Tidal Control
	5.1 Study of Multidimensional Coupling Mechanism of an AC-DC Hybrid Grid
		5.1.1 Methodology for Evaluating the Degree of Commutation Bus Voltage Interactions in Hybrid DC Networks with Different Control Methods
		5.1.2 Calculation of the Maximum Delivered Power of HVDC Based on Equivalent Impedance
		5.1.3 Short-Circuit Ratio and Operational Evaluation Method for Multifeed-In Operation Based on Equivalent Impedance
		5.1.4 Multifeeder System Tuner Capacity Calculation Method Based on Power Support Requirements
	5.2 Multi-indicator Static Security Domain for AC-DC Hybrid Grids
		5.2.1 Definition and Model of a Multimetric Static Safety Domain for AC-DC Hybrid Grids
		5.2.2 A Method for Inscribing the Full-Dimensional Static Safety Domain of Hybrid AC-DC Grids Considering Different Control Methods
		5.2.3 Methodology for Inscribing Low-Dimensional Focal Variable Safety Sections (Profiles) in the Static Safety Domain of AC-DC Hybrid Grids
		5.2.4 Static Safety Domain Inscription Method for AC-DC Hybrid Grids Containing Controllable Series Capacitor Converters
		5.2.5 Methods for Inscribing the Decoupled Security Domain of an AC-DC Hybrid Grid
		5.2.6 Evolutionary Characteristics and Impact Analysis of the Static Safety Domain of Hybrid AC-DC Grids
	5.3 Coordinated Control Objectives and Control Methods When Multiple DC Systems Are Involved in the Rapid Control of Tidal Currents
		5.3.1 AC-DC Static Safety Domain Under Meter and Time Characteristic DC Active Adjustment Method
		5.3.2 Safety Correction Strategy for Hybrid AC-DC Grids Based on Safety Distance Sensitivity
		5.3.3 Optimal Scheduling Based on Safety-Corrected Control in the Static Safety Domain of Hybrid AC-DC Grids
		5.3.4 Preventive Correction Coordination Control Based on Static Safety Domain for Hybrid AC-DC Grids
		5.3.5 Fast Tidal Control Based on Decoupled Security Domains
	5.4 Summary
6 Adaptive Overload Protection for Overhead Transmission Lines
	6.1 Introduction
	6.2 Line Emergency Current-Carrying Capacity Analysis
		6.2.1 Mechanical Strength
		6.2.2 Arc Drape
		6.2.3 Fittings and Various Types of Connectors
		6.2.4 Summary of Emergency Current-Carrying Capacity
	6.3 Line Adaptive Overload Protection Action Time
		6.3.1 Line Temperature Calculation and Action Time Analysis
		6.3.2 Prediction Based on the Echo State Network Method
	6.4 Component Scheme for Line Adaptive Overload Protection
		6.4.1 Rectification Scheme and Action Logic
		6.4.2 Algorithm Flow
		6.4.3 Applications and Calculations
		6.4.4 Summary
Appendix Transient Temperature Calculations
Joule Heat Absorption
Heat Absorption by Insolation
Convection Heat Dissipation
Radiation Heat Dissipation
Method of Calculation
Wire Parameters
Bibliography