Table of Contents

Part I: AC/DC Interaction Phenomena
1 Overview
   1.1 Scope
   1.2 Purpose
   1.3 General
   1.4 References
   1.5 Definitions
   1.6 Acronyms and abbreviations
2 AC/DC system strength
   2.1 Introduction
   2.2 High-impedance systems
   2.3 Inadequate and zero mechanical inertia
   2.4 Numerical examples of CSCRs and TOVfc values
   2.5 Calculation of CSCRs
   2.6 Numerical examples of power reduction due to ac
        system impedance increase and ac voltage reduction
   2.7 AC/DC system strength - summary tables
3 DC power transfer limits
   3.1 Description of phenomena
   3.2 Power limits of an inverter
   3.3 Power limits of a dc link
   3.4 Principal parameters
   3.5 Trends and sensitivities of system parameters
   3.6 Possible improvements
   3.7 Influence of dc controls
   3.8 Methods of study
   3.9 Discussion of power curves
4 Control and protection for dc transmission
   4.1 Introduction
   4.2 Hierarchical division of the dc control system
   4.3 Types of interaction between controls and the ac
        system
   4.4 Current control
   4.5 Power control
   4.6 Reduction of the direct current at low voltage
   4.7 AC system instabilities
   4.8 Influence on the control of resonances in the ac
        network
   4.9 Summary of convertor control instability control
   4.10 System parameters of principal interest to the
        controls
   4.11 AC voltage variations
   4.12 AC network frequency and stabilization control
   4.13 Control and protection considerations for back-to-back
        schemes
   4.14 Control and protection considerations for multiterminal
        schemes
   4.15 Higher-level controller characteristics for dc schemes
        in operation
   4.16 Protection
5 Resonances, instabilities and harmonic transfer
   5.1 Introduction
   5.2 Basic concepts
   5.3 Harmonic resonance-related instabilities and solutions
   5.4 Factors influencing harmonic problems
   5.5 Trends and sensitivities of system parameters
   5.6 Methods of study
   5.7 Different types of schemes and harmonic problems
   5.8 Comments
6 Subsynchronous torsional interactions between dc
   convertors and nearby turbine-generators
   6.1 Introduction and summary
   6.2 Description of the phenomenon
   6.3 Principal parameters
   6.4 Trends and sensitivities of system parameters
   6.5 Influence of dc controls
   6.6 Methods of study
7 Transient, steady-state, low-frequency and
   power-frequency stabilities
   7.1 Introduction
   7.2 Descriptions of stability types
   7.3 Main parameters and effects
   7.4 Trends and sensitivities of system parameters
   7.5 AC and dc parallel operation
   7.6 Influence of dc control
   7.7 Methods and tools for study
   7.8 Different types of schemes
8 Temporary overvoltages (TOVs)
   8.1 Description of phenomena
   8.2 Main parameters affecting the phenomena
   8.3 Trends and sensitivities of the system parameters
   8.4 Influence of dc control
   8.5 Methods and tools for study
   8.6 Measures for the limitation of TOVs
   8.7 Different types of schemes
9 Zero- and low-inertia systems
   9.1 Introduction
   9.2 Zero-inertia systems - Island of Gotland
   9.3 Low-inertia system - Island of Corsica
10 Recovery of dc systems from ac and dc system faults
   10.1 Introduction
   10.2 Parametric behavior of the phenomena
   10.3 Different types of schemes
   10.4 System experience and examples
   10.5 Methods and tools for studies
Annex A (informative) The dc conversion process
Annex B (informative) Bibliography
Part II: Planning guidelines
1 Overview
   1.1 Scope
   1.2 Purpose
   1.3 General
2 References
3 Performance criteria and evaluation
   3.1 General considerations
   3.2 Power transfer limits and SCR
   3.3 Recovery from ac and dc faults
   3.4 Reactive compensation
   3.5 Temporary overvoltages (TOVs)
   3.6 Operation under low ac voltage conditions
   3.7 Power transfer during ac and dc faults
   3.8 Operation with and without ground return
   3.9 DC line re-energization
   3.10 Overload considerations
   3.11 Operation without communication
   3.12 Commutation failures
   3.13 Voltage changes during reactive switching
   3.14 Availability (adequacy and security)
   3.15 Economic and reliability criteria for comparison of
        different solutions to interaction problems
   3.16 Multiterminal considerations
4 Planning considerations
   4.1 General aspects
   4.2 Power transfer limits
   4.3 Electromechanical stability
   4.4 Planning considerations of HVDC controls
   4.5 Planning of ac/dc performance enhancement
   4.6 Consideration of existing dc schemes in the same
        system
5 System economics and reliability
   5.1 General considerations
   5.2 Aspects of alternative solutions to solve ac/dc
        interaction problems
   5.3 Reliability and economic aspects of different dc
        system configurations
   5.4 Study methods, sources of data and assumptions
6 Planning and initial design studies
   6.1 Introduction
   6.2 Planning studies
   6.3 Initial design studies
   6.4 Required system data
7 Examples of system studies
   7.1 Introduction
   7.2 Itaipu transmission system
   7.3 Chateauguay
   7.4 Highgate
   7.5 Gotland
   7.6 Virginia Smith (formerly Sidney)
   7.7 MTDC system studies
   7.8 Reliability studies
   7.9 Additional references
8 Examples of existing low and very low SCR systems
   8.1 Introduction
   8.2 Miles City converter station
   8.3 Virginia Smith (formerly Sidney)
   8.4 Highgate
   8.5 Chateauguay
   8.6 Blackwater
   8.7 Cross channel
   8.8 Vindhyachal
   8.9 Gotland
   8.10 Comerford
   8.11 Nelson river
   8.12 Itaipu
   8.13 McNeill
Annex A (informative) Bibliography

Abstract

Describes the effects of various aspects of the ac/dc interactions on the design and performance of dc schemes where the ac system appears as a high impedance at the ac/dc interface bus; i.e., low and very low short-circuit (short-circuit ratio [SCR]) conditions.

General Product Information

Published
Document Type	Standard
Status	Current
Publisher	Institute of Electrical & Electronics Engineers
Pages
ISBN
Supersedes	IEEE DRAFT 1204 : APR 95