Part 6 Traction Power Supply Requirements for Railroad AC Electrification Systems - 2021 - TABLE OF CONTENTS Section/Article Description Page 6.1 General .................................................................................................................................................................. 33-6-3 6.1.1 Purpose (2021) ......................................................................................................................................... 33-6-3 6.1.2 Scope (2021) ............................................................................................................................................ 33-6-3 6.2 Electrification System Load ................................................................................................................................ 33-6-3 6.2.1 General (2021) ......................................................................................................................................... 33-6-3 6.2.2 Traction Power Demand (2021) ............................................................................................................... 33-6-3 6.3 AC Electrification System Configuration .......................................................................................................... 33-6-5 6.3.1 General (2021) ......................................................................................................................................... 33-6-5 6.3.2 Traction Power Supply System (2021) .................................................................................................... 33-6-6 6.3.3 Traction Power Distribution System (2021) ............................................................................................ 33-6-7 6.3.4 Traction Power Return System (2021) .................................................................................................... 33-6-13 6.3.5 Normal and Contingency Operation (2021) ............................................................................................. 33-6-13 6.4 Electrification System Selection .......................................................................................................................... 33-6-14 6.4.1 System Configuration (2021) ................................................................................................................... 33-6-14 6.4.2 Substation Spacing (2021) ....................................................................................................................... 33-6-15 6.4.3 Electrification Voltage (2021) ................................................................................................................. 33-6-15 6.4.4 Utility Power Availability (2021) ............................................................................................................ 33-6-15 6.4.5 Electromagnetic Interference (2021) ....................................................................................................... 33-6-16 6.4.6 Voltage Rise Along the Return System (2021) ........................................................................................ 33-6-16 6.4.7 Achieving Cost Effective Electrification System Design (2021) .............................................................. 33-6-16 6.5 System Studies ...................................................................................................................................................... 33-6-17 6.5.1 General (2021) ......................................................................................................................................... 33-6-17 6.5.2 Train Operation Simulation and Load-Flow Study (2021) ...................................................................... 33-6-17 6.5.3 Distribution System Conductor Temperature Study (2021) .................................................................... 33-6-17 Pending6.5.4 Power and Electronic Circuit CompatibilityFinal Study (2021) ...................................................................... Approval 33-6-17 6.5.5 Voltage Flicker Study (2021)................................................................................................................... 33-6-18 © 2018, American Railway Engineering and Maintenance-of-Way Association 33-6-1 Traction Power Supply Requirements for Railroad AC Electrification Systems TABLE OF CONTENTS (CONT) Section/Article Description Page 6.5.6 Phase Unbalance Study (2021). 33-6-18 6.5.7 Harmonic Distortion and System Resonance Study (2021) . 33-6-18 6.5.8 Short Circuit Study (2021) . 33-6-19 6.5.9 Arc-Flash Hazard Study (2021) . 33-6-19 6.5.10 Insulation Coordination Study (2021) . 33-6-19 6.5.11 Grounding Design Study(2021). 33-6-19 6.5.12 Protective Device Coordination Study(2021) . 33-6-19 6.5.13 Atmospheric Corrosion Control Study(2021) . 33-6-19 6.5.14 Geotechnical Study (2021) . 6.6 System Design . 33-6-20 6.6.1 Functional Requirements (2021) . 33-6-20 6.6.2 Standards, Codes, and Regulations (2009) R(2021). 33-6-20 6.6.3 Environmental Considerations (2021) . 33-6-21 6.6.4 Service Conditions (2009)R(2021) . 33-6-22 6.6.5 Equipment Design (2021). 33-6-22 6.6.6 High (Primary) Voltage Circuit Breakers and Disconnect Switches (2009)R(2021) . 33-6-23 6.6.7 Traction Power Transformers (2021) . 33-6-23 6.6.8 Medium (Secondary) Voltage Switchgear (2009)R(2021) . 33-6-24 6.6.9 System Protection (2021) . .Approval . 33-6-25 6.6.10 Special Equipment (2021) . 33-6-26 6.6.11 Signal Power Generating System (2021) . 33-6-26 6.6.12 Supervisory Control and Data Acquisition System (SCADA) (2021). 33-6-26 6.7 Utility Metering. 33-6-27 6.7.1 Typical Rate Structure (2021) . 33-6-27 6.7.2 Location of Metering Equipment (2021) . 33-6-28 6.7.3 Billing Concepts (2009)R(2021) . 33-6-28 6.7.4 Rate Structure Negotiation (2009)R(2021)Final . 33-6-28 6.8 Construction . 33-6-28 6.8.1 Quality Assurance/Quality Control (2021) . 33-6-28 6.8.2 Installation Verification Testing (2021) . 33-6-28 6.8.3 System-Wide Integration Testing (2021) . 33-6-29 6.8.4 Pre-Revenue Operation Testing (2021) . 33-6-29 LIST OF FIGURES Figure Description Page 33-6-1 Typical Direct-Fed AC Traction Power System - Simplified One-Line Diagram . 33-6-8 33-6-2 Typical Direct-Fed AC Traction Power System with Booster Transformers - Simplified One-Line 33-6-10 33-6-3 Typical Autotransformer-Fed AC Traction Power System - Simplified One-Line Diagram . 33-6-11 Pending © 2018, American Railway Engineering and Maintenance-of-Way Association AREMA Manual for Railway Engineering 33-6-2 Traction Power Supply Requirements for Railroad AC Electrification Systems SECTION 6.1 GENERAL 6.1.1 PURPOSE (2021) Part 6 of Chapter 33 provides recommendations for study, design, and construction methods for the implementation of modern 60 Hz alternating current (ac) Traction Power Supply (TPS) systems for railroad electrification projects. Further, the purpose of these guidelines and recommendations is to ensure that the traction power supply systems are designed, manufactured, constructed, installed, and tested to deliver sufficient power to rolling stock and to provide safe, efficient, and continuous operation of the systems under normal and contingency conditions under the environmental conditions prevalent in the project locale. 6.1.2 SCOPE (2021) The scope of the Part 6 includes new electrification systems for regional commuter rail, intercity rail, intercity high-speed rail, and freight railroad systems considered for operation at electrification voltages recommended in Part 3, Chapter 33; that is, at 12.5 kV ac, 25 kV ac, or 50 kV ac nominal electrification voltage, obtained through transformation of utility ac power at commercial frequency of 60 Hz. It also includes the expansion or modification of existing 25 Hz and 60 Hz ac electrification systems. Some existing ac electrification systems operate at 12 kV ac nominal electrification voltage and 25 Hz frequency. Construction of new systems at 25 Hz frequency is not recommended as the cost of wayside frequency conversion equipment increases the overall system costs. Approval Other electrification systems and subsystems, such as the traction power distribution system, the traction power return system, signal system, communications system and rolling stock are discussed only when essential to operation of the traction power supply system. SECTION 6.2 ELECTRIFICATION SYSTEM LOAD 6.2.1 GENERAL (2021) Final Railroad traffic can be broadly divided into two major types, passenger and freight. Passenger rolling stock typically operates with higher acceleration rates than freight rolling stock, and therefore, their power demand is relatively high during acceleration and decreases considerably once the train has attained its normal cruising speed. Freight trains operate with heavy tonnage and at relatively low acceleration rates and their power demand during acceleration and cruising can be of the same order of magnitude. The train power demand is influenced by factors including train consist size, weight, maximum acceleration, maximum train operation speed, alignment gradients, density of traffic, operating practices and rolling stock propulsion equipment design. 6.2.2 TRACTION POWER DEMAND (2021) 6.2.2.1 Power Demand Characteristics Power demand of traction power supply systems is significantly different from power demand produced by the usual utility Pendingloads. Although there are exceptions, most utility loads change in magnitude relatively slowly, are well distributed amongst the © 2018, American Railway