Electrical Distribution Substations

Course Description

ETP2137C — Electrical Distribution Substations — is a combined lecture and laboratory course (3 credit hours) in the Engineering Technologies: Energy Power Technology taxonomy of the Florida Statewide Course Numbering System (SCNS). The course provides students with a comprehensive study of the design, components, operation, protection, and maintenance of electrical distribution substations. Emphasis is placed on substation equipment identification, one-line diagram interpretation, switching procedures, protective relay systems, SCADA, and safe work practices in a live substation environment. This course is aligned with Florida's Electrical Power Technology program pathway and prepares students for entry-level employment as substation technicians and electrical and electronics repairers in the power utility industry.

Learning Outcomes

Required Learning Outcomes

Upon successful completion of this course, students will be able to:

• Demonstrate a functional knowledge of a substation one-line diagram, including reading, interpreting, and verifying schematic accuracy.
• Identify all major equipment found in a typical distribution substation (transformers, circuit breakers, disconnect switches, bus structures, capacitor banks, voltage regulators, and metering equipment).
• Read and interpret nameplate data on substation equipment including transformers, circuit breakers, and protective relays.
• Plan and execute a complete substation switching order, including bus tie closures and the transfer of individual circuit breaker loads.
• Describe the function and components of a recloser relay unit and diagnose targets and lockout modes of a substation recloser.
• Describe the component parts of various circuit breaker technologies, including air-blast, oil, vacuum, and gas-insulated (SF₆) designs.
• Demonstrate safe work practices in electrical transmission and distribution substations, including OSHA regulations and utility industry safety standards.
• Demonstrate knowledge of a typical SCADA (Supervisory Control and Data Acquisition) control system used in substation operations.
• Check and service a substation battery bank used for DC control power backup.
• Apply per-phase analysis and three-phase power theory to evaluate substation electrical circuits and protection schemes.
• Identify and apply overcurrent protective devices — including fuses, relays, and circuit switchers — using time-current curve analysis for feeder protection.
• Explain the principles of transformer protection, including transformer faults, differential protection, and overcurrent protection schemes.

Optional Learning Outcomes

Depending on institutional emphasis and available laboratory facilities, students may also:

• Perform hands-on testing and commissioning of substation components such as transformers, circuit breakers, regulators, and capacitor banks.
• Describe substation grounding principles and safety requirements, including grounding grid design and step/touch potential hazards.
• Identify and explain NERC Critical Infrastructure Protection (CIP) standards as they relate to physical and cybersecurity at distribution substations.
• Explain the function of surge protective devices and lightning shielding systems installed at substations.
• Describe smart grid metering integration and communications protocols used at the substation level.
• Discuss environmental and structural considerations specific to Florida substations, including hurricane-rated design, coastal corrosion, and flood mitigation.

Major Topics

Required Topics

1. Substation Overview and Types
   • Role of substations in the generation–transmission–distribution system
   • Types: transmission, distribution, collector, and switching substations
   • Voltage levels: bulk transmission (115 kV–500 kV), sub-transmission, and distribution (2 kV–35 kV)
2. Substation Equipment Identification
   • Power transformers: construction, cooling methods (ONAN, ONAF, OFAF), nameplate data
   • Circuit breakers: air-blast, bulk oil, minimum oil, vacuum, and SF₆ gas-insulated technologies
   • Disconnect switches, bus structures, and insulators
   • Voltage regulators and capacitor banks
   • Current transformers (CTs) and potential transformers (PTs) / coupling capacitor voltage transformers (CCVTs)
   • Station service transformers and DC battery banks
3. One-Line and Three-Line Diagrams
   • Electrical symbols and legend interpretation
   • One-line diagram layout, content, and verification
   • Three-line schematics and control wiring diagrams
   • Creating and maintaining accurate one-line diagrams
4. Substation Switching and Operations
   • Developing and executing switching orders
   • Bus tie closures and load transfers
   • De-energizing and re-energizing procedures
   • Tagging and lockout/tagout (LOTO) procedures
5. Protective Relaying and Feeder Protection
   • Principles of overcurrent protection; time-current curves
   • Recloser relay units: function, targets, and lockout diagnosis
   • Fuses, circuit switchers, and protective relays: types and application
   • Transformer protection: differential, overcurrent, and fault types
   • Distribution feeder protection schemes
6. Applied Electrical Theory for Substations
   • Three-phase power theory: balanced systems, per-phase analysis
   • Phase-to-phase and phase-to-neutral quantity relationships
   • Kirchhoff's Current Law applied to substation protection
   • Reactive power, power factor, and voltage control
7. SCADA and Control Systems
   • SCADA architecture overview: RTUs, HMI, communication infrastructure
   • Remote control and monitoring of substation equipment
   • Alarm systems and event logging
8. Safety Practices in Substations
   • OSHA general industry and electrical safety regulations (29 CFR 1910.269)
   • Personal protective equipment (PPE) for substation environments
   • Arc flash hazard awareness and arc flash boundary requirements
   • Safe work distances for energized equipment
   • Battery bank maintenance safety
9. Substation Maintenance Fundamentals
   • DC control power: battery bank inspection, testing, and service
   • Transformer oil sampling and routine inspection
   • Preventive maintenance checklists and work orders

Optional Topics

• Substation Grounding: ground grid design, step and touch potential, IEEE 80 overview
• Lightning Protection and Surge Arresters: lightning shielding masts, surge arrester types and placement
• Smart Grid Integration: advanced metering infrastructure (AMI), IED communications, DNP3 and IEC 61850 protocols
• NERC CIP Physical and Cybersecurity: CIP-014 physical security standards, access control, and perimeter protection
• Substation Civil and Structural Elements: yard layout, foundations, oil containment pits, conduit systems, and lighting design
• Florida-Specific Environmental Considerations: hurricane-rated structures, coastal corrosion, flooding and high water table mitigation
• Renewable Energy Collector Substations: solar and wind farm substation configurations

Resources & Tools

• Textbook: Electric Power Substations Engineering (McDonald, CRC Press / IEEE Press) — widely used reference for substation technology programs
• Standards and References:
  • IEEE Standard 80 – Guide for Safety in AC Substation Grounding
  • IEEE Standard C37 series – Circuit Breaker and Switchgear Standards
  • OSHA 29 CFR 1910.269 – Electric Power Generation, Transmission, and Distribution
  • NFPA 70E – Standard for Electrical Safety in the Workplace
  • NERC CIP Standards (Physical and Cybersecurity)
  • Florida Building Code (FBC), 7th Edition – Electrical Volume (NEC 2017 base)
• Laboratory Equipment: Substation equipment simulators or scale models, relay test sets (Doble, Megger), insulation resistance testers (megohmmeter), CT/PT burden test equipment, battery discharge testers, digital multimeters, clamp-on power analyzers
• Software / Technology: SCADA simulation software, AutoCAD Electrical or similar for one-line diagram drafting, relay coordination software (e.g., SEL-5030 AcSELerator)
• Multimedia: Florida Power & Light (FPL), Duke Energy, and JEA educational and training videos on substation operations; IEEE PES educational resources

Career Pathways

Successful completion of ETP2137C prepares students for employment in Florida's expanding electric utility sector. Florida is the second largest electricity generator in the nation, with major utilities including Florida Power & Light (FPL), Duke Energy Florida, JEA, and TECO Energy operating hundreds of substations statewide.

• Substation Technician — installs, inspects, tests, and maintains high-voltage equipment at transmission and distribution substations (SOC 49-2095: Electrical and Electronics Repairers, Powerhouse, Substation, and Relay)
• Distribution Lineworker / Utility Electrician — performs switching operations and maintenance on distribution feeders and associated substation equipment
• Relay and Protection Technician — tests, calibrates, and maintains protective relaying systems and SCADA equipment at utility substations
• Utility System Operator — monitors and controls transmission and distribution systems via energy management and SCADA platforms
• Electrical Power Engineering Technician — supports substation design, commissioning, and project management for utilities or consulting firms

This course is a component of the Electrical Power Technology AS Degree and associated College Credit Certificate programs at Florida colleges, aligned to CIP Code and SOC 49-2095 workforce demand.

Special Information

Lab Designation: The "C" suffix in ETP2137C designates this as a combined lecture and laboratory course meeting in the same location at the same time, per Florida SCNS lab indicator conventions. Students should expect both theoretical instruction and hands-on practical exercises in each class session.

Safety Requirement: Due to the hazardous nature of high-voltage electrical work, students must comply with all lab safety protocols, complete arc flash awareness training, and use required PPE before participating in any laboratory exercises involving energized equipment or substation simulations.

Workforce Certification Alignment: Course content is aligned with the competencies assessed by the Electronics Technicians Association International (ETA) Power Quality Technician and the NCCER (National Center for Construction Education and Research) Electrical curriculum, supporting students pursuing industry-recognized credentials. The course also provides foundational knowledge applicable to the IBEW Apprenticeship program for utility line workers.

Program Context: This course is part of the Florida DOE Electrical Power Technology program (CIP 46.0302) and is typically offered in the second year of study. It is designed to follow foundational coursework in electrical theory, AC/DC circuits, and introduction to power systems.