Protective Relay Engineering

Protective Relay Engineering is a complete substation design firm that specializes in control system design, protection system design, and relay settings. Capabilities include:

Protective Relay System Design and Programming

  • High Voltage Transmission Line Protection Systems Utilizing:
    • Communication Aided Directional Comparison (POTT/DCB/DCUB/etc.)
    • Communication Based on Power Line Carrier, Fiber Optic, Leased Line, Microwave, Shortwave Radio, etc.
    • Stepped Distance
    • Line Differential and Phase Comparison
    • Coordinated Directional Ground Overcurrent
  • Bus Protection
    • High and Low Impedance Differential
    • Zone Interlocked Schemes
  • Medium Voltage Distribution System Protection
    • Overcurrent
    • Reclosers
    • Fuses
  • Generator Protection Systems
    • Current Differential
    • Current and Voltage Unbalance
    • Overcurrent, Transient and Steady State
    • Field and Rotor Protection Schemes
    • Thermal¬†Protection with RTDs and Rotor Resistance Modeling
    • Vibration Sensing
  • Transformer Protection Systems
    • Current Differential
    • Overcurrent/Overload
    • Sudden Pressure/Pressure Relief
  • Motor Protection Systems
    • Induction/Synchronous Machine Protection
    • Similar Protection Design to Generators
  • Low Voltage Protection
    • Phase and Ground Circuit Breaker Overcurrent Settings
    • Automatic Transfer Schemes
    • Bus Protecting with Zone Interlocking
    • Arc Flash Protection Schemes using Optical and Overcurrent Concepts
  • All Major Manufacturers of Relay Systems Supported
    • Schweitzer Engineering
    • General Electric
    • ABB/Westinghouse
    • Siemens
    • RFL
    • etc, see Links Page

System Analysis

  • Overcurrent Coordination for Transmission Line Ground Faults
  • Overcurrent Coordination for Low Voltage Breakers
  • Arc Flash and Employee Safety
  • Equipment Short Current Withstand Ratings
  • Load Flow/Equipment Steady State Ratings


  • Commissioning, Testing, Startup Procedure Write-up
  • Startup Testing with Advanced Test Equipment

Physical, Structural, Civil Design

  • Protective Relay Engineering consults and contracts with Salient Power Engineering ( for work related to physical, structural, and civil design.

Protective Relay Engineering, Inc.
7000 South Broadway, Suite 2C
Centennial, CO 80122
303-882-3686 (cell)