Objectives

Grounding of power systems and equipment has great impact on system performance, system equipment integrity, safety of personnel as well as safety of the public at large. It acquires special relevance for distribution systems where grounding directly affects the reliability of supply to the customer, survivability of end-use equipment and safety of individuals. The main objectives of this course are

  • Discuss in detail the basic safety issues for low, medium and high voltage systems.
  • Designing a reliable grounding system.
  • Discuss the safety management and organizational Structure and the human factor the affect electric safety

Content

No. Of Weeks Topics Sub-Topics
1 Hazardous of Electricity & Electrical Safety Equipment
  • Electric Shocks, Affected Body Parts, Summary of Causes-Injuries and Death, Flash and Thermal Protection, Safety Grounding Equipment
1 Safety Procedure and Methods
  • The Six Step-Safety Methods, Safe Switching of Power Systems
  • Energy Control Program, Placement of safety Grounds
  • Flash Hazard Calculations and Approach Distances
  • Tool and Test Equipment
1 Transmission Line Modeling
  • Line Inductance, Resistance, Capacitance
1 Power System Grounding: Modeling Techniques
  • Analysis of Simple Grounding Systems
  • Body Currents Due to Touch and Step Voltages
  • Grounding System safety Assessment
  • Equivalent Circuit Representation of Grounding Systems
  • Parametric Analysis of Substation Ground Mats
1 Transmission Line Analysis
  • The General Transmission Line Model
  • Modal decomposition, Equivalent Circuit, Transmission Line Power Equations
1 Power System Fault Analysis
  • Sequence Models of Three Phase Apparatus
  • Fault Analysis Based on Sequence Models
  • Ground Potential Rise During Faults
  • Fault Current Distribution Based on Sequence Models
  • Direct Phase Analysis
  • Transfer Voltage During Faults
1 Power System Ground: Design Procedure
  • Problem Formulation, Determination of Soil Model
  • Computation of Ground Resistances, Maximum Ground Potential Rise
  • Investigation of Touch and Step Voltages, Safety Assessment
  • Mitigation of Touch and Step Voltages, Design Examples
1 Regulatory and Legal Safety Requirement and Standards
  • The regulatory Bodies, The National Electric Safety Code (NESC)
  • The National Electrical Code (NEC) - ANSI/ NFPA 70
  • Electrical Equipment Maintenance (ANSI/NFPA 70B)
  • Electric Safety Requirements for Employee Workplaces ANSI/NFPA 70 E
  • Occupational Safety and Health Administration (OSHA) Standards
1 Low Voltage Safety Synopsis
  • Low Voltage Equipment, Grounding Low Voltage Systems
  • Safety Equipment and Procedures
  • Electric Safety Around Electronic Circuits, Stationary Battery Safety
1 Medium and high Voltage Safety Synopsis
  • High Voltage Equipment Grounding Systems of Over 1000 V
  • Safety Equipment and Procedures
1 Human Factors in Electrical safety
  • Mythic Beliefs
  • Human Factors: Vision, Hearing, Reaction times
1 Safety Management and Organizational Structure
  • Electric Safety Program Structure
  • Electric Safety Program Development
  • Employee Electric Safety Teams, Safety Meetings

Recommended text

A.P. Sakis Meliopoulos, Power System Grounding and Transients, An Introduction, Marcel Dekker Inc., ISBN 0-8247-7908-8, 1988

Other references

  1. John Cadick, Mary Capelli-Schellpfeffer, Dennis K. NeitzelElectrical Safety Handbook, McGraw-Hill Professional, ISBN 0-07-012071-4, 2000
  2. IEEE Std. 142- 1991, IEEE Recommended Practice for Grounding of Industrial and Commercial Power Systems (IEEE Green Book).
  3. ANSI/IEEE Std. 80-2000, IEEE Guide for Safety in AC Substation Grounding
  4. ANSI/IEEE Std. C62-92.2-1989, IEEE Guide for the Application of Neutral Grounding in Electrical Utility Systems: Part II- Grounding of Synchronous Generator Systems
  5. ANSI/IEEE Std. C62-92.5-19921, IEEE Guide for the Application of Neutral Grounding in Electrical Utility Systems Part V- Transmission Systems and Subtransmission Systems
  6. IEEE Std. 367-1996, IEEE Recommended Practice for Determining the Electric Power Substation Ground Potential Rise and Induced Voltage from a Power Fault.
  7. Electric Power Research Institute (EPRI), Analysis Techniques for Power Substation Grounding Systems Volume 1: Design Methodology and tests, EPRI Publication, Palo Alto, California, 1982.
  8. V. Manoilov, Fundamentals of Electrical Safety, MIR Publication Moscow, 1975.

Requisites

Basic knowledge of power systems analysis is required.