Short Course on

Induction Voltage from Power Lines

Mohamed A El-Sharkawi

Department of Electrical Engineering

University of Washington

Seattle, WA 98195

Course Description

Power lines induce voltages on nearby structures such as de-energized transmission lines, buildings, railroads, pipelines and communication lines. This induced voltage can create hazards of electric shocks, arcing and even fire or explosions.

The assessment of the hazards due to induction is probably one of the misunderstood phenomenon in power systems. It is often overlooked leading to severe consequences. Hazardous working environments can be present if workers are not fully aware of the electromagnetic field effect on induction voltage.

With the full knowledge of the electromagnetic induction, utilities can acquire acceptable right-of-way for their power lines, industries and commercial buildings can allocate their business at sufficient distances from the power lines, housing projects can determine the height of their buildings, and utilities can decide on the separation of their pipelines and railroads from power lines.

The course will provide the technical information needed to assess the hazards of sharing the right-of-way with utility lines as well as the  worksite hazards for power line work. The course will also deal with mitigation techniques to reduce the hazards of induction voltage.

This course is intended to provide the knowledge needed to compute the induced voltages due to the electromagnetic fields of energized lines. The computation is simplified without loss in accuracy so it can be implemented by using handheld calculators.

Who should attend?

Electric power engineers

Engineers in the railroads and pipelines companies

Non-power Engineers who are working in the power field

Field engineers

Construction engineers and developers

Managers of utility companies

Topics Covers

· Electromagnetic Phenomenon

Electric Field

Magnetic field

Definition of induction voltage

Safety codes

· Electric field

Charge

Equipotential Surface

Ground effect

Induced voltage due to nearby energized conductor

Step by step techniques to perform quick and accurate computation of induced voltage due to electric field.

Test cases and examples

Mitigation techniques

· Magnetic field

Flux and flux linkage

Ground effect

Induced voltage due to nearby energized conductor

Step by step techniques to perform quick and accurate computation of induced voltage due to magnetic field.

Test cases and examples

Mitigation techniques

· Aggregated induced voltage due to electromagnetic field

Step by step techniques to perform quick and accurate computation of induced voltage due to electromagnetic fields

· Electric field under power lines and within the right-of-way

Step by step techniques to perform quick and accurate computation of electric field strength anywhere near the power lines

Electric field profile

Allowable limits of electric field strength

Standards and Guidelines

Computation of the Minimum Vertical Clearance, National Electrical Safety Code

Measurements of electric field strength

Test cases and examples

mitigation techniques

· Pipelines, Railroads and Communication Cables

Induced voltage due to electric field coupling

Induced voltage due to magnetic field coupling

Induced voltage due to electrical conductance

Insulated versus bare metal

Over versus under ground metals

Test cases and examples

Mitigation techniques