ECE 5334 - Transients in Power Systems

Course Description

Wave propagation, wave propagation on multiconductor systems, lightning phenomena, grounding for protection against lightning, direct lightning strokes to overhead lines without and with shield wires, fundamental concepts of switching transients, switching surge phenomena, system performance under switching surges, dynamic overvoltages, performance of power apparatus under transient voltages, surge arresters, insulation coordination, electromagnetic transient programs (EMTP).

Why take this course?

Transients are resulted from interactions between the magnetic fields of inductances and the electric fields of capacitances in the system. Transients in power systems result in overvoltages, and although the transient period is usually very short, these transients are extremely important since, at such times, the power system components are subjected to the greatest stresses. This may disable a machine, shut down a plant, or blackout a city, depending upon the circuit involved. Transients in power systems are generated by lightning and switching surges. Modern theories of the generation, propagation, and interaction of transients with power systems are taught in this course. It also covers practices for the protection of power system components against transients. Electromagnetic transient program (EMTP), the software tools used to analyze transients and associated insulation issues, is also taught.

Transient models of transmission lines, cables, transformers, and electric machines developed in EMTP are presented in detail. Accurate knowledge of electromagnetic power system transients is crucial to the operation of an economic, efficient, and environmentally-friendly power system network, without compromising the reliability and quality of the electrical power supply. This course supports and complements the available graduate study courses in Power Systems offered at Virginia Tech. Models of electric machinery, transmission lines, transformers and other components are necessary to conduct advanced research in power systems and to understand the results provided by advanced simulation packages such as the EMTP available today to the power industry.

Learning Objectives

• Apply traveling wave theory and Lattice diagram to obtain transient voltages and currents at transition points
• Implement Modal Analysis for multiconductor systems
• Analyze switching transients to obtain transient recovery voltage across circuit breakers and transient voltages across power system apparatus
• Analyze transient voltages by discrete-time models of power system apparatus and nodal equations
• Analyze electromagnetic transients by Electromagnetic Transients Programs (EMTP)
• Apply Geometric Model to determine the number and location of shield wires
• Evaluate and formulate steady-state and dynamic tower-footing resistances
• Analyze direct lightning strokes to overhead lines without and with shield wires
•  Assess and analyze transient behavior of transformers and reactors
• Determine characteristics of surge arresters for insulation coordination