The development of the Electromagnetic Transients Program (EMTP), a general-purpose computer program for simulating high-speed transient effects in electric power systems, is briefly described. To illustrate the EMTP's capabilities, three examples of its use are presented. As part of the planning activities of the Athabasca Electric System in northern Saskatchewan, Canada, EMTP studies were done to provide recommendations on equipment characteristics and operating procedures for power line and transformer energization. These two studies were performed using the DCG/EPRI EMTP Version 1.0. The third application is to the 2000 MW high voltage direct current (HVDC) link between France and Great Britain. As part of a simulation exercise to check the protection settings and calculate the transient disturbances due to the switching-in of equipment or fault clearing near the station, the converter transformers were modeled using the EMTP saturated transformer model. Comparisons between the simulations and actual field tests are shown for the line energization and transformer switching transients studies. The accuracy of replication of the results is good. >

EMTP-a powerful tool for analyzing power system transients

The Electromagnetic Transients Program (EMTP) is a computer program for the simulation of electric power system transient phenomena. The program provides a large set of device models permitting accurate modeling of power system components over a wide frequency range. Traditionally, this program has existed only in mainframe and minicomputer environments, limiting its use to engineers and companies with access to these facilities. Recently, the EMTP has been made available for use on IBM and compatible personal computers using the IBM OS/2 and Microsoft Windows operating systems. >

Running EMTP on PCs (power systems)

Failures Related to Design and Material Selection

Electromagnetic transients are the tidal waves of electric power systems. These momentary voltage surges generally lasting only fractions of a second can be powerful enough to disrupt normal operations and even cause serious damage to major pieces of equipment, such as transformers. Created by lightning, line faults, substation switching functions, and other sudden events along a utility network, transients must be taken into account both in choosing equipment ratings for a power system and in setting its operating parameters. Like the builders of a seawall that must withstand the highest expected waves from the ocean, engineers trying to guard against damage from transients face an extraordinary design task. Most of the huge computer simulation codes related to power systems either model steady-state conditions or deal with system stability problems. The analysis of electromagnetic transients, on the other hand, requires a much more detailed examination of how some critical portion of a power system will react to conditions that can change greatly in microseconds. For many years, simulation of transient effects was performed by special-purpose analog computers called transient network analyzers (TNAs). These machines, which are still in use, recreate a portion of the power system in miniature, complete with voltage sources representing generators and various kinds of capacitive or inductive loads. TNAs are generally adequate but relatively inflexible, tedious to set up, and cumbersome to use. Once a system configuration is modeled, many simulations can be performed. Given the need to manually reconfigure TNA circuits to represent changes in a system, however, the analyzers can also be quite expensive to use. During the late 1960s, Herman Dommel of the Bonneville

J. Douglas

Papers

Designing for Disaster