Switching Surge Voltage Research Articles

Transmission line switching surges

RECENT IMPROVEMENTS in arrester impulse protective levels have permitted the application of power apparatus having insulation reduced two voltage classes on well-grounded systems where 75% or 80% arresters can be applied. Although the insulation of such apparatus can be adequately protected against impulse voltages, the adequacy of lightning arresters to protect the reduced insulation against switching surges is not so well established. Some of the areas receiving increased attention by the electrical industry are: 1. Determination of magnitude, wave shape, and duration of switching surge voltages. 2. Establishment of the insulation strength of apparatus subject to switching surge voltages. 3. Determination of the duty that arresters will be subjected to in providing protection for apparatus when exposed to excessive switching surge voltages.

Switching surge voltages in high-voltage stations

SWITCHING SURGES, lightning surges, and 60-cycle voltages are, in general, the three types of voltages involved in the design and protection of insulation of stations and station equipment. Under switching surges may be classified various groups dependent upon the manner of initiation, the circuit parameters involved, and the circuit configuration. Of the numerous kinds of transient abnormal voltages caused by switching, the type receiving primary consideration in line and station insulation design has been that resulting from circuit breaker performance in the interruption of charging kva such as occurs in line or cable dropping or in switching a capacitor bank.

Switching Surge Voltages in High-Voltage Stations [includes discussion

SWITCHING SURGES, lightning surges, and 60-cycle voltages are, in general, the three types of voltages involved in the design and protection of insulation of stations and station equipment. Under switching surges may be classified various groups dependent upon the manner of initiation, the circuit parameters involved, and the circuit configuration. Of the numerous kinds of transient abnormal voltages caused by switching, the type receiving primary consideration in line and station insulation design has been that resulting from circuit breaker performance in the interruption of charging kva such as occurs in line or cable dropping or in switching a capacitor bank.

Control of the switching surge voltages produced by the current-limiting power fuse

Control of the switching surge voltages produced by the current-limiting power fuse

Control of the Switching Surge Voltages Produced by the Current-Limiting Power Fuse

A new transient condition unique to fuses of the current-limiting type is described and it is recommended that these fuses be designed to inherently control switching surge voltage magnitudes to meet the following conditions: 1. The transient recovery voltage should not exceed the insulation level of rotating machines √2(2E+1,000) where E is the rated terminal-to- terminal rms voltage of the lowest rated machine involved. 2. The transient recovery voltage should preferably not exceed the 60-cycle crest spark-over voltage of associated lightning arresters. 3. If the transient recovery voltage does exceed the 60-cycle crest spark-over voltage of associated arresters, the interrupting rating of the fuse should be determined and assigned to limit the arrester current to a safe magnitude.

Control of the switching surge voltages produced by the current-limiting power fuse

Control of the switching surge voltages produced by the current-limiting power fuse