US 11,728,641 B2
System and method for controlling and monitoring parallel surge arresters and bushings of a power transformer and motor
Adel F. Abu-Rejailah, Dammam (SA); and Thamer K. Al-Harbi, Dhahran (SA)
Assigned to SAUDI ARABIAN OIL COMPANY, Dhahran (SA)
Filed by Saudi Arabian Oil Company, Dhahran (SA)
Filed on Jan. 10, 2022, as Appl. No. 17/572,192.
Prior Publication US 2023/0223748 A1, Jul. 13, 2023
Int. Cl. H02H 9/04 (2006.01); H02H 1/00 (2006.01)
CPC H02H 9/04 (2013.01) [H02H 1/0007 (2013.01)] 16 Claims
OG exemplary drawing
 
1. An over-voltage protection system for protecting electrical equipment from over-voltage transients from a power source, the system comprising:
a protection circuit comprising:
a first electrical bus, wherein the first electrical bus is energized by the power source;
a second electrical bus configured to feed power to the electrical equipment;
a first surge arrester and a second surge arrester arranged in parallel, the first surge arrester having one end electrically connected to the first electrical bus via first normally closed contact and having an opposite end connected to ground, the second surge arrester having one end electrically connected to the first electrical bus via a second normally closed contact and having and an opposite end connected to ground;
a main bushing and a backup bushing, wherein the main bushing is connected between the first electrical bus and the second electrical bus by a third normally closed contact, wherein the backup bushing is connected between the first electrical bus and the second electrical bus by a first normally open contact, wherein the first normally open contact is provided in series with the backup bushing and configured to isolate the backup bushing from at least one of the first electrical bus and the second electrical bus while in an open state and is configured to electrically connect the backup bushing to the one or more of the first electrical bus and the second electrical bus when in a closed state; and
a controller configured to selectively open or close one or more of the first normally closed contact, the second normally closed contact, the third normally closed contact, and the first normally open contact, and wherein the controller is configured to:
selectively isolate the first surge arrester and thereby remove it from service in the protection circuit by opening the first normally closed contact,
selectively isolate the second surge arrester and thereby remove it from service in the protection circuit by opening the second normally closed contact,
selectively isolate the main bushing and thereby remove it from service in the protection circuit by opening the third normally closed contact, and
selectively place the backup bushing into service in the protection circuit by closing the first normally open contact thereby electrically connecting the backup bushing to the first electrical bus and the second electrical bus.