Experiences with condition monitoring of HV circuit breakers

ABB's condition monitoring units (CMU) have been installed for several years and valuable field experience has been gathered in cooperation with customers such as Allegheny Power. Allegheny Power's 500 kV network is comprised of 76 breakers, 45 of which are ABB Type PM breakers. In 1996, Allegheny committed to the CMU breaker monitoring package by including it on all future 500 kV circuit breaker orders. As a result, Allegheny Power has 29-500 kV breakers with CMU installations. The CMU has proven to be an effective tool in Allegheny Power's move towards a condition-based maintenance program for substation equipment. The CMU has undergone significant improvements that were based on this type of field experience. These improvements address hardware reliability, sensor accuracy, algorithm functionality, user-friendliness and practicality. This paper presents the on-line condition monitoring strategy of Allegheny Power and describes the field experiences and resulting enhancements to the CMU.