Search

Pre-insertion resistor (PIR) is an important component of circuit breaker. The healthiness of the circuit breaker (CB) depends upon that of PIR contact. With the increasing demand of uninterrupted power supply, failure in major equipment like CB may incur huge loss to the utility. The existing study reveals that mechanical failures are more dominant than other types of failures. Thus, many industries prefer to undertake preventive maintenance of equipment rather than break down maintenance. This paper describes the actual problem detected in PIR contact of North Eastern Regional Transmission System, having a 400 kV, 3000 A, SF6 CB through testing and rectification thereafter. The results obtained from the graph helped in detecting mechanical dis-alignment of the connecting link in the link arm and the tubular contact of the PIR. Furthermore, a model has been developed to show the possible threat that would have occurred, had the problem been not rectified. This paper will help the utilities to emphasize on detecting the problem by undergoing preventive maintenance and thereby saving unprecedented failure of equipment. [ABSTRACT FROM AUTHOR]

Traditional switchgear current measurement techniques use closed-loop current modules to accurately measure and control current, and in switchgear, there is also interphase interference, these modules usually require a large core that surrounds the entire busbar as well as a shielded shell, because the compensation current generated inside the module is proportional to the busbar current, so the power consumption can be as high as several watts. In view of this, this paper proposes a magnetic sensor-based switch cabinet busbar current measurement method, and through theoretical deduction, it is determined that the magnetic sensor with two magnetic sensitive directions opposite and vertically placed in the busbar can eliminate the interference from the busbar phase and the stray field. Through simulation analysis, it was determined that the opening hole of the switch cabinet bus row was a circular hole, and the placement of the two magnetic sensors was at the edge of the circular hole, so that the practical application of the method in the switch cabinet had certain guiding significance. [ABSTRACT FROM AUTHOR]