Evaluating, Quantifying, and Reducing the Capacitive Effect of an Existing AC Mitigation System Utilizing Advanced Modeling Techniques

Abstract An evaluation of the capacitive effect of solid-state decouplers (SSDs) was completed on a transmission pipeline in the Midwest region of the United States. The existing alternating current (AC) mitigation system was comprised of 95 SSDs and approximately 33,000 ft (10058.4 m) of electrode installed along 14 mi (22.5308 km) of multi-pipeline right-of-way (ROW). The cumulative capacitive effect of the existing system required any indirect survey to be performed on a severely elongated interruption cycle to obtain accurate IR-free potentials, resulting in a significant increase in survey cost and reduced efficiency. Computer modeling was used to better understand the effect of multiple variables on the system’s capacitance. The results were analyzed using a multiple regression model; existing assets and survey data were reviewed, and opportunities were identified to reduce the number of decoupling devices required to adequately protect the system. The remaining devices were ranked for replacement to a newer model of SSD that masks its capacitive effect. This paper will discuss the approach to the study, results, and future work to be completed.