On-Load Tap Changer Health Assessments: A Dynamic Approach to Preventive Maintenance

摘要

In January 2010, LCRA TSC Asset Performance and Reliability (APR) developed a health-assessment program for LCRA's on-load tap changers (LTCs) for transmission and distribution voltage regulation. Each LTC is assigned a score on a 100-point scale, based on an educated and objective evaluation of various factors. These factors, including operations history, maintenance history, age, internal condition, and LTC type, are weighted according to their importance in determining equipment health. The weight of each factor is kept constant when assessing each LTC, and a comparison of health scores is made across the entire fleet of LTCs. This approach allows LCRA to center preventive maintenance efforts on those LTCs which fall in the caution zone. An LTC whose overall health is determined to be exemplary may qualify for deferred preventive maintenance. Under the current program, LCRA deferred maintenance on six LTCs (50% of those due for preventive maintenance) in 2010. This dynamic approach to preventive maintenance saves valuable time and O&M costs, and provides LCRA's maintenance engineers with broad knowledge on the health of a vital fleet of equipment.