PowerPAC™: Acoustic Emission Testing Technology Packages
PowerPAC™ is a Technology Package for detecting, locating and assessing not only partial discharge in power transformers but also thermal faults by utilizing Acoustic Emission technology. Transformers are instrumented with AE sensors covering both the tank and the LTC compartment (if one is present).
In addition, other sensors (used to monitor pump current, fan current, load current, tank wall temperature and LTC compartment wall temperature) are used to collect data for comparison with the AE data during post test data analysis. Data is collected over a period of 24 hours in order to observe the effects of a complete load cycle. Results are presented showing the location (three dimensional or zonal) and types of faults.
Developed under an EPRI sponsored Tailored Collaboration (Project I.D. No. 051481), this technology package includes:
• Hardware and Software. The system in based on the Physical Acoustics Corporation (PAC) model DiSP, digital AE instrument. It operates using application specific software designed for data acquisition during field testing of power transformer and has several utilities for post test analysis and interpretation such as automatic filtering of normal operating noise and determination of synchronicity with the system voltage. Key features of this software is its ability to perform three dimensional source location and a database and grading system used to evaluate each fault and to provide a combined grading of the transformer that can be used for maintenance prioritizing.
• Classroom and On the Job Training. Training on Acoustic Emission Basics, use of PowerPAC software as well as data acquisition in the field is provided. The training follows the latest test procedure introduced in the EPRI Tailored Collaboration project and refined throughout two Phases of program development in which several hundred tests were performed.
• EPRI Reports and Publications. The EPRI reports of Phases I, II & III of this Technology Package development are included as well as any PAC publication available.