Transformers and Tap Changers (OLTC’s)
Online Monitoring of Power Transformers with AE SENSOR HIGHWAY II™
Introduction and Overview The Sensor Highway System™ is an Acoustic Emission (AE) Monitoring System with up to 16 high-speed monitoring channels and 4 parametric input channels. The Sensor Highway II™ has been developed for unattended use in “Asset Integrity Monitoring” management and condition monitoring applications. The system consists of a 16 channel unit (node) in…
Intranet/Internet Remote Monitoring Software & Systems
Acoustic emission has been proven to be a highly effective method for on-line plant asset management for critical status monitoring of materials, structures and processes. Increasing demands for on-line plant asset management mandates the use of Intranet (LAN) or Internet condition monitoring. Physical Acoustics Corporation has pioneered the acoustic emission remote monitoring market with the early introduction of…
Bus Bar Fault Case Study 02-5-2002
Generator Step Up (GSU) Transformer, 25/500 kV, 784 MVA, FOA, Westinghouse, three phase, two pumps groups, shell form. This unit started gassing the last month of 2001 after being in service for more than 20 years. Dissolved Gas Analysis (DGA) indicated the existence of overheating by all seven methods applied. The gas generation rate increased…
Autotransformer Core Degradation Case Study 5-01-2005
In 2003, a bank of three single-phase autotransformers,500/230/13.8 kV, OA/FA/ FA class, 146/194/243 MVA capacity, core type, was installed in a substation on the East Coast of the United States. These transformers replaced three single-phase unitsthat were in operation since1965. Thermal faults were detected on those units usinga combination of Dissolved GasAnalysis and Acoustic…
Fault Detection On-Line Monitoring
Transformer On-line monitoring Case Study 206 2006 October 2006 – April 2007 3 phase, 300/336 MVA, 230/100/44 kV FOA Class This transformer exhibited periodic sudden increases of combustible gases. The unit was tested acoustically in June 2006, two areas of acoustic activity detected A DGA was performed using a portable gas chromatograph DGA indicated a…
Services & Products for Power Transformers
MISTRAS Group Inc., has been a leader in the evaluation of Power Transformers for over 20 years. Over the years, we have developed state of the art instrumentationand successful test procedures to help maintenance engineers make decisions based on the actual condition of equipment. Field Testing of Power Transformers We have been continuously improving our…
Acoustic Emission Diagnostic and Monitoring of Power Transformers
Power transformers account for the largest portion of capital investment in transmission and distribution substations. Failure of a single power transformer carries a multimillion-dollar impact with a build or replacement timeline of18-24 months. Yet 53 percent of transformer failures are preventable. But what if there was a way to protect that substantial investment while safeguarding…
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…