Partial Discharge Services
Electrical systems are among the most valuable assets in your plant and can have the biggest impact on your bottom line. Their production and management cost is high and failures almost always lead to catastrophic losses. Electrical systems are being operated at higher levels, even while systems are aging – which affects both the life and the reliability of assets.
Today’s Asset Managers are facing the increased challenge of maximizing their aging electrical infrastructure with fewer qualified technical in-house resources, stricter regulatory requirements for worker safety, and shrinking maintenance budgets. Advances in technology, including the use of Partial Discharge Testing, are giving Asset Managers new approaches to achieve improved reliability and performance of critical electrical assets.
Partial Discharge types include:
- Void in solid insulation
- Cavity in liquid
- Electrical tree (void) around a sharp point
- Electrical floating potential
- Surface discharge
- Corona
Online Partial Discharge Testing
Online testing is performed while the equipment is energised at normal operating voltages. The testing is conducted during real operating conditions, under typical temperature, voltage stresses, and vibration levels. It is a non-destructive test (NDT) and does not use over voltages that could adversely affect the equipment. Online Partial Discharge Testing is relatively inexpensive compared to offline testing that requires interruption of service and production. For critical facilities that operate 24/7, this is the best solution for identifying insulation condition.
The Benefits of On-Line Partial Discharge Field Measurements
- It is truly a predictive test, indicating insulation degradation in advance of the failure
- It is a non-intrusive test, requiring no interruption of service and is performed under normal operating voltage and load
- It is a non-destructive test: it does not test to failure or adversely affect the equipment under test
- It need not use any overvoltage, thereby not exposing the tested equipment to higher voltage stresses than those encountered under normal operating conditions
- Trending can be accomplished by storing results to allow comparison with future tests
- In many instances the site of partial discharge occurrence can be located within the test object, so that the localised problem can be repaired
- The cost to perform a PD survey is relatively inexpensive compared with off-line testing, allowing annual surveys to be performed economically at most facilities.