Knowing and understanding the condition of your power assets is vital in controlling the risks presented to your business, allowing your asset managers to plan and schedule your maintenance programme around actual asset condition rather than presumptions and set time intervals.
EA Technology’s Partial Discharge (PD) surveys are available worldwide, using our market-leading instruments. They are conducted by qualified personnel, who are expert at analysing the results to provide you with valuable reports on the condition of your assets. Our experts will provide you with an easy to understand, ‘traffic light’ status report which contains clear recommendations and guidance for managing your power assets based on their condition.
Put simply: Because 85% of disruptive substation failures are PD related. Once you have PD present, it will always increase and if left will inevitably cause a failure which may be sudden and catastrophic. PD is the most reliable indicator of the condition of insulation within live assets.
PD surveys can be carried out on indoor metal clad switchgear, outdoor switchyards and the cable termination boxes of transformers.
PD surveys can be delivered as part of a larger package of condition assessment measures, such as oil sampling of transformers for dissolved gas analysis purposes and trip profiling of circuit breakers.
Using instruments manufactured by EA Technology, we can detect partial discharge activity via the emissions of ultrasound, TEV and/or RF associated with the phenomena. This service provides a snapshot of an asset’s condition at a point in time, and has been used to great effect in reducing catastrophic failures and network outages by customers all over the world for more than 30 years. Our technical staff attend site and complete the survey on the desired part of your network. Later they will provide a detailed written report of the results, the conclusions that can be drawn and our recommendations on how to address issues or manage the assets.
Where issues have been identified during a handheld survey, where intermittent PD activity is suspected or if an asset is of a critical nature, the use of a monitoring system that is installed for a period of time may be advised. The UltraTEV Monitor™ continuously measures and records PD activity (both TEV and ultrasonic) and allows detailed analysis of the data. Ambient temperature and relative humidity are also recorded, as these can strongly influence the level of surface discharge activity if it is present. Finally, this method can also be used where there are high levels of radio frequency background interference (caused by variable speed drives, uninterruptable power supplies, etc.) to differentiate between noise and discharge.
We are also able to measure partial discharge directly by energising a component’s phase conductors using a low-current test supply and applying special test equipment. This testing can be carried out as part of commissioning of switchgear prior to the connection of cables, routine testing of busbars or as part of further investigation work following on-line detection or remedial work on switchgear.
We can also provide a custom solution to help in diagnosing a problem and provide advice on how best to proceed; this is often a combination of several of our products and services backed up by our experience in the management and operation of HV assets.