What Is Partial Discharge?

Posted by adairsawyer on August 28th, 2011

The term ‘partial discharge’ might seem to denote a particularly complex concept that would be difficult for a layperson to understand, but it really is a relatively simple concept to grasp. Partial discharge is really an electrical phenomenon that takes place where there are pieces of high voltage equipment covered by insulating materials that have developed small flaws or imperfections. These imperfections manifest themselves in the form of small cracks or gaps in the insulating material, and the term partial discharge refers to the movement of electricity across that gap, from one point on the insulating material to another. The question of what is partial discharge is thus relatively easy to answer. What is partial discharge also differs between different equipment such as motors generators cables switchgear transformer and other types of high voltage equipment.

Another way of answering the question of what is partial discharge could be through the symptoms or consequences of a partial discharge. When a partial discharge develops in the insulation of a particular piece of high voltage equipment and electricity is released, it causes certain symptoms that can be detected. These symptoms can be used first to determine that there is, in fact, partial discharge taking place and also to pinpoint exactly where on a piece of equipment that partial discharge is taking place.

From a business perspective, it is not sufficient merely to ask the question of what is partial discharge, but once that question has been answered, it is necessary to ask the question of what can be done about partial discharge. Partial discharge is a sign that the insulation on a particular piece of equipment has deteriorated and should be taken as a warning of more serious things to come. Once partial discharge has been detected, it is of the utmost importance that the equipment be inspected for faults and flaws and maintenance work be carried out immediately. The effects of insulation failure vary widely from one case to the next, but in the worst case scenario, it could result in a fire or even an explosion, causing damage to property and even human injury.

The next question should then be, what is partial discharge monitoring? This is the next step in the logical progression of approaching the subject of partial discharge. Motors generators cables switchgear transformers and other high voltage equipment place a large amount of strain on their insulators because of the high levels of electricity flowing through them. It is therefore not surprising that insulation failure is a relatively common occurrence and it is not uncommon for companies to lose a great deal of money in terms of revenue due to such occurrences.

With modern technology, however, partial discharge monitoring systems have been developed that allow for continuous monitoring of electrical equipment to determine if, and when, partial discharge occurs. Once partial discharge is detected, the exact source and location of the partial discharge can be pinpointed and repairs carried out or, if necessary, the piece of equipment scrapped and a replacement brought in.

With motors generators cables switchgear transformer and other high voltage equipment placing such a big strain on their insulation materials, it is no wonder that the question ‘What is partial discharge’ is one often asked by operations managers facing this problem. Dynamic Ratings provides the answer in the form of monitoring systems that allows for early detection and identification of partial discharges, safeguarding the safety of your operation and playing a key role in warding off catastrophic accidents.