As the world's transformer population ages and as the world's utility budgets tighten, there is an increasing need to extend the life of major assets. One such asset is the transformers. Their value is not only determined by their high cost of up front investment but also by the revenue lost when a transformer fails or is not used to its full potential.
In an effort to maximize the efficiency of their transformers, utility companies are turning to technologies that will allow them to continuously monitor various parameters. One important parameter is the continuous monitoring of dissolved fault gases contained in the insulating oil.
The monitoring of dissolved gases in oil has long been accepted as the best way of evaluating the overall health of a transformer. It is common practice for utility companies to regularly (one to two times per year) send oil samples of critical transformers to a specialized laboratory for a complete dissolved gas analysis (DGA) using gas chromatography.
DGA is still recognized as the best way to analyze the complete health of a transformer, however a DGA sample is only a snapshot of the health of the transformer for that particular time that the sample was drawn. Problems may occur, and most often do, between DGA tests. This threatens the life of the transformer as potential problems could go unnoticed until the next DGA test.
The Hydran technology allows for the continuous monitoring of dissolved gases in oil and monitors their evolution. Connecting easily to an existing valve on the transformer, the Hydran 201 instruments measure key fault gases dissolved in the oil and, for simplicity, displays the value as a composite PPM reading. This reading becomes the base line in which to measure the trend or evolution of dissolved gases between DGA testing. A rise in the composite PPM value warns utility personnel of increasing concentration of gases and warns them that a closer look at the transformer may be necessary. At this point an additional DGA test can be performed allowing for timely and well informed decisions. The transformer load can be reduced and scheduled service can be performed on the transformer, ultimately extending its life.
The Hydran technology has been commercially available for nearly 20 years and has evolved into a reliable and proven complementary tool to DGA testing. Able to withstand the harshest environments, it has become a utility industry standard and is currently being used by over 250 users worldwide. A list of users includes an assortment of major utilities, industrials and transformer manufacturers.
Developed by Syprotec Inc. of Pointe-Claire, Quebec, Hydran technology has proven itself to users as a reliable, cost saving investment, as early fault detection also allows for preventive maintenance, resulting in transformer life extension.
The Hydran 201i System is the newest generation of the Hydran 201R and can be retrofitted easily onto transformers to provide continuous monitoring. Unlike the Hydran 201R which is an analog device, the Hydran 201R model i, offers a fully digital system and allows for local and remote communications, networking, and digital processing of information. A portable unit is also available, the Hydran 103B, which allows frequent spot checking of less critical transformers.