The numbers don't lie; the current state of monitoring transformer assets is a recipe for disaster.
Research shows that up to 75 percent of power transformers in the US are more than 25 years old, and much of the electricity grid is relying on 45-year-old transformers that were designed to survive 40 years. Electricity demand in the US is expected to increase 19 percent during the next 10 years, but resources needed for this demand will only increase some 6 percent. This means the existing, aged transformer fleet is going to be stressed further, and transformer failures are expected to increase 500 percent during the next 15 years.
In summary, the grid is relying on too many transformers that have aged past their originally intended lifecycles, and those transformers will only be pushed harder. Considering the move towards the smart grid, this is the worst time for this perfect storm of potential transformer failures.
One of the most proven-albeit imperfect-methods to determine when a transformer is starting to fail is dissolved gas analysis (DGA). Performing DGA on transformers and load tap changers (LTCs) is common practice globally and cited in many standards with specific action levels dependent on gas concentrations found in the dissolved oil of transformers and LTCs. For years, this analysis has been performed by taking samples of the transformer and LTC oil in the field for lab analysis. Unfortunately, this is typically done once or twice a year and can take up to two weeks for results. Much can happen between samples. And, if an abnormality is found with the oil sample, this would require many samples be taken in a shorter time period, which drains manpower resources and can become expensive.
Some 20 years ago, efforts were made to take DGA analysis online and attach them to transformers. This technique was slowly adopted, but has proven to be a supplemental technique many utilities use globally to gain additional information about their transformers performance and behavior. This analysis method is typically placed on larger power transformers because of their criticality and because of the cost of the monitors. In addition, there are high costs associated with the installation and maintenance of these monitors that, along with questions about the reliability and accuracy of the monitors, have proven barriers to wide-scale adoption of this method across transformer fleets and into the grid's distribution segment. As a result, less than 5 percent of transformers globally have online DGA monitoring.
So what can be done to increase this adoption rate? The industry's newest line of online DGA monitors plans to address this issue by using a well-known gas monitoring technology that has been used for decades in other industries: non-dispersive infrared (NDIR).
Drawing from more than 40 years of gas-sensing expertise and utility market knowledge, LumaSense Technologies recently launched its SmartDGA line of online monitors. The company has provided more than 400,000 NDIR instruments for applications such as automotive exhaust monitoring, environmental monitoring and anesthesia monitoring. Leveraging knowledge gained from supplying NDIR instruments to these industries and from supplying to industrial and semiconductor customers, LumaSense has developed a compact and easy-to-install DGA monitoring line that is half the cost of others.
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