How Smart Monitoring Safeguards Heavy-Duty Power Transformers
Heavy-duty power transformers are the most valuable assets of an electrical infrastructure. A single failure can cause a business several months behind, millions of dollars in repairs and lost revenue as well as a major safety and environmental hazard. The traditional protection was founded on manual checks carried out at intervals and on simple relays a reactive model that identifies the failures when they are too late and cause harm. This paradigm is changed by modern monitoring because now predictive maintenance can be conducted in order to identify which failures are likely to occur, and how to avoid them. To deliver the intelligence that the new utility and industry environment demands to protect the most valuable assets on the grid, Jiangsu Ryan Electric has developed excellent monitoring capabilities into our power transformers to 132kV.
Real-Time Thermal Monitoring for Dynamic Loading
Temperature is the most important indicator of the health of the transformer. Every 6°C to 10°C rise higher than rated temperature doubles the rate at which the insulation ages, a direct factor in determining the life of the transformer. The standard best-oil thermometers can provide only an approximate idea of the actual conditions, not taking into consideration the hot spots that do influence the life of the insulation.
The smart monitoring solutions designed by Ryan Electric possess fiber optic sensors which are incorporated in windings during manufacturing. These sensors will provide real-time temperature indicators in the most intensively insulated regions, the hot spots of the windings. This information combined with our newer thermal models that have been tested in our laboratories enable the calculation of dynamic loading that maximizes transformer utilization without compromising their life cycle. Here, in the example of using renewable energy where the output is variable, this can be construed as production as much energy as can be obtained when production is at its highest point, and there should never be a thermal limit to production. With respect to utility, it may provide operators with the confidence to operate transformers to their true capacity, not estimations, and one way to defer capital expenditure without impairing the safety margin.
Dissolved Gas Analysis: The Early Warning System
When the transformers themselves begin to malfunction internally, be it through overheating or discharge or arcing, insulating oil begins to break down. Hydrogen, arcing of high-energy, acetylene, and grave overheating all indicate the corona discharge. Dissolved gas analysis (DGA), the gold standard in transformer diagnostics is time-consuming to run with a manual sample and requires days or weeks before it becomes available.
DGA is administered online in real time and smartly monitored. In our liquid immersed transformers, Jiangsu Ryan Electric uses multi-gas sensors that monitor the presence of large fault gases and moisture content on a continuous basis. These systems will also report to utility control rooms to give real time information when the quantity of gas in circulation is too large or when the rates of generation vary rapidly- typically the fastest method of realizing that something has gone wrong. In the example of critical systems like data centers or industrial complexes, this real time visibility would enable the operator to plan the maintenance to take place during the planned down time and prevent unexpected breakdowns. The problem at the least repairable point is identified by the trending functionality of the system over time that reveals slow and steady worsening of the system that would otherwise not be detected in periodic samples.
Partial Discharge Detection for Insulation Integrity
Partial discharge (PD) the little electrical sparks within insulation gaps is the silent murderer of high-voltage transformers. Unchecked, PD will peel away insulation in a corrosive manner until catastrophic collapse occurs. In conventional offline testing of PD, the transformer must be placed offline, and this is during the period when PD activity is load and temperature dependent.
Ryan Electric smart monitoring solutions also feature permanent partial discharge sensors that are operational at all times when using the transformer. The typical PD activity signatures are hunted down by such ultra-high frequency (UHF) and acoustic sensors that normal external noise is assumed to be decoupled and regarded as perilous internal discharges. Our systems detect arising insulation problems only months or years before they cause a failure by relating PD activity to load, temperature, and other operating conditions. This PD monitoring provides the same protection as conventional liquid-filled units, and is available in data centers, or other business buildings, where the fire risk of oil-filled transformers is too great to tolerate the use of a liquid-filled unit, and where the desired level of protection is sufficiently reliable to meet the demands of a mission-critical facility.
Integrated Asset Management and Predictive Analytics
The data can be interesting in situations where individual sensors are employed, but when it is aggregated, processed and transformed into actionable intelligence, the real potential of smart monitoring unfolds. The Ryan Electric monitoring platforms integrate temperature sensors, DGA detectors, PD detectors, load tap changers and cooling systems to provide an overall view of transformer health.
Advanced analytics is a means of juxtaposing the current operating parameters with the previous data and database of failures in the industry and indicating patterns that give hints of mode of failure that is about to occur. The machine learning algorithm continually improves predictive capabilities, because it is more prone to ignore those nuanced influences that the human operators might miss. This integrated view gives utility engineers with geographically dispersed fleets of transformers the capability to implement risk-based asset management, such as investing in maintenance where they provide the greatest increases in reliability, postponing treatment on healthy units, and extending the service life of the entire transformer population. Ryan Electric is equipped with both IEEE and IEC certification and country in addition to being tested by our CNAS-accredited laboratories and the smart monitoring solutions can provide the intelligence needed to safeguard heavy-duty power transformers in end-users like Microsoft data centers via national utility companies in more than 50 countries.
