TOTUS G5 — online 5-gas DGA monitor plus moisture (photoacoustic spectroscopy) for critical transformers

Description

TOTUS G5 sits in the middle of the company's range of DGA monitors. It is installed on critical power transformers where a hydrogen sensor alone is no longer enough, but the full nine-gas profile is not yet required. Typical sites are transformers of distribution and transmission networks, power plants, and wind and solar farms. The monitor measures hydrogen, methane, ethylene, acetylene, carbon monoxide and oil moisture content around the clock.

Each gas points to its own group of faults. Hydrogen responds to almost any damage, methane and ethylene indicate thermal faults, acetylene indicates high-energy discharges and arcing, and carbon monoxide points to involvement of cellulose insulation. Measurement is carried out by photoacoustic spectroscopy (PAS), which the manufacturer describes as highly accurate and stable. Alarms are raised only when a real problem appears, so the maintenance schedule is built on condition rather than on the calendar.

The built-in software with a touchscreen shows trends right at the substation, without a laptop or a separate application. DGA results are also available remotely from any browser. For fleet-wide analysis the data is passed to the TOTUSPro software and the Sapient Asset Insights platform, where it is combined into a risk assessment. The interface is clear to operating staff, so the condition of the transformer can be assessed immediately during a substation round.

G5 is expanded with the same modules as the other TOTUS monitors. These are monitoring of partial discharges, bushings (BM) and through-fault currents (TFC), and analytical models, including thermal, moisture, load and insulation ageing models. They calculate the hot-spot temperature, overload capability and moisture in the paper insulation. The architecture and interface are common to the whole platform, so monitoring can be extended without replacing the monitor.

The company's case study collections describe how TOTUS DGA monitors work in utilities. One example concerns a 31.5 MVA transformer of a European distribution company. After the monitor was installed in December 2017, gas generation (H2) was noticed and oil crossover between the OLTC and the main tank was suspected. A repair was planned, and afterwards the same monitor confirmed that no new gases were being formed, and the transformer was left in service for longer. Another case, from an Italian transmission company, describes PD fluctuations of very high energy, above 20 V and above 80 nC, which the TOTUS monitor recorded in real time.

Technical specifications

Customs codes

Codes are for reference: the final code is determined at declaration for the specific model.

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