Dissolved gas analysis in transformer oil is an important means of detecting latent internal faults. Periodic sampling testing is limited by the testing cycle and makes it difficult to capture sudden gas increases; online monitoring devices can continuously collect data and reflect gas content change trends. The DRD-7700 is suitable for operating condition monitoring of power transformers of 110kV and above and high-voltage shunt reactors of 330kV and above, providing continuous monitoring data for O&M personnel to assist in judging equipment status. Online data and laboratory test results complement each other, and O&M personnel can arrange sampling verification based on trend changes.
The device monitors components such as hydrogen, carbon monoxide, methane, ethane, ethylene, and acetylene in dissolved gases, with a measurement range covering 0 to 1000 ppm (slight differences among components), and the lower detection limit meets the monitoring needs for early fault characteristic gases. O&M personnel can pay attention to the growth rates of key components such as acetylene and hydrogen, and make comprehensive judgments in combination with load and ambient temperature.
The device is designed for an operating ambient temperature of -40°C to +70°C, adapting to outdoor temperature conditions in substations. During installation, the oil sampling pipeline must be connected from the oil sample interface on the transformer body to ensure oil circuit sealing and smooth oil return. The device supports local data storage and remote communication, and O&M personnel can view real-time data and historical curves through the station network or background system.
It is recommended to regularly check carrier gas pressure, oil circuit flow, and sensor status, and perform standard gas calibration according to the manufacturer's recommended cycle. When online data shows abnormal growth or a large deviation from laboratory test results, check whether the oil sampling pipeline leaks and whether the oil sample is representative, and if necessary, take samples for verification. The device provides an alarm threshold setting function, and O&M personnel can configure attention values according to regulatory requirements.
Periodic sampling testing requires less manpower, but the data interval is long; online monitoring can continuously record changes in gas content and is suitable for state trend tracking of important transformers. Used together, the two help O&M personnel keep abreast of equipment status and reasonably arrange maintenance plans.
