GMP Periscope-Enhanced Dissolved Gases and Moisture in Insulating Oil Sensor

Product Information

Monitoring the presence and evolution of gases dissolved in insulating oil of high voltage equipment such as power transformers and reactors, is an effective tool for diagnosing its operation conditions.

However, measurements of these gases in the laboratory, through tests of gas-chromatography in oil samples collected periodically can allow a problem to start and evolve to a failure during the period between samples, usually several months if not years.

Treetech’s GMP Sensor fillsthis gap by providing real-time monitoring of hydrogen dissolved in insulating oil. Hydrogen is considered a key gas for the detection of defects in equipment immersed in oil. The GMP performs this measurement without cross interference from other gases such as carbon monoxide, in order to obtain maximum sensitivity in detecting defects so that changes in hydrogen concentrations are not obscured by constant and/or elevated CO.

The new sensor for gas and moisture Treetech’s GMP presents the following innovative

features:

        — Compact size, saving space and reducing installation costs. Smart and cost effective;
        — Can be installed in a valve with thread ½”. So there are more choices of locations for installation of the sensor.
        — It can be installed in places of high oil circulation. For example, you can use pipes, radiators, installing it in deaeration plugs. Hence it is possible to avoid stagnant oil at the bottom of the tank;

The GMP measures moisture and gases dissolved in insulating oil, communicating signs of:

        — Hydrogen (H ) dissolved in the oil and its developmenttrend, with a prediction of time to alarms;
        — Percentage of water saturation (H2O ) in oil and associated oil temperature;
        — Water content (ppm) in the insulating oil at current temperature and at reference temperature, both calculated through water saturation;
        — Alarms for concentrations of H2 and H2O high or very high, and for trends of increased concentration of H2 and H2O;

Features:

        — Autonomous equipment. It has a display and indicators (LEDs) for measurement and configuration. The use of the SDG or IDG HMI is optional;
        — RS-485 communication systems for monitoring or supervision systems;
        — Open protocols Modbus RTU or DNP3 Level 1 with support for 1ms resolution time-stamp;
        — Robust design, exceeding the EMC standards for operation in substations with severe electromagnetic conditions.
        — Operating temperature -40 to 85 ºC, suitable for severe operating regimesand ambient conditions;
        — Universal Power Supply, 38 to 265 Vdc or Vac;
        — 4 programmable output relays;
        — 2 current loop (mA) programmable outputs;
        — Self-diagnosis of the condition of the sensor;
        — IP-65Protection Degree, withstands severe conditions for field exposed to the weather.

Operating Principle

The sensors used by the Periscope to measure gasand moisture concentration use semiconductor technology, whicheliminates cross-sensitivity to other combustible gases.

The hydrogen dissolved in the oil represents the general status of the transformer.For the measurement of dissolved hydrogen to be effective for diagnosis of the equipment, the oil must be in contact with the GMP sensor.