The MTRAB® 2.5 DB200D with beta-control is a self-learning system, recommended for use on transformers with cyclic loads (generator transformers, network coupling transformers, phase shifters, reactors, HVDC transformers). In addition to monitoring the humidity, the device determines a time window in which the oil conservator exhales and the desiccant is regenerated.
The main function of dehydrating breathers is to dehumidify the ambient air. As a result of the thermal compression of the insulation medium, the ambient air flows from the environment to the expansion tank of the transformer and tap changer (referred to as inhalation). During inhalation, moisture must be prevented from penetrating into the equipment with the air flow, as this reduces the insulating effect due to the contamination of the insulating medium.
This reduction of the dielectric strength of the insulation medium leads to massive malfunctions in the operational sequence. This could even result in the equipment being destroyed. When the flow is reversed from the expansion tank of the transformer and tap changer to the environment (referred to as exhalation), there must be no significant flow resistance that blocks the flow.
The devices of the MTRAB® 2.5 series regenerate the silica gel via sensor control through installed heating elements. This eliminates the periodic visual inspections normally needed; the cost-intensive, regular replacement of the used desiccant is completely eliminated.
In ongoing operation, the air flowing to the oil conservator is directed across the silica gel desiccant and thereby dried through optimized flow control. The humidity of the air in the piping is measured constantly using a sensor. If the humidity level (%rH) of the air in the piping exceeds a standardized value, the regeneration process (heating the silica gel) is activated. The water vapor escaping from the silica gel condenses and drips out of the stainless steel filter installed in the bottom section. An additional sensor monitors the controller and the correct operation of the heating elements. An optional heating unit for the output filter prevents escaping condensation from possibly freezing in Arctic regions.
The MTRAB® 2.5 is equipped with a data logger of the latest generation as standard (optional software needed).
The device can be integrated easily into ETOS® (Embedded Transformer Operating System) with the optional Modbus RTU. Furthermore, it can be integrated into a SCADA system or control room at any time via the analog and digital interfaces.