Continuous online monitoring with SCADA Ready SMART* Dehydration Control

Smart Grid Application of The DryKeep® SYSTEM

All DryKeep® SMART (SCADA Monitoring Analysis and Reporting Technology) systtems include permanently installed moisture-in-oil sensors and a flow rate monitor that feed data to an intelligent controller.  The intelligent controller monitors and controls the dehydration process while logging all moisture-in-oil, estimated moisture in the paper insulation and oil temperature data.  A built-in RTU provides remote access to all real-time and logged data, alarms, and control of the system thru cellular, VPN, Ethernet, fiber, and/or SCADA with:All DryKeep® SMART (SCADA Monitoring Analysis and Reporting Technology) systtems include permanently installed moisture-in-oil sensors and a flow rate monitor that feed data to an intelligent controller.  The intelligent controller monitors and controls the dehydration process while logging all moisture-in-oil, estimated moisture in the paper insulation and oil temperature data.  A built-in RTU provides remote access to all real-time and logged data, alarms, and control of the system thru cellular, VPN, Ethernet, fiber, and/or SCADA with:

• DNP3 – Slave SCADA and MODBUS RTU/TCP/ASCII/RTU protocols.
• Cellular alarming with multi-carrier 4G LTE support with 3G/2G fallback.
• RJ45 Ethernet ports, 62.5/125 um (SC) Mulitmode Fiber Converter.
• Cellular VPN for remote system monitoring, control and reporting.

Moisture is always in a dynamic state, migrating between oil and cellulose insulation which means that a moisture reading from an oil sample taken at a single point in time may not by typical. These variable factors can provide a false sense of reliability and consistency when taking individual samples for Karl Fischer testing. Many issues need to be considered when collecting, transporting and storing oil samples. The samples can easily become contaminated if sampling instructions are not strictly followed. The new SMART DryKeep® continuous on-line monitoring system eliminates these variables.

The permanently installed sensors at the inlet and outlet points of the SMART DryKeep® system provides a repeatable engineering-based process that continuously measures the water content and temperature of the oil.

All data is plotted on trending screens and is logged for retrieval for historical analysis.

All logged data can easily be downloaded to a laptop in .CSV format through the RJ45 Ethernet Panel Interface Connector mounted on the inner swing panel of the controller enclosure. All data and alarms can be retrieved remotely through the user’s SCADA system with DNP3 and MODBUS protocols supported. All alarms can be sent through the user’s SCADA system and can also be sent via cellular to appropriate personnel’s mobile devices.

Over-Drying protection is just as important as drying!

Power transformer windings are designed to withstand high axial forces which result from short circuit events. To withstand these forces, the winding assembly is clamped to a predetermined pre-load pressure during manufacture. The cellulose insulation of in-service transformers that did not have the benefit of a DryKeep system installed when new will have adsorbed moisture and swell. As moisture is removed in the dry-out process, the swelling will subside. Removing too much moisture will cause the windings to come loose, making them susceptible to failure during a short circuit.

DryKeep® SMART technology prevents over-drying.

The DryKeep® SMART dehydration control system prevents over-drying of transformers by controlling the flow of oil through the system based on the calculated estimated percent moisture in the paper insulation. When the DryKeep® system brings the transformer down to a safe moisture level, the SMART controller will signal the T-divertor valve actuator to change the path of the oil flow to bypass the drying cylinder(s) to prevent over-drying. The system pump will continue to run allowing the oil to flow past the embedded sensors to continue to provide all system data and monitor the estimated percent moisture in paper of the transformer in this bypass mode. If the system sees the percent moisture in paper rise above the safe level, the system will signal the T-divertor valve actuator to change the path of the oil flow back through the drying cylinders to remove moisture until the safe level is reached again.

Alarming is provided for saturated cylinder and possible leak detection notification. All alarms are shown on the HMI, via the stack lights mounted on the controller enclosure, through the user’s SCADA system, and/or via cellular to appropriate personnel’s mobile devices.

All DryKeep® SMART monitoring and dehydration systems feature:

• Two (2) permanent moisture-in-oil sensors.
• Flow indicator switch to monitor for any potential leaks.
• Solenoid safety isolation valves at inlet and outlet to isolate DryKeep® from the transformer in the unlikely event of a leak.
• Deaerator tank with oil bleed valve and hose to remove any oxygen in the system.
• One (1) or three (3) regeneratable adsorption cylinders.
• Static dissipative PTFE stainless steel braided hoses between cylinders.
• 7” color touchscreen HMI with 12MB on-board data, 4GB Micro SD card for data logging and 2 USB ports.
• Built-in RTU for remote access thru SCADA, CPU, and/or cellular with: – DNP3 – slave and MODBUS RTU/TCP/ASCII/RTU SCADA protocols. – Cellular alarming with multi-carrier 4G LTE support with 3G/2G fallback. – RJ45 Ethernet ports and a fiber optic port.
• Visual and remote alarm/signaling for flow rate integrity, leak detection, and cylinder saturation.
• Approximately 1.5 LPM flow rate using 120V/60Hz or 230V, 50Hz, seal-less, leak proof, canned, rotor type pump.
• Stainless steel frame, cylinders, valves, and hardware. Unit is of substation quality durability.
• Hydraulic quick couplers for fast saturated cylinder change-outs while transformer remains energized.
•  24VDC power supply for sensors and control cabinet components.
• RJ45 Ethernet Panel Interface Connector to permit downloading of logged data without having to open enclosure.
• 1-micron particle filter with visual status indicator.
• Two (2) oil sampling ports.
• Ultra-wide band 2G/3G/4G LTE/Cellular/CDMA and Wi-Fi antenna for 2G/3G/4G applications.

All PLC materials and protective devices are enclosed in a pad lockable NEMA 4-IP65 enclosure with hinged door, an inner swing panel and outer cover.

We reserve the right to make changes to any described details and technical data contained herein without notice.  Continuous product enhancement by DryKeep® and local conditions may also result in deviations.