Description
Introduction
• FRTU Feeder Terminal Unit
• TTU Transformer Terminal Unit
Distribution transformers are implemented widely as electric-energy converters between medium-voltage and low-voltage lines in distribution networks, guaranteeing stable urban power supply. Faced with wide distributions of users, complex installing environments and strong periodicity of electric consumption, distribution transformers has a large varieties of equipment types and and unstable electric loads, leading to high costs in running and maintaining.
With the advancement of Distributed Energy Resources (DER) and a further refinement in the operation of power grids, automatic design of distribution transformers and intellectual upgrading of low-voltage lines have become key points in the constructions of electric infrastructures.
• In automatic transformers, TTU equipped with DF1725IED as core can achieve some significant functions as follows.
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- The device can monitor the output voltages and currents of the transformers and simultaneously calculating related parameters such as active power, reactive power, power factor and etc.
- It collects the statistics of the transformer’s output electric meters and send it to the main station system.
- It can control the circuit breakers of the transformer’s output lines on and off.
- The electric loads can be controlled.
- TTU can monitor the qualities of the electric powers and connect the reactive-power controllers.
- The load states of the transformer can be judged automatically by the operational temperatures.
- The environmental factors including wind speeds, wind directions, rainfalls, smokes and etc can be recorded.
- TTU equips the transformer with a burglar alarm.
- The applications of DF1725IED in low-voltage power distribution grids are as follows.
- Collecting statistics of low-voltage electric meters within controlled areas
- Monitoring the status of the low-voltage air switches.• User arrearages control
- Electricity anti-stealing.
- Power quality management.
- Coordinated-charging management.
- Distributed access of power resources.
- Managements of energy storage system.
- Edge calculations of IOT.
System composition and structural design
DF1725IED can be installed flexibly in different combinations of functions and capacities in order to fit various running conditions
- Typical mode. The voltages, currents and locations of the circuits breakers of the output lines can be collected. This mode is suitable for basic load monitoring.
- Pro mode.The voltages, currents and locations of the circuits breakers of the output lines can be collected. The switching on/off of the circuit breakers can be controlled and the faults will be blocked. FA function in medium- voltage grids can be achieve which can significantly improve the reliability of power supply.
- IOT-EDGE mode. Overall monitoring and managements of user-oriented power supply covering “Lines among the last kilometer” can be achieved by collecting multiple sensor signals and combining them with the basic statistics collected in typical modes，contributing to power-stealing prevention, the reductions of line loss and increasing marketing profits. This mode can support various communication methods, for example, HPLC and low-power radios, dramatically improve the convenience of system construction and reduce the running costs.
Installation
DF1725IED can be fixed either in a external cabinet or inside the electric box. It can be installed flexibly in various locations, such as under the cross arm of the transformers, up one side of a pole or on the ground, to fit severe environments.
Operation
DF1725IED is compatible with general maintaining software. Maintenance staff can debug various devices from FRTU to RTU using standardized operational software.It can be repaired by maintaining the cables, remotely accessing the channels, maintaining locally and wirelessly. LCD panel is optional for data view and on-site operations instead of external PC and mobiles.
Product overview
• Modular Design of Hardware
• Wide adjusting ranges of three-remote capacities
• More alternatives of software logic
• Ensurence of security （passed 62351 test）
• More kinds and quantities of communication interfaces and signal interfaces
• Smaller size and more ways of installation
• Better adaptability to severe environment
Technical highlights
• AC/ DC sampling. Various sensors including transformers, digital sensors and etc can be linked to the device.
• Telemeter and telecontrol.
• Detecting the faults of feeder.
• Three-step protection against over currents and short circuits.
• Two-step protection of zero-sequence currents.
• Data collections of the master meter of the transformer and user’s electric meters.
• Monitoring and improving the qualities of electric power. Optimizing the reactive power.
• Remotely turning off/on the power distribution systems.
• Managing power loads of the transformers and monitoring the service life of the equipment; anti-theft;
• On-site/remote operations of the switches. The status of the switches can be indicated by the signal lights.
• Parameters can be input on the interfaces with strict anti-error and anti-misinput functions.
• Power monitoring. Online managements of the batteries.
• Both on-site and remote maintenance are available.
• The device supports various protocols including IEC60870-5-101、IEC60870-5-103、IEC60870-5-104、DNP、MODBUS and etc.
• Self check,mutual check and false alarm. Overall alarm information will be shown in the system and indicated by the LED lights on the panel of main control unit.
• A fault-indicating light of the feeders is fixed outside the cabinet for line patrol.
• Various communication modes can be supported including EPON, optical fiber Ethernet, double-loop self-repaired optical fiber Ethernet, public / private network, radio station, power line carrier and etc.
• The external structure is designed compactly in divided modular. The pluggable terminals are easy to use and maintain.
• Industrial-class quality. It can adapt to a wide temperature range and has anti-magnetic, shockproof, damp-proof and lightning-proof functions.
Applications
In public transformers, special transformers, box transformers and etc.
The product has gotten the certificates of general and special type test and IEC62351 test report in a variety of countries. Please contact technical support staff for relative documents.
