FTU adopts advanced DSP digital signal processing technology, multi CPU integration technology, high-speed industrial network communication technology, and an embedded real-time multitasking operating system. It has strong stability, high reliability, good real-time performance, wide adaptability to environments, and powerful functions. It is a new generation of feeder automation remote terminal device that integrates telemetry, remote signaling, remote control, protection, and communication functions. Suitable for automation engineering of urban, rural, and enterprise distribution networks, it completes automation functions such as monitoring, control, and protection of ring main units, pole mounted switches, and communication. Cooperate with the power distribution station and main station to achieve normal monitoring and fault identification, isolation, and restoration of power supply to non faulty sections of the distribution line.

telemetry

(1) Communicating electrical measurements
Any combination of Ia, Ib, Ic, In, Uab, Ucb, Ua, Ub, Uc, Un, etc., usually Uab and Ucb are taken on both sides of the switch to monitor the power supply situation at both ends of the feeder.
       (2) Two table method or three table method, the software calculates P, Q, Pa, Pb, Pc, f, cos ∧, etc., and uploads them according to the needs of the main station;
       (3) Protect the upload of records for Ia and Ic;
       (4) DC analog quantity: two channels, battery voltage, temperature, etc.

remote signaling

(1) Switch status signal, SOE;
(2) Switching energy storage signal, operating power supply;
(3) Pressure signals, etc;
(4) Battery low voltage alarm;
(5) Protect actions and abnormal signals;
(6) Other status signals.

remote control

(1) The switch can be opened and closed at least twice after power failure;
(2) Maintenance of batteries;
(3) Protection signal remote reset;
(4) Other remote controls.

Data transmission function

Capable of communicating with the superior station, sending and receiving control commands from the superior station for the collection and processing of information.
        During school hours with superiors.
        Forward information from other terminals upwards.
        Forward electrical energy information upwards.
        Proactively upload accident information (optional function).
        Having a locally maintained communication interface.
        Communication protocol: Supports various communication protocols such as DL/T 634.5101-2002 (IEC60870-5-101), DL/T 634.5104-2002 (IEC60870-5-104), DL/T 451-91 cyclic telecontrol protocol, DNP3.0, SC1801, MODBUS, etc., and can be expanded as needed.
        Communication interface: RS-232/485, Industrial Ethernet, CAN.
        Communication channel: It can support various communication forms such as fiber optic, carrier wave, wireless spread spectrum, wireless data transmission radio, CDMA, GPRS, and ADSL, which can be selected by users.

Fault identification, isolation, restoration of power supply and protection

It has the functions of quick break, delayed overcurrent (composite low voltage) protection, and reclosing, and can be selected according to the feeder automation scheme.
        Monitor the fault current, record the overcurrent time and maximum overcurrent value, and report to the distribution substation and main distribution station.
        Based on the overcurrent fault information and switch tripping information reported by each switch DTU, the distribution substation and main station determine the fault area according to the dissipative topology model of the distribution network transformer structure, identify the fault area, generate fault isolation command sequence and non fault area restoration power supply command sequence. Automatic or human-machine interactive execution.

On site operation

There are opening and closing buttons inside the DTU for on-site operation.
        There are local/remote selection switches, maintenance discharge buttons, etc.

Ring network function

When DTU is set as the contact switch, the switch is automatically controlled to open and close according to the set value based on the power status of one or both PT sides. When there is electricity on both sides of the switch, it is forbidden to close the contact switch. For those that require network operation, the main station needs to be specifically set up and confirmed. When one side loses power, according to the FA scheme and the settings of the main station, automatic closing is allowed and controlled to quickly restore power supply.

Fixed value download and upload function

Quickly determine the value and enable it;
       Overcurrent setting, time constant, enable;
       Re closing time and enable;
       Setting and canceling the ring network function.

Local maintenance function

Debugging and maintenance are carried out using specialized maintenance software through the standard communication maintenance interface on DTU.
       Including parameter setting configuration and inspection; Remote telemetry, remote signaling, remote control, and time synchronization testing; Data uploading, communication, etc.

Self diagnosis and self recovery functions

Equipped with self diagnostic function, it immediately records and reports any abnormalities in DTUs memory, clock, I/O, etc.
       It has a self recovery function when powered on.

Power UPS and battery maintenance function

Meet the power requirements for operating mechanisms, terminal equipment, and communication devices.
       DTU is powered by dual power sources, and can continue to operate even after one side of the power supply loses power.
       Usually, the DTU is powered by the main power supply, while the battery is float charged. After the bilateral power supply loses power, the DTU can continue to work for 24 hours (except for the radio) powered by the battery.
       Battery low voltage alarm protection function.
       Battery automatic maintenance: Within the specified time, the dispatcher issues a battery maintenance command, and the battery begins to discharge. When the battery voltage is low, it automatically stops discharging, switches to the main power supply, and charges the battery. The battery charging adopts constant voltage and current limiting charging to ensure safety.

■ "Four in One" comprehensive function
Integrating four functions: metering, power quality monitoring, distribution transformer condition monitoring, and reactive power compensation.
Intelligent reactive power compensation
Intelligent capacitors can form their own system, with automatic switching of capacitors to achieve automatic reactive power compensation
       ■ Flexible networking
Following the current distribution monitoring system regulations of State Grid Corporation of China and Southern Power Grid Corporation of China, it is convenient to access the existing load management system and distribution management system of the power enterprise, provide complete real-time voltage and reactive power information, and can also independently form a reactive power real-time information system
       ■ Simple engineering
The device has a simple structure, with few and clear internal connections. The capacitors are assembled in a modular manner, which is easy to install and maintain, and more convenient for optimizing and adjusting the compensation capacity

(1) Collect status data and send it to a remote location, with photoelectric isolation and priority transmission for remote signal displacement;
(2) Collect data volume and send it to a remote location with optoelectronic isolation;
(3) Directly collect the power frequency of the system, measure voltage, current, active and reactive power, and send them to a remote location to calculate the forward and reverse electrical energy;
(4) Collect pulse electrical measurements and send them to a remote location with optoelectronic isolation;
(5) Receive and execute remote control and return to school;
(6) Program self recovery;
(7) Equipment self diagnosis (fault diagnosis to plugin level);
(8) Equipment self adjustment;
(9) Channel monitoring;
(10) Receive and execute remote adjustment;
(11) Receive and execute timing commands (including optional GPS timing function);
(12) Communicate with two or more main stations;
(13) Collect event sequence records and send them to distant locations;
(14) Provide multiple digital interfaces and multiple analog interfaces;
(15) Remote/local settings can be made for each interface feature;
(16) Provide several communication protocols, each interface can transmit data of different protocols according to remote/local settings;
(17) Accept remote commands and select to send various types of information;
(18) Can forward remote control information from multiple sub stations;
(19) Local display function, local interface with isolator;
(20) Support communication with spread spectrum, microwave, satellite, carrier and other devices;
(21) Optional and multi protocol simultaneous operation, such as DL451-91 CDT protocol, should support POLLING protocol and other international standard protocols (such as DNP3.0, SC1801, 101 protocol);
(22) Remote settings can be made through telecommunications networks and power system channels.
Note: Taken from the Power Grid Think Tank. If you are dissatisfied, please contact us for deletion.