תיאור
Switch unit description
Recloser principle
Reclosers are used in overhead lines and in substations. Like circuit-breakers they are capable of switching normal and fault currents. They are equipped with sensors and controller being the protection and control device. In case of a temporary line fault, they can trip and reclose up to four times, thus avoiding longer network interruptions.
Recloser cycle
In case of a network fault, the recloser opens and recloses several times. In case of temporary faults, the automatic reclosing significantly reduces the outage times. While the trip settings for each operation can be set individually.
Design of switch unit
Each vacuum interrupter is embedded in a solid-insulated pole made of weatherproof cycloaliphatic epoxy-resin. The vacuum interrupter is vertically mounted inside the pole, providing a long service life. Each pole is equipped with an integrated current transformer and a resistive voltage sensor.
Operating mechanism
The recloser is operated by a magnetic actuator#the actuator is a bi-stable system, locked in the end positions by permanent magnets.lf not in operation, the magnet coils do not consume any power.
The operating mechanism housing is made of stainless steel for outdoor applications, it also accommodates the position indicator and a mechanical operations counter.Mechanical lockout
The recloser can be tripped manually. If the handle is pulled, the recloser opens and is simultaneously locked out electrically and mechanically. The handle stays extended, thus indicating the interlocked state.
To close the recloser again, the handle must first be pushed back to the operation position in order to release the lockoutThen the recloser can be closed electrically via the controller.
Controller description
Controller
The Microprocessor Based controller provide protection, control, monitoring, instrumentation and metering with integrated input and output logic, data logging & fault reports.
Communication access to controller functionality is via electrical RS485 port for remote connection. Additional rear port options including RS232 port is available. The controller is mounted in the control cubicle. Along with the controller, this cubicle also contains the auxiliary power supply with batteries for uninterruptible power supply, electronic boards and circuit breakers.
The controller contains a large number of protection functions (elements) which can be selected or deselected through the menu driven display.
Enhanced features
–Analysis of current/voltage normal & negative sequence for power quality monitoring.
–Recording of PQM with fault waveform of 128 sampling and 20 cycles.
–Harmonics analysis of electric data.
–Monitoring of Sag, Swell, Interruption, over & low voltage, unbalance and etc. –Improvement of fault detection algorithm.
–Automatic isolation of faulted section site and interconnection with other healthy section.
–Improved measuring accuracy
–Multi-Protocol support (DNP3.0, MODBUSJEC60870-5-101/104 & IEC61850). –User programmable logic(PLC) support
Cubicle
The cubicle includes the complete electronics, the protection relay and the UPS system of the recloser. Additional components and features can be selected via order.