The electrical recloser is a modern automatic switchgear, integrated with intelligent sensors and technology to protect power lines, grid systems as well as electrical equipment.
Table of contents:
4. What is the role and function of a recloser?
5. Installation location and conditions
1. What is a Recloser?
Recloser (or Automatic Circuit Reclosers) is electrical equipment, precision automatic switchgear device with high reliability.
2. Structure of Recloser
For electrical systems, Automatic Recloser is a collection of the following parts:
Overload protection
Close automatically
Switchgear
Control by hand
3-phase Recloser, for column installation, vacuum chamber arc stamping, insulated by SF6 gas or solid dielectric. On the outside Recloser has an available position for lightning protection.
Recloser components
The control unit is installed in an outdoor pole mounted cabinet under tropical conditions, using an electronic chip, includes functions for measuring, protecting and saving events, and capable of allowing monitoring, control locally and remotely, and connect to the system.
Basically, the Recloser consists of a conventional circuit breaker with a controller that allows programming of the number of repetitive closings according to predetermined requirements. At the same time will measure and store important values such as P, U, I, time of circuit break,...
3. How does a recloser work
When a short circuit occurs, Recloser opens (cut-off), after a period of time t1 (initial setting) it will close automatically. At this time, if the problem persists, the recloser will continue to open the circuit, after a while t2 recloser will automatically close the circuit. Just like that, the recloser works according to the program originally set up and the 3rd time it will completely disconnect the circuit from the electrical system. And the number of cuts and the switching time are programmed by the user, so it can be changed.
Recloser has the ability to repeat at least 3 times, the ability to cut 4 times before locking. The dwell time (closing time) is adjustable
4. What is the role and function of a recloser?
Recloser provides important real-time data about the line status, such as power (A, W, VAR), voltage (V) or frequency (f) values. This data enhances the mid-voltage grid operation, enables fault analysis, system diagnostics, and ultimately improves MV grid operation efficiency.
The Recloser can recognize a fault area and restore power in a problem-free area with a fuse switch or load breaker. It can be used on overhead distribution lines as well as in distribution transformer stations integrating control, protection, measurement, communication, fault detection, on-line monitoring of closing or opening circuit.
Functions:
l Improve SAIDI and SAIFI indices by automatically reducing outages
l Defer capital works by offering features that reduce network stresses
l Easily integrated into Smart Grid applications with advanced capabilities such as Loop Automation and Automatic Changeover
l Flexible applications from complex substation or standalone pole mounted through powerful automation and communication features
Since many short-circuit cases occur at medium voltage supply sources that are transient in nature, the recloser is a necessary device to improve the continuity and quality of electricity in medium voltage grids in the whole world.
5. Installation location and conditions
The Recloser can be placed anywhere on the electrical system whose ratings meet the system requirements.
The logical locations are:
Set at the station as the main protection device of the system
Placed on the main lines but far from the station to segment long lines, thus preventing from affecting the whole system when there is a problem from the source.
Placed on the trunk lines to protect the mainline line from damage caused by branch failures.
Installation and operating conditions:
l The air temperature ranges from -450C to below + 850C
l Air humidity up to 100%.
l Maximum installation height 3000m above sea level
l Not often vigorous shaking
Post time: Oct-22-2022