ABB REF 542plus Multifunctional Protection and Switching Controls

Functions

The REF542plus multifunctional protection and switchboard control unit integrates all auxiliary functions in one unit.

The multifunctional unit also has a self-monitoring function. All functions are designed as freely configurable software modules.

As a result, the various operational requirements of a MV station can be met without any problems.

The versatility of the software allows the REF542plus to be used on every switchboard regardless of the specific application requirements.

Configuration

Each protection and control application can be easily configured via the software function module, which allows the following functions to be arbitrarily defined as part of the secondary system:

LEDs for local indication (meaning and colour)

Single line diagrams showing the status of switching devices

Protection programme

Control programmes

Interlocking programmes

Automation sequences

All functions of the switchboard can be specified in co-operation with ABB. The configuration results are saved and delivered to the user together with the switchboard.

By using the "Function Block" programming language (FUPLA), the REF542plus multifunctional protection and switchboard control unit provides engineers, in

especially non-software specialists, the opportunity to easily update switchboard operation and handling.

With the REF542plus, users can fully integrate secondary systems into a true programmable controller.

This flexibility is very favourable for defining control functions for automation sequences.

This can include, for example, interlocking of switchgear, preventing the release of specific protective functions and initiating switching sequences.

The REF542plus multifunction unit offers a wide range of logic functions so that the various required control schemes can be configured.

The required control schemes are configured. The range of logic functions includes

AND logic gates

NAND logic gates

OR logic gates

NOR gates

XOR gates

Bistable and Monostable Flip-Flops

Bistable and Monostable Flip-Flops

Timers

Pulse Generator

Memory

Similar to the free definition of control schemes, each required protection scheme can be configured by combining the available protection function modules.

For example, the following protection functions are available:

Timed overcurrent protection

Inverse time overcurrent protection

Directional overcurrent protection

Undervoltage or overvoltage protection

Distance protection

Transformer and motor differential protection

Cable, transformer and motor thermal protection

Reverse power protection

Synchronisation check

The parameters of the protection scheme can be changed via the HMI control unit without the use of a personal computer.

Additional functions can be performed using a personal computer running configuration software and connected to the optical interface on the front of the HMI unit.

These additional functions include

Parameter setting for the protection programme,

reading out of current measured values

Reading out the status of binary inputs and outputs,

reading out the fault recorder

Viewing the status of FUPLA logic inputs/outputs

The REF542plus allows convenient local operation and is fully interlocked to prevent switching errors.

The switching positions of the various switching devices in the switch box can be displayed on the LCD display of the HMI control unit.

If the local control mode is selected, switching operations can be entered locally via the control buttons on the HMI control unit.

Switching to other control modes is only possible using the correct electronic pushbuttons.

In remote control mode, switching operations can only be performed via a remote control unit (e.g. station automation system).

For users who wish to switch locally and remotely at the same time, a special control mode, the local and remote mode, is also available.

Interlocking is also possible between switchgear connected to the same busbar system. This requires the provision of status information between switchgear and other switchgear.

The status information must be provided by a conventional hard-wired ring bus system or by the more sophisticated ABB station automation system.