ABB Multifunction Protection and Switchbay Control Unit REF542plus
Multifunction Protection and Switchbay Control Unit
REF542plus
The REF542plus Multifunction Protection and Switchbay Control Unit is the further
development of the former REF542 unit. Like its predecessor, it features the following
functions:
Protection
Measurement
Control
Monitoring
All functions mentioned above and power quality functions are integrated in a
programmable environment. The exceptional flexibility and scalability of these new
generation devices lead to a smart and clean solution where the traditional approach
would be ineffective and expensive.
The following figures show examples of the REF542plus installation in several
switchboards.
The REF542plus is based on a real-time microprocessor system. The measurement and
protection functions are executed by a Digital Signal Processor (DSP), while a Micro
Controller (MC) is executing the control functions. Due to this task separation there is no
impact between the start and the trip behavior of the implemented protection scheme,
should the control scheme be modified. The Communication Processor (CP) is needed
for connection to a station automation system. A block diagram of the REF542plus is
shown in figure 3.
REF542plus, as shown in figure 3. consists of two parts, a Central Unit and a separate
Human Machine Interface (HMI). The Central Unit contains the power supply, processor
and analog and binary Input and Output (I/O) modules, as well as optional modules for
supplementary functions.
The HMI Control Unit is a stand-alone unit with its own power supply. It can be installed
on the Low Voltage (LV) compartment door or in a dedicated compartment close to the
Central Unit. The HMI is normally used to set the protection parameters and to locally
operate the switching devices in the switchbay. The HMI is connected to the Central Unit
by a shielded, isolated twisted pair according to the RS485 interface. Figure 4 shows an
installation of the Central Unit and the HMI Control Unit in the LV compartment of a
switchboard for the switchbay.
REF542plus
The HMI Control Unit, as shown in figure 5. features a back-illuminated Liquid Crystal
Display (LCD), eight push buttons, several LEDs and an electronic key interface. The
language of the display can be selected via the related configuration software tool, which
is also used to define the protection and the control scheme.
The left half of the LCD display is reserved for the Single Line diagram. The right half is
used to display the appropriate menu or submenu as determined by the user. Two
different electronic keys with different access rights are available. Each of the keys are
programmed to permit either:
protection functions parameterization of the
mode selection of the control functions
Three freely programmable LED bars have been provided on the front of the HMI Control
Unit. Each LED bar consists of ten green and two red LEDs and is user configurable to
display any required measurement value. The red LEDs are used to indicate values
above the rated value.
The functions of the REF542plus can be tailored to the system requirements via a user
specific configuration. The user-specific configuration is loaded during commissioning.
For that purpose the configuration computer, normally a personal computer (notebook)
running Windows NT, is connected to the optical interface on the front side of the HMI
Control Unit.
The interface of the multifunctional unit REF542plus to the Medium Voltage (MV) primary
process is as follows:
Analog inputs to measure current and voltage signals from instrument transformers or
non conventional sensors
Binary inputs with optical couplers for the galvanic separation of the external signals to be
processed;
Binary outputs with conventional mechanical relays or static outputs for the control of
switching devices;
Optional four channel analog outputs 0 to 20mA or 4 to 20 mA
Optional connection to ABB or third party station automation system.
REF542plus is a certified product for compliance to the IndustrialIT architecture concept of
ABB.
IndustrialIT products can be effectively combined together into value-added systems and
solutions in a “Plug&Produce” manner.
Compliance according to “Level 0: Information” ensures that all relevant product
documentation – including the operation manual, instructions for installation and
maintenance, electrical and mechanical drawings, test reports and specific order
information -is online available, in electronic format, for access via software products and
systems based on the ABB Aspect Integrator Platform.
In this way, significant benefits are enabled to the final user for much easier and effective
installation, configuration, operation and maintenance of the product in the plant.
Functions
REF542plus Multifunction Protection and Switchbay Control Unit integrates all the
secondary functions in a single unit. This multifunctional unit also features a self
monitoring function. All functions are designed as freely configurable software modules.
Therefore, a wide range of operation requirements in MV stations can be met without any
problems. The versatility of the software makes it possible to use the REF542plus on
every switchboard independent on the specific application required.
2.1 Configuration
Each application for protection and control can easily be configured by software function
modules, which make arbitrary definition of the following features as part of the secondary
system possible:
LED’s (meaning and colors) for local indication
Single Line diagram to show the status of switching devices
Protection schemes
Control schemes
Interlocking schemes
Automation sequences
All functions in the switchbay can be specified in collaboration with ABB. The result of the
configuration is saved and delivered together with the switchboard to the users. By using
the “FUnctional block” Programming LAnguage (FUPLA) the REF542plus Multifunction
Protection and Switchbay Control Unit offers engineers, especially those who are not
software experts, the opportunity of easily updating the operation and handling of the
switchbay.
With REF542plus the user has the benefit of a secondary system that is fully integrated in
a true programmable controller. This flexibility is very advantageous for defining control
functions for automation sequences, which can, for example, include the interlocking of
the switching devices, blocking the release of specific protection functions, as well as
starting switching sequences.
REF542plus multifunctional unit provides a wide range of logical functions so that each
required control schemes can be configured. The range of logical functions includes: