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.

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.