ABB REG316 Numerical generator protection
Features • Selectable protection functions
• Multitude of applications
• Setting menu-assisted with personal computer by means of the Windows-based
operator program CAP2/316
• Fully numerical signal processing
• Continuous self-monitoring by hardware
• Cyclically executed testing routines, mostly
by software
• Setting of parameters and recording of the
settings
• Display of measured values
• Display of events, their acknowledgment
and printout
• Disturbance recording
• Self-documentation
• Long-term stability
• Serial port for communication
• Available for 19" rack mounting in panel,
surface or flush mounting.
• Four independent, user-selectable parameter sets able to be activated via binary
input
• Multi-activation facility of the available
functions
Application The main areas of application of the
REG316*4 terminal are the protection of generators, motors and unit transformers.
The modular design makes it extremely flexible and simple to adapt to the size of the
primary system installation and the desired protection schemes to be included. Economic
solutions can thus be achieved in the full
range of applications for which it is intended.
Different degrees of redundancy are possible,
availability and reliability of the protection
can be chosen to suit the application by duplicating of REG316*4 units, but also by multiple configuration of the protection functions.
The use of standard interfaces makes
REG316*4 compatible with process control
systems. Different forms of data exchange
with higher process control levels are possible, e.g. one-way reporting of digital states
and events, measured values and protection
parameters.

Protection functions
All important protection functions required
for the protection of generators, motors and
unit transformers are included. The system
can therefore replace several relays of a conventional protection scheme. The following
table gives a survey of the most significant
protection functions of REG316*4.
The desired protection functions to suit the
particular application can simply be selected
from a comprehensive library using the personal computer. No knowledge of programming whatsoever is required.
All setting ranges are extremely wide to make
the protection functions suitable for a multitude of applications. The following main parameters can be set, among others:
• input channel or channels
• pick-up setting
• time delay
• definition of the operating characteristics
• tripping logic
• control signal logic
Setting a corresponding parameter enables
the protection functions to be ‘connected’ to
particular input channels. Digital input and
output signals can also be connected together
logically:
• The tripping outputs of each protection
function can be allocated to channels of the
tripping auxiliary relay assembly in a manner corresponding to a matrix.
• The pick-up and tripping signals can be allocated to the channels of the signalling
auxiliary relay assembly.
• Provision is made for blocking each protection function with a digital signal (e. g.
digital inputs or the tripping signal of another protection function).
• External signals applied to the digital inputs can be processed in any desired fashion.
• Digital signals can be combined to perform logical functions, e.g. external enabling or blocking signals with the output
signals of an internal protection function
and then used to block one of the other
protection functions.
Design The REG316*4 belongs to the generation of
fully numerical generator protection terminals, i.e. analogue to digital conversion of the
input variables takes place immediately after
the input transformers and all further processing of the resulting numerical signals is performed by microprocessors and controlled by
programs.
Standard interfaces enable REG316*4 to
communicate with other control systems.
Provision is thus made for the exchange of

Protection functions:
Generator differential
Transformer differential
Definite time overcurrent (undercurrent)
(optionally with inrush detection)
Instantaneous overcurrent (undercurrent)
Voltage-controlled overcurrent
Inverse time overcurrent
Directional overcurrent protection with definite
or inverse time characteristic
Negative phase sequence current
Definite time overvoltage (undervoltage)
Stator earth fault (95%)
Rotor earth fault
Instantaneous overvoltage (undervoltage)
with peak value evaluation
Voltage balance
100% stator earth fault (+ rotor earth fault)
Underimpedance
Minimum reactance (loss of excitation)
Power
Overload
Inverse negative phase-sequence current
Overtemperature
Frequency
df/dt
Overexcitation
Logical functions
Pole slip protection
ratio between its mean time in service without failure and the total life, is most certainly
the most important characteristic required of
protection equipment. As a consequence of
the continuous supervision of its functions,
this quotient in the case of REG316*4 is typically always close to 1.
The menu-based HMI (human machine interface) and the REG316*4 small size makes the
tasks of connection, configuration and setting
simple. A maximum of FLEXIBILITY, i.e.
the ability to adapt the protection for application in a particular power system or to coordinate with,
or replace units in an existing protection scheme, is provided in REG316*4 by
ancillary software functions and the assignment of input and output signals via the HMI.
REG316*4’s RELIABILITY, SELECTIVITY and STABILITY are backed by decades
of experience in the protection of generators
and motors in transmission and distribution
systems. Numerical processing ensures consistent ACCURACY and SENSITIVITY
throughout its operational life.
Hardware The hardware concept for the REG316*4
generator protection equipment comprises
four different plug-in units, a connecting
mother PCB and housing (Fig. 1):
• analog input unit
• central processing unit
• 1 to 4 binary input/output units
• power supply unit
• connecting mother PCB
• housing with connection terminals
In the analog input unit an input transformer
provides the electrical and static isolation
between the analogue input variables and the
internal electronic circuits and adjusts the signals to a suitable level for processing. The
input transformer unit can accommodate a
maximum of nine input transformers (voltage-, protection current- or measuring
transformer).
Every analog variable is passed through a
first order R/C low-pass filter on the main
CPU unit to eliminate what is referred to as
the aliasing effect and to suppress HF interferences (Fig. 2). They are then sampled 12
times per period and converted to digital signals. The analog/digital conversion is performed by a 16 Bit converter. A DSP carries
out part of the digital filtering and makes sure
that the data for the protection algorithms are
available in the memory to the main processor.