Analog Inputs; Introduction; Operation Principle - ABB Relion 650 Series Technical Manual

1MRK 505 263-UUS A
Section 3
3.1

Introduction

Analog input channels are already configured inside the IED. However the IED has to be set
properly to get correct measurement results and correct protection operations. For power
measuring and all directional and differential functions the directions of the input currents must
be defined properly. Measuring and protection algorithms in the IED use primary system
quantities. Set values are done in primary quantities as well and it is important to set the data
about the connected current and voltage transformers properly.
The availability of CT and VT inputs, as well as setting parameters depends on the ordered IED.
A reference
channels phase angle will always be fixed to zero degree and all other angle information will be
shown in relation to this analog input. During testing and commissioning of the IED the reference
channel can be changed to facilitate testing and service values reading.
3.2

Operation principle

The direction of a current to the IED depends on the connection of the CT. The main CTs are
typically star (WYE) connected and can be connected with the Star (WYE) point to the object or
from the object. This information must be set to the IED.
Directional conventions for current or power, for example
• Positive value of current or power means quantity direction into the object.
• Negative value of current or power means quantity direction out from the object.
Directional conventions for directional functions (see figure 2)
Forward means direction into the object.
•
Reverse means direction out from the object.
•
Busbar protection REB650
Technical manual

Analog inputs

PhaseAngleRef must be defined to facilitate service values reading. This analog
© Copyright 2011 ABB. All rights reserved
Section 3
Analog inputs
SEMOD55010-1 v3
SEMOD55003-5 v7
SEMOD55028-5 v5
33