Overall Operation - Siemens SIPROTEC 4 7UT6 Series Manual

Introduction

1.1 Overall Operation

1.1 Overall Operation
The digital differential protection devices SIPROTEC 4 7UT6x are equipped with a powerful microprocessor
system. This provides fully numerical processing of all functions in the device, from the acquisition of the
measured values up to the output of commands to the circuit breakers
[hardwarestruktur-270203-st, 1, en_GB]
Figure 1-1
Analogue Inputs
The measuring inputs MI transform the currents and voltages derived from the instrument transformers and
match them to the internal signal levels for processing in the device. Depending on the version, the device
features between 8 current inputs (7UT612), 12 current inputs (7UT613/7UT633) and 16 current inputs
(7UT635). Three current inputs are provided for the input of the phase currents at each end of the protected
zone (= measuring points) of a 3-phase protected object; depending on the version, one or more further
single-phase measuring inputs (= additional inputs) may be used for any desired current, e.g. the earth current
measured between the starpoint of a transformer winding and earth, or other single-phase measuring
16
Hardware structure of the digital differential current protection relay 7UT6x — Example of a
7UT613 for a three-winding transformer with measuring locations M1, M2 and M3, with 3
auxiliary 1-phase inputs X1, X2 and X3
SIPROTEC 4, 7UT6x, Manual
C53000-G1176-C230-5, Edition 09.2016