ABB ret650, Technical Manual

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Because the transformer impedance is dominantly inductive, it is possible to use just
the transformer reactances in the above formula. At the same time this means that T1
circulating current lags the busbar voltage by almost 90°, while T2 circulating current
leads the busbar voltage by almost 90°.
12.3.4.2 Tap changer control and supervision, 6 binary inputs TCMYLTC
Reading of tap changer position
The tap changer position can be received to the tap changer control and supervision,
6 binary inputs TCMYLTC function block in the following ways:
1. Via binary input signals, one per tap position (max. 6 positions).
2. Via coded binary (Binary), binary coded decimal (BCD) signals, or Gray coded
binary signals.
Via binary input signals, one per tap position
In this option, each tap position has a separate contact that is hard wired to a binary
input in the IED. Via the Signal Matrix tool in PCM600, the contacts on the binary
input card are then directly connected to the
• inputs B1 – B6 on TCMYLTC function
Via coded binary (Binary), binary coded decimal (BCD) signals or Gray coded
binary signals
The Tap changer control and supervision, (TCMYLTC) decodes binary data from up
to six binary inputs to an integer value. The input pattern may be decoded either as
BIN, BCD or GRAY format depending on the setting of the parameter
CodeType .
It is also possible to use even parity check of the input binary signal. Whether the
parity check shall be used or not is set with the setting parameter
UseParity .
The input BIERR on (TCMYLTC) can be used as supervisory input for indication of
any external error ( Binary Input/output Module) in the system for reading of tap
changer position. Likewise, the input OUTERR can be used as a supervisory of the
Binary Input/output Module.
The truth table (see table 235 ) shows the conversion for Binary, Binary Coded
Decimal, and Gray coded signals.
1MRK 504 135-UEN A
Section 12
Control
345
Technical manual