Page 129 - Practical Power System and Protective Relays Commissioning

128 Practical Power System and Protective Relays Commissioning

11.5 TYPES AND THREE-PHASE CONNECTIONS OF VOLTAGE
TRANSFORMERS

The voltage transformer connection can be shown in Fig. 11.7.

11.6 OPTICAL CURRENT AND VOLTAGE TRANSFORMERS

A new optical technology was introduced within a substation to replace
conventional current and VTs with the advantage that technology being that
it makes the new devices simple, compact, and reduces the Ferroresonance
effect associated with conventional VTs, and also gives a direct connection
digitally to the protection and automation system of the substation. The
optical current transformer and the optical voltage transformer are used in
substations which allow a direct connection from transducers to the substa-
tion communication network via IEC 61850.

11.6.1 Advantages of Optical Instruments
Optical instruments is more suitable and matching to the new digital protec-
tion and automation.

FIGURE 11.7 Voltage transformer connection components.