30-06-2012, 12:28 PM
CURRENT & VOLTAGE TRANSFORMERS
VOLTAGE TRANSFORMERS
Voltage Transformers (VTs) are also classified along with Current Transformers (CTs) as Instrument Transformers. These are
shunt connected devices intended to reproduce Secondary Voltages in fixed proportion to the Primary system Voltage. VTs
contrast with Power, Distribution & Control Transformers (which are also shunt devices) in having very small rated power
compared with Power, Distribution, Grounding & Control Transformers. Main purpose of Power, Distribution & Control
Transformers on one hand is to deliver Power from one system to other system or systems with or without galvanic isolation
between each system (e.g. an Auto-Transformer which may be Power Transformer transforms power from one system to other
without galvanic isolation). Main purpose of a VT is to produce replica of a system voltage which can be used in Metering &
Relaying systems maintain required accuracy over range of Voltage.