• Truvolt Engineering Company Private Limited

Potential Transformer

Truvolt Engineering Company Private Limited offers Potential Transformer. Direct Measurement of voltage in high voltage system is not possible because of difficulty in electrical isolation of measuring instruments. It is also not possible to use voltage for the system protection due to its high value and difficulty in electrical isolation of protective relays. Therefore, Voltage Transformers are used to step-down the high system voltage to standard value accurately in proportion to their ratio. Basic Functions of voltage Transformer are:  To reduce the line Voltage to a value, which is suitable for standard measuring instruments, relays, etc., To isolate the measuring instruments, meters, relays etc. From high voltage side of an installation, To sense abnormalities in voltage and give voltage signals to protective relays to isolate the defective system. Power transformer design also apply to the voltage transformers but there are certain considerations of performance which are of particular importance. In the electromagnetic voltage transformers, accuracy depends on leakage reactance and winding resistance. These determine how the phase error and voltage error vary as the burden on secondary increases. The permeability and power dissipation of core material affects the exciting current and thus the error at zero burden. To comply with the requirement of IS:3156/IEC: 60044-2, Flux density employed in Voltage transformer is much less than the value generally used in power transformer. The turns ratio and voltage drop due to leakage. Design: Single Phase Electromagnetic Voltage Transformer (EMV) is manufactured in two types, Single Pole (To connect between line & Earth) Both Pole (To connect between Line-to-Line), Hase Voltage Transformers are of star/star connected or star/Open delta connected (residual Voltage Transformer) type. Single – Phase voltage transformers are manufactured for 11kV to 132kV system voltage, where as 3 phase voltage transformer are manufactured for 11 kV to 33 kV system voltage.