What is the purpose of instrument transformers in substation?
Instrument transformers (current and potential transformers) provide insulation against the high voltages of the power circuit and to protect the apparatus and the operating personnel from contact with the high voltages of the power circuits.
What principle makes the instrument transformer working?
The current transformers operating principle is based on the law of electromagnetic induction. With a certain number of turns, the voltage from the external network is supplied to the primary power winding and overcomes its total resistance.
What makes instrument transformers of such vital importance in industry?
To extend the ranges of the instruments and measuring parameters such as voltage, current, power, industries need Instrument transformers. They are used to measure current and voltages of the circuit where current and voltage levels are high.
What are the advantages of instrument transformers over Ammeter shunts?
They have the following advantages.
- The power loss in a transformer is small, whereas the power loss in a resistance shunt or multiplier may be considerable.
- The instrument operated may be well removed from all high-voltage conductors.
What are advantages of instrument transformers over Ammeter shunts and voltmeter multipliers?
Important Points The advantages of instrument transformers over ammeter shunts and voltage multiplies are the metering circuit is electrically isolated from the power circuit thereby providing safety in use to both the instruments and the operator and small power losses in comparison to those in ammeter shunt and …
What is function of CT and PT?
The current transformer and potential transformer (also called voltage transformer) are both measuring devices. A CT lowers the current signals for measurement purposes, while a PT lowers high voltage values into lower ones. The transformers are designed to measure whether power systems are both accurate and safe.
What are different types of instrument transformers explain?
two types like wound type & closed core. These transformers are used to measure current, power, monitoring the operation of power grid & protective relay. These transformers are used to measure, operating protective relay & power source.
What are the advantages of current transformer?
Current transformers offer electrical isolation among measuring instruments & high voltage power circuits. So that electrical insulation requirements can be reduced in protective circuits & measuring instruments.
Which instrument is used to voltage and current of the system?
Voltmeters and ammeters are used to measure voltage and current, respectively.
Where are instrument transformers used?
Instrument Transformers are used in AC system for measurement of electrical quantities i.e. voltage, current, power, energy, power factor, frequency. Instrument transformers are also used with protective relays for protection of power system.
When should Instrument Transformer be used?
The most common usage of instrument transformers is to operate instruments or metering from high voltage or high current circuits, safely isolating secondary control circuitry from the high voltages or currents.
What is an in- instrument transformer used for?
Instrument transformers are current and voltage transformation devices that are used to step down the transmission and distribution line voltages and currents to levels that can safely operate measuring instruments, protection devices and control relays by isolating it from the supply voltages.
What are the advantages of a transformer?
Damaged parts can be easily replaced. These transformers offer electrical isolation among measuring instruments & high voltage power circuits. So that electrical insulation requirements can be reduced in protective circuits & measuring instruments. By using this transformer, various measuring instruments can be connected to a power system.
What are the disadvantages of instrument transformers?
The only disadvantage of instrument transformer is, these can be used simply for AC circuits but not for DC circuits Instrument transformers like CTs or current transformers play an essential role while monitoring and protecting electrical power systems.
What is the function of current transformer?
Current Transformer (C.T.) Current transformer is used to step down the current of power system to a lower level to make it feasible to be measured by small rating Ammeter (i.e. 5A ammeter). A typical connection diagram of a current transformer is shown in figure below.