Potential transformers are notes as Voltage Transformers or instrument transformers, that is employed to measure voltage in a power system network. It has large number of primary turns and a less numbers of secondary turns. It is used to control the large value of voltage.
The potential transformer is connected in parallel with the circuit to be monitored. The potential transformer works on an equivalent principle of different transformers. It converts voltages from high to low. It will take the thousands of volts behind power transmission systems and stepdown the voltage to measurable value. The primary could also be connected phase to ground or phase to phase. The secondary is typically grounded on one terminal. These transformers work for single and 3 phase systems, and are connected at some extent wherever it's convenient to measure the voltage.
There are 3 primary forms of voltage transformers(VT): magnetic force (electromagnet), capacitor, and optical. The magnetic force voltage transformer may be a wire-wound transformer. The electrical condenser voltage transformer uses a capacitance resistor associated is employed at higher voltages because of a lower cost than an magnetic force. An optical voltage transformer exploits the electrical properties of optical materials.