What are the types of voltage transformers?
What are the types of voltage transformers?
Voltage transformer - according to the principle of electromagnetic induction type and capacitance type two categories.
According to the purpose, voltage transformers are divided into two categories: measurement and protection.
① electromagnetic induction type voltage transformer. The working principle is the same as that of transformer. The basic structure is also iron core and primary and secondary winding. It is characterized by small and constant capacity and close to no-load state during normal operation. The impedance of the voltage transformer itself is very small, once the short circuit occurs on the secondary side, the current will increase sharply and burn the coil. For this reason, the primary side of the voltage transformer is connected with a fuse, and the secondary side is grounded, so as to avoid the occurrence of high potential to the ground on the secondary side when the primary and secondary side insulation is damaged. The equivalent circuit of the electromagnetic induction voltage transformer is the same as that of the transformer.
② capacitance divider type voltage transformer. Made on the basis of capacitive voltage divider. Capacitive voltage transformers are used in combination with the coupling capacitors of the power system carrier communication to simplify the system and reduce the cost. At this time, it also needs to meet the requirements of communication operation. Voltage transformers are classified by structure, including oil-filled type, dry type, three-core five-column type and single-phase type, as well as fully insulated type and semi-insulated type.
