Transformer on Load and No Load Operation
What is main difference between no load transformer and on load transformer?
The most significant difference between a no-load transformer and on-load transformer is that a no-load transformer has a open-circuited secondary winding where no electrical load is connected across its terminals, whereas an on-load transformer has a close-circuited secondary winding. In the case of a no-load transformer, the secondary winding current is always equal to 0 A, but an on-load transformer has certain secondary winding current whose magnitude depends on the load connected across it.
What happen if a current transformer is operated on no-load?
When a current transformer (a type of instrument transformer used in electrical measurement) is operated under no-load condition i.e., open circuited secondary winding, a very large voltage is developed between its secondary winding terminals. Due to high voltage, air between the terminals gets ionized and causes an electric spark of very high intensity that can lead to an electrical accident.
What happens when a transformer is loaded by a short circuit?
When a transformer is loaded by a short-circuit, the secondary winding current becomes too high that will destroy the insulation between the winding and core. This results in burning of the secondary winding.
Theory of Transformer on Load and No Load Operation
In this article, we will study the theory of transformer on load and no load operation. A transformer is a static electrical machine used to increase or decrease the value of voltage and current in an electrical circuit. The transformer operates on the principle of electromagnetic induction and mutual inductance. A transformer typically consists of two copper winding and a magnetic core. The windings are named as primary winding and secondary winding. The input supply is connected to the primary winding and the output electrical supply is taken from the secondary winding. Hence, the secondary winding is one to which the electrical load is connected.
Let us understand the operation of a transformer on load and no-load conditions.