The difference between autotransformer and ordinary transformer

The difference between autotransformer and ordinary transformer:

1. The primary side and the secondary side are not only magnetically connected, but also have electrical connections, while ordinary transformers are only magnetic connections.

2. The capacity of the power supply through the transformer is composed of two parts: the electromagnetic induction power between the primary winding and the common winding, and the conduction power directly conducted by the primary winding.

3. Since the autotransformer winding is composed of a primary winding and a common winding, the number of turns of the primary winding is reduced correspondingly to the number and height of the primary winding of the common transformer and the common winding current and the leakage reactance, and the self-coupling is short-circuited. The reactance X is the (1-1/k) times of the short-circuit reactance of the ordinary transformer, and k is the transformer ratio.

4. If the autotransformer is provided with a third winding, its third winding will occupy the common winding capacity, affecting the auto-coupling operation mode and switching capacity.

5. Since the neutral point of the autotransformer must be grounded, the setting and configuration of the relay protection is complicated.

6. The autotransformer is small in size, light in weight, easy to transport, and low in cost.