1. The primary side and the secondary side are not only magnetically connected, but also electrically connected, while ordinary transformers are only magnetically connected.
2. The capacity of the power supply passing 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 auto transformer winding is composed of primary winding and common winding, the number of turns of the primary winding and the height of the primary winding and the current of the common winding and the leakage reactance generated by the common transformer are correspondingly reduced, and the short circuit of the auto transformer The reactance X is (1-1/k) times of the short-circuit reactance X of ordinary transformers, and k is the transformation ratio of the transformer.
4. If the auto transformer has a third winding, the third winding will occupy the common winding capacity, which will affect the operation mode and exchange capacity of the auto transformer.
5. Since the neutral point of the auto transformer must be grounded, the planting setting and configuration of the relay protection are complicated.
6. The auto transformer is small in size, light in weight, easy to transport, and low in cost.