The parallel operation of transformers means that the primary windings of two or more transformers are connected in parallel on the busbar of the same voltage, and the secondary windings are connected in parallel on the busbar of another voltage.Its meaning is: when one transformer fails, other transformers running in parallel can still continue to operate to ensure the power consumption of important users; or when the transformer needs to be repaired, the standby transformer can be connected in parallel, and then the transformer to be repaired is powered off and repaired. , which can not only ensure the planned maintenance of the transformer, but also ensure that the power supply is not interrupted and improve the reliability of the power supply.