Reactive power compensation device of no-load transformer

The utility model provides a reactive power compensation device of a no-load transformer, which comprises a transformer bus, the transformer bus is connected with a supplementary compensation circuit through a circuit mutual inductor, and one end of the supplementary compensation circuit is connected with a first capacitor through a first fuse, a first alternating current contactor and a first thermal relay in sequence. By calculating the compensation reactive electric quantity, adding low-voltage reactive compensation and additionally arranging a low-voltage power capacitor, the reactive power compensation device ensures that the economic loss caused by the increase of power loss due to overcompensation and reverse reactive power transmission is avoided in a no-load or light-load state, the reactive power does not flow back, and the power factor of a user is always in a lagging state, so that the reactive power compensation device is favorable for the user, and also is favorable for the power supply of the u