METHOD FOR REDUCING INRUSH CURRENT OF SINGLE-PHASE TRANSFORMER WHEN RE-ENABLING IN IDLE MODE Russian patent published in 2017 - IPC H02H9/00 

FIELD: electricity.

SUBSTANCE: method comprises a switch contact closure when connecting the transformer to the network at the time of the maximum instantaneous voltage value in phase 90°. Herewith, prior to the switch contact closure when the transformer is connected to the network, demagnetization of the transformer magnetic circuit is completed by removing the residual magnetization of the transformer magnetic circuit by supplying direct current to the primary transformer winding of the amount sufficient to bring its magnetic circuit to saturation. Then, current is switched off and damped oscillatory discharge of the transformer current produces remagnetization of the magnetic system through the discharge capacitor with a gradual decrease of the magnetic induction amplitude to zero, and the switch contact closure with the transformer connected to the network, is performed by switching the device to the specified voltage phase comprising a switch control circuit, while the switch contacts are closed at the given phase after constant voltage supplying to the switch control circuit for synchronization with network voltage.

EFFECT: increasing efficiency of the inrush current reduction .

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