Method and device for inhibiting transformer no-load switchon surge

Abstract

This is a device to avoid transformer flow upon switch on in idling and the method. The device includes more than one switching sets linked between the power switch and the transformer, each phrase of the alternating current is linked to at least one switching set; a side contactor parrell linked to the switching sets; a control unit; a front end voltage transformer for testing power voltage; a current transformer for testing transformer current; a back end voltage transformer for testing transformer voltage whose signal output is linked to the control unit and calculates the size and phase of the magnetic flux linkage of the internal pre-incharged magnetism of the transformer, and calculates the link time for the premier winding sets to decide the connecting time for the contactor, as well as the link time for other winding sets for contacting of the side switch sets.

Description

technical field [0001] The invention relates to a device for suppressing transformer excitation inrush current generated when a transformer is put into operation without load in a power supply and distribution system, in particular to a device and method for suppressing transformer no-load closing inrush current. Background technique [0002] The excessive excitation inrush current generated when the transformer in the power supply and distribution system is turned on without load often causes problems such as the malfunction of the microcomputer protection device, the increase of the mechanical stress of the winding, and the deterioration of the power quality. At present, for this situation, the second harmonic braking coefficient is basically changed in the front-end microcomputer protection device to avoid the no-load closing surge, thereby preventing the protection device from malfunctioning. However, when the transformer is closed with no load, due to the uncertainty of...

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Problems solved by technology

[0003] In view of the fact that the currently widely used methods cannot efficiently solve the problems of microcomputer protection malfunctions caused by transformer no-load closing inrush current, the patent of the present invention focuses on eliminating and suppressing transformer no-load closing inrush current, and provides a method for suppressing transformer no-load closing inrush current. A device and method for gate inrush current, thereby effectively solving problems such as microcomputer protection malfunctions caused by excessive excitation inrush current in power supply and distribution systems

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