On-load tap-changer of transformer and on-load tap changing transformer

Abstract

The invention relates to an on-load tap-changer of a transformer. The on-load tap-changer of the transformer comprises a plurality of tap-changer units and a switch control circuit, wherein each tap-changer unit comprises two relay switch contacts and corresponding contact protection circuits; one end of each of two switch contacts is connected with a corresponding transformer winding tap and the other end is connected with a power supply after being connected in parallel; two switch contact protection braches are a series circuit of an MOS tube and an auxiliary relay contact and the other series circuit of a diode and the other auxiliary relay contact respectively; two series circuits are connected with two ends of the corresponding switch contacts in parallel respectively; the plurality of tap-changer units are connected with one another in parallel to form a multi-winding branch tap-changer; and the switch control circuit controls all main switches, auxiliary switches and MOS tubes to act according to a certain time order, so that switching of transformer windings is achieved. Compared with an existing on-load tap-changer, the on-load tap-changer of the transformer provided by the invention has the advantages of being high in tapping speed, free of an inrush current in a tapping process, continuous in current, simple to operate, high in reliability, small in volume, light in weight, low in cost and the like.

Description

technical field [0001] The invention relates to an AC voltage regulating device, in particular to an on-load voltage regulating tap changer and a transformer with an on-load voltage regulating tap changer for changing the secondary output voltage of the transformer by changing the number of turns of the primary winding of the transformer. Background technique [0002] During the operation of the power transformer, the output voltage will change due to the change of the incoming line voltage or the change of the load. By changing the number of turns of the primary winding of the power transformer, the secondary output voltage can be changed, so as to achieve the purpose of adjusting or stabilizing the voltage. Using a tap changer to change the number of turns of the coil can achieve the purpose of changing the output voltage. The on-load tap changer of the transformer is to change the primary turns of the transformer (ON-LOAD TAP CHANGING) with the on-load tap changer under t...

AI Technical Summary

Problems solved by technology

But when this kind of tap changer is in operation, when the two sets of switches are switching at the moment, because it is impossible to accurately control the closing or opening time of the auxiliary relay, the two sets of auxiliary switch circuits will generate short-circuit current, which will cause cut-off or short-circuit of the winding. case, this creates inrush current on the regulator winding and shortens the life of the switch

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