Patent ID: 9513654
Filing Date: 2016-12-06
CPC Classification: G05F,H01F

Claim Text:
1. A method of switching an on-load tap changer between winding taps of a tapped transformer by switches, the method comprising the steps of: dividing the switching process into a plurality of phases, identifying critical and non-critical switching states of the switches, monitoring each of the phases, detecting at the start of an intended switching process a value of the supply voltage as a decision basis by a voltage monitoring device in dependence on a decision logic parameterized in a controller and switching to a next defined phase of the switching process only if the supply voltage is present, and overcoming in the case of a voltage drop in the supply voltage and thus in the case of failure of the energy supply of the electric drive during a switching process, the respective critical switching states that are identified for a switching sequence of the respective switches with the help of the residual energy present in capacitors of the controller in that switching to the succeeding phase that is identified as non-critical of the switching states is carried out.