APPARATUS AND METHOD FOR CONTROLLING POWER TRANSFORMER WITH LIGHT LOAD

摘要

The present invention relates to an electric power transformer for a semiconductor transformer and a control method thereof. More specifically, the present invention relates to an electric power transformer for a semiconductor transformer and a control method thereof, wherein the electric power transformer comprises multiple electric power transformer unit modules connected in parallel and can enhance electric power transform efficiency at light loads and inhibit voltage imbalance which can occur between the electric power transformer unit modules by operating a part of all electric power transformer unit modules in rotation when operating, at light loads. The control method of an electric power transformer according to the present invention includes the step of transforming alternating current input power into direct current output power by having a structure in which the electric power transformer unit module includes an alternating current-direct current converter and a direct current-direct current converter. The control method of an electric power transformer according to the present invention comprises: a light-load mode activation step for operating a part of the multiple electric power transformer unit modules, if an amount of electricity of the electric power transformer is less than a preset light-load reference; and a rotation activation step for stopping electric power transformer unit modules which are operated and for operating a part of or all of the remaining electric power transformer unit modules, if voltage imbalance occurs according to a preset reference between the electric power transformer unit modules in a state of being activated in a light-load mode.