is one kind of distribution transformers, which has two capacities ( one is small, another one is large) and can adjust according to the load size. The changing of high voltage winding connection mode, the conversion of low voltage winding parallel series and the adjustment of every connection are finished by special no excitation modulating capacity switch. Meanwhile, when large capacity is adjusted to small capacity, no-load loss and no-load current will be reduced because the increasing of low voltage turns and the decrease of core's magnetic flux density reduce unit loss of silicon steel, thus reaches the purpose of lowing loss and energy-saving. Double voltage distribution transformer has one small and one large voltage, and can adjust according to electric grids voltage. The conversion of high voltage winding parallel series and the adjustment of every connection are finished by special no excitation modulating capacity switch.  

General introduction 

SZ11-T load modulating capacity transformer is one kind of distribution transformers with new technology and energy-saving. It has two kinds rated capacity, one is small and another one is large, and the operation mode of these two capacity can be automatically converted which solves the problem of transformers' large loss caused by relatively large changes of 10 kV distribution grids seasonable magnitude, and also solve the operational maintain problem because capacity must be adjusted by hand after the outage of no-load modulating capacity transformer power. Modulating capacity transformer not only suits rural electric grids which seasonable magnitude changes are relatively large, but also suits downtown, development zones, industrial zones and other distribution work area where circadian load changes are obvious. 

 Working principle

Load modulating capacity transformer is adjusted by the intelligent controller externally modulating- switches, thus completing the convert process of high capacity and low capacity, more details as below: intelligent controller determines the current load size by detecting transformer's voltage and current of low voltage side; determines related constraints based on the capacity setting value; if meet the setting conditions, intelligent controller will issue the corresponding control commands to load modulating capacity switch, then modulating capacity switch can finish the star,angle change and the parallel series convert of transformer's inner high voltage winding, low voltage winding; completes the process of capacity adjustment under conditions with power.