A self-adaptive distribution transformer can automatically regulate its tap changer position rated operating capacity

online load phase rotation

and phase by phase reactive compensation according to the system voltage and loading conditions without disconnecting the load. The functional architecture of self-adaptive distribution transformer is described. The controlling principles of online load phase rotation

on-load capacity regulating

phase by phase reactive compensation

and on-load voltage regulation are analyzed. The methods to determine control setting points are proposed with simulation model. Simulation and analysis results demonstrate the obvious advantages of the proposed distribution transformer. It is suitable to be used in rural distribution network

which features seasonal load

low annual average load rate

high no-load losses

and under voltages at the end user terminals and low power factor. By using self-adaptive distribution transformers

the economic operation level of distribution area can be improved

the quality of power supply for end-users will be improved

the operation loss of power network will be reduced

the energy-saving and emission reduction at the distribution network level will be maximized.