A transformer with on-load voltage regulation was equipped with to restrain the worsening trend and avoid emergency events when the transformer s tap changer did not function well.

In order to make shift capacity raised continuously and more completed in arc extinction method,based on serious analysis and summary and wide investigations for arcless on-load voltage regulation technology both at home and abroad,techni-cal plan with power electronic switch was raised as the key part of arcless on-load voltage regulation.

Design of OLTC based on Single-chip Microcomputer Automatic System;

Design of automatic system for power electronics OLTC;

Design of 35kV, 16MVA Resin-Cast Dry-Type Transformer with OLTC;

A novel arcless on-load tap-changing model is proposed,which adopts inverse parallel high-power thyristor as a control switch and regulates the output voltage by switching corresponding tap-changing windings,and uses thyristor s null-current cut-off characteristic to cancel transition resistor input process to simplify the regulation process and accelerate the regulation speed effectively.

Two practical methods are introduced to renovate the power transformer with no-load tap changer into that with on-load one.