Research on Key Technologies of the 10kV Wide Range and Arcless on-Load Automatic Voltage Regulation Distribution Transformer

At present, a small number of distribution transformers with on-load tapping mode are used, which still adopts the combination of traditional mechanical devices and electric operating mechanisms. The moving speed is slow, the number of voltage regulation is limited, and the mechanical and electric parts have high failure rate. The arc generated by the switch causes the insulation of the transformer oil to age, which greatly affects the reliability of the power supply of the grid. Aiming at the above problems, an arcless on-load voltage regulation scheme using power electronic devices as OLTC auxiliary contacts is proposed, and the control hardware and software control flow design of the arcless on-load automatic voltage regulation module is completed, and the arcless switching of the power electronic switch is utilized. The use of the power electronic switcher has the advantages of arcless turn on or off and controllability of turn on or off time, which reliably triggers the turn on or off of the switcher. Thereby achieving the purpose of fast and frequent phase separation of the transformer and precise wide amplitude regulation.