801 / 2022-03-31 23:12:46

Experimental technology study on diverting characteristics of UHV vacuum on-load tap changer based on electro-optic effect

diverting characteristics,Experimental technology,UHV vacuum on-load tap changer,electro-optic effect

Purpose/Aim

In the development process of diverter switch of UHV vacuum on-load tap changer (OLTC) , it is necessary to carry out DC detection test, detect the DC detection waveform of each vacuum interrupters and transfer contact in the switching process of diverter switch, and judge whether the switching sequence meets the design requirements. However, due to the low voltage of DC detection test, there is no expected pre-breakdown arc and breaking arc in the switching process of diverter switch, which is difficult to accurately reflect the actual switching timing of vacuum interrupters and transfer contact under rated voltage and current conditions. Therefore, it is urgent to detect the switching sequence of each vacuum interrupters and transfer contact under rated voltage and current conditions.

Experimental/Modeling methods

In this paper, a test method for diverting characteristics of UHV vacuum on-load tap changer based on electro-optic effect is proposed. Under the condition of rated voltage and current, the voltage and current waveform of each vacuum interrupters and transfer contact in the switching process are detected through the internal fully insulated optical fiber electric field sensors and optical fiber current sensors, so as to obtain the switching sequence of each vacuum interrupter and transfer contact. In order to verify the effectiveness of the method, the prototype test platform and measurement system of UHV on-load tap changer are built. The tap changer diverting test is carried out under the rated voltage and current conditions, and the switching sequence of the switch is obtained.

Results/discussion

The effectiveness of the method is  verified  comprehensively comparing with the switching voltage, current synthesis waveform and DC detection waveform.

Conclusions

The detection of switching sequence of each vacuum interrupters and transfer contact in the switching process of diverter switch under rated voltage and current conditions is realized through the internal fully insulated optical fiber electric field and optical fiber current sensors .