Modeling of X-ray Radiation of High-Voltage Vacuum Interrupters and Experimental Verification

The X-ray generated by vacuum interrupters (VIs) has received increasing attention as VIs develop towards higher voltage level. In this paper, a model is proposed to simulate the X-ray generation and transport in VIs based on measured voltage and current, which considers the electron field emission and acceleration, the bremsstrahlung, and the interaction between X-ray and material, enabling the calculation of X-ray dose and spectrum. Experimental measurements were then conducted on 126 kV and 252 kV VIs during power frequency voltage tests to verify the model, including the longitudinal and angular dose distribution, and the X-ray dose and spectrum using a custom-designed absorption spectrometer. For both VIs, the calculated X-ray spectrum shows more than 93% similarity compared to the measurement, and the calculated dose value shows about 35% negative deviation. By considering charge accumulation on the shield, which notably alertes the electron trajectories, the dose deviation was reduced to below 30%. This study aims to provide a foundation for further in-depth investigation of X-ray characteristics and effects in high-voltage vacuum interrupters.