X-Radiation Emission of High-Voltage Vacuum Interrupters: Dose Rate Control under Testing and Operating Conditions

The present study investigates the possible emission of X-radiation from vacuum interrupters when applying high voltages between the separated contacts. Vacuum interrupters have to comply with the dose rate limits for X-radiation emission regulated by protection laws and relevant standards in order to ensure a save working environment during testing and operating conditions in the field. Our work focuses on the X-ray emission of vacuum interrupters to be used in high-voltage transmission systems. Different contact separations up to several 10 mm and different conditions of the interrupter (new vs. operated) are investigated. Additionally, the emission sources inside of the vacuum chamber are located. In general, the radiation emission increases with applied voltage and decreasing contact gap. In conclusion, it can be stated that 145/170 kV voltage levels can safely be served with single-break interrupters in terms of X-radiation. All relevant standards are fully complied with.