Irradiation Uniformity Improvement of High-Voltage Power Supplies for Sterilization Irradiation

Sterilization irradiation technology is widely used in the field of food and medical device sterilization due to its advantages of no chemical residue and high efficiency. The irradiation uniformity directly determines the sterilization effect - insufficient local irradiation dose easily leads to incomplete sterilization, while excessive dose will damage product quality. As the power supply core of the electron beam or X-ray generating device, the output energy stability and distribution control ability of the high-voltage power supply (HVPS) for sterilization irradiation are the keys to improving irradiation uniformity.
In terms of energy stability control, a series resonant topology is adopted. Through automatic frequency tracking technology, HVPS works at the resonant frequency point, reducing the impact of load changes on the output voltage, and controlling the voltage fluctuation within ±0.5%. At the same time, an energy feedback adjustment mechanism is introduced, and dose detectors are used to collect dose data in the irradiation area in real time. When a dose deviation is detected, the output current of HVPS is adjusted to achieve dose compensation, ensuring stable irradiation energy.
To solve the problem of uneven distribution in the irradiation area, a multi-source coordinated power supply system is designed: 3-5 groups of HVPS power supply units are arranged according to the size of the sterilization cavity, and each group of units independently controls the output energy; an infrared thermometer is used to monitor the temperature changes in different areas of the sterilization cavity (temperature is positively correlated with irradiation dose), an irradiation dose distribution model is constructed, and a fuzzy control algorithm is used to dynamically adjust the output parameters of each HVPS unit, so that the internal irradiation dose difference of the cavity is controlled within ±3%.
In addition, the pulse output mode of HVPS is optimized, and variable pulse width technology is adopted to adjust the pulse width (0.1-1ms adjustable) according to the product thickness, avoiding local irradiation dose unevenness caused by product thickness differences. After the application of this scheme in a food sterilization enterprise, the qualified rate of product sterilization increased from 89% to 99.2%, and the irradiation uniformity index met the requirements of ISO 11137 standard, providing a guarantee for the high-quality application of sterilization irradiation technology.