Research on Temperature Adaptive Control for Electron Beam High-Voltage Power Supplies

Electron beam technology plays a vital role in modern industry and scientific research, and its performance stability largely depends on the output quality of the high-voltage power supply. The temperature stability of the high-voltage power supply directly determines the quality and efficiency of the electron beam. Especially in ultra-precision manufacturing and fundamental scientific research, higher requirements are placed on the temperature adaptive control of high-voltage power supplies. Traditional temperature control methods often rely on static models and struggle to cope with dynamic thermal disturbances under complex working conditions. In contrast, temperature adaptive control technology significantly enhances the operational stability and reliability of electron beam high-voltage power supplies through real-time sensing, prediction, and dynamic adjustment.
Impact of Temperature Fluctuations and Control Challenges
The temperature sensitivity of electron beam high-voltage power supplies primarily stems from the thermal characteristics of power devices, magnetic core components, and high-voltage insulating materials. Temperature fluctuations can cause drift in power output parameters (such as voltage stability), leading to deviations in electron beam energy and focusing characteristics. For example, in electron beam welding, temperature fluctuations may result in inconsistent welding depth; in scientific research facilities (such as electron cooling rings), they may cause degradation in beam quality. 
Main sources of thermal disturbances include: 
• Load fluctuations: During electron beam extraction, uncollected secondary electrons form time-varying load currents, causing variations in internal power losses. 
• Ambient temperature changes: High-voltage power supplies often operate in enclosed environments with limited heat dissipation, leading to temperature rises in components like controllers, voltage multipliers, and dividers over prolonged operation. 
• Electromagnetic interference: High-voltage power supplies often use magnetic coupling for isolated power transfer. External magnetic field changes can introduce conductive and radiative interference, affecting temperature measurement and control accuracy. 
These disturbances are characterized by time-variance, randomness, and multi-source origins, making them difficult to suppress accurately with traditional linear control and conventional PID regulation.
Core Principles of Temperature Adaptive Control
Temperature adaptive control is essentially a closed-loop control method based on real-time feedback, prediction, and compensation. Its core lies in using multi-sensor fusion to collect temperature and related parameters, employing algorithmic models to predict temperature trends, and dynamically adjusting cooling systems or power supply operating parameters to achieve thermal stability. Specifically, the system typically includes the following modules:
1.  Perception layer: Various types of sensors (such as thermistors, thermocouples, infrared sensors, rotational induction meters, capacitive coupling sensors, etc.) monitor temperature and stability frequency domain fluctuations (low-frequency and high-frequency) at key points of the power supply. For example, low-frequency fluctuations are measured by rotational induction meters, while high-frequency disturbances are captured by capacitive couplers. 
2.  Decision layer: Relies on time-varying parameter prediction control algorithms to analyze the sensed data. These algorithms typically use Fast Fourier Transform (FFT) to parse the frequency components of temperature and stability signals, establish time-varying predictive controlled parameter models, and solve for optimal control outputs based on state-space methods. Additionally, adaptive fuzzy control or neural network algorithms can be incorporated to enhance the system's ability to handle nonlinear and time-varying characteristics. 
3.  Execution layer: Drives actuators such as high-frequency voltage waveform amplifiers, pulse current protection circuits, and cooling modules (e.g., fans, electronic water pumps, semiconductor coolers, or even micro-injectors) based on decision signals. These generate compensatory signals or cooling actions that are phase-opposed and amplitude-matched to the thermal disturbances, achieving active suppression of temperature fluctuations.
Technical Implementation Approaches
Efficient temperature adaptive control requires hardware-software co-design: 
• Hardware aspects: Involve constructing high-low frequency decoupling measurement circuits, high-speed analog-to-digital converters (ADCs), and high-frequency compensation amplifiers. For example, high-low frequency series decoupling circuits separate signals, and pulse current protection mechanisms prevent overcurrent damage. For localized hot spots, micro-electric controlled injectors can be introduced to atomize low-temperature media for point-to-point precise cooling. 
• Software and algorithm aspects: The core is building accurate mapping models between temperature and stability and achieving online parameter self-tuning. For instance, state estimators continuously update predictive model parameters, and iterative learning refines control outputs, enabling the system to adapt to different operational phases and environmental conditions.
Application Prospects and Conclusion
Temperature adaptive control technology for electron beam high-voltage power supplies is key to enhancing the precision, reliability, and intelligence of electron beam equipment. It finds widespread application in electron beam welding equipment, high-energy physics research facilities (such as electron cooling rings and colliders), electron beam lithography, coating, and other precision processing equipment. 
In the future, with the integration of artificial intelligence algorithms, more advanced sensor networks, and high-performance computing chips, this technology will evolve towards more accurate prediction, faster response, and higher integration. Meanwhile, digital twin technology is expected to build virtual models for high-voltage power supplies, enabling proactive temperature control and health management, further advancing the application of electron beam technology in high-end manufacturing and frontier scientific exploration.
In summary, temperature adaptive control technology effectively addresses the thermal management challenges of electron beam high-voltage power supplies through multi-dimensional perception, intelligent decision-making, and precise execution, providing a solid foundation for their stable operation in more demanding and precise application scenarios.