Intelligent Heat Dissipation Control for Electron Beam High-Voltage Power Supply

During the operation of the high-voltage power supply (with output voltage often reaching tens of kV) for electron beam equipment (e.g., electron beam evaporation, electron beam lithography), a large amount of heat is generated in power modules (e.g., high-voltage transformers, rectifier bridges). If heat dissipation is not timely, the service life of devices will be shortened by 50% for every 10℃ increase in temperature, and the output voltage ripple will increase (exceeding 5%), affecting the electron beam focusing accuracy (deviation exceeding 0.5μm). Traditional heat dissipation uses fixed-speed fans or constant-current liquid cooling, which has the contradiction of "excessive heat dissipation and energy consumption at light load, and insufficient heat dissipation at heavy load". At light load, the energy consumption of the fixed heat dissipation scheme accounts for 15% of the total power supply energy consumption, while 30% of the heat still accumulates at heavy load.
Intelligent heat dissipation control needs to build a "perception-decision-execution" closed-loop system: the perception layer uses distributed temperature sensors (accuracy ±0.1℃) to monitor the temperature of three points (power module, heat sink, cooling medium), and at the same time collects the power supply load current through current sensors (load rate is linearly related to heat generation), realizing dual-dimensional perception of "temperature + load"; the decision layer uses the fuzzy PID algorithm to establish the mapping relationship between temperature, load, and heat dissipation power. When the load rate is <30% and the temperature is <45℃, the fan speed is reduced to 30% or the liquid cooling flow is reduced to 50%, reducing energy consumption by 40%; when the load rate is >80% or the temperature is >65℃, the fan is started at full speed, the liquid cooling flow is increased to 100%, and the auxiliary heat sink (using phase change materials with thermal conductivity increased by 3 times) is triggered to realize rapid heat transfer; the execution layer uses brushless DC intelligent fans (speed adjustment range 500-5000rpm) and electromagnetic proportional valve liquid cooling systems, with a response time of <0.5s, ensuring that the heat dissipation speed matches the heat generation rate.
In practical application, after adopting this scheme in an electron beam lithography equipment, the maximum temperature of the power module decreased from 82℃ to 58℃, the output voltage ripple decreased from 6.2% to 2.1%, the electron beam focusing deviation was controlled within 0.2μm, and the energy consumption ratio of the heat dissipation system decreased from 15% to 8%, saving more than 2000 kWh of electricity annually.