High voltage power supply is a special power supply device that converts input electrical energy into DC or AC output of thousands of volts to tens of thousands of volts. It is characterized by multi-stage transformer and rectifier modules, closed-loop feedback control systems, high-voltage insulation structures and protection circuits. It is widely used in precision fields such as medical imaging, industrial testing, and scientific research instruments. Output voltage fluctuations directly affect the performance accuracy and operation safety of terminal equipment.
Factors that affect the stability of the output voltage of high voltage power supply may be caused by internal circuit failure. Abnormal response of the feedback control loop is a common source of failure. Aging or temperature drift of resistor elements in the voltage sampling and voltage divider network leads to distortion of actual output value detection. The temperature drift characteristics of the error amplifier reference voltage may destroy the closed-loop regulation balance. The conduction characteristics of power switching devices such as IGBT or MOSFET degrade, causing primary energy input pulsation. Partial discharge between high-frequency transformer winding layers will cause high-frequency oscillation of secondary output.
Another factor affecting stability is environmental factors. Spatial electromagnetic interference invades the control circuit routing, especially the sensitive path of pulse width modulation signal. Drastic changes in temperature and humidity cause condensation on the surface of high-voltage components, inducing partial discharge or insulation parameter drift. Overheating of power devices caused by poor heat dissipation will change the switching characteristics and efficiency of the power module.
How to maintain it? First, perform a no-load test to distinguish the power supply body failure from the load impact, and then gradually approach the actual working condition by simulating the load. The oscilloscope monitors the output ripple to determine the state of the filter circuit, and infrared thermal imaging can locate abnormal heating points. Regular maintenance should focus on detecting the insulation resistance value of high-voltage components, the integrity of power device solder joints, and the working condition of the cooling fan.
