Image Quality Optimization of High-Voltage Power Supplies for X-Ray Machines

1. Connection Between High-Voltage Power Supplies and Image Quality
The image quality of X-ray machines depends on the intensity stability, energy consistency, and radiation uniformity of X-rays, all directly determined by the high-voltage power supply (providing tube voltage and tube current). Tube voltage fluctuations cause changes in X-ray penetration, resulting in uneven image grayscale (e.g., in medical X-ray machines, a 1% voltage fluctuation causes a 5%-8% grayscale deviation); tube current fluctuations affect X-ray dose, reducing image clarity (a 0.5% current fluctuation decreases image signal-to-noise ratio by 10%); power supply output ripple introduces X-ray intensity noise, generating image noise. Therefore, optimizing high-voltage power supply performance is the core path to improving X-ray machine image quality.
2. Technical Measures for Image Quality Optimization
(1) High-Precision Voltage Stabilization Technology
A composite voltage stabilization scheme of "multi-stage feedback voltage stabilization + linear voltage stabilization compensation" is adopted: the front stage uses a switching voltage stabilization topology (e.g., LLC resonant topology) for high-voltage output, reducing switching losses; the rear stage uses a linear voltage stabilization circuit for fine adjustment of output voltage, reducing ripple. Meanwhile, a high-voltage voltage division sampling circuit (accuracy ≤0.01%) monitors tube voltage in real time, and a PID closed-loop control adjusts the parameters of the voltage stabilization circuit, controlling tube voltage fluctuation within ±0.1%. In medical diagnostic X-ray machines, this scheme reduces tube voltage ripple from 1.5% to 0.2%, decreasing image grayscale unevenness by 80%.
(2) Constant Current Control Optimization
A constant current strategy of "high-precision current sampling + fast feedback adjustment" is adopted: shunts (current sampling accuracy ≤0.005%) or Hall current sensors collect tube current in real time, transmitting sampling signals to a high-speed control chip (response time ≤1μs). The chip adjusts the power supply's output current based on the deviation between the set current value and the actual value. For dynamic load changes during X-ray machine exposure (e.g., tube current suddenly increasing from 100mA to 500mA), a predictive control algorithm adjusts the power supply's drive signal in advance to avoid current fluctuations. In industrial CT X-ray machines, this strategy reduces tube current fluctuation from ±0.8% to ±0.1%, improving image clarity by 30%.
(3) Fast Response Design
The power supply topology is optimized to reduce parasitic parameters (e.g., line inductance, capacitance): short-path wiring design shortens the length of high-voltage output lines, reducing distributed inductance; high-voltage ceramic capacitors replace traditional electrolytic capacitors, reducing parasitic resistance. Meanwhile, fast-response switching devices (e.g., SiC MOSFETs) improve the power supply's response speed to load changes. In dynamic X-ray machines (e.g., cardiovascular angiography X-ray machines), the power supply's dynamic response time is reduced from 10μs to 2μs, enabling real-time tracking of X-ray dose requirements during heartbeats and avoiding image blurring.
(4) Anti-Interference Design
An anti-interference scheme of "EMC filtering + shielding isolation" is adopted inside the power supply: common-mode inductors and differential-mode capacitors are added to the input side to suppress grid interference; the high-voltage output side uses a metal shield to prevent high-voltage electric field interference to external circuits; optical coupling isolation is used between control circuits and high-voltage circuits to avoid high-voltage noise entering the control terminal. Meanwhile, in X-ray machine systems, twisted-pair cables transmit control signals between the power supply and imaging system to reduce signal interference. Through anti-interference design, the electromagnetic interference (EMI) of the power supply output is reduced by 40%, and image noise is reduced by 60%, significantly improving image signal-to-noise ratio.
3. Application Cases and Future Development
Optimized high-voltage power supplies for X-ray machines have been applied in medical DR (digital radiography) equipment (image resolution up to 300dpi, 50% higher than traditional equipment) and industrial CT testing equipment (clearly identifying 0.1mm micro-defects). In the future, with the integration of AI technology, high-voltage power supplies will achieve collaborative optimization with imaging systems: AI algorithms analyze image quality feedback to automatically adjust tube voltage and current parameters, realizing adaptive matching of "image quality - power supply parameters"; meanwhile, digital twin technology simulates imaging effects under different power supply parameters, optimizing power supply settings in advance to further improve the imaging accuracy and stability of X-ray machines.