Improved Particle Swarm Optimization Algorithm based Model Parameter Identification of Tube Current in High Voltage Power Supply for X-ray Machine

High voltage power supply with X-ray tube serves as the key component of X-ray machine. The tube current is essential to X-ray generation as well as tube current overshoot prevention. Currently, the control of tube current relies on experienced relation with filament current, which varies with the aging of tube and can only be regularly adjusted by tube training. This paper derives the mathematical model of tube current for X-ray generator based on hot electron emission and heat dissipation. The unknown parameters in the mathematical model are identified by an improved particle swarm optimization (IPSO) algorithm. Experiments on a practical 900W/90kV digital controlled high voltage power supply serving an X-ray generator are carried out. The effectiveness and accuracy of proposed model and parameter identification algorithm are verified.