Abstract
This paper presents a repetitive learning control approach processed in combination with a type-1 optimal digital servo controller which is designed for a series and parallel resonant PWM inverter type DC-DC converter with a high voltage transformer link for a medical-use X-ray power generator. This control scheme is introduced in order to achieve rapid transient and dead-beat output voltage responses without any overshoots in addition to output voltage characteristics with low voltage ripple in its steady-state within widely specified setting ranges of output high-voltage and output current for X ray tube. An effectiveness of the repetitive learning control scheme to achieve a variety of quick transient performances in starting state based on abruptly-changed drooping operation of rectified voltage of input-side in the converter system for X ray power generator is discussed on the basis of computer simulation results and the experimental data. Furthermore, an optimal type-1 digital servo control scheme with error compensation loop is implemented in order to eliminate periodic voltage ripple fluctuations of rectifier circuit with a smoothing filter as well as abrupt voltage drooping in rectified DC input of this converter when X ray power generator is started and to realize stable and reduced voltage ripple operation in an X ray power generator.
