A DC/AC power inverter control unit of a resonant-type power converter circuit (400), in particular a DC/DC converter, for supplying an output power for use in a high-voltage generator circuitry of an X-ray radiographic imaging system, a 3D rotational angiography device, or X-ray computed tomography device, comprises an interphase transformer (406) connected in series to at least one series resonant tank circuit (403a and 403a′ or 403b and 403b′) at the output of two DC/AC power inverter stages (402a+b) supplying a multi-primary winding high-voltage transformer (404). The interphase transformer (406) removes a difference (ΔI) in resonant output currents and (I1 and I2) of the DC/AC power inverter stages (402a+b). In addition, a control method is disclosed which assures that the interphase transformer (406) is not saturated. Furthermore, the control method ensures zero current operation and provides for minimized input power losses.