Principle of a novel component minimized active power filter for high-power magnet supplies

The advent of grid-connected power electronics applications calls for a good understanding of the possible control methods. A well-defined class of applications refers to three-phase diode rectifiers able to supply current to a highly inductive load. Given the standard requirements for the grid current, a three-phase power converter is usually employed as a shunt filter to compensate the quasi-square-wave current into a sinusoidal waveform. Controlling the IGBT devices on the phase without any diode rectification only, this paper proposes a new current control arrangement able to use the power converter without neither an additional DC power supply nor a capacitor bank. Moreover, the rating of the three-phase power converter for a given load current yields minimized. Performance evaluation is considered with Intelligent Power Modules (IPM).