Contents I. Introduction
Near-field and self-parasitic effects are known to create issues with the high frequency performance of filters [1]. The impact of near field coupling on LC filter was demonstrated in [2]. The extension to CLC filter stage was shown in [3], where an optimized layout was recommended. Besides these very specific applications, self and mutual cancellation techniques have also been documented in [3]–[6]. However, so far literature has focused mainly on low power, single-phase applications. For three-phase high-power systems, several limitations should be considered when applying the existing techniques. For instance, the thermal issue arises due to the high winding losses contributed by PCB windings [7], [8] or cancellation turns [9], [10] for high current applications. The physical layout is limited by creepage and clearance requirements for enough isolation in high voltage applications. Besides, there is additional complexity to implement the cancellation network for three-phase applications, such as the cross-coupling between phases can results in a much severe CM to DM mode conversion during cancellation compared to single-phase systems. As such, this paper focuses on extending the pre-existing concepts to three-phase high-power systems.
