Improved High-Frequency Planar Transformer for Line Level Control (LLC) Resonant Converters

Abstract

In this letter, an improved structure of High Frequency (HF) magnetic integrated planar transformer is proposed and the prototype transformer is demonstrated. In comparison to conventional planar integrated magnetics; the improved structure has a better ability on leakage inductance adjustment. Also; instead of using expensive Printed Circuit Board (PCB) windings on the primary side, multi-strand Litz wires are used for the design. The transformer is fabricated with two common EE shape magnetic cores along with magnetic insertions placed between the primary and secondary windings (outside the main core). To analyze the proposed transformer, the numerical 3-D Finite Element Method (FEM) technique is employed to investigate the eddy current losses and the adjustment of the leakage inductance.

Design and Control of a DC Collection System for Modular-Based Direct Electromechanical Drive Turbines in High Voltage Direct Current Transmission

“…Nevertheless, researchers have proved theories in initiating state-of-the-art H-XFMR prototypes (i.e., >20 kHz) by materialising fusion magnetic core materials that proffer higher flux density tolerance and saturation region (i.e., B sat [mT] > 1450) while provisioning large power density (i.e., 10 kVA < P < 500 kVA) with low core losses [23][24][25][26][27]. Table 1 depicts aggrandising technological trends in H-XFMR interests to condone rapid transitioning of SST technologies for power converters.…”

Investigation of non-linear phenomenon for integrated magnetics used in LLC converters

“…Due to the non-linear behavior of the magnetics, implementation of magnetic integration needs to be carefully considered . The saturation of magnetics is normally not a concern in high voltage input applications [1], but becomes a serious issue when designing the low voltage input and high power applications . The inserted magnetic integration has been categorized into two types according to the position of their magnetic insertions .…”

“…The inserted magnetic integration has been categorized into two types according to the position of their magnetic insertions . The inserted magnetic structure MIO as presented in [1], and MIP structure introduced in [2] . They performs poorly in high power and low voltage input applications over add-on type of magnetic integration structure [3] .A brief discussion of these two categories is presented .…”

Investigation of Nonlinear Phenomenon for Insertion Type Integrated Magnetics Used in Linear Level Control Converters

“…Thus, magnetic integration was introduced, which effectively increases the L s required while keeping the total size of the magnetics small [3]- [7]. Among these integration structures, the inserted type is the most compact and inexpensive configuration due to its inherent geometry characteristics [8].…”