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Variations in the coupling coefficient of loosely coupled transformers and dynamic loads have a significant impact on the overall performance of bidirectional inductive power transfer (BIPT) systems. However, a wide range of load and coupling coefficient variations are common in the actual charging process, which may cause the converter on both sides to operate in a hard switching state, resulting in switching noise, reduced efficiency, and potential safety concerns. In this paper, a triple-phase-shift control (TPSC) strategy is proposed to study the zero-voltage switching (ZVS) operating range and constant-voltage output (CVO) characteristics of the double-side-LCC (DS-LCC) topology. To ensure a CVO over the wide range of coupling coefficient variations, a dual-phase-shift control is introduced for AC voltage matching. Based on this, the third phase-shift angle control between the converters on both sides is introduced to ensure the ZVS realization. Meanwhile, the time-domain model is developed to analyze the rationality of the proposed third phase-shift angle and the ZVS operating range. Finally, the effectiveness of the proposed TPSC strategy is validated through a 1.5 kW experimental prototype with an air gap of 100–150 mm. [ABSTRACT FROM AUTHOR]

Compensation topologies of the inductive power transfer (IPT) converter for electric vehicles (EVs) have been researched in previous works. However, a methodology for designing a compensation topology based on the efficiency of the IPT converter has been barely discussed. This paper proposes an optimal design methodology for compensation parameters to achieve optimal efficiency of the IPT converter with LCC-S. The optimal output voltage is derived using the losses analysis of the IPT converter, and the IPT converter is designed for the optimal output voltage to achieve the optimal efficiency. Furthermore, the battery management (BM) converter on the receiving side is designed based on the output voltage of the IPT converter, the fluctuation range of the coupling coefficient, and the battery charging voltage. The validity of the proposed IPT converter design methodology is verified by designing different compensation parameters and BM converters. The power rating of the three design cases is 3.3 kW with the same magnetic pads satisfying the SAE J2954 WPT 1 class. [ABSTRACT FROM AUTHOR]

In low power energy storage systems, to match the voltage levels of the low-voltage battery side and high-voltage direct current (DC) bus, a high voltage gain converter with bidirectional operation is required. In this system, the cost effectiveness of the design is a critical factor; therefore, the system should be designed using a small number of components. This paper proposes a set of bidirectional converters with high voltage gain range based on the integration of the boost converter with a Ćuk converter, single ended primary inductor converter (Sepic), and buck-boost converter. The proposed converters consist of a small number of components with a high voltage gain ratio. Detailed comparisons are made with respect to the operating mode, number of components, voltage, and current ripple and efficiency. The efficiency of proposed converters are higher than the conventional converters in entire power range, and 6% higher efficiency can be achieved in large duty cycle by calculating loss analysis. To verify performances of the proposed converters, three 200-W prototypes of the converters are developed under the same experimental conditions. The results revealed that converter I exhibits the highest efficiency in the boost mode (92%) and buck mode (92.2%). The experimental results are shown to verify the feasibility and performances of the set of converters. [ABSTRACT FROM AUTHOR]