DC Modeling of an LCC Resonant Compensation Network in Wireless Power Transfer Systems

In this paper, an equivalent dc model of an LCC resonant compensation network is presented. The LCC topology is commonly used as a matching network at the secondary (receiver) side of Wireless Power Transfer (WPT) systems. The power delivered to the secondary side is usually rectified and delivered to some energy storage unit or load using a dc-dc converter. In order to design an optimum controller, understanding of the system dynamics is essential. However, the presence of the ac resonant circuit along with the dc-dc converter complicates the small signal modeling of the system. In this paper, an equivalent dc model is proposed for the ac resonant network that allows for a complete dc system. This dc model satisfies three conditions: i) provides the same energy storage capability as the ac model, ii) delivers the same active power to an equivalent dc load Rdc as the ac circuit does to the equivalent ac resistance Rac, iii) demonstrate the same step response as the ac circuit. Finally, the dc model dynamics is compared with the ac model.