Series Filter Computational Method for CCM Recovery in Double Side LCC WPT System

In this article, fundamental harmonic analysis (FHA) model is widely used for wireless power transfer due to its physical insight and compact form (for example, 8R(L)/pi(2)) of diode rectifier equivalent resistance. Because this compact form is valid for continuous conduction mode (CCM), and resonant tank parameters, such as inductance and capacitance, are independent of equivalent resistance, when designing these parameters based on double side LCC FHA model, the selected optimal parameters may not satisfy the CCM prerequisite. This will make actual system characteristics deviate from the FHA model predictions, especially the output voltage and power. Therefore, the original optimal design is invalid, and designer needs to execute a circular design, namely designing resonant tank parameters based on the FHA model, then judging or simulating whether satisfy CCM operation, redesigning parameters if not satisfy CCM. In order to validate the original optimal design even if CCM is not established and make design process straightforward, an effective remedy, which is adding a series LC filter in secondary side, is proposed, and a computational method about the required minimum filter parameter is provided. The effectiveness of the proposed remedy is verified by simulation and experiment. Besides, the computational method is packaged as a program to help researchers design rapidly.

Automated summary

This article introduces the characteristics and applications of the fundamental harmonic analysis (FHA) model, which is widely used in wireless power transfer. Due to the compact form of the model's equivalent resistance, a circular design process may be required when designing the resonant tank parameters. To address this issue, the article proposes an effective solution of adding a series LC filter on the secondary side, and provides a computational method for determining the required minimum filter parameter.