Abstract
The concept of a coupling factor was introduced in International Electrotechnical Commission (IEC) 62311 and 62233 to provide a product safety assessment that considers the localized exposure when an electromagnetic field (EMF) source is close to the human body. To calculate the coupling factors between the human body and EMF source, a numerical calculation should be carried out to calculate the internal quantities of the human body models. However, at frequencies below 10 MHz, the computed current density or internal electric field has computational artifacts from segmentation or discretization errors. Specifically, coupling factors are calculated based on the maximum values, which may include computational artifacts due to abnormal peaks. In this study, we propose an improved calculation method to remove computational artifacts by applying the 99.99th percentile in calculating the coupling factors without underestimation. The performance of the proposed method is verified through a comparison based on various human body models with wireless power transfer (WPT) systems and compliance with the reference levels and basic restrictions. The results indicate that the proposed method can provide uniform coupling factors by reducing the computational errors by up to 65.3% compared to a conventional method.
Highlights
Wireless power transfer (WPT) technology has been continuously developed and is currently used in various applications
We propose the use of 99.99th percentile for calculating a coupling factor at low frequency, which can objectively evaluate the exposure of the human body to electromagnetic field (EMF) by eliminating computational artifacts
We proposed an improved coupling factor calculation method for removing computational artifacts to achieve uniform assessment results in human body models exposed to EMFs from WPT systems
Summary
Wireless power transfer (WPT) technology has been continuously developed and is currently used in various applications. It has been studied in various categories, such as energy transmission using resonance in a low-frequency band or RF energy transmission, depending on the application [1–3]. WPT technology is already being used to charge batteries to increase operating time and improve user convenience. As it is being studied steadily, its use is expected to increase further in the future. Advances in this technology have led to concerns about the potential adverse effects on health caused by human exposure to electromagnetic fields (EMFs) from
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have