1. A Systematic Approach for Load Monitoring and Power Control in
Wireless Power Transfer Systems Without Any Direct Output
Measurement
Abstract:
A systematic method is presented in this paper to show that, based only on
the measurements of the input voltage and current, the load impedance of
a wireless power transfer system can be instantaneously monitored and
load power controlled without using any direct measurement from the
load. A new mathematic procedure for deriving the output load
information based on input voltage and current is explained. This
systematic method, which can be applied to wireless power systems with
two or more coils, eliminates the need for sensors and communication
devices on the load side, thereby greatly simplifying the power control
circuitry. The principle of the load estimation method, the power loss
optimization and control scheme are described and favorably verified with
measurements obtained from an eight-coil wireless power transfer system.