Simulation of Maximum Efficiency Point Tracking in Wireless Power Transfer Systems using Pulse Density Modulation

摘要

This paper presents a method of control known as maximum efficiency point tracking (MEPT). This method of control is used for wireless power transfer (WPT) systems to provide maximum value of efficiency against load variations and coupling with achieving power demands of the system. In traditional MEPT systems, on both transmitting and receiving sides dc/dc converters are used in order to achieve maximum efficiency and for the regulation of output voltage. But this arrangement increases the complexity of network with increasing power loss. Some implementations lead to new problems like hard switching, large dc voltage ripples and low average efficiency. An implementation of MEPT based on pulse density modulation is explained in this paper which removes all the drawbacks in existing implementation. A PDM circuit is used in both transmitting and receiving side to achieve maximum efficiency. A simulation circuit is built in matlab in this paper to get maximum efficiency. By varying load resistances and pulse densities in the matlab Simulink circuit an efficiency and output voltage is checked By comparing the results of existing MEPT implementation with this simulation circuit of WPT using PDM it achieved efficiency upto 83% for various load resistances and pulse densities.