Power Distribution of a Multiple-Receiver Wireless Power Transfer System: A Game Theoretic Approach

Wireless power transfer (WPT) has shown its potential over conventional charging systems in recent years. However, it is still challenging to determine the power distribution of a multiple-receiver WPT system for its high sensitivity, complex coupling and load relationships. This paper discusses a game theory based control approach for the power distribution of a multiple-receiver WPT system. The power receiver systems (i.e., a receiving coil, a DC-AC rectifier, a DC-DC converter, and an ultracapacitor pack in this paper.) are modelled as independent agents with different preferences under the Matlab simulation environment where the preferences of each agent are represented by utility functions. Then a non-cooperative power distribution game is set up and a generalized Nash equilibrium is found which is used as the reference solution formula to be updated at every control instant. Meanwhile, the generalized Nash equilibrium is found through finding out the variational equilibrium by Karush Kuhn-Tucker conditions (KKT) conditions. The simulation results show that the game theory based control is comparable to the highest efficiency impedance distribution approach in a three-receiver WPT system.