The impact of variations in component values on power-frequency control of bi-directional Inductive Power Transfer systems

Inductive Power Transfer (IPT) is a technology that is suitable for supplying power to a wide range of applications with no physical contacts. Amongst numerous control strategies that have been reported to regulate both uni-directional and bi-directional contactless power flow of IPT systems, power-frequency control strategy can be regarded as the most recent technique. The power-frequency control technique regulates and limits the power flow without any dedicated communication by changing the frequency of operation in accordance with the power-frequency characteristic of the IPT system. This paper examines the impact of variations in component values on the effectiveness of the power-frequency control strategy, which is yet to be investigated. Mathematical expressions are derived for control variables to theoretically determine the degree of influence of component values on both reactive and active power flows in the system. A MATLAB/PLECS model is also developed for a 1 kW bi-directional IPT system to validate the mathematical analyses. Sensitivity of the power-frequency control technique and its effectiveness on IPT systems are investigated for variations in parameter values. Theoretical and simulated results indicate that the power-frequency control strategy is robust and not affected by the variations in component values when operated within its frequency band.