Active and Reactive Currents Decomposition-Based Control of Angle and Magnitude of Current for a Parallel Multiinverter IPT System

In order to improve the power capacity of the resonant inverter that feeds the inductive power transfer (IPT) system for high-power applications, a parallel multiinverter IPT system is presented here to upgrade the power level of the IPT system. Besides, a quick and accurate active and reactive currents decomposition method without phase-locked loop is also proposed so that the active and reactive currents can be controlled independently. This method can minimize the circulating current caused by asymmetrical resonant components and different dc input voltages. Meanwhile, the track current can be regulated at its designed value with a fast response performance. Moreover, a protection device and a protection scheme are designed to disconnect the fault inverter unit, which can ensure that the whole system works continuously so as to improve the reliability and availability dramatically. Finally, a 3-kW experimental setup using a two-inverter IPT system is conducted to verify the performance of the proposed method. The overall efficiency of the improved IPT system is up to 93.5% at 2.87 kW output, and the experimental results also indicate that the proposed method improves the stability of track current control and achieves circulating current minimization.