Front-end voltage regulations of inductive power transfer systems with switched LCL compensators

Abstract

In conventional inductive power transfer (IPT) systems, the output voltages are regulated by either the user-end DC regulators or the front-end inverters via wireless communications. However, the bulky sizes of the DC regulators and the communication devices may deteriorate the power densities of the receivers. To this end, a communication-free voltage regulation scheme is proposed for an LCL-S compensated IPT system by controlling the switched LCL compensator at the primary side. By measuring the front-end AC current of the transmitter resonator at the nominal condition, the output voltage of the IPT system can be estimated without any communication feedbacks. Based on the estimated output voltage, the primary-side controller can automatically switch on the desired compensated inductors, such that the output voltage can track the reference. The proposed scheme is validated by the simulation results in PSIM9.0.