Balancing of Common DC-Bus Parallel Connected Modular Inductive Power
Transfer Systems
Abstract
The aim of this paper is to design a modular, fault tolerant multi
transmitter(Tx) -multi receiver(Rx) parallel connected common DC bus
inductive power transfer(IPT) system to replace slip rings in wind
turbines or brushless exciters. In parallel connected common DC bus
systems, current unbalance is a major issue which results in thermal
stresses and over current or voltages. In this paper, two different new
current balancing methods are proposed: Cross-coupled Rx modules and
intentional miss-tuning of Rx side resonant frequency. These methods are
investigated both analytically and experimentally for a single Tx and
two Rx system for a 500 W prototype. The proposed methods are tested
independently, and then the combined current balancing method is also
investigated. For the same missalignment case cross-coupled/de-tuned has
a 55.8% current balancing improvement compared to de-coupled/fullytuned
topology.