Multiple Output Inductive Charger for Electric Vehicles

Abstract

Multiple output chargers have widely been adopted in various electronic devices due to their benefit concerning cost, power density, and space for installation. On the contrary, Inductive Power Transfer (IPT) has been applied increasingly in electric vehicles (EV) since it is safer and more convenient as compared to conductive chargers. However, researches on multiple output chargers using IPT system for EV charging applications are rarely presented. This paper proposes a new concept of a multiple output IPT charger, which can charge several output batteries independently and simultaneously by adopting only one full bridge inverter at the primary side combining with multiple transmitters. Two possible IPT-coil structures are analyzed, and the minimum distance between each channel's coils is determined to neglect the cross-coupling between them. Two options are proposed to attain Zero Phase Angle (ZPA) condition for primary inverter of the proposed system. First option is to operate the compensation tanks of every output channel at exact ZPA frequencies. The other option is to let one channel working in inductive region of its input impedance and other channel working in capacitive region. By adopting an appropriate design, the reactive powers of these tanks can be nearly cancelled each other and the phase of inverter current can be nearly in-phase with the input voltage as a result. Two proposed options are compared to give recommendation whether option 1 or 2 should be selected according to various of application's requirements. To simplify control complexity, IPT output current sources topologies are selected, compared and analyzed to construct the proposed multiple output system in both above options. Double-sided LCC and Series-Parallel (SP) topologies are adopted to demonstrate the proposed idea for Option 1 and 2, respectively. In order to verify feasibility and validity of the proposed method, experimental results of two output channels with the total output power of 1.5 kW are provided. Experimental results indicate that the ZPA is achieved for primary inverter with both of two above options even under the different load conditions. Some comparisons between the conventional and the proposed IPT charging structure in terms of cost, reliability and complexity are included in discussion session. Index Terms-Inductive power transfer; multiple output charger; IPT compensation topologies, wireless EV charging.

A Concept of Multiphase Dynamic Charging System with Constant Output Power for Electric Vehicles

“…Assuming the inverter produces equal voltages (i.e. with phase shift of π/n) across each resonant tank, therefore the currents through transmitter windings can be expressed by: (4) Consequently, Vs can be further expressed as follows: (5) Where: (6) In (6) Z1=e j(2π/n) . Considering (6), the final expression of |Vs| is given as:…”

“…As a result, the battery size of EVs can be greatly reduced and the driving range limitation can be completely alleviated. WDC is commonly developed based on inductive power transfer (IPT) technology, where a time varying magnetic field is generated by transmitter coils; which are installed underneath road surface, to wirelessly power receiver coils, which charging the EV's battery continuously [3]- [5].…”

A High-Power Multiphase Wireless Dynamic Charging System With Low Output Power Pulsation for Electric Vehicles

“…completely alleviated. WDC is commonly developed based on inductive power transfer (IPT) technology, where a time varying magnetic field is generated by transmitter coils; which are installed underneath road surface, to wirelessly power receiver coils, which charging the EV's battery continuously [3]- [5].…”

A Cascaded Topology and Control Method for Two-Phase Receivers of Dynamic Wireless Power Transfer Systems

“…Wireless power transfer (WPT) has been studied intensively in order to improve the charging process and solve the problems mentioned above [2]. Dynamic wireless power transfer (DWPT), as a case of WPT, is proposed expecting the achieve continuous charging to extend the driving range of EVs and lighten the bulky batteries [3]- [6].…”