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

Abstract

Wireless Dynamic Charging (WDC) of Electric Vehicles (EV) is a new initiative aimed to increase EV uptake. However, pulsating output power along the driving direction is a major problem with this technology. Moreover, in order to deliver enough driving power for EVs, WDC systems must operate at high power. This paper proposes a WDC system that has the capability of providing a low pulsating and high output power to EVs. The proposed WDC utilizes multiple primary windings that guarantees a homogeneous mutual magnetic flux for the receiver along the driving direction. This results in a constant induced voltage across the receiver and hence constant output power to charge the EV battery. High output power is realized by using multiple transmitter windings which have been arranged in a novel winding method. The structure layout of the proposed WDC, including ferrite cores, windings and resonant tanks is presented. Furthermore, a theoretical analysis is conducted to determine conditions of each winding's current phase and amplitude for achieving constant output power. The crossing mutual inductances between the different transmitter's phases are compensated by adding small capacitors in series with each transmitter winding. An optimization analysis using Maxwell 3D simulation for both, transmitter and receiver is carried out to achieve the highest coupling factor by using minimum ferrite material. The effectiveness of the proposed system is analytically demonstrated and experimentally verified using a 3-kW laboratory prototype. Finally, the performance of the proposed method is compared with similar systems presented in the literature. The comparison shows that the proposed system has the advantages of using simple control, it also eliminates communications between the primary and secondary side and delivers a normalized power of 2.25 which is 125% higher compared to conventional single-phase systems.

Inductive Wireless Power Transfer Charging for Electric Vehicles–A Review

“…In article [186], a DWC system proposed to drive multiple transmitter coils with single multi-phase inverter with different polarities proposed. This method practically applied to three phase 3kW DWC system achieved efficiency nearly 90% and achieved constant power output.…”

A Hybrid Charger of Conductive and Inductive Modes for Electric Vehicles

“…By utilizing two different power transfer paths, the inductive charging mode can deliver higher power to the battery with the same VA ratings of the on-board components. However, it is necessary to take into account that 1 and 2 are physically placed closed to each other and cross coupling 12 is relevant in the inductive mode [27]. This could cause higher current stresses through the resonant components in the on-board side as well as a reduction of the output power.…”

Review on Control Techniques for EV Bidirectional Wireless Chargers

“…Then, the generated DC signal is the input of a DC/AC converter. This converter is usually performed using a full-bridge inverter [42][43][44][45], but there are some other topologies, such as single-ended converters [46] or multi-phase systems [47,48]. Some authors choose to include a DC/DC converter between the grid rectifier and the primary inverter.…”