The paper discusses the development status of the inductive power transmission for automotive applications. This technology is, in fact, gaining the interest of electric vehicle manufacturers as an effective strategy to improve the market penetration of electric mobility. Starting from the origin of this technology, the paper presents an overview of the current state of the art as well as the current research and industrial projects. Particular attention is devoted to the description of a prototypal system for the dynamic inductive power transmission whose goal is to extend the battery range by a fast partial recharging during the movement of the vehicle.

This paper proposes a technique for the control of the charging process in a dynamic inductive power transfer system for automotive applications. This technique is based on an impedance control loop on the receiver side. The proposed control allows different phases of the charging process to be carried out in the absence of a communication link between the ground and the vehicle side. The charging process starts with a sensorless procedure for the identification of the actual presence of the vehicle over the receiver. The same control technique introduces several advantages of interoperability between systems having different requirements in terms of the power demand. A 11-kW prototype has been implemented based on a transmitter 1.5-m long as compromise solution between the long track coil and the lumped one. The power management of the receiver side is provided by a nine-phase interleaved boost converter. The experimental results prove the effectiveness of the proposed control together with a good matching with the developed theoretical equations set for the system description.

The paper presents a particular Pulse Width Modulation (PWM) strategy to reduce the (Direct Current) DC-link capacitor stress for multi-n-phase drives. A multi-n-phase drive is composed of multiple independent systems of n inverter supplying a multi-n-phase electric machine. The paper focused on the investigation of the best phase shifting between carriers for a triple-3-phase drive compared to the 3-phase counterpart in order to reduce the capacitor bench design point. Simulation and experimental results show as the control technique proposed is able to reduce the value of the DC-link capacitor current in any operating condition including fault case. In this sense, the PWM carrier displacement appears like an additional degree of freedom that can be exploited in multi-n-phase drives but also in multi-motor application.

In multi‐ n ‐phase machines, the n ‐phases are grouped in separated stars. A particular subcategory of multi‐ n ‐phase machines is the multi‐3‐phase machines. This study presents the design considerations and their validation for tooth coil wound multi‐3‐phase machines. A generic algorithm to design multi‐3‐phase machines is proposed. Although this study mainly focuses on multi‐3‐phase machines the approach is generalised and is applicable to any multi‐ n ‐phase machine. The resulting machines exhibit a low torque ripple value, and a mathematical formulation is proposed in order to justify this behaviour. All the multi‐3‐phase machines designed according to the proposed algorithm can be studied, and directly compared, thanks to the generalised harmonic formulation of the stator MMF and the torque performances here proposed. This study is enriched with some design hints useful to realise a machine with low mutual coupling between phases, and some considerations that can help the machine designer in the choice of the number of poles. The design algorithm is applied for the design of a triple‐3‐phase PM‐inset machine solution, with nine slots ten poles. The performances, evaluated by finite element analysis and experimental analysis, demonstrate the effectiveness of the design algorithm proposed in a very simple structure machine.

This study investigates the angle of phase shift between interleaved carriers in pulse‐width modulation, as an additional design parameter to reduce the DC link stress of a five‐phase drive. Several phase shift strategies are studied and defined with a focus on the DC link root‐mean‐square current. The effect of adjusting the phase shift between interleaved carriers on the DC link stress is analysed and a general mathematical model is proposed to estimate the effect for any phase shift strategy. The trends predicted by simulations and analytical models have been validated through the application of the control algorithm on a five‐phase motor drive system.