A novel magnetic coupling mechanism with steady output and low cost is proposed in this paper. It composed of n-type power supply rail and dual-phase coil receiver. The conventional I-type power supply rail has advantages of narrow width, large lateral tolerance and low electromagnetic field (EMF) radiation which are suitable for dynamic wireless charging. The double-D (DD) coil is used as the receiver which is also seen as single-phase coil receiver. However the induced voltage of the receiver has a sinusoidal variation with large fluctuation and has zero point along driving direction. The dual-phase coil receiver is proposed to solve this issue and enhance the output power simultaneously. Compared with I-type power supply rail, the n-type power supply rail is proposed to improve the utilization of the magnetic core and reduce the construction cost which are crucial for commercialization of dynamic wireless charging of electric vehicles in the future. The advantages of I-type are also preserved. The enhanced output power of dual-phase coil receiver is verified by circuit analysis. We focus on the influence of the structure size by finite element analysis (FEA) simulation and the design method of structural parameters is proposed to achieve larger lateral tolerance, greater coupling performance and lower cost. The structure size is optimized and the analyses are verified by a 10 kW prototype system. The fluctuation of induce voltage has been reduced from 100% to 30%. When the lateral displacement of the receiver is 30 cm at airgap of 20 cm, induced voltage drops by only 30%. The EMF is also measured to ensure safety on the environment.

A Modular Cascade Machine (MCM) system is composed of several electric machines instead of a unique one. The MCM system is expected for application to electric vehicles (EVs). This paper aims to compare a MCM-based EV with a classical single drive EV in normal operations. The Energetic Macroscopic Representation formalism is used to organize the system model and control of both studied EVs. An optimal energy management strategy of the MCM-based EV is developed for minimizing its energy consumption. Simulation results demonstrate the interest of the MCM-based EV in terms of energy saving. Different driving cycles are analyzed and the comparison of both vehicles highlights the interest of this new multi-machine system despite the increase of its mass and cost.

Modular cascade machines (MCM), as a new multi-machine system, are expected to be applied for electric vehicles (EVs). This paper focuses on the sizing of MCM systems. Expanding MCM high-efficiency area and reducing MCM mass are selected as optimization targets for sizing. The proposed machine efficiency map and MCM mass evaluation methods are the means to achieve this goal without machine pre-design. The efficiency evaluation method enables to evaluate machines efficiency maps only with four basic design specifications (rated speed, rated torque, overload factor, and speed expansion ratio). Neither finite element (FE) nor experimental data (inductance and resistance) are used. Its calculation is fast and can be finished within several milliseconds. The method is validated by comparisons with the experimental efficiency maps of two prototypes. The proposed methods are proven having an accuracy that is acceptable for the MCM definition and pre-design. The exemption of machine pre-design saves a lot of time during sizing stage. The sizing optimization is realized by genetic algorithm. And the comparisons of different sizing are conducted with the same vehicle model. Moreover, general sizing rules for the similar EVs are proposed. For the studied EV, the number of machines is proposed as a function of traction power. The sized specifications could be used for more accurate machine design by the FE method in future. The sizing method could be extended for the other kind of multi-machine systems.