Fei Lin

An efficient wireless power transfer system with security considerations for electric vehicle applications

This paper presents a secure inductive wireless power transfer (WPT) system for electric vehicle (EV) applications, such as charging the electric devices inside EVs and performing energy exchange between EVs. The key is to employ chaos theory to encrypt the wirelessly transferred energy which can then be decrypted by specific receptors in the multi-objective system. In this paper, the principle of encrypted WPT is first revealed. Then, computer simulation is conducted to validate the feasibility of the proposed system. Moreover, by comparing the WPT systems with and without encryption, the proposed energy encryption scheme does not involve noticeable power consumption.

Investigation of energy harvesting for magnetic sensor arrays on Mars by wireless power transmission

This paper proposes the energy harvesting for magnetic sensor arrays on Mars, which can receive the power from Mars Rover by wireless power transmission (WPT). The schematic idea is presented with the energy receiver as the magnetic sensor and the energy transmitter as the transducer on Mars Rover. The key is to adopt the resonant inductive power transmission (IPT) topology between the magnetic sensor and Mars Rover. The basic topology and its operating principle are discussed. By using the magnetic frequency analysis with the finite element method, the output power and efficiency of the WPT system are calculated. The results show that Mars Rover could flexibly transmit its power to different types of small-size magnetic sensors based on their energy on demand using different resonant frequencies and distances.

Magnetic vibration analysis of a new DC-excited multitoothed switched reluctance machine

This paper proposes a combined numerical and analytical approach for magnetic vibration analysis of a new dc-excited multitoothed switched reluctance (MSR) machine. First, the machine design is artfully to incorporate the dc-excited winding into the MSR topology, hence breeding a new flux controllable, high-torque, low-torque ripple, and doubly salient magnetless machine. Then, the finite-element-method is used to calculate the machine force and torque. A series of analytical equations are formulated to calculate the magnetic vibration parameters of the proposed machine. The analysis process and the corresponding results are given to verify the validity of the proposed approach for magnetic vibration analysis of the new machine.

Quantitative Comparison of Dynamic Flux Distribution of Magnetic Couplers for Roadway Electric Vehicle Wireless Charging System

This paper gives a quantitative comparison of magnetic couplers for electric vehicle (EV) wireless charging applications. Circular pad with ferrite spokes and coreless rectangular coils are specially selected for analysis. The dynamic flux density between couplers under high misalignment is studied by calculating the uncompensated power of the pick-up coupler. By using finite element analysis, the performance of each type of coupler is evaluated, and its adaptation to on-road EV charging are compared according to the flux distribution and effective charging area.

Multiple-receptor wireless power transfer for magnetic sensors charging on Mars via magnetic resonant coupling

This paper proposes a new idea for magnetic sensors charging on Mars, which aims to effectively transmit energy from Mars Rover to distributed magnetic sensors. The key is to utilize wireless power transfer (WPT) to enable multiple receptors extracting energy from the source via magnetic resonant coupling. Namely, the energy transmitter is located on the Mars Rover, whereas the energy receptor is installed in the magnetic sensor. In order to effectively transfer the power, a resonator is installed between the transmitter and the receptors. Based on the proposed idea, the system topology, operation principle, and simulation results are developed. By performing finite element magnetic field analysis, the output power and efficiency of the proposed WPT system are evaluated. It confirms that the Mars Rover carrying with the energy transmitter is capable of loitering around the resonator, while the magnetic sensors on the receptors can be simultaneously charged according to energy-on-demand.

A new hybrid-structure machine with multi-mode fault-tolerant operation for Mars Rover

Recently, Mars exploring draws more and more attention due to the successful landing of Mars Rovers. It was over 64 months for the Spirit Rover working on Mars. Also, since January 25, 2004, the Opportunity Rover works over 10 years on Mars. These two Rovers work much longer than their design period of 3 months. Furthermore, another NASA Mars Rover, the Curiosity Rover, works very actively on Mars. Thus, it tells that the electromagnetic devices are capable to survive in the Mars Environment. The purpose of this paper is to propose a new hybrid-structure machine for Mars Rover driving, which possesses the multi-mode fault-tolerant merit. That is, the propose machine possesses three operation modes, namely Mode I: the normal operation mode, Mode II: the remedial field-excited operation mode, and Mode III: the remedial rotor operation mode. By using the finite-element-method, three operation modes are analyzed and discussed. The analysis results show that the proposed machine achieves the high fault-tolerant operating capability. And this capability demonstrates that the machine can serve for Mars Rover in a severe environment.

Design and Analysis of a Magnetless Flux-Switching DC-Excited Machine for Wind Power Generation

This paper proposes a new outer-rotor magnetless flux-switching DC-excited (FSDC) machine which can offer low-speed operation to directly capture the wind power for power generation. Compared with its permanent-magnet (PM) counterparts, the proposed machine equips no PM such that it enjoys the definite cost benefit. One of the key designs of the proposed machine is the multitoothed per stator pole structure. With the multitoothed structure, the proposed machine not only offers the flux-modulation effect to boost up its torque density, but also is favorable for the low-speed operation. In addition, the external DC-field excitation can be controlled independently to offer the flux-controlled ability to achieve constant voltage output among various wind speeds. By performing the time-stepping finite element method (TS-FEM), the performances of the proposed machine can be analyzed, and hence verifying the design.

A feasibility study on a new brushless and gearless contra-rotating permanent magnet wind power generator

In this paper, a novel fully integrated contra-rotating permanent magnet (PM) generator is proposed. In order to efficiently capture wind energy, two contra-rotating rotors are integrated, based on magnetic field modulating principle, into a single PM machine. A relatively high angular velocity is created and the torque density is improved. The steady-state and transient performance of the machine is simulated using time-stepping finite-element method. The computation results are used to showcase the validity of the proposed machine design.

An efficient offshore wind-wave hybrid generation system using direct-drive multitoothed rotating and linear machines

This paper presents an offshore wind-wave hybrid generation (WWHG) system, which can efficiently harness the offshore wind and wave energy. The key is to use the multitoothed doubly-salient permanent-magnet (MDSPM) machines for serving the rotating generator and the linear generator. Different from the traditional wind or wave generation system, this WWHG system integrates the wind generation part and wave generation part together to directly harness the wind and wave energy without gear box. The system configuration and machine design are analyzed and discussed in detail. Also, the finite-element method is performed to verify the validity of the proposed two machine design. The results tell that the system has the high reliability and can be upgraded to the suitable size for offshore hybrid-source energy conversion in practical application.

Electromagnetic design of a new hybrid-excited flux-switching machine for fault-tolerant operation

In this paper, a new hybrid-excited flux switching (HEFS) machine with outer-rotor is proposed, which possesses distinct feature of high fault-tolerant operation. Comparing with the conventional permanent-magnet (PM) machine, it combines the merits of flux switching, low-cost, and high mechanical integrity. Furthermore, its fault-tolerant feature ensures its continuous operation in the event of winding faults. Hence, a new 12/10-pole HEFS machine is designed and implemented. The proposed machine is shown. The outer-rotor is merely a single piece iron, the stator contains 12-slots armature coils, 12-slots field excitation coils (FECs), and 12-pole PMs, where armature coils and FECs are located in alternate way.