Spectral analysis of a new six-phase pole-changing induction motor drive for electric vehicles

In this paper, a new six-phase pole-changing induction motor drive is proposed to extend the constant-power operating range for electric vehicle application. The double Fourier series is newly employed to analyze the spectra of the motor phase voltage and current. Consequently, the harmonic expression of the inverter-dc-link current can be derived. In order to reduce the dc-link harmonics, a new sinusoidal pulsewidth-modulation strategy is developed for the proposed six-phase inverter. Experimental results, particularly the spectra of the phase current and the dc-link current, are given to verify the theoretical analysis.published_or_final_versio

A fast fourier transform of modulated signals based on double fourier series

У статті описано принцип представлення модульованих сигналів на основі ряду Фур’є двох змінних. Показано переваги незалежного опису несучої і модулюючої функцій. Наведено формули розрахунку спектральних складових і гармонік на основі ряду Фур’є двох змінних. Отримано дискретизовані формули для розрахунку спектру на основі ряду Фур’є однієї та двох змінних. Показано доцільність використання формул швидкого перетворення Фур’є для зменшення обсягу математичних розрахунків. Проведено адаптацію методики швидкого перетворення Фур’є для розрахунку спектру модульованих сигналів на основі ряду Фур’є двох змінних, для чого додатково здійснюється процедура сумування та перегрупування гармонік за номером. Проведено аналіз трудомісткості розрахунків за пропонованою методикою розрахунку спектру та показано в скількі разів вона зменшується у порівнянні з безпосереднім розрахунком спектру за початковими формулами.Pulse modulated signals is useful to represent based on double Fourier series. The article describes the principle of representation of modulated signals based on double Fourier series. The advantages of an independent description of carrier and modulating functions are shown. The expediency of using the double Fourier series to analyze the spectrum of modulated signals, where the modulation multiplicity does not have an integer value, or the law of modulation or carrier functions change is parametric, which may cause the appearance of subharmonic oscillations, is shown. The formulas for calculating the spectral components and harmonics on the basis of the Fourier series of two variables are given. The discrete formulas for calculating the spectrum based on Fourier series of one and two variables are obtained. It is shown the expediency of using Fourier transforms to reduce the amount of mathematical calculations. The adaptation of the Fast Fourier Transform method to the calculation of the spectrum of modulated signals based on the double Fourier series is carried out, in addition, the procedure of summation and rearrangement of harmonics by the number is carried out. The number of the function descrete values for given number of spectrum harmonics based on Kotelnikov theorem are estimated. An analysis of the complexity of calculations according to the proposed method for calculating the spectrum and shows how many times it decreases in comparison with the direct calculation of the spectrum by the initial formulas. The recommendations for spectrum calculation proposed based on proposed procedure depend on descrete values of primary function are given

A six-phase transverse-flux-reversal linear machine for low-speed reciprocating power generation

In this paper, a 6-phase permanent-magnet flux-reversal linear machine for low-speed reciprocating power generation is presented. By increasing the phase number, the phase current is reduced for the same rated power which results in a lower ohmic loss. In addition, the thrust force ripple can be reduced accordingly. By borrowing the transverse-flux concept, the electric loading and the magnetic loading is decoupled and the thrust density can be improved accordingly. The stator of the proposed machine adopts the modular design, and each phase is magnetically decoupled with each other which gives more flexibility and controllability of the generator. Based on the same topology, the proposed machine can be extended to a machine with an arbitrary number of phase to suit different applications.published_or_final_versio

Multilayer framework for vehicle-to-grid operation

In recent years, electric vehicles (EVs) have been widely accepted by general publics due to their low emissions. Particularly, those EVs which are able to be connected to power grid have earned lots of attention. In this paper, a multilayer framework is newly proposed for vehicle-to-grid operation. In this framework those gridable EVs can serve as resources to provide their capacity and energy service or as loads to be charged directly. The corresponding aggregator works as a smart controller for the framework, which is responsible for forming aggregations of gridable EVs and determining which vehicle to be a resource or a load. Cost-emission analysis is carried out based on this framework. Hence, operation cost and emissions can be reduced by using these gridable EVs. © Copyright 2011 IEEE - All Rights Reserved.published_or_final_versionThe 2010 IEEE Vehicle Power and Propulsion Conference (VPPC), Lille, France, 1-3 September 2010. In Proceedings of VPPC, 2010, p. 1-

Design of a new outer-rotor flux-controllable vernier PM in-wheel motor drive for electric vehicle

This paper proposes a new in-wheel motor drive for electric vehicle (EV), which utilizes the outer-rotor topology to directly couple with the tire rims and hence removing the mechanical transmission. The key is to use the vernier structure for obtaining the high-speed to low-speed gear effect and achieving the high output torque at low speed operation. Also, the proposed motor drive adopts the DC field winding for performing the flux weakening control at high speed operation. Thus, this new in-wheel motor drive can smoothly operate within the speed range of 0∼1000rpm at different operation modes for EVs. The motor drive and its three-operation modes for EV operation, as well as the steady-state and transient performances are analyzed by using the time-stepping finite-element-method. © 2011 IEEE.published_or_final_versionThe 2011 International Conference on Electrical Machines and Systems (ICEMS 2011), Beijing, China, 20-23 August 2011. In Proceedings of ICEMS, 2011, p. 1-

Analysis and control of chaos for lateral dynamics of electric vehicles

In this paper, the nonlinear dynamic model of the lateral system for electric vehicles (EVs) is proposed. Different from the traditional steering system, a driver’s reaction model is introduced and meanwhile the disturbance caused by irregularities of road surface is also considered in this paper. Based on the integrated nonlinear dynamic equations, it shows that the stability of lateral system of EVs is closely related to the heading speed of the vehicle. The lateral system has a Hopf bifurcation when the vehicle heading speed equals a critical value, and then enters into chaos domain along with the increment of the vehicle heading speed. The unstable behaviors may make EVs spin and even turn over, which are quite harmful to the safety of EVs. As for this issue, a control method is proposed and implemented to protect the vehicle from spinning and thus improve the safety of EVs. The computer simulation is utilized in this paper to analyze nonlinear dynamics, as well as to validate the existence of chaotic motions and the feasibility of the control scheme. From the simulation results, it shows that the chaotic motions existing in the EV lateral dynamics can be suppressed by the proposed control method, and thus the corresponding cornering performance and safety are improved.published_or_final_versio

Electric Motor Drive Selection Issues for HEV Propulsion Systems: A Comparative Study

International audienceThis paper describes a comparative study allowing the selection of the most appropriate electric propulsion system for a parallel Hybrid Electric Vehicle (HEV). This study is based on an exhaustive review of the state of the art and on an effective comparison of the performances of the four main electric propulsion systems that are the dc motor, the induction motor, the permanent magnet synchronous motor, and the switched reluctance motor. The main conclusion drawn by the proposed comparative study is that it is the cage induction motor that better fulfils the major requirements of the HEV electric propulsion

Simulation of a linear permanent magnet vernier machine for direct-drive wave power generation

This paper proposes a linear permanent magnet (PM) vernier machine for direct-drive wave power generation. Firstly, the machine structure is proposed and its parameters are indentified by finite element analysis (FEA). Secondly, the mathematical modeling of wave power absorption system was established. The control strategy for maximizing absorbed wave power is discussed. Then, by using Matlab/Simulink, the wave power generator system is modeled and simulated. A vector control scheme is implemented which controls power flow between the generator and the load via a bi-directional AC/DC converter. The simulation results verify the feasibility of the proposed machine used for direct-drive wave power generation. © 2011 IEEE.published_or_final_versionThe 2011 International Conference on Electrical Machines and Systems (ICEMS 2011), Beijing, China, 20-23 August 2011. In Proceedings of ICEMS, 2011, p. 1-

Overview of permanent-magnet brushless drives for electric and hybrid electric vehicles

With ever-increasing concerns on our environment, there is a fast growing interest in electric vehicles (EVs) and hybrid EVs (HEVs) from automakers, governments, and customers. As electric drives are the core of both EVs and HEVs, it is a pressing need for researchers to develop advanced electric-drive systems. In this paper, an overview of permanent-magnet (PM) brushless (BL) drives for EVs and HEVs is presented, with emphasis on machine topologies, drive operations, and control strategies. Then, three major research directions of the PM BL drive systems are elaborated, namely, the magnetic-geared outer-rotor PM BL drive system, the PM BL integrated starter-generator system, and the PM BL electric variable-transmission system. © 2008 IEEE.published_or_final_versio

Multiphase induction motor drives - a technology status review

The area of multiphase variable-speed motor drives in general and multiphase induction motor drives in particular has experienced a substantial growth since the beginning of this century. Research has been conducted worldwide and numerous interesting developments have been reported in the literature. An attempt is made to provide a detailed overview of the current state-of-the-art in this area. The elaborated aspects include advantages of multiphase induction machines, modelling of multiphase induction machines, basic vector control and direct torque control schemes and PWM control of multiphase voltage source inverters. The authors also provide a detailed survey of the control strategies for five-phase and asymmetrical six-phase induction motor drives, as well as an overview of the approaches to the design of fault tolerant strategies for post-fault drive operation, and a discussion of multiphase multi-motor drives with single inverter supply. Experimental results, collected from various multiphase induction motor drive laboratory rigs, are also included to facilitate the understanding of the drive operatio