An Advanced Permanent Magnet Motor Drive System for Battery-Powered Electric Vehicles

Recent availability of high-energy neodymium-ironboron (Nd-Fe-B) permanent magnet (PM) material has focused attention on the use of the PM synchronous motor (PMSM) drive for electric vehicles (EV's). A new Nd-Fe-B PMSM is proposed for the drive system, which possesses high power density and high efficiency, resulting in greater energy and space savings. The design and optimization of the motor employ finite element analysis and computer graphics. Increasingly, a new PWM inverter algorithm is developed for the drive system, which can handle the nonconstant battery voltage source. An efficiency optimizing control is adopted to further improve the energy utilization of the drive system. Both the control strategy and the PWM generation are implemented in a single-chip microcontroller. As a result, the motor drive achieves high power density, high efficiency, and compactness. A prototype of the 3.2-kW battery-powered drive system has been designed and built for an experimental mini-EV. © 1996 IEEH.published_or_final_versio

Spectral modeling of switched-mode power converters

A new modeling approach for the spectral analysis of pulsewidth modulated (PWM) converters with independent inputs is developed. The key of this approach is to extend the Volterra functional series to nonlinear systems with multiple independent inputs. After formulating the state-space equations describing the dynamical behavior of PWM converters, the Volterra transfer function characterizing the output frequency response can be obtained, which is then symmetrized to form the spectral model. Since the model is developed in a closed form, it is suitable for computer analysis. The modeling approach has been applied to various PWM converters, and the results are verified. The spectral models of different power converters can readily be obtained by using this general approach.published_or_final_versio

Nonlinear identification of power electronic systems

This paper presents a new approach to modelling power electronic systems using nonlinear system identification. By employing the nonlinear autoregressive moving average with exogenous input (NARMAX) technique, the parametric model of power electronic systems can be derived from the time-domain data. This approach possesses some advantages over available circuit-oriented modelling approaches, such as no small-signal approximation, no circuit idealization and no detailed knowledge of system operation. Moreover, it is found that the inclusion of nonlinear terms in the model of power electronic systems is particularly necessary during the presence of large-signal perturbation.published_or_final_versio

A SPICE compatible model of permanent magnet DC motor drives

A SPICE compatible model for the computer simulation of permanent magnet (PM) DC motor drives is presented. The key of the proposed model is to take into account the armature reaction and magnet demagnetization, hence the shift of operating point at load conditions can be considered. Making use of this model, the PSpice simulation of a typical PM DC motor drive is performed. Apart from the steady-state simulation, transient behaviours of the PM DC motor drive, including start-up, sudden load change and sudden reference change conditions, have been simulated conveniently. Based on a low-cost circuit simulator-PSpice, the developed model is especially helpful for undergraduate students.published_or_final_versio

An overview of power electronics in electric vehicles

In response to concerns about energy cost energy dependence and environmental damage a rekindling of interest in electric vehicles (EV's) has been obvious. Based on the California rules on zero emission vehicles in the United States as well as similar tightened air pollution regulation in Europe Asia and much of the rest of the world the market size of EV's will be enormous. Thus the development of power electronics technology for EV's will take an accelerated pace to fulfill the market needs. This paper reviews the current status of multidisciplinary technologies in EV's. Various challenges of power electronics technology for EV propulsion battery charging and power accessories are explored. © 1997 IEEE.published_or_final_versio

An overview of electric vehicles-challenges and opportunities

In response to concerns about energy cost, energy dependence and environmental damage, a rekindling of interest in electric vehicles (EVs) has been obvious. Based on the “California rules” on zero emission vehicles in the United States as well as similar tightened air pollution regulations in Europe, Asia and much of the rest of the world, the market size of EVs will be enormous. Thus, the development of power electronics technology for EVs will take an accelerated pace to fulfil the market needs. This paper reviews the current status of multidisciplinary technologies in EVs. Various challenges of power electronics technology for EV propulsion, battery charging and power accessories are explored.published_or_final_versio

Static characteristics of a new doubly salient permanent magnet motor

In this paper, magnetic field analysis of a new doubly salient permanent magnet (DSPM) motor is carried out based on the finite element method (FEM). Hence, the corresponding static characteristics, including PM flux-linkage, self-inductance and mutual-inductance, are deduced (the interaction between PM field and armature field are taken into account). A method for measuring the motor inductance is newly proposed. The theoretical analysis is verified by experimental results.published_or_final_versio

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

A novel dead-time vector approach to analysis of DC link current inPWM inverter drives

An analysis on the DC link current of space-vector PWM AC drives using novel dead-time vector (DTV) concept has been presented. By employing the DTV, a bi-value function to quantify the polarities of three phase winding currents, inverter output voltages and DC link current at dead time state can be expressed in close vectored forms. Thus, the entire drive system is considered as a whole to investigate the characteristics of DC link current at both normal and dead time states during steady and transient operations, increasingly, a phenomenon of negative spikes on DC link current caused by dead time effect is newly observed and highlighted. This phenomenon can be accurately predicted and mathematically characterized by using the proposed DTV approach. Both computer simulation and experimental results have been used for verification.published_or_final_versio

Nonlinear varying-network magnetic circuit analysis for doubly salient permanent-magnet motors

In this paper, a nonlinear varying-network magnetic circuit (VNMC) modeling method is developed for doubly salient permanent-magnet (DSPM) motors. The method is used to analyze the static characteristics of DSPM motors by specific permeance calculations, in which the interaction between the permanent-magnet field and the armature current field, as well as magnetic saturation, are taken into account. Two newly proposed DSPM motors (12/8-pole and 6/4-pole) are used as examples. There is good agreement between the results of the nonlinear VNMC modeling method and finite-element analysis. Moreover, the nonlinear VNMC method offers the advantage of calculating, effectively and efficiently, the static characteristics of DSPM motors having different dimensions, parameters, and conditions. Finally, the proposed method is verified by experimental testing of a 6/4-pole prototype. © 2000 IEEE.published_or_final_versio