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

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

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 new switched-capacitor boost-multilevel inverter using partial charging

In this brief, a new switched-capacitor-boost-multilevel (SCBM) inverter is proposed and implemented. This inverter possesses the distinct features of both voltage boost up and near-sinusoidal staircase output voltage. The key is to utilize partial charging in such a way that multiple voltage steps per capacitor can be realized, hence significantly reducing the number of capacitors for a given number of levels. Based on using only two capacitors, a 13-level SCBM inverter is designed and analyzed, with emphasis on assessing its total harmonic distortion. Both simulation and experimental results are given to confirm the theoretical analysis. © 2007 IEEE.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

Modeling of electric vehicle chargers

The chargers of electric vehicles (EV) are highly non-linear devices. They are characterized by high harmonic current distortion and poor power factor. Different models of chargers and converters had been studied and a number of papers were published. In order to study the impacts of a large number of electric vehicles to the power system, an appropriate charger model for a population of EVs should be developed. To illustrate the process in using Monte Carlo method to describe the interaction of EV chargers, the mean value of the total harmonic distortion (THD) is estimated as it is one of the most important parameters should be studied. Different charging algorithms will have different performance and harmonic distortion. Since current-voltage control charging method is widely adopted for various types of batteries, a model based on this algorithm is presented.published_or_final_versio

A novel soft-switching inverter using resonant inductor freewheeling

A novel topology of the voltage-source soft-switching inverter for induction motor drives is presented. The key of this topology is to employ two fractional-duty auxiliary switches and one resonant inductor per phase to provide a favorable zero-voltage turn-on condition for those main switches. By fully utilizing the inherent natural freewheeling of the inverter, the auxiliary switches need to operate in the resonant inductor freewheeling only in a fractional duty. Apart from providing a soft-switching environment with minimum voltage and current stresses, the distinct advantage of this topology is its capability to control the operation of each phase individually. Therefore, this inverter can readily adopt the well-established PWM techniques while possessing the advantages of soft switching-namely PWM-oriented soft switching. Moreover, a new concept of the zero-voltage soft-switching vector is introduced to determine whether the auxiliary circuit needs to operate to achieving soft switching. A theoretical analysis has been conducted and then verified by using both computer simulation and experimental results.published_or_final_versio

A unified analysis of DC link current in space-vector PWM drives

A unified analysis of the DC link current in space-vector PWM drives, comprising induction motor, inverter and space-vector PWM scheme, is presented. The DC link current is investigated in a unified way, whether the inverter is operating at normal or dead-time switching modes. The key is to introduce a dead-time vector, which is mathematically similar to the well-known space voltage vector, to express the DC link current and inverter output voltages into a unified form. Moreover, the formation of positive and negative spikes on the DC link current is discussed. In particular, the occurrence of negative spikes is mathematically formulated. The proposed unified approach is verified by means of both computer simulation and experimental results. The occurrence of positive and negative spikes is also verified by using circuit-oriented and device-oriented computer simulations as well as experimental results.published_or_final_versio

A novel two-quadrant zero-voltage transition converter for DC motor drives

A novel zero-voltage-transition (ZVT) two-quadrant (2Q) power converter for DC motor drives is presented. It possesses the definite advantage that both main transistors and rectifiers can operate with zero-voltage switching in both motoring and regenerating modes, while both of these switches are only subjected to unity voltage and current stresses, namely the same as its PWM counterparts. This power converter is particularly useful for DC traction systems in which both motoring and regenerative braking are desired to have high efficiency. The corresponding theoretical analysis and its high-efficiency performance are supported by both simulation and experimental results.published_or_final_versio