6,268 research outputs found
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
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
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
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
Visual servo control with artificial neural network
In this paper a robotic manipulator system is presented, which uses visual feedback to control both the position and orientation of the manipulator. In this system, visual data from the camera are directly used in the servo control process of the manipulator, without calculations of the inverse kinematics. This approach is achieved by the use of an artificial neural network (ANN) to learn the relationship between the position and the orientation of the manipulator and the joint angles. As there are no pre-stored parameters of the manipulator, the system is adaptable to slight changes in the kinematics of the manipulator or the working environment. Hence, this technique should able to extend the application of robotic technology in some special industrial areas. The results of computer simulations of this system are also presented in the paper.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
Implementation of real-time parallel processing in a motion control system
The paper proposes an architecture and implementation of a motion control system, with a master-slave multiprocessor mode. Some major problems which must be considered in multiprocessor systems design, including multiprocessor system architecture, interconnection network, hardware circuit design and software design are studied.published_or_final_versio
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