Mehrdad Ehsani

Hybrid Electric Vehicles: Architecture and Motor Drives

Electric traction is one of the most promising technologies that can lead to significant improvements in vehicle performance, energy utilization efficiency, and polluting emissions. Among several technologies, hybrid electric vehicle (HEV) traction is the most promising technology that has the advantages of high performance, high fuel efficiency, low emissions, and long operating range. Moreover, the technologies of all the component hardware are technically and markedly available. At present, almost all the major automotive manufacturers are developing hybrid electric vehicles, and some of them have marketed their productions, such as Toyota and Honda. This paper reviews the present technologies of HEVs in the range of drivetrain configuration, electric motor drives, and energy storages

A Matlab-based modeling and simulation package for electric and hybrid electric vehicle design

This paper discusses a simulation and modeling package developed at Texas A&M University, V-Elph 2.01. V-Elph facilitates in-depth studies of electric vehicle (EV) and hybrid EV (HEV) configurations or energy management strategies through visual programming by creating components as hierarchical subsystems that can be used interchangeably as embedded systems. V-Elph is composed of detailed models of four major types of components: electric motors, internal combustion engines, batteries, and support components that can be integrated to model and simulate drive trains having all electric, series hybrid, and parallel hybrid configurations. V-Elph was written in the Matlab/Simulink graphical simulation language and is portable to most computer platforms. This paper also discusses the methodology for designing vehicle drive trains using the V-Elph package. An EV, a series HEV, a parallel HEV, and a conventional internal combustion engine (ICE) driven drive train have been designed using the simulation package. Simulation results such as fuel consumption, vehicle emissions, and complexity are compared and discussed for each vehicle.

Making the case for applications of switched reluctance motor technology in automotive products

Switched reluctance machines (SRM) offer attractive attributes for automotive applications. These include robustness to harsh operational conditions, rugged structure, fault resilient performance, and a wide range of speed. The main debate over the adequacy of switched reluctance drives in automotive applications has often focused on efficiency and position sensorless control over the entire speed range, adaptation of control algorithms in the presence of parameter variations, and high levels of acoustic noise and vibration. The present paper demonstrates three key technologies developed over the past few years that have resulted in tangible improvements in the performance of SRM/generators (SRM/G) as related to the above areas of interest. This paper intends to illustrate the new possibilities and remaining challenges in applications of SRM in automotive industry. The proposed technologies have been validated by simulation and experimental results

Vehicular Electric Power Systems : Land, Sea, Air, and Space Vehicles

INTRODUCTION TO ELECTRICAL POWER SYSTEMS Fundamentals of Electric Circuits Control Systems Electrical Systems References FUNDAMENTALS OF POWER ELECTRONICS AC/DC Rectifiers DC/DC Converters DC/AC Inverters Selected Readings ELECTRIC MACHINES Electro-Mechanical Power Transfer Systems Fundamentals of Electromagnetism DC Machines Induction Machines Synchronous Machines Selected Readings AUTOMOTIVE POWER SYSTEMS Conventional 14V Electrical System Architecture Advanced Electrical Loads Increasing the System Voltage to 42V Advanced Distribution Systems Starter, Alternator, and Integrated Starter/Alternator Automobile Steering Systems Semiconductors for Automotive Applications Automotive Communication Networks and Wireless Techniques References ELECTRIC AND HYBRID ELECTRIC VEHICLES Principles of Hybrid Electric Drivetrains Architectures of Hybrid Electric Drivetrains Electrical Distribution System Architectures More Electric Hybrid Vehicles Hybrid Control Strategies Hybridization Effects 42V System for Traction Applications Heavy Duty Vehicles Electric Dragsters Modeling and Simulation of Automotive Power Systems References AIRCRAFT POWER SYSTEMS Conventional Electrical Systems Power Generation Systems Aircraft Electrical Distribution Systems Stability Analysis References SPACE POWER SYSTEMS Introduction International Space Station Spacecraft Power Systems Modeling and Analysis Real-Time State Estimation Stability Assessment References SEA AND UNDERSEA VEHICLES Power System Configurations in Sea and Undersea Vehicles Power Electronics Building Blocks (PEBBs) Controller Architecture for Power Electronic Circuits Power Management Center (PMC) Electrical Distribution System in Sea and Undersea Vehicles Advanced Electric Drives in Sea and Undersea Vehicles References FUEL CELL BASED VEHICLES Structures, Operations, and Properties of Fuel Cells Important Properties of Fuel Cells for Vehicles Light-Duty Vehicles Heavy-Duty Vehicles Current Status and Future Trends in Fuel Cell Vehicles Aerospace Applications Other Applications of Fuel Cells Conclusion References ELECTRICAL MODELING TECHNIQUES FOR ENERGY STORAGE DEVICES Battery Modeling Modeling of Fuel Cells Modeling of Photovoltaic (PV) Cells Modeling of Ultracapacitors Conclusion References ADVANCED MOTOR DRIVES FOR VEHICULAR APPLICATIONS Brushless DC Motor Drives Switched Reluctance Motor Drives References MULTI-CONVERTER VEHICULAR DYNAMICS AND CONTROL Multi-Converter Vehicular Power Electronic Systems Constant Power Loads and Their Characteristics Concept of Negative Impedance Instability Negative Impedance Instability in the Single PWM DC/DC Converters Stability of PWM DC/DC Converters Driving Several Loads Stability Condition in a DC Vehicular Distribution System Negative Impedance Stabilizing Control for PWM DC/DC Converters with Constant Power and Resistive Loads Conclusion References EFFECTS OF CONSTANT POWER LOADS IN AC VEHICULAR SYSTEMS Vehicular AC Distribution Systems Modeling of AC Constant Power Loads Negative Impedance Instability Conditions Hybrid (DC and AC) Vehicular Systems with Constant Power Loads Conclusion References INDEX

Sensorless control of the BLDC motors from near-zero to high speeds

This work presents the theory and implementation of a novel sensorless control technique for the brushless DC (BLDC) motor. The proposed new sensorless drive method solves the problem of the sensorless BLDC motor drives at very low speeds. It provides a highly accurate and robust sensorless operation from near zero to high speeds. For this purpose, an approach, a new flux linkage function is defined, that is speed-independent. The validity of the proposed method is verified through both simulation and experimental results and discussion.

On the feasibility of four-switch three-phase BLDC motor drives for low cost commercial applications: topology and control

The main purpose of this paper is to describe a low cost four-switch brushless DC (BLDC) motor drive for commercial applications. For effective utilization of the developed system, a novel direct current controlled PWM scheme is designed and implemented to produce the desired dynamic and static speed-torque characteristics. Also, the feasibility of the four-switch converter is extended to two-phase BLDC motor drives and the six-switch converter for power factor correction and speed control. The operational principle of the four-switch BLDC motor drive and the developed control scheme are theoretically analyzed and the performance is demonstrated by both simulation and experimental results.

Four-quadrant sensorless brushless ECM drive

A four-quadrant brushless electronically commutated motor (ECM) drive is presented which provides high-quality torque control without discrete current sensors or a rotor position sensor. Rotor position feedback is developed by extracting sufficient information from the motor back-EMF voltage waveforms, and current feedback is provided by current sensors integrated into MOS-gated power switches (MOSFETs or IGBTs). Controller parts count is minimized using a custom VLSI chip which performs the rotor position sensing, pulse-width-modulated (PWM) current regulation, and various protection functions. The interface between the low-power logic and inverter power switches is accomplished using a high-voltage integrated circuit (HVIC) gate-driver for each of the three phase legs. Experimental results using a compact prototype ECM drive card are presented which demonstrate the desired four-quadrant performance without discrete sensors.<<ETX>>

Analysis of power electronic converters using the generalized state-space averaging approach

Power electronic converters are periodic time-variant systems, because of their switching operation. The generalized state-space averaging method is a way to model them as time independent systems, defined by a unified set of differential equations, capable of representing circuit waveforms. Therefore, it can be a convenient approach for designing controllers to he applied to switched converters. This brief shows that the generalized state-space averaging method works well only within specific converter topologies and parametric limits, where the model approximation order is not defined by the topology number of components. This point is illustrated with detailed examples from several basic dc/dc converter topologies.

Development of a Unipolar Converter for Variable Reluctance Motor Drives

A new converter concept for driving the switched reluctance motor has been developed. This converter has only one switching device per phase, uses a unipolar dc supply, returns all the trapped energy to the source, and does not require bifilar windings; it is called a C-dump converter because the trapped energy is dumped in a capacitor and then returned to the dc source. The topology for several different C-dump converters is presented. In addition, the design and experimental results for a C-dump converter using a chopper to recover the energy dumped on the capacitor are presented.

New modulation encoding techniques for indirect rotor position sensing in switched reluctance motors

Two novel indirect switched reluctance motor (SRM) rotor position (RP) sensing schemes based on winding current amplitude and phase modulation are presented. An off phase is supplied with a stiff sinusoidal carrier voltage from the sensing circuit to be modulated by an RP dependent phase inductance function. The modulated signal is decoded to obtain the information signal and is calibrated to obtain the RP angle continuously. A combination of phase modulation and amplitude modulation encoder techniques was designed and tested on a 5 hp three-phased 6-4 SRM over a wide range of speed. The position detection scheme kept excellent track of the rotor angle continuously under both load and no-load conditions. This scheme is extremely robust to switching noise present in the sensing phase due to mutually induced voltages.<<ETX>>