Ali Bazzi

University of Connecticut | UConn · Department of Electrical and Computer Engineering

This paper discusses power generation, transmission, distribution, storage, and power consumption, as well as power flow control and energy management in extraterrestrial microgrids that will be critical for deep space habitation. It also highlights the modeling, operational constraints and environmental challenges associated with extraterrestrial...

Large voltage transients due to power electronic inverters are one of the major factors influencing the insulation lifetime. This paper studies the effect of square voltage transients and switching frequency on insulation breakdown time based on series of voltage endurance tests. A medium-voltage power-electronics inverter testbed is built to stres...

Due to the successive switching actions in a power electronic system, considerable conducted electromagnetic interference (EMI) is generated. This has been a major concern in designing power converters, which requires additional EMI filtering efforts. Passive EMI filters are the most common solutions to EMI reduction but usually consume a large por...

Multilevel Inverters (MLIs) are widely sought after in medium-voltage applications like electric ships, electric aircraft, and renewable energy integration due to excellent advantages like lower device stress, better power quality, and modularity. However, non-sinusoidal excitations from MLIs pose a serious problem to motor-insulation and lead to t...

Power electronics (PE) and high-frequency switching circuits are key to superior performance of electric vehicles. It is vital to monitor the condition of the PE components in real-time for safety and reliability. In this article, we propose two anomaly detection methods based on a combination of data preprocessing to suppress noise and outliers, m...

There are many methods for real-time estimation and identification for induction motor (IM) drives. In this study, dynamic mode decomposition with control (DMDc) and its variants are explored for voltage source inverter fed IM. For real-time identification, online variants of the DMDc are explored, including windowed online DMDc. These algorithms a...

Supplying peak energy demand in a reliable, cost-effective manner is a critical focus for all utility companies. Recently, electricity systems have been examined worldwide for their environmental impact and the consistently rising cost of electricity to customers due to the investment required for continuously upgrading infrastructure. All these is...

This paper proposes a model-based voltage quality analysis and optimization method for post-fault reconfigured N-level Neutral Point Clamped (NPC) inverter. It is found that the voltage quality of post-fault reconfigured Multi-level inverters (MLIs) has significant degradation which could cause issues in critical applications. To analyze and solve...

Since the introduction of mica paper and synthetic resin-based taping insulation for rotating-machines in 1950s, only evolutional improvements in their properties and processing have been made. Due to its challenging nature, much of recent insulation research has been focused on the aspect of reliability rather than performance enhancement. This pa...

Common-mode voltage produced by voltage source inverters (VSI) is of great concern in motor drive systems. Significant amount of conducted common-mode/bearing current will be induced and will interfere with system operation. As an alternative to inserting bulky passive filters to combat the adverse effect by common-mode voltage, this paper proposes...

Conducted electromagnetic interference (EMI) has been a major concern in designing power converters, requiring additional filtering components. Passive EMI filters, which are composed of inductors and capacitors, usually occupy a great portion of the volume and weight in power converters. Active EMI filters (AEF) or hybrid EMI filters (HEF) are bes...

One of the major issues with pulse-width modulation (PWM) is that considerable conducted emissions will be generated from power electronics converters. Random modulations are considered one of the viable solutions to reduce conducted electromagnetic interference (EMI) without adding bulky passive filtering components. Literature that investigates t...

This paper investigates the effect of impact factors (IFs) to harmonic content of an electric machine drive circuit, post-fault reconfigured multilevel inverters (MLIs) by using an accurate mathematical model, and impact of reconfiguration methods on THD. Due to the difficulty of analyzing harmonic content of MLIs mathematically, software tools are...

This paper $^1$ proposes an unsupervised learning approach for fault prognosis of Silicon Carbide (SiC) MOSFETs. The proposed approach utilizes the changing trend of a device's voltage, current, temperature and other device characteristics with its degradation. The failure modes of semiconductors are reviewed along with existing methods for fault...

In electric drives, semiconductor devices are susceptible to faults due to high switching stresses. An unsupervised principal component analysis (PCA) approach that utilizes the on-state median values of voltage and current signals as features is proposed; it is computationally efficient for realtime operation. A key innovation is handling variatio...

Rapid growing demand in higher power/torque density and payload efficiency of marine electrical propulsion can be addressed by a high heat transfer, indirect cooled stator insulation system. A novel nanocomposite insulation has been developed for high torque density machine through proper dispersion of 2D nanoclay in epoxy resin matrix to obtain im...

Electric vehicles (EVs) were among the first automobiles ever built. In fact, in 1900, over 30% of the 2,370 cars in New York, Chicago, and Boston were EVs (Sulzberger 2004). Efficiency, cost-effectiveness, and lightweight energy storage and conversion capabilities have been the main developmental barriers since the first EV circa 1884 (Chan 2002)....

A smooth fault-tolerant control (FTC) of induction motor drives with sensor failures is presented in this paper. The drive uses concurrently active direct torque control (DTC), indirect field-oriented control (IFOC), and volts-per-hertz (V/f) controllers as replacements of each other in the case of sensor failure or recovery. Speed encoder, current...

This paper proposes an optimal efficiency control scheme for a wind system with doubly fed induction generator (DFIG). The suggested control scheme combines loss minimization (LM) in the DFIG and maximum power point tracking (MPPT) in the wind turbine and therefore maximum electrical energy generation, by the same wind energy potential, is achieved...

This paper reviews electric machinery and energy storage technologies that have been used in EVs and HEVs for over a century, i.e., since the automotive industry started until now. The review is intended to show trends in the evolution of these technologies in relationship with major technological breakthroughs and global events that shaped the EV...

In this paper, a novel topology and control scheme for active electromagnetic interference (EMI) filter based on the idea of virtual impedance enhancement is proposed. To ease analysis, a general and simplified equivalent circuit is introduced to predict the conducted emissions incurred from switched-mode power converters. In addition, theoretical...

The main focus of this paper is to propose a reconfiguration method to mitigate short circuit faults in a neutral point clamped multilevel inverter which is widely used as a power conversion system with distributed energy resources. Existing reconfiguration methods use either a redundant strategy or need a large number of additional devices pre-ins...

This paper introduces a new model-based analytical method for locating the maximum power point (MPP) of solar photovoltaic (PV) panels under partial shading conditions. It also provides an analytical model to obtain maximum power line as a function of the panel voltage for changing weather conditions. A series of analytical equations that can accur...

Electric machines and drives have enjoyed extensive applications in the field of electric vehicles (e.g., electric ships, boats, cars, and underwater vessels) due to their ease of scalability and wide range of operating conditions. This stems from their ability to generate the desired torque and power levels for propulsion under various external lo...

It has been identified in ONR Next Generation Integrated Power System (NGIPS) Roadmap that fundamental research in dielectric insulation research enables payload efficiency and affordable high power density of integrated electric propulsion motors. The objective of this study is to revolutionize electrical insulation in the manufacturing of NGIPS m...

This paper proposes a generalized logic-based method for fault diagnosis in multilevel inverters that can be integrated with reconfiguration methods. Thus, both effective fault diagnosis and fault tolerance can be accomplished. To validate such integration, the proposed fault diagnosis method is applied to a five-level neutral point clamped inverte...

Preventing induction motors (IMs) from failure and shutdown is important to maintain functionality of many critical loads in industry and commerce. This paper provides a comprehensive review of fault detection and diagnosis (FDD) methods targeting all the four major types of faults in IMs. Popular FDD methods published up to 2010 are briefly introd...

An analytical three-phase induction machine model is proposed, derived, and validated in this paper. This model is capable for arbitrary qd0-frame analysis and core loss estimation at both line-fed and inverter-fed situations. Detailed model-based machine copper and core loss estimations are presented. A simulation verification of the model consist...

This paper presents a time-efficient modeling and simulation strategy for aggregated microinverters in large-scale photovoltaic systems. As photovoltaic microinverter systems are typically comprised of multiple power electronic converters, a suitable modeling and simulation strategy that can be used for rapid prototyping is required. Dynamic models...

Reports on the activities and events sponsored by the IEEE Transportation Electrification community.

This paper compares two main topologies used for capacitive-coupled consumer wireless charging which has several advantages over inductive coupling including lower cost and no shielding requirements. There has been minimal data in the literature on preferred transmitter topologies. Two types of transmission systems are compared in simulations and e...

Due to rising awareness on environmental protection and for maintenance of clean habitable communities, current and next generation micro-grids are desired to have significant penetration of renewable and clean energy sources. However, a critical issue is the growth of faults in various components of micro-grids, which comprise the underlying energ...

In this paper, power loss and cost models of power electronic converters based on converter ratings and datasheet information are presented. These models aid in creating rapid prototypes which facilitate the component selection process. Through rapid prototyping, users can estimate power loss and cost which are essential in design decisions. The pr...

After a switched reluctance motor (SRM) has been designed and built, a set of tests should be performed to obtain its parameters and characteristics for motor drives application. In general industrial application, it's assumed that the self-inductance is linearly varied with respect to the rotor position and the mutual inductance is negligible. How...

This paper presents a real-time integrated model of a micro-grid to simulate its electrical energy infrastructure. This infrastructure includes two PV arrays, a fuel cell, and a diesel generator that support building loads when islanded from the utility grid. The paper reviews existing models, which are usually available either as 1) low-level dyna...

This paper presents generalized logic-based methods for intelligent fault diagnosis in power electronic converters based on correlation between faults and basic measurements. Fault recovery is then applied based on this correlation by using necessary signals and quantities from existing measurements. The main purpose of the proposed fault diagnosis...

This paper presents a threshold-based approach for power grid fault diagnosis in a power system based on correlation between fault types and basic measurements. The main focus is on faults that may occur on transmission and distribution lines due to uncontrolled events. The proposed method utilizes simple voltage and current measurements in transmi...

The combination of voltage feedforward and feedback control is a conventional approach for correcting the power factor in single-phase ac-dc boost converters. The feedback duty ratio increases significantly with an increase of the line frequency and input inductance. Therefore, the performance of the conventional approach is highly dependent on the...

Implementation of advanced control algorithms can result in improved drive performance, reliability, and efficiency, but may increase embedded system hardware requirements. Through use of tunable automated optimization methods, development of controller code for embedded systems is refined to reduce performance requirements of the target hardware....