The authors proposed a transgenerator-flywheel system for wind power generation and storage in a previous paper. The transgenerator is a three-member dual-mechanical-shaft (DMS) electric machine consisting of a wound stator, a permanent magnet (PM) rotor, and a wound rotor. Due to the structural and control complexity of the transgenerator, the double d-q axes-based field-oriented control (FOC) is applied to control the two rotors independently for different purposes. This paper reviews the proposed transgenerator-flywheel system and illustrates how the control references of the current components are calculated using double d-q axes. Simulations are performed in MATLAB/ Simulink to verify the independent control of the two rotors and evaluate the control performance. Results show that with the double d-q axes, the inner and outer rotors can be controlled independently with accurate and fast control response.

Electrification is rapidly becoming the dominant trend in transportation, with electric vehicles (EV s) leading the charge. However, persistent challenges such as large battery size and degradation, compromised multi-form power conversion ef-ficiency, and the limitations of traditional transmissions continue to undermine their potential. This paper reviews the Transmo-tor/Transgenerator, a pioneering three-port electric machine with two mechanical ports and one electrical port, simultaneously integrating motor/generator and magnetic clutch functionalities within a single system. By enabling the seamless integration of key components such as flywheels and ultracapacitors, the Trans-motor/Trangenerator redefines power delivery and recovery, providing a more efficient and scalable solution for both electric vehicle powertrains and renewable energy systems. Simulation-based case studies demonstrate its superiority over conventional electric powertrains, while experimental results further substan-tiate its performance enhancements and scalability, confirming its transformative potential.

In an era where residential energy consumption and management have become pivotal components of modern power grids, it is essential to develop tools that enable a deeper understanding of household energy dynamics. This paper responds to this point by introducing a Residential Load Simulator (RLS) for dynamic load modeling. The simulator features unique aspects of the user interface, different types of household appliances, and incorporates the modeling of renewable energy resources. It can be customized to different types of residential setups or geographic locations. This includes various household sizes, climatic conditions, or energy consumption patterns. Also, it can be used as an educational tool for students, homeowners, or energy professionals, offering a comprehensive platform to test and refine home energy management strategies. These features make it an excellent resource for both academic and practical learning, helping to bridge the gap between theoretical knowledge and real-world applications.

Electrified autonomous vehicles have become quite popular and have a wide range of applications. The traction and steering motors to be used on an electrified autonomous vehicle are designed considering the lateral and longitudinal forces in the environment where the vehicle operates, and they are selected with extra safety margins and “over-engineering” features. This causes wastage of rare earth elements, along with both cost and energy inefficiencies. For autonomous shuttle vehicles, traction and steering performances can be analyzed based on driving scenarios. The reference speed and steering signals for the selected driving scenarios were run on a dynamic vehicle model and the minimum performance requirements for the traction and steering motors were determined. Then, the determined design parameters by DoE (Design of Experiments) were trained in two different ANN (Artificial Neural Networks) models created for motor models. The trained ANN models were run according to the minimum performance criteria and predicted motor models with new design parameters for the traction and steering motors. The performance results of the predicted traction and steering motor models showed a significant improvement in terms of the minimum performance requirements.

A new type of generator, a transgenerator, is introduced, which integrates the wind turbine and flywheel into one system, aiming to make flywheel-distributed energy storage (FDES) more modular and scalable than the conventional FDES. The transgenerator is a three-member dual-mechanical-port (DMP) machine with two rotating members (inner and outer rotors) and one stationary member (stator). The transgenerator–flywheel system is introduced with its configuration, transgenerator overview, flywheel operation principle and power management strategies, and control system. Simulations are performed in MATLAB 2023b/Simulink to verify the system viability, including control system verification and flywheel storage performance evaluation. The results show that the inner and outer rotors can be controlled independently with an accurate and fast control response, and the grid-side control works properly. The flywheel performs well, with considerable charging power and storage capacity.

Electric vehicles (EVs) are considered an alternative to conventional internal combustion engine vehicles (ICEVs) for reducing tailpipe CO2 emissions. However, their higher initial manufacturing pollution raises concerns about their lifetime CO2 emissions. Hybrid electric vehicles (HEVs) and plug-in hybrid electric vehicles (PHEVs) are traditionally viewed as intermediate solutions in terms of emissions. Previous research on emission comparisons among these vehicle types was often confined to specific regions. This study conducts a worldwide assessment of the lifetime CO2 emissions of the 2020 Chevrolet Bolt EV, a commercially available EV, and globally compares it with an ICEV, two types of HEVs, and three types of PHEVs, all with equivalent vehicle performance. The analysis utilizes the dynamic programming (DP) algorithm to theoretically optimize the lifetime emissions of HEVs and PHEVs. The findings indicate that, with DP optimization, HEVs and PHEVs can achieve lower worldwide lifetime emissions than both comparable EVs and IC engine vehicles without sacrificing vehicle performance.

This paper addresses the urgent challenges of escalating global warming, rapid ozone layer depletion, and persistent greenhouse gas (GHG) emissions exacerbated by nations’ reluctance to limit industrial emissions for economic growth. This has prompted a global shift towards exploring alternative strategies for pollution mitigation, including transitioning from conventional power generation to sustainable energy resources and a move from gasoline-based transportation to electric vehicles (EVs). Particularly critical is the question of whether this transition genuinely yields environmental benefits, or if it potentially exacerbates existing challenges, especially in underdeveloped or developing countries heavily reliant on fossil fuel-generated electricity. The paper presents a concise comparative analysis between Electric Vehicles (EVs) and Internal Combustion Engine Vehicles (ICEVs), examining GHG emissions throughout their lifetimes, during manufacturing, and in terms of fuel consumption. Additionally, it explores the energy mix of developing countries compared to the global scenario, presenting results for the comparison between ICEVs and EVs using electricity from coal, gas, nuclear, and a balanced energy mix-dominated power system. The study identifies opportunities for improvement in EV adoption and emission mitigation strategies, offering valuable insights into sustainable practices and environmental conservation.

In this brief, a hidden Markov model (HMM) is used to diagnose the severity of permanent magnet synchronous motors (PMSMs) with interturn short-circuit (SC) fault. The fault diagnosis result in this brief is an extension of similar result for dc motors. When the fault severity allows for continuing operation of the motor, a bisecting search method is proposed to reduce torque ripples while maintaining maximum torque capability. The advantages of the new fault-tolerant control (FTC) method over other existing methods in the literature are analyzed. Torque ripples are significantly reduced compared with the existing FTCs in the literature. The assumption of SC resistance equal to zero made in another paper was eliminated.

Increased efforts toward climate change mitigation and achieving net zero (NZ) are occurring globally. This research addresses three challenges to meeting the target NZ goals: (1) quantifying energy use reduction approaches, including energy efficiency and renewable power; (2) obtaining measured data to verify NZ achievements; and (3) providing NZ definitions to a globally understandable concept. To do so, a reorganized NZ concept (NZX%(ORG)) is proposed that is practical, measurable, and adaptable to different regions and requirements. The “X%” presents the fraction of renewable energy to the total energy used, and the “ORG” defines the organization’s NZ definition that a project uses. The objective of this proposal is to create a universally NZ concept and method, using measured utility power data, by (1) determining a baseline NZX%(ORG); (2) projecting an optimized NZX%(ORG); (3) measuring and reporting the actual NZX%(ORG). This application is extendable from a building level to the community, city, and country levels (NZCX%(ORG)). The Serenbe community, a monitored case study in Georgia, was analyzed. The baseline NZ rating using metered data was NZC16%(ASHRAE). The analysis showed that improved energy efficiency measures (lighting, windows glazing, air sealing) along with increased on-site solar power generation (from 10% to 25% of all roof space), provided a projected NZC80%(ASHRAE). In addition, publicly available documentation of the measured utility power is required for reporting the actual NZCX%(ORG) in Serenbe. Using NZX%(ORG) provides recognition of partial success in moving toward 100% renewable power.

An economic feasibility study of a grid-connected photovoltaic (PV) energy system, that is designed to meet the electrical load demand of Yarmouk University in Jordan, is investigated. The PVsyst commercial software is used to size the system elements. Various layouts and technical options are proposed. The major benefit of the system is shown to be reduction in the electricity cost. Four options are simulated based on peak sun hours (PSH) and the possible footprints on campus. The new designed systems can reduce the annual electricity cost by about 62.56% to 96.76S%. The case of 96.76S% PV system will save around 2.4 million JD per year with a payback period of 1.3 years.

Battery electric vehicles (BEVs) can recuperate the kinetic energy of the moving vehicle by the process of regenerative braking. However, this feature is limited by the battery recharge power rating that is often significantly less than the BEV propulsion power rating. This study proposes a powertrain for BEVs that is capable of improving regenerative braking significantly by utilizing a lightweight flywheel and small ultracapacitor pack as power buffers. In order to connect the flywheel and ultracapacitor to the drive shaft effectively and more efficiently, a two-shaft electric motor called the transmotor is utilized. Further, the proposed powertrain, transmotor–flywheel assisted by ultracapacitor, enables us to reduce the power rating of the battery pack to the extent that it only be used for low power demand loads such as cruising. A braking scenario simulation followed by an emulation test is presented to demonstrate the above enhancement.

Buildings contribute to greenhouse gas emissions that cause environmental impacts on climate change. Net Zero Energy (NZ) buildings would reduce greenhouse gases. The current definition of NZ lacks consensus and has created uncertainties, which cause delays in the adoption of NZ. This paper proposes a Process for Clarification to Accelerate the Net Zero (PC-A-NZ) through three integrated steps: variations, strategies, and requirements. We expand on the results in published NZ literature to clarify the differences in definition and strategy. The objective of this review is to (1) distinguish current variable parameters that are slowing the acceptance of NZ, and (2) focus the discussion internationally on moving faster toward applying NZ to a larger common agreement. The publications of global NZ target assessment and energy efficient strategies will be reviewed to address the main requirements in expediting NZ’s successful progress. Our NZ review analysis highlights (1) how the existing NZ definitions and criteria differ, (2) how calculation strategies vary, and (3) how standards and requirements are often localized. The proposed PC-A-NZ will help policymakers and stakeholders to re-evaluate the existing definitions, standards, and requirements to optimize the use of renewable technologies, improved energy efficiency and electrification to speed up achieving the NZ targets. Definition: There are multiple NZ definitions that vary in source and supply requirement, timescale, emission source, and grid connection.

All-wheel-drive (AWD) multimotor electric powertrains offer greater potential for system performance, efficiency, and reliability improvements. In this article, a new AWD electric powertrain that can increase the overall powertrain efficiency and battery lifetime is introduced. The proposed powertrain is based on a compact and efficient flywheel-based kinetic energy recovery system (KERS) that overcomes most of the shortcomings of the conventional electric KERS. Here, a significant part of the mechanical power transfer takes place without conversion to electrical power. Therefore, a selectable fraction of the recoverable kinetic energy is processed by power electronics. Thus, no energy exchange is necessary between the battery and the powertrain during acceleration and deceleration, resulting in a reduced battery power rating. This article compares the proposed powertrain with a conventional AWD electric powertrain. Mathematical modeling and simulations based on the space vector method were used for both powertrains that show the advantage of the proposed powertrain over the conventional one. The experimental data are also presented from our proof of the concept laboratory setup.

Most commercially available hybrid electric vehicle (HEV) drivetrains are made of small internal combustion (IC) engines and large electric drives to improve fuel economy. They usually have higher cost than the conventional IC-engine-based vehicles because of the high costs of the electric drives. This paper proposes a hybridized powertrain composed of the original full-size engine of the vehicle and a universally optimum size parallel electric drive. The dynamic programming (DP) algorithm was used to obtain the sensitivity of the maximum miles per gallon (MPG) values versus the power rating of the electric drive. This sensitivity was then analyzed to determine the optimal window of the electric drive power ratings. This was proven to be universal for all passenger cars of various masses and engine powers. The fuel economy and vehicle performance of this HEV was compared with those of the 2019 Toyota Corolla, a conventional IC-engine-based vehicle, and the 2019 Toyota Prius, a commercially available HEV. The results showed that the proposed universally optimized HEV powertrain achieved better fuel economy and vehicle performance than both the original ICE and HEV vehicles, at low additional vehicle cost.

DC-DC converters with galvanic isolation are a key element in the aircraft DC distribution system and Dual and Triple Active Bridge converters are one of the most interesting candidates in this application. The high-frequency transformer leakage inductances play a key role in the AC Link of these converters. This leakage inductances determine the power transfer capability of the converter and shape the AC link currents. The leakage inductance value is related to the distribution of the transformer windings and it changes with the RMS value of the AC link current. In this paper, first a high frequency transformer is designed for a Dual and Triple Active Bridge converter for the More Electric Aircraft DC power system. Then, an Ansys/Maxwell Finite Element analysis is performed on the leakage inductances of the transformer in three different winding configurations and in different AC link RMS current values. Finally, the transient performance of the design is validated by the Ansys/Maxwell Transient.

Land transportation over the past two centuries has experienced astonishing advancement. Up until the 1860s, it took more than six months to get from the East Coast to the West Coast of the United States. Today, it may take only three days by automobile. We are even considering flying cars and there are air-taxi startup companies that have announced going public [1]. Vehicle propulsion electrifica...

Electric and hybrid electric vehicles (EV/HEV) are promising solutions for fossil fuel conservation and pollution reduction for a safe environment and sustainable transportation. The design of these energy-efficient powertrains requires optimization of components, systems, and controls. Controls entail battery management, fuel consumption, driver performance demand emissions, and management strategy. The hardware optimization entails powertrain architecture, transmission type, power electronic converters, and energy storage systems. In this overview, all these factors are addressed and reviewed. Major challenges and future technologies for EV/HEV are also discussed. Published suggestions and recommendations are surveyed and evaluated in this review. The outcomes of detailed studies are presented in tabular form to compare the strengths and weaknesses of various methods. Furthermore, issues in the current research are discussed, and suggestions toward further advancement of the technology are offered. This article analyzes current research and suggests challenges and scope of future research in EV/HEV and can serve as a reference for those working in this field.

Compared to Doubly-Fed Induction Machines (DFIMs), the dynamic and steady-state behavior of the Brushless Doubly-Fed Induction Machine (BDFIM) is more complicated. This fact is due to the coexistence of the undesirable asynchronous torques (disturbance torques) with the expected synchronous torque. In this paper, first, an analytical relationship between Control Machine (CM) currents, regarded as the system's input, and the total output torque, regarded as the system's output is derived. The relationship is expressed in both frequency and time domains to have a more clear vision of the BDFIM dynamic behavior. In the introduced equations, all types of torques that coexist in the BDFIM are considered. Then, by examining the obtained relationship, a motor drive with Feed-forward torque compensation is proposed that actively predicts the dynamic behavior of the BDFIM and attempts to eliminate undesirable dynamic responses. The dynamic behavior of the BDFIM with and without torque compensation method are compared for both open-loop and closed-loop torque control drive schemes, and the simulation results are presented. Field oriented control assumptions are made to obtain a suitable dynamic model for the BDFIM.

The Cascaded (Brushless) Doubly-Fed Induction Machine (CDFIM) is a promising substitute for the commonly used Doubly-Fed Induction Machines (DFIM) for wind power application. The CDFIM offers reliable performance and low maintenance due to the absence of slip rings and graphite brushes. In this study, a detailed analytical model for the CDFIM is proposed in order to clearly show the input (i.e., current from inverter side) and output (i.e., total output torque) relationship. The proposed model is expressed in the frequency (Laplace) domain. Field oriented (i.e., vector) control approach is adopted in order to achieve a precise dynamic model for the grid connected CDFIM. Each term of the derived relationship is classified into the possible types of torque based on the term's nature and then is discussed in detail. Then, the steady state and dynamic behavior of these terms are presented and explained individually. The total output torque dynamic response is calculated both analytically and numerically in a simulation environment, and the results are compared.

Four-wheel-drive (4WD) full-electric powertrains offer great potential for vehicle performance and efficiency improvements. This study introduces a novel 4WD electric powertrain that significantly increases the overall powertrain performance and battery lifespan. The proposed powertrain benefits from a new compact and highly efficient flywheel-based kinetic energy recovery system (KERS) that enables us to overcome most of the shortcomings of the conventional battery-based KERS. The utilized KERS is capable of capturing or providing much higher mechanical power than its electrical power ratings. Meaning that, without overloading, the powertrain can capture more mechanical power than traction motors’ nominal values. Moreover, since a significant part of the energy exchange takes place in mechanical form, only a portion of the initial kinetic energy (slip energy) needs to be converted into electrical form and be processed electrically. In the proposed powertrain, there is no energy exchange necessary between the battery and the powertrain during each accelerations or braking event, thus also reducing the battery power rating. Mathematical modeling and simulations were performed using space vector modeling method for the proposed powertrain. The results prove the functionality of the proposed 4WD powertrain. Experimental results are also presented for the proof of the concept.