Hasil untuk "Applications of electric power"

Manisha Vangari, T. Pryor, Li Jiang

Murugesan M, Suganya N, Sivaranjani S et al.

A novel multilevel inverter design for electric vehicle applications is presented in this research. In order to generate the necessary twenty-nine levels of output voltage and current waveforms, this multilevel inverter is developed using ten power switches and four distinct asymmetrical DC sources. Pulse width modulation is the most often utilized control method in multilevel inverters. This multilevel inverter uses sinusoidal pulse width modulation to remove low order harmonics. MATLAB is used for simulation, and a resistive load and resistive-inductive load is used for testing. A 210V, single phase, 29 level proposed architectural prototype uses MOSFETs as switching devices. In the hardware configuration, IRF840 MOSFETs are used. For inverter switches, the Ardiuno micro controller generates the gate signal. To achieve a twenty-nine level output waveform, typical multi-level inverters require a greater number of power components, which raises switching losses, costs, and harmonic distortion. By using 10 switches, the suggested inverter greatly reduces switching losses, low order harmonics, and switching costs, which in turn lowers overall harmonic distortions

John L. Christensen, J. Newman

Sadjad Shafiei, Tohid Sharifi, Mohammad Ali Noroozi Dehdez et al.

Abstract This study proposes a modified partitioned‐stator flux‐switching permanent magnet (PS‐FSPM) machine and reduces the permanent magnet usage in conventional PS‐FSPM machines. To achieve this goal, the stators of the conventional PS‐FSPM with outer‐armature/inner‐PM (OA/IPM PS‐FSPM) structure are swapped to realise a PS‐FSPM with outer‐PM/inner‐armature (OPM/IA PS‐FSPM) design. The machine topology along with the operating principles are described in detail, and an analytical airgap permeance model is introduced for the proposed machine. The number of rotor modules, the widths of the magnets and rotor modules, as well as the split ratio (SR), are optimised through sensitivity analysis to achieve higher torque density and reduced torque ripple, compared with the conventional structure. Moreover, a flux barrier in the exterior surface of the outer stator is adopted to improve the proposed structure to reach a higher flux concentration in the airgap and reduce iron volume consumption. The thermal analysis results using the computational fluid dynamics modelling indicate that the temperatures of both insulation and permanent magnets remain within specified operating limits. Finally, apart from the finite element analysis (FEA), an experimental study is performed to evaluate the feasibility of fabricating a machine equipped with a high number of rotor modular teeth.

Mathieu Ginet, Eric Feltrin, Nicolas Jeanniot et al.

Single-Input, Multi-Output (SIMO) converters present significant challenges when operated under current-mode control, due to their strongly non-linear dynamics and susceptibility to bifurcation phenomena. To mitigate the effects on the converter’s steady-state, a double slope compensation solution is proposed. The compensation parameters play a critical role in shaping the system dynamics and rejecting the susceptibility to bifurcation. This paper proposes a detailed analysis methodology to investigate the design parameter space regarding the slope compensations with respect to bifurcation phenomena. The approach is validated on a CMOS integrated converter, where theoretical predictions are compared to the simulation results of a full transistor-level model of the circuit.

Mohammad Reza Karafi, Pedram Asef

Hybrid Gas–Magnetic Bearings (HGMBs) are an emerging technology ready to completely change high-speed oil-free rotor support in aerospace electric motors. Because HGMBs combine the stiffness and load capacity of gas bearings with the active control of magnetic bearings, enabling oil-free, contactless rotor support from zero to ultra-high speeds. They offer more load capacity of standalone magnetic bearings while maintaining full levitation across the entire speed range. Dual-mode operation, magnetic at low speeds and gas film at high speeds, minimizes control power and thermal losses, making HGMBs ideal for high-speed aerospace systems such as cryogenic turbopumps, electric propulsion units, and hydrogen compressors. While not universally optimal, HGMBs excel where extreme speed, high load, and stringent efficiency requirements converge. Advances in modeling, control, and manufacturing are expected to accelerate their adoption, marking a shift toward hybrid electromagnetic–aerodynamic rotor support for next-generation aerospace propulsion. This review provides a thorough overview of emerging HGMBs, emphasizing their design principles, performance metrics, application case studies, and comparative advantages over conventional gas or magnetic bearings. We include both a historical perspective and the latest developments, supported by technical data, experimental results, and insights from recent literature. We also present a comparative discussion including future research directions for HGMBs in aerospace electrical machine applications.

Shuping Gao, Zhe Quan, Xinyu Wu et al.

ABSTRACT As the core hub equipment of offshore wind power low‐frequency transmission systems, low‐frequency transformers generate complex harmonic disturbances during internal faults, severely compromising the reliability of traditional current differential protection. To address this engineering challenge, this paper innovatively proposes a transformer fast main protection method based on excitation inductance parameter identification. Rooted in the unique application scenarios of offshore wind power, the research focuses on overcoming the limitations of existing ratio‐restraint differential protection constrained by magnetising inrush current identification. Specifically, the distinctive harmonic characteristics exhibited during low‐frequency transformer faults can invalidate second‐harmonic restraint principles. A novel identification model based on the dynamic characteristics of instantaneous excitation inductance is developed, which breaks through the limitations of traditional harmonic analysis methods and achieves precise discrimination between fault currents and magnetising inrush currents using single‐terminal current‐voltage data. Simulation experiments demonstrate that this method can reduce protection operation time to less than 10 ms, particularly suitable for special offshore platform conditions characterised by space constraints and maintenance difficulties. The proposed approach provides critical technical support for enhancing low‐frequency transformer protection in offshore wind farm grid‐connected low‐frequency transmission systems, demonstrating significant engineering application value.

Zhu Shihao, Hu Hongming, Du Banghua et al.

The integrated hydrogen energy utilization system (IHEUS) exhibits great potential for microgrid applications. However, its practical application faces significant challenges mainly due to the low energy conversion efficiency and rapid aging of the electrolyzers and fuel cells, especially when handling highly fluctuating power flows. To this end, this study proposes a multi-objective optimal dispatch scheme for off-grid IHEUS operations, where waste heat recovery and life cycle cost are taken into consideration to address the above problems. We first establish a first-principle model that describes the electric-hydrogen-heat output characteristics of the system, where the waste heat recovery and utilization systems have been focused. By correlating the aging behaviors and lifetime to voltage degradation, a life-cycle operational cost function is derived for a multi-objective optimization (MOO) model. In this MOO model, we adopt comprehensive energy efficiency and energy supply loss probability as the performance evaluation and optimization criteria so as to improve energy efficiency and supply stability, and the designed MOO problem is solved and ranked by a proposed NSGA-III joint entropy-weighted TOPSIS strategy. Comprehensive comparative studies exhibit that this proposed NSGA-III joint entropy-weighted TOPSIS strategy can effectively determine the optimal operation dispatch scheme. Consequently, a 46.13% reduction in operating costs can be achieved at the same the comprehensive energy efficiency and ESLP.

Tripti Kunj, Kirti Pal

The rapid expansion of Electric Vehicles (EVs) has initiated significant advancements in charging infrastructure to support sustainable transportation. This paper reviews the role and integration of the Internet of Things (IoT) in Smart EV Charging Management, highlighting how IoT technology enhances operational efficiency, energy management, and user experience. Drawing on real-world implementations such as Tesla’s predictive maintenance systems, Enel X’s JuiceNet for smart charging, and Nissan Leaf’s Vehicle-to-Grid (V2G) capabilities, the paper discusses IoT applications in areas including real-time monitoring, energy optimization, predictive maintenance, and user-centric services. These integrations demonstrate measurable benefits such as improved battery health monitoring, reduced charging downtime, and enhanced grid interaction. Furthermore, the synergy between IoT and renewable energy sources, such as solar power, is explored as a pathway to further optimize charging efficiency and minimize environmental impact. Despite the benefits, challenges such as cybersecurity risks, interoperability barriers, and the lack of communication protocol standardization are also identified. Additionally, the paper emphasizes the importance of adaptive algorithms and machine learning models for predictive maintenance and efficient resource allocation. This review serves as a key reference for policymakers, researchers, and industry leaders aiming to develop resilient and intelligent EV charging ecosystems, contributing to a more connected and sustainable electric mobility future.

D. Das, N. Weise, K. Basu et al.

In vehicle-to-grid applications, the battery charger of the electric vehicle (EV) needs to have a bidirectional power flow capability. Galvanic isolation is necessary for safety. An ac–dc bidirectional power converter with high-frequency isolation results in high power density, a key requirement for an on-board charger of an EV. Dual-active-bridge (DAB) converters are preferred in medium power and high voltage isolated dc–dc converters due to high power density and better efficiency. This paper presents a DAB-based three-phase ac–dc isolated converter with a novel modulation strategy that results in: 1) single-stage power conversion with no electrolytic capacitor, improving the reliability and power density; 2) open-loop power factor correction; 3) soft-switching of all semiconductor devices; and 4) a simple linear relationship between the control variable and the transferred active power. This paper presents a detailed analysis of the proposed operation, along with simulation results and experimental verification.

Yong‐Lai Zhang, Li Guo, Shu Wei et al.

V. Pires, A. Cordeiro, D. Foito et al.

Most fuel cell electric vehicles require wide voltage-gain DC–DC converters to increase and equalize the relatively low voltage of fuel cell stacks with DC link bus or energy-storage devices, such as supercapacitors or batteries. This paper proposes two new non-isolated DC–DC converters suitable for such applications, which can be extended to other electric vehicles as well. The proposed converters combine the main characteristics of both quadratic Boost and Ćuk converters, offering high step-up voltage and control simplicity using only one ground referenced active power switch. Additionally, the proposed topologies present reduced voltage stress across the active power switch when compared to other boost converters. Considerations about the design of the proposed converters will also be presented. Experimental results obtained using a laboratory prototype validate the effectiveness and feasibility of the proposed topologies and its suitability for fuel cell electric vehicles.

Zhanlu Yang, Shuo Sun, Mengmeng Wu et al.

Abstract An overall investigation of the electromagnetic force, vibration, and average torque of the Interior Permanent Magnet Synchronous Motors (IPMSM) in the dq model for electric propulsion ships is carried out, and the electromagnetic vibration characteristics of the PMSM under the vector control strategy is explored. Firstly, the space and frequency characteristics of the electromagnetic force of the dq model motor are derived using the Maxwell stress tensor method, and the influence of the dq‐axes magnetic field on the electromagnetic force under different loads is discussed in detail. Secondly, the finite element method is used to verify the influence of dq‐axes currents on motor electromagnetic force, vibration, and average torque. Finally, the experiments are conducted on an 8‐pole 48‐slot IPMSM, and the results are consistent with the theoretical analysis and simulation results. The results indicate that the electromagnetic vibration of the PMSM for electric propulsion ships increases with the increase of the current i q and decreases with the increase of the current i d . The electromagnetic vibration of the motor can be reduced by selecting the appropriate dq‐axes current under the output torque constraint.

K. Shenai, R. S. Scott, B. Baliga

Rita F. Constantino, Guilherme Brites, Pedro D. R. Araujo et al.

Anisotropic magnetoresistance (AMR) sensors are pivotal in various applications due to their low power consumption, scalability, and cost-effectiveness due to the simple sensor structure, comprising one NiFe film, usually encased in a buffer and cap layer. In this work, we explore the effects of inserting MgO and Pt dusting layers between the NiFe sensing layer and adjacent capping and buffer layers, on the electric, magnetic and structural properties of AMR sensors. We describe results on sensors based on Ta/NiFe/Ta, with an as-processed AMR value of 2.0 %. The insertion of Pt thin films had a positive impact, with AMR values increasing to 2.2 %, contrary to the observed with MgO dusting films. Magnetic annealing up to 370 °C caused an increase of the resistivity and reduction in AMR (with Pt dusting layers), on the contrary, MgO dusting layers improved the sensor performance upon annealing, with AMR increasing to 2.5 % (5 h at 370 °C). In light of the findings, the incorporation of Pt and MgO dusting layers enables tailoring the grain size and resistance of Ta/NiFe/Ta films, while combined with proper annealing, which is relevant for applications where Ta and NiFe are available for AMR sensor fabrication.

Wenlong Li, Qingle Wu, Guolai Yang et al.

Abstract To the challenges posed by the complex structure and low reliability of existing hydraulic actuators used for more electric aircraft landing gear, this paper proposes an optimised design method for an electric actuator based on the principles of tubular permanent magnet linear motor employing a Halbach array. For this electric actuator, a subdomain model considering the longitudinal end effect is established by setting virtual permanent magnet regions at both ends of the Halbach array. The effectiveness of the proposed method is verified through a comparison with the finite element method. Subsequently, a surrogate model is developed using the proposed subdomain model, and an uncertain optimisation model considering machining and assembly errors is developed based on the interval possibility and the interval order theory. Compared to its initial design, the optimised structure increased the average thrust by 13.4% and reduced the thrust ripple rate by 87.2%, significantly improving the overall performance of the electric actuator. Finally, prototype experiments are carried out to verify the effectiveness of the proposed subdomain method and optimised approach.

Fumiaki Kato, Urara Maruoka, Akitoshi Nakano et al.

Abstract The thermal properties of semimetal Ta2PdSe6 are studied, which exhibits a large thermoelectric power factor at low temperatures, by combining chemical substitution, transport measurements, and inelastic X‐ray scattering. A serious violation of the Wiedemann‐Franz law (WFL) is observed, which establishes the relationship between conductivity and thermal conductivity of metals. This violation leads to a thermal conductivity of Ta2PdSe6 lower than expected from the WFL and resistivity below 20 K, resulting in the highest figure of merit below 20 K among the p‐type thermoelectric materials thus far. Furthermore, electric and thermal resistivity show a non‐Fermi liquid‐like temperature dependence, indicating an exotic electronic state with an unconventional scattering process for heat and charge carriers. This study suggests that semimetals in the non‐Fermi liquid regime may be an intriguing platform, not only for fundamental physics but also for exploring novel thermoelectric materials tailored for low‐temperature applications.

Padmanabhan Balasubramanian, Douglas L. Maskell

An N-bit priority resolver having N inputs and N outputs functions as polling hardware in an embedded system, enabling access to a resource when multiple devices initiate access requests at its inputs which may be located on-chip or off-chip. Subsystems such as data buses, comparators, fixed- and floating-point arithmetic units, interconnection network routers, etc., utilize the priority resolver function. In the literature, there are many transistor-level designs for the priority resolver based on dynamic CMOS logic, some of which are modular and others are not. This article presents a novel gate-level modular design of priority resolvers that can accommodate any number of inputs and outputs. Based on our modular design architecture, small-size priority resolvers can be conveniently combined to form medium- or large-size priority resolvers along with extra logic. The proposed modular design approach helps to reduce the coding complexity compared to the conventional direct design approach and facilitates scalability. We discuss the gate-level implementation of 4-, 8-, 16-, 32-, 64-, and 128-bit priority resolvers based on the direct and modular approaches and provide a performance comparison between these based on the design metrics. According to the modular approach, different sizes of priority resolver modules were used to implement larger-size priority resolvers. For example, a 4-bit priority resolver module was used to implement 8-, 16-, 32-, 64-, and 128-bit priority resolvers in a modular fashion. We used a 28 nm CMOS standard digital cell library and Synopsys EDA tools to synthesize the priority resolvers. The estimated design metrics show that the modular approach tends to facilitate increasing reductions in delay and power-delay product (PDP) compared to the direct approach, especially as the size of the priority resolver increases. For example, a 32-bit modular priority resolver utilizing 16-bit priority resolver modules had a 39.4% reduced delay and a 23.1% reduced PDP compared to a directly implemented 32-bit priority resolver, and a 128-bit modular priority resolver utilizing 16-bit priority resolver modules had a 71.8% reduced delay and a 61.4% reduced PDP compared to a directly implemented 128-bit priority resolver.

E. Martinez-Laserna, E. Sarasketa-Zabala, Igor Villarreal Sarria et al.

Lingyun Shao, Davide Tavernini, Ahu Ece Hartavi Karci et al.

Abstract The design and optimisation of a permanent magnet‐assisted synchronous reluctance (PMaSynR) traction machine is described to improve its energy efficiency over a selection of driving cycles, when installed on a four‐wheel‐drive electrically powered vehicle for urban use, with two on‐board powertrains. The driving cycle‐based optimisation is defined with the objective of minimising motor energy loss under strict size constraints, while maintaining the peak torque and restricting the torque ripple. The key design parameters that exert the most significant influence on the selected performance indicators are identified through a parametric sensitivity analysis. The optimisation brings a motor design that is characterised by an energy loss reduction of 8.2% over the WLTP Class 2 driving cycle and 11.7% over the NEDC and Artemis Urban driving cycles, at the price of a 4.7% peak torque reduction with respect to the baseline machine. Additional analysis, implemented outside the optimisation framework, revealed that different coil turn adjustments would reduce the energy loss along the considered driving cycles. However, under realistic size constraints, the optimal design solutions are the same.