Search

Power transformers are critical for grids, facilitating transmission, distribution, and voltage conversion. However, its insulation degrades over time, instigating catastrophic failures. This article investigates the emerging trends of artificial intelligence (AI) driven transformer prognostic health management (TPHM) strategies to mitigate such risks, emphasizing AI’s role in overcoming traditional methodology’s computational limitations. Hybrid approaches enhance dissolved gas analysis accuracy, while frequency response analysis is interpreted using machine learning. Deep-learning automates feature-weight assessment in partial-discharge and insulation analysis, eliminating manual health-index formulation. The implications and strategies for optimizing AI-driven TPHM efficiency are discussed, providing valuable trends in fostering a prognostic diagnosis ecosystem.

This article puts forward the analysis and design of single-phase bridgeless Cuk-derived dc–dc converter for a novel vehicle-to-vehicle (V2V) charge transfer technique. V2V charging adds flexibility to electric vehicle (EV) charging process and aids in mitigating range anxiety. The proposed V2V charge transfer technique has only one power conversion stage and only one onboard charger is used to charge the battery. The charger is capable of both grid-to-vehicle and V2V charging. The converter design is in discontinuous conduction mode which reduces the control complexity. The converter has a lower component count rendering the charger lightweight, power dense, and cost effective. The overall converter efficiency is high owing to low switching losses. This work has been compared to several state-of-the-art V2V topologies and configurations. The complete steady-state analysis and converter design operating in dc charging mode have been presented. Moreover, to validate the analysis, design, and applicability of the converter for dc V2V charge transfer, PSIM simulation, and laboratory-based hardware prototype have been built and the experimental results are provided.

Power conditioning systems are performing a key role in smart grid operation. The increase in renewable energy installation leads to an increase in the power electronic converters installation for distributed generation, rural electrification, and grid integration. As the numbers are increasing, the reliability of the grid is impacted mainly due to the power conditioning weak link. Thus, there is a need to improve the reliability and efficiency of overall power processing. One way to achieve this is to improve health by smart monitoring and make the controller fault-tolerant. For example, approaches that monitor the health of the devices along with fault-tolerant control architecture can be implemented in the controller to detect failures and to get timely alarm signals. For this, relevant data gathering and analysis are extremely critical. Machine learning (ML) and deep learning (DL) are approaches that analyze the data, learn from the data, and then apply it during the decision-making process. The Special Issue on Machine Learning Techniques in Power Electronics invites the articles related to data gathering/analysis and improvements of reliable operation of power conditioning and renewable energy resources with applications to the smart grid.

The IEEE Industry Applications Society (IAS) congratulates the winners of the 2023 Society Awards.

A novel tranformerless single-stage grid-connected solar inverter with a combination of a bidirectional dc/dc boost converter followed by a flyback inductor inverter is proposed. The inverter shares a common ground with the photovoltaic (PV) panel and the grid, which realizes a zero leakage current and it is the most desired feature in transformerless inverters. Further, the proposed inverter provides the boost voltage operation, hence it does not require a second stage which decreases the system cost and increases the system reliability. The other advantage of the proposed inverter is that it provides both the symmetrical positive voltage gain and negative voltage gain, which allows to use simple sinusoidal pulsewidth modulation technique for realizing the ac sinusoidal output voltage. The proposed inverter steady-state operation and the design equations are presented in detail. The converter dynamic model is developed using state-space averaging approach, and a proportional resonant current controller is designed for inverter closed-loop operation with the grid. The presented analysis and the design are verified with both the simulation and experimental results.

Kaushik Rajashekara , professor of engineering at the University of Houston, United States, has won the prestigious Global Energy Prize for outstanding contributions to transportation electrification and energy efficiency technologies while reducing power generation emissions.

This paper proposes a novel zero-current assisted soft-switching bidirectional single-stage single-phase isolated power factor correction (PFC) based converter for plug-in EV charger. An isolated topology consists of a current-fed full-bridge converter with bidirectional switches on the ac-side that is connected with a full-bridge converter on the dc-side of a high-frequency transformer (HFT). HFT offers galvanic isolation for safety and high power density, and it is the most desired specification for a battery charger. The converter enables zero current switching (ZCS) of ac-side switches and zero current turn-ON for dc-side switches without any active clamp circuit or passive snubbers, which significantly reduced switching losses, footprints, and cost. The proposed modulation strategy and control technique are presented for promising the soft-switching operation of all semiconductor devices throughout the range for all modes with bidirectional power flow capability. These merits make the converter more feasible, robust, and reliable with high power density for an EV application. A comprehensive study of proposed steady-state operation, design, and simulation results is reported. A proof-of-concept hardware laboratory prototype rated at 1.5 kW is established and tested to validate the claims and proposed converter performance.

Presents the recipients of IAS Society awards for 2024.

A three-inductor current-fed converter leveraging short pulse series resonance to facilitate zero-current switching (ZCS) and voltage clamping of the semiconductor devices is proposed and investigated in detail. The circuit exploits series resonance characteristics during conduction overlap of any two switching signals that naturally reduce the current in outgoing switch to zero accomplishing zero-current turn-off. It succeeds in natural switch voltage clamping eliminating the traditional snubber requirement. Owing to the short resonance period, circulating current through the converter limits the conduction losses particularly at light load, thus improving the light-load efficiency. In addition, current-sharing topology offers reduced current stresses through the primary side devices and simpler gate driving requirements because of common source grounded with power supply. Detailed analysis and design are reported. Experimental results from 1-kW proof-of-concept hardware prototype are established to validate the projected claims and confirm the performance and the efficacy of proposed converter. This concept has been verified in single-phase topologies and first time studied for three-phase current-fed circuit.

This article proposes a single-phase switched-mode bridgeless ac–dc buck–boost derived converter that can serve as a front-end converter for the on-board electric vehicle (EV) charging application. The bridgeless scheme rules out the orthodox bridge rectifier and the affiliated losses. The proposed converter operates in discontinuous current conduction mode (DCM), thus achieving natural power factor correction for variable ac input. In addition to this, sensing of input voltage and input current is fended off because of DCM operation making the converter reliable, cost-effective, and robust compared with conventional continuous current conduction mode converters. Furthermore, the control becomes simple with the employment of a single sensor and the elimination of the phase-locked loop. The proposed front-end converter is well suited for low-voltage battery chargers ranging between 1.0 and 3.3 kW installed in golf-carts and E-rickshaws. A comprehensive steady-state analysis for one switching cycle and the design equations of the proposed converter are presented. The small-signal model of the proposed converter is presented for the implementation of the closed-loop control. Experimental results from a 1.0-kW concept-proof hardware prototype have been demonstrated, which upholds the converter analysis.

Prostate cancer is one of the leading causes of death due to malignancy in men. Occult malignancy presenting with no primary symptoms could be a challenge to the diagnostician. Metastasis of prostate carcinoma to the mandible is rare and usually presents with non-specific symptoms. Only 1% of oral cancers account for lesions which present as metastasis of other primary malignancies. We report a rare case of prostate carcinoma being diagnosed as metastasis to the mandible with the patient presenting with numb chin syndrome.

Reports on changes to the IAS Outstanding Educator/Mentor Award that was established in 2019 to honor an individual who has made an outstanding contribution to the education and mentorship of students and young engineers within the fields of interest of the IEEE IAS.

Do you know a dedicated IEEE Industry Applications Society (IAS) member that deserves to be nominated for a 2023 Society Award? As discussed by Dave Durocher in the “From the Editor’s Desk” column “The Power of Recognition” on page 3 [A1], it is critically important to show our appreciation for the service and achievement of our Society volunteer leaders and these awards do just that!

Presents the recipients of IAS members who won 2023 IEEE Technical Field Awards.

In distributed generation, high power capability and high efficiency are very important requirements. For this reason, this paper proposes a new analytical procedure for selective harmonic elimination in five-level inverters operating at fundamental frequency. For each modulation index, the proposed method calculates all possible switching angles eliminating a specified odd harmonic from the output voltage. The method has limited computational complexity, simple and cost-effective real-time implementation, and full capability of integration with closed loop control. Simulation and experimental results highlight full elimination of selected harmonic.

This paper investigates a novel half-bridge cycloconverter configuration on load side with devices operating at line frequency, thus providing direct high-frequency ac to line frequency ac conversion with transformer isolation. This paper also presents a detailed comparative study and evaluation of double-ended converters, viz., full-bridge, half-bridge, and push–pull-based microinverter topologies for solar photovoltaic ac module. Double-ended converters offer merits of no transformer saturation, reduced transformer, and filter size. Simple sinusoidal pulsewidth modulation for standalone mode and current control for grid-tied mode are implemented for front-end devices. Comparative study reveals that half-bridge topology is cheaper than the other two topologies and has comparable efficiency with full bridge. A 250-W laboratory prototype of half-bridge microinverter is developed, and experimental results are demonstrated to show its performance under various conditions, i.e., standalone, grid-tied, and change of current references.

Low power inverter mounted on each photovoltaic (PV) panel, i.e., microinverter is gaining popularity due to the increased energy harvest. This paper proposes a novel single-stage zeta microinverter for PV applications. The proposed topology is based on zeta converter with high-frequency transformer isolation and a single low side switch on the primary side of transformer. The most distinctive feature of the proposed inverter is its ability to work in continuous conduction mode (CCM) over a wide load range, which results in high efficiency, reduced current stress, and components’ rating. All the secondary switches operate at line frequency, thus reducing switching losses significantly. A comprehensive study of the proposed microinverter, including steady-state analysis and design, has been reported. A 220-W microinverter was designed, developed, and tested in the laboratory. Experimental results are demonstrated to verify the CCM operation of the inverter and its performance over a wide load range.

Solar-powered membrane distillation (SP-MD) technology has proven to be an ideal solution for providing fresh water in remote and off-grid locations. In this study, a novel solar energy-driven direct contact membrane distillation (DCMD) cycle is proposed in which a nanofluid-based volumetric absorption solar collector (VASC) is used to drive the DCMD process. The present work focuses on the use of volumetric collector instead of commercially available surface absorption-based solar collector in case of two-loop indirect SP-MD systems, which are installed to control the scaling and corrosion issues in solar collectors. The thermodynamic performance of this two-loop indirect solar-powered DCMD (SP-DCMD) system has been evaluated with the help of a mathematical model prepared in matlab. For modeling the DCMD unit, the ɛ-number of transfer unit (NTU) method used for designing heat exchangers has been employed. The performance of the overall system is evaluated by gained output ratio (GOR), thermal efficiency (η) of the membrane distillation, and water flux (Jw), and effects of various operating parameters related to both DCMD and VASC systems have been understood on the overall system performance. Finally, it has been shown that VASC-driven DCMD system has been approximately 4–15% higher gained output ratio compared to surface absorption-based solar collector (SASC)-driven DCMD system under similar operating conditions.

High-altitude wind power (HAWP) generating system uses dc-dc converter to transform the dc link voltage to an optimal medium voltage dc for efficient transmission to ground-based station. This paper presents a comparative study of current-fed and voltage-fed (VF) isolated dc-dc converters for HAWP application. VF converters (VFCs) with inductive and capacitive filters are compared with current-fed converters for a 100-kW rated power. The power electronic converters used maintain zero-voltage switching on the primary side switches to reduce switching losses. The current and voltage ratings of the components used are provided to realize higher power-to-weight (P/W) ratio. Losses and P/W ratio are assessed using the components' datasheets and compared with evaluate the converters that exhibit higher P/W ratio and efficiency. It is observed that VFC with capacitive filter exhibits higher P/W ratio and efficiency. Small signal modeling of VFC with capacitive filter is carried out to obtain the state-space model. Transmission voltage is controlled at optimal value using voltage control loop for efficient power transmission. Simulation studies of VFC with capacitive filters are carried out to verify the steady state analysis and performance using the software PSIM-9 at 100-kW power level that converts 600-8000 V. A 1-kW scaled down laboratory prototype is designed, built, and tested using modular devices and accessed to validate the performance. It yields an efficiency of 94.2% at full load converting a ten-times scaled down voltage of 60-800 V.

This paper proposes a new modulation technique dual three-pulse modulation (DTPM) to switch dual full-bridge output capacitorless dc/dc converters to develop a pulsating dc link voltage encoding six pulse rectified output information. The pulsating voltage is directly fed to a standard six-pack inverter to develop three-phase ac output voltage. Proposed inverter and modulation are suitable for electric, hybrid electric, and fuel cell vehicles. The absence of the dc link capacitor and DTPM produce pulsating dc voltage that retains the sine-wave information (six- or three-phase rectified output) at the input of three-phase inverter. Inverter devices are modulated for 33% (one-third) of the line cycle and remains in their unique switching state (either on for 33% or off for 33%) and results in average device switching frequency of one-third of switching frequency. This results in 66% savings in switching losses. In addition, devices are not switched when the current through them is at its peak value and total savings in switching loss accounts to be up to 86.7% in comparison with a standard voltage source inverter with sine pulsewidth modulation. This paper presents operation and analysis of the pulsating dc link two-stage inverter controlled by the proposed DTPM at the front end and 33% modulation for the six-pack inverter along with the implementation. Design of the two-stage three-phase inverter has been illustrated. Analysis has been verified through simulation results using PSIM 9.0.4. Experimental results on a lab prototype have been demonstrated to validate the claims and the proposal.

Based on a systematic classification of dc source to utility interfacing schemes, this paper presents six major interfacing schemes for connecting fuel cells to a single-phase utility line using high-frequency transformer isolated power converters. The operation, advantages and disadvantages are discussed for each scheme with examples and operating waveforms. Several features e.g., utility line power factor, line current THD, size, ease of connection to utility line and simplicity of control, are compared. Based on their performance and fuel cell characteristics, a suitable scheme is selected. The selected scheme (#4) uses a dc/dc converter followed by a current controlled voltage source inverter. Details of the power conditioning unit (PCU) based on the selected scheme are given with some PSIM simulation results.

Presents information on the actitivities of IEEE ITEC India.

•Vision for 100% electric vehicle by 2030 in Indian vehicle market.•Recent initiatives and various subsidies by the Indian government could promote battery technology.•The Battery Electric Vehicle could reduce the carbon dioxide emission from the light-duty vehicle fleet and dependency on fossil-fueled vehicles.•Barriers can be addressed from various prospective such as market, technical policy and infrastructure.•Vehicle-to-Grid is an important aspect in energy security, renewable energy and giving a great impact to deal with global warming issues.