Comprehensive Reliability Assessment of Buck Quasi-Resonant Converter

Publisher Copyright: © 2022 IEEE.This paper explores reliability assessment of various Quasi-Resonant (QR) buck DC-DC converters including zero current/voltage switching and half-wave/full-wave topologies. The impacts of output power, input voltage, output voltage, and time duration on the failure rate of each component are investigated, then overall reliability performance of each converter is evaluated. A detailed comparison is performed in which reliability metric of buck soft switching topologies is compared with each other as well as their parent hard switching topology. Eventually, mean time to failure of the converters is analyzed. This approach provides insightful information for selecting the topology or components for the purpose of designing QR converters. To achieve the reliability of these converters, first, the required equations to evaluate the effective factors on the reliability are obtained. Then reliability metric values are calculated for three cases in each of which a key parameter of the converters varies over a specified range.Peer reviewe

Single-Input Quadruple-Boosting Switched-Capacitor Nine-Level Inverter with Self-Balanced Capacitors

Publisher Copyright: AuthorThis paper suggests a single-input switched-capacitor Nine-level inverter configuration advantaging from quadruple voltage-boosting ability, natural voltage balancing of capacitors, and reduced components per level. Also, the single-source character of the proposed topology makes it cheaper and more compact. The cascaded version of the suggested topology has also been introduced, by which high boosting factors, as well as large number of steps, can be obtained. The proposed topology can effectively supply the resistive-inductive or pure inductive load types. The capacitors' impulsive-charging-current issue has been solved by simple small-inductance-based inductor-diode (L-D) networks. The comparative analysis affirms the fewer device-usage in suggested configuration per equal gain or level count than existed structures, resulting in less size and cost. The usage of Nearest-Level modulation guarantees the low-frequency operation of semiconductors and reduces the switching losses. The comparative analysis and experimental outcomes affirm the competitiveness and accurate functionality of suggested configuration.Peer reviewe

Operation and Design Consideration of an Ultra High Step-Up DC-DC Converter featuring High Power Density

Publisher Copyright: IEEEA new dual-coupled inductor (CI) single-switch high step-up dc-dc topology featuring high power density is proposed in this study. Various capacitive power transfer methods, as well as inductive power transfer techniques, are utilized to act as a more efficient power interface between the input and the load. Three ports in the output terminal are employed to distribute the overall output voltage, diminish the voltage ripple in high-voltage gain ratios, and decrease the voltage stress on the port component. In the proposed converter, first, the voltage gain is high in lower duty cycles of the switching. Second, the stored energy of magnetizing and leakage inductances is recycled in both Cls. Third, the switch voltage spikes are alleviated. Fourth, the operation is done with no circulating current. Fifth, low-size passive components are presented. Sixth, high power density is obtained, and the voltage range is widened. Finally, a simple pulsewidth modulation (PWM) utilizing a wide control range is provided. In this study, the steady-state operation is analyzed under both continuous conduction mode (CCM) and discontinuous conduction mode (DCM), and the performance of the converter is evaluated using comparisons with similar works. In addition, the experimental results have been provided to justify the feasibility of the design.Peer reviewe

Improved Resonant Converter for Dynamic Wireless Power Transfer Employing a Floating-Frequency Switching Algorithm and an Optimized Coil Shape

Publisher Copyright: © 2013 IEEE.This paper offers a new EF-class converter for dynamic wireless power transfer application. The proposed high-frequency converter employs a floating-frequency switching algorithm to control the converter in a continuous frequency range, eliminate the requirement to any additional operational data from the secondary (receiver) side, accelerate the load impedance match while moving, maximize the transferred power rate, reduce charging interval and compensate power transfer tolerances. Moreover, an optimized super elliptical shape coil is designed to cope with lateral misalignment, enhance coil coupling, and increase efficiency. In the proposed converter, (i) soft switching is implemented to increase switching frequency, decrease passive components size, and improve power density, (ii) undesired voltage harmonics are attenuated to reduce peak voltage stress of the power switch in a wide frequency range, (iii) the receiver side is enabled for higher mobility with stable power transfer, and (iv) the resonant frequency is updated to compensate non-accurate values of passive components in experimental prototyping. In this study, the operational analytics, compensation method, control algorithm, coil design and converter optimization are followed with some comparisons to present the converter capabilities. In addition, simulation and experimental results are provided under different degrees of misalignment to verify the accuracy of theoretical analytics.Peer reviewe

Non-Isolated High Step-Up DC-DC Converters: Comparative Review and Metrics Applicability

Publisher Copyright: AuthorDue to the extensive role of non-isolated high step-up DC-DC converters (NHSDC)s in industrial applications and academic research, many of these pulse width modulation converters have been presented in recent years. For each of these NHSDCs, some claims are introduced to verify its capabilities and features, which has been investigated in some review papers with different frameworks. Dissimilar to previous review papers, which have focused on the classification and derivation of voltage boosting techniques, this paper aims to evaluate the converters from various topological and operational points of view, and determine the superiority of each technique and converter according to applications. Some of these metrics are voltage gain, stresses, ripple, cost, power density, weight, size, control complexity and components count which lead to a comprehensive comparative study. Then, as the main purpose of this paper, effectiveness of these metrics is assessed to show how well they can lead us to the fair comparisonresults. Moreover, some new figures of merit are proposed in this paper to provide a helpful guideline in power electronic converters comparison studies. Finally, the feasibility discussion of single- and multi-objective figures of merit is followed by general practical conclusion and outlook about the NHSDC structures.Peer reviewe

Reliability Analysis on Winding Configurations of Variable Reluctance Resolver Under Faulty Conditions

Publisher Copyright: AuthorOwing to the use of the Permanent Magnet Synchronous Motor (PMSM) widely in Electrical Vehicles (EVs), the mandatory existence of rotor angle sensor in its control algorithm, higher reliability of the resolver than the other instance, and eventually, the significant effect of resolver errors on the system stability, comparing the reliability of two winding configurations in resolver is regarded analytically and numerically in the following study. Firstly, the employed assessment model is defined. Subsequently, it is necessary to investigate the failure modes in the resolver thoroughly. Among the methods used to assess reliability, the Markov model is chosen for the reliability analysis. Finally, by using an experimentally verified Finite Element (FE) resolver model, the faulty conditions in the Variable Turn Overlapping Winding (VTOW) and Constant Turn Non-Overlapping Winding (CTNOW) configurations of the Variable Reluctance (VR) resolver are investigated. The accuracy degradation of the resolver under faultyconditions is used as the reliability criteria to define the reliability state of the resolver.Peer reviewe

Fault Management Techniques to Enhance the Reliability of Power Electronic Converters

Publisher Copyright: © 2013 IEEE.The reliability of power electronic converters is a major concern in industrial applications because of using prone-to-failure elements such as high-power semiconductor devices and electronic capacitors. Hence, designing fault-tolerant inverters has been of great interest among researchers in both academia and industry over the last decade. Among the three stages of fault management, compensating the fault is the most important and challenging part. The techniques for fault compensation can be classified into three groups: hardware redundancy methods which use extra switches, legs, or modules to replace the faulty parts directly or indirectly, switching states redundancy methods which are about omitting and replacing the impossible switching states, and unbalance compensation including the techniques to compensate for the unbalances in the system caused by a fault. In this paper, an overview of fault-tolerant inverters is presented. A classification of fault-tolerant inverters is demonstrated and major cases in each of its categories are explained.Peer reviewe

An Overview of Lifetime Management of Power Electronic Converters

Publisher Copyright: © 2013 IEEE.An expected lifetime of converters is of great importance for optimal decision-making in the planning of modern Power Electronic (PE) systems. Hence, the lifetime management of power electronic systems has attracted a lot of attention in academia and industry. This paper is a guideline for managing the lifetime of power converters. Analyzing the different kinds of failures, failure modes and their corresponding mechanisms are investigated in the first section along with the failure data needed as input parameters of the assessment. In the second section, lifetime prediction in two aspects of component-level and system level is discussed and all the possible techniques to achieve them are investigated and compared. All the steps required to predict the lifetime in the component-level including electrothermal modeling, cycle counting, lifetime model, damage accumulation, parameter estimation, and lifetime distribution are described and then system level methods consisting of reliability block diagrams, fault-tree analysis, and Markov chains are examined and compared. The last section contains the roadmap of the lifetime extension including the reliable design and condition monitoring.Peer reviewe