Design Guidelines For Components Research Articles

A Single-Phase Seven-Level Triple Boost Inverter for Grid-Connected Transformerless PV Applications

A new seven-level common ground (CG) switched capacitor (SC)-based grid tied transformerless inverter has been introduced in this paper, which has three times boosting capability of input voltage. Thus, this inverter is preferable for low voltage PV applications without any boost conversion stage. To step-up the input PV voltage and facilitate seven steps in output voltage, two SC cells are connected in parallel. A virtual dc link capacitor serves key role for negative half cycle on behalf of H-Bridge and helping in constructing topology with common ground. The common grounding configuration of this inverter helps in bypassing the stray capacitance, which eliminates the leakage current and consequently reduces EMI considerably. Hence, further no requirement of any electro-magnetic interference (EMI) filter for electro-magnetic compatibility (EMC). Additionally, this inverter handles reactive power during the grid's lagging/leading power factor (pf) condition. To regulate active and reactive grid power, a proportional resonant (PR) current controller is designed. The proposed modulation scheme helps in balancing capacitor's voltages at their base values with allowable ripple. A detailed comparison also has been presented with other contemporary seven level inverters. The inverter circuit details, control technique, PWM scheme, thermal modeling, and loss analysis with component design guidelines are described in detail. Experimental results are presented to validate the effectiveness and feasibility of this proposed inverter.

A single-phase direct buck-boost AC–AC converter with minimum number of components

In this paper, a single-phase direct pulse width modulation (PWM) buck-boost AC–AC converter is proposed. The proposed converter utilizes a minimum number of semiconductor switches and passive components that decreases the converter power losses and offers high efficiency. It can be operated with simple PWM control and doesn’t require soft-commutation strategies. It does not suffer from input source shoot-through and commutation problems. Moreover, it supplies both continuous input and output currents. The common sharing ground of the input and output gives the proposed converter the feature that it can be utilized for voltage sag and swell compensation. A comparison of the proposed converter performance with similar existing converters is presented. Also, detailed circuit analysis, component design guidelines, and simulation results using the MATLAB/Simulink environment are demonstrated. A laboratory prototype has been built and tested to validate the converter performance and confirm the results obtained by computer simulation.

A New Nine-Level Highly Efficient Boost Inverter for Transformerless Grid-Connected PV Application

Transformerless grid-connected multi-level <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">PV</i> (photovoltaic) inverter has the major concern of leakage current and buck behavior of output voltage, hence not suitable for low voltage PV applications. A new <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">9L4x</i> (nine-level quad boost) highly efficient inverter based on the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">SC</i> (switched capacitor) with a <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">CG</i> (common ground) configuration has been proposed in this paper, which provides four times the gain of input voltage. Hence, this inverter is preferable for low voltage <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">PV</i> applications without any boost dc/dc converter intermediate stage. The inverter is designed in such a way that total conducting switches for different level generation is minimum. This technique helps to increase the efficiency of the inverter. Two <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">SC</i> cells are utilized to step-up the input <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">PV</i> voltage and facilitate nine steps in output voltage. The common grounding feature of the proposed inverter topology helps mitigate the leakage current. Additionally, this new inverter can handle reactive power during the grid’s lagging/leading pf (power factor) condition. To regulate the active and reactive grid power, a <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">PR</i> (proportional resonant) controller is designed. The proposed modulation strategy balances the voltages of switched capacitors at their base voltage with allowable ripple. The inverter circuit details, control strategy, <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">PWM</i> (pulse width modulation) scheme, thermal modeling, and loss analysis with component design guidelines are described in detail. Experimental results are presented to validate the effectiveness and feasibility of this proposed inverter.

A Novel Single Phase Three Level Triple Boost CG Switched-Capacitor Based Grid-Connected Transformerless PV Inverter

A new three-level inverter based on the switched capacitor (SC) with a common grounding (CG) configuration has been introduced in this article, which is capable of boosting the input voltage up to three times. Therefore, this inverter is configured without any boost dc/dc converter stage for low voltage PV application. To step up the input PV voltage and facilitate three level in output voltage, two SC cells are connected in parallel. This inverter's common grounding configuration helps in bypassing the stray capacitance, which eliminates the leakage current and consequently reduces electro-magnetic interference (EMI) considerably. Hence, for electro-magnetic compatibility (EMC), this inverter does not require any EMI filter. Additionally, this inverter handles reactive power during the grid's lagging/leading power factor (pf) condition. A proportional resonant (PR) current controller is designed to regulate active and reactive grid power. The proposed modulation strategy helps in balancing capacitor voltages at their base values with allowable ripple. The inverter circuit details, control technique, PWM scheme, thermal modeling, and loss analysis with component design guidelines are described in detail. Experimental results are presented to validate the effectiveness and feasibility of this proposed inverter.

An Isolated Multilevel DC–DC Converter Topology With Hybrid Resonant Switching for EV Fast Charging Application

This article proposes a multilevel dc–dc converter topology for fast charging of electric and plug-in hybrid electric vehicles (EVs and PHEVs). The proposed dc–dc converter topology converts the front end ac–dc converter output and provides regulated supply to the EV propulsion battery. The proposed topology consists of full-bridge converter at the primary, while the secondary side consists of voltage doubler rectifier units and combination of diodes and <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">mosfet</small> for reconfiguration of the voltage doubler rectifiers to generate the multilevel voltage. The multilevel voltage at the output helps in reducing the output filter size and increases the power density of the converter. The topology utilizes the resonance between leakage inductor of high frequency transformer, parasitic output capacitors of full-bridge <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">mosfet</small> s and voltage doubler capacitors to achieve soft switching (ZVS turn- <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</small> ) for all the full-bridge devices and soft turn- <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">off</small> for the rectifier diodes. The load limited ZVS turn <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</small> capability of conventional full-bridge topologies is mitigated through the use of resonance between magnetizing inductance of transformer and <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">mosfet</small> output capacitors. The converter is designed for 650 V dc bus input and 200–400 V EV battery output at 100 kW rated charging power. The analysis of the proposed converter in continuous and discontinuous modes of operation, soft switching operation, and the component design guidelines are presented in this article. The proposed converter is validated through detailed PLECS simulation results for 100 kW charging power. Experimental results from laboratory prototype of 500 W power are also presented to validate the design methodology and converter performance.

Online UI/UX Platform (Crafter)

UI/UX has evolved a lot over time and is one of the trending fields in thistech world. Companies aretrying to improve their UI UX of products to makecustomers more interact with their product A lot of designers do not get proper guidance as to which things theyshould use while practicing UI and get better results. They start taking either something beyond their capabilities or far below their skills. As a result, knowing just gives them the idea of coding but they lack in designing UI which is these days a more focused topic as clients need attractive UI where their users will get attracted towards for betterment of their product and betterment of their small or big business/company. So, for making these things simple, we’re making thing web-application called CRAFTER for making all the problems solved for web-developers. Our goal is to build a strong design community for everyone out there who wants to contribute and learn UI UX designing. In the proposed system we’re going to use Mean stack technology to design and for backend and Mongo DB as database. A blog system will also be designed where the UI UX designers can write their blog articles and shareit with our users. The beginner can get into our UI/UX guidelines and get started with the fundamentals of UI/UX designing. They will also have access to project starter folders which they can download and start building the product without any extra effort. The intermediate designers can refer to our component design guidelines to implement those designsand improvisethem. They can upload their UI UX workon our Behance clone platform where other users can viewappreciate and save their work.

Single-Phase Symmetric-Bipolar-Type High-Frequency Isolated Buck-Boost AC–AC Converter With Continuous Input and Output Currents

A single-phase symmetric-bipolar-type high-frequency isolated buck-boost ac–ac (SBT-HFI-BBAC) converter is proposed. The converter is composed of two full-bridge inverter modules, input/output <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LC</i> filters, and a high-frequency transformer (HFT) with series capacitors. It can provide identical noninverting and inverting buck-boost output voltages with symmetric-bipolar voltage gains of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$ \pm D/({1 - D})$</tex-math></inline-formula> . The frequency of the output voltage can also be adjusted in discrete steps, similar to single-phase matrix converters (MCs). It supplies continuous input and output currents and works well with nonunity power factor loads. The magnetizing current of the HFT has no line frequency component due to the presence of the series blocking capacitors. Moreover, due to the absence of <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ac</i> switches, the converter has a simple commutation process, unlike conventional ac-ac/MCs. Two switching strategies are proposed; Strategy-I with fewer high-frequency switches and Strategy-II with reduced switch currents, providing more flexibility in switch power loss optimization. The proposed SBT-HFI-BBAC converter is well suited for application as a dynamic voltage restorer, compensating a wide range of grid voltage sags and swells, without the need for a low-frequency voltage injection transformer. Its step-changed frequency operation can also find use in various applications, such as high-gain ac–dc converters, traction systems, etc. A comprehensive description of circuit operation is presented along with component design guidelines and appropriate comparisons. Experimental verification results are provided using a 400-W laboratory test circuit.

A High-Frequency Isolated Multilevel Cascaded-Type Bipolar Direct PWM AC–AC Converter for Utility Voltage Compensation

A high-frequency isolated multilevel cascaded-type bipolar direct PWM ac-ac converter is proposed. By cascading N-unit cells, the converter can produce symmetric bipolar voltage gain of ±ND. It does not require a separate ac source for each unit cell, and can provide higher ac output voltages with multiple levels using low-voltage rating devices, decreasing output voltage harmonics and filtering requirements. Moreover, phase-shift PWM switching is employed, increasing the effective frequency of the output filter, further reducing its requirements. The converter can be utilized as a dynamic voltage restorer (DVR) for grid voltage regulation, with the following features: No need for an external dc source, separate ac sources, and a line-frequency voltage injection transformer. Injection of higher voltage magnitudes than the line voltage, mitigating deep voltage sags. Injection of a negative series voltage to provide compensation for voltage swells. The detailed circuit operation is explained together with component design guidelines and application as DVR. Finally, experimental results are provided using an 800-W scale-down laboratory prototype.

A Reliable Single-Phase Bipolar Buck–Boost Direct PWM AC–AC Converter With Continuous Input/Output Currents

In this article, a single-phase bipolar buck-boost direct pulsewidth-modulated ac-ac converter is proposed, comprised of six insulated-gate bipolar transistors, a small film capacitor, and input/output LC filters. The converter can provide discrete noninverting buck (NIBu) and boost (NIBo) operations with voltage gains of D and 1/(1 - D), respectively. Moreover, it provides symmetric noninverting buck-boost (NIBB) and inverting buck-boost (IBB) operations with voltage gains of D/(1 - D) and -D/(1 - D), respectively. It supplies both continuous input/output currents, and it is well suited for reactive loads. It is immune from the commutation problem, and thus, has enhanced the reliability. The various modes of operation of the proposed converter make it suitable for diverse applications, including the following: 1) application as a direct ac voltage regulator when operating in NIBu and NIBo modes; 2) IBB operation can be utilized along with NIBu/ NIBo or NIBB operation to compensate both voltage sag and swell, when used as dynamic voltage restorer; and 3) symmetric NIBB/IBB operations can provide step-changed frequency output, similar to the single-phase matrix converters, for applications as induction motor drive or high-gain ac-dc rectifier. Extensive circuit analysis, component design guidelines, and appropriate comparisons are provided, followed by experimental results obtained using a laboratory prototype.

Bidirectional Twisted Single-Stage Single-Phase Buck-Boost DC-AC Converter

This paper describes a bidirectional twisted single-phase single-stage buck-boost dc-ac converter based on an output unfolding circuit. This solution is derived by the combination of an inverting buck-boost dc-dc converter and an unfolding circuit. The operation principle, component design guidelines, along with the control approach are presented. The zero-crossing distortion problem is discussed and solved by a simple approach. The simulation and experimental results confirm all theoretical statements. Loss distribution and achievable efficiency are analyzed. Finally, the pros and cons of the proposed solution, along with the most promising application field, are analyzed and discussed in the conclusion.

Novel Family of Single-Stage Buck–Boost Inverters Based on Unfolding Circuit

This paper describes a novel family of single-phase single-stage buck–boost inverters using output unfolding circuits. Operation principles and component design guidelines along with modulation techniques are presented and discussed. The simulation results confirm all theoretical statements. Experimental setup of the most promising solution is assembled and tested, where the efficiency for different operation modes is analyzed. Finally, the pros and cons along with applications of the proposed solutions are discussed in the conclusions.

Quantification of rail transit wheel loads and development of improved dynamic and impact loading factors for design

An increase in the number of rail transit track construction and rehabilitation projects in North America has generated increased interest in optimizing the design of the track infrastructure and its components. Many rail transit track component design guidelines use historical wheel loads and loading factors that were derived from freight railroad design practices. These design factors may not be representative of the loading experienced on the rail transit networks today, leading to over-designed, sub-optimal infrastructure components. Therefore, researchers at the University of Illinois at Urbana–Champaign are conducting research to lay the groundwork for improved understanding of the loading environment entering the track structure using wheel loads data obtained from recently deployed field instrumentation and existing wheel impact load detectors. This paper evaluates the existing design impact factors and assesses their effectiveness when applied to the rail transit sector, using data from three representative rail transit agencies in the United States. New dynamic loading factors are also proposed to represent the rail transit loading environment more accurately. A quantitative approach to addressing design factors may provide economies in future designs and facilitate the use of probability of exceedance and other metrics that relate to factors of safety.

Novel Family of Single-Phase Modified Impedance-Source Buck-Boost Multilevel Inverters With Reduced Switch Count

This paper describes novel single-phase solutions with increased inverter voltage levels derived by means of a nonstandard inverter configuration and impedance source networks. Operation principles based on special modulation techniques are presented. Detailed component design guidelines along with simulation and experimental verification are also provided. Possible application fields are discussed, as well as advantages and disadvantages. Finally, future studies are addressed for the new solutions.

Three-level three-phase quasi-Z-source neutral-point-clamped inverter with novel modulation technique for photovoltaic application

This paper presents a three-phase three-level neutral-point-clamped quasi-Z-source inverter as a novel solution for photovoltaic applications. The topology was derived by combining properties of the quasi-Z-source networks with those of three-level neutral-point-clamped inverters. A case study system, a steady state analysis and a novel special modulation technique for shoot-through states distribution during the whole operation period are described. Component design guidelines for a three-phase system are presented. All theoretical findings have been confirmed by simulation and experimental results. A “full SiC” experimental prototype was developed. A comprehensive study of the converter's efficiency is provided.

Single phase three‐level neutral‐point‐clamped quasi‐Z‐source inverter

This study presents a novel three-level neutral-point-clamped quasi-Z-source inverter in the single-stage buck-boost multilevel inverter family. The topology was derived by combining the properties of the quasi-Z-source network with those of a three-level neutral point clamped inverter. It features such advantages as low voltage stress of the switches, single-stage buck-boost power conversion, continuous input current, short-circuit withstandability and low total harmonic distortion of the output voltage and current. The authors present a steady state analysis of the topology along with a special modulation technique to distribute shoot-through states during the whole fundamental period. Component design guidelines for a single-phase case study system are described. All the findings have been confirmed by simulations and experiments. The topology could be recommended for applications requiring continuous input current, high input voltage gain and enhanced quality of the output voltage.