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Power Electronics, Power Systems, Industrial Electronics, Renewable Energy, Electrical Machines

Power Electronics, Power Systems, Industrial Electronics, Renewable Energy, Electrical Machines

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    • www.coretronix.org POWER ELECTRONICS 1. A Novel ZVT-ZCT-PWM Boost Converter Abstract: A new boost converter with an active Snubber cell is proposed. The active Snubber cell provides main switch to turn ON with zero-voltage transition (ZVT) and to turn OFF with zero-current transition (ZCT). The proposed converter incorporating this Snubber cell can operate with soft switching at high frequencies. Also, in this converter all semiconductor devices operate with soft switching. There is no additional voltage stress across the main and auxiliary components. The converter has a simple structure, minimum number of components, and ease of control as well. 2. Analysis, Design, and Experimental Results of a Novel Soft-Switching Snubberless Current-Fed Half-Bridge Front-End Converter-Based PV Inverter Abstract: A new novel Snubberless current fed half-bridge front-end isolated dc/dc converter-based inverter for photovoltaic applications. It is suitable for grid-tied (utility interface) as well as off-grid (standalone) application based on the mode of control. This converter attains clamping of the device voltage by secondary modulation, thus eliminating the need of Snubber or active-clamp. Zero-current switching or natural commutation of primary devices and zero-voltage switching of secondary devices is achieved. Soft-switching is inherent owing to the proposed secondary modulation and is maintained during wide variation in voltage and power transfer capacity and thus is suitable for photovoltaic (PV) applications. 3. Bridgeless SEPIC Converter with a Ripple-Free Input Current Abstract: Conventional power factor correction (PFC) single ended primary inductor converter (SEPIC) suffers from high conduction loss at the input bridge diode. To solve this problem, a bridgeless SEPIC converter with ripple-free input current is proposed. In the proposed converter, the input bridge diode is removed and the conduction loss is reduced. In addition, the input current ripple is significantly reduced by utilizing an additional winding of the input inductor and an auxiliary capacitor. Similar to the conventional PFC SEPIC converter, the input current in a switching period is proportional to the input voltage and near unity power is achieved. Speak to: +91-9940798943 Write to me: coretronixprojects@gmail.com www.facebook.com/coretronix -1-
    • www.coretronix.org 4. High Performance Voltage Fed AC-DC Full-Bridge Single-Stage PFC with Reduced DC Bus Capacitor Abstract: Full-Bridge Single-Stage, FBSS, AC-DC converters allow regulating both the output voltage and the input current that achieves a near sinusoidal waveform using only the four bridge transistors. Independently of this feature, these converters still need to be optimized in order to become an interesting and attractive solution for modern Switch Mode Power Supplies with PFC function. One of the most important improvements needed is the downsizing of the DC bus capacitor, with the inherent cost reduction. This action introduces complex issues in the regulation of the input current and it is also responsible for the generation of high output voltage ripple. These consists of a set of power circuit optimizations and control techniques in a Full Bridge Single-Stage PFC converter that solves the referred issues in order to enable the reduction of the DC bus capacitor’s size and cost. 5. High-Efficiency Hybrid Full-Bridge–Half-Bridge Converter with Shared ZVS Lagging Leg and Dual Outputs in Series Abstract: A novel soft-switching hybrid converter combining the phase-shift full-bridge (FB) and half-bridge (HB) LLC resonant converters’ configuration with shared zerovoltage switching (ZVS) lagging leg is proposed to ensure the switches in the lagging leg operating at fully ZVS condition. The dual outputs of the proposed hybrid FB–HB converter are connected in series and the whole dc-output voltage can be regulated by the PWM phase-shift control within the desired voltage range. A resonant circuit is used in the secondary side of the FB converter to reset the primary current during the freewheeling period, as well as to transfer more input energy and clamp secondary rectifier voltage. 6. Low-Common Mode Voltage H-Bridge Converter with Additional Switch Legs Abstract: H-bridge converter with additional switch legs (HA converter) and its offspring circuit are proposed in this paper with the intent to reduce the common mode noise. The proposed topology connects grounds of the input and output terminals, which gives zero common mode current in the ideal case. The operation of the proposed circuit is flexible and allows for the circuit to be capable of both ac–dc and dc–ac conversions. The proposed topology is especially advantageous when it is applied to the photovoltaic Speak to: +91-9940798943 Write to me: coretronixprojects@gmail.com www.facebook.com/coretronix -2-
    • www.coretronix.org power conditioning system in dc distribution system or stand-alone power system because they include large stray capacitances and are prone to common mode EMI. 7. Analysis and Design of a Push–Pull Quasi Resonant Boost Power Factor Corrector Abstract: A novel power-factor corrector (PFC), which is mainly composed of two-phase transition-mode (TM) boost-type power-factor correctors (PFCs) and a coupled inductor. By integrating two boost inductors into one magnetic core, not only the circuit volume is reduced, but also the operating frequency of the core is double of the switching frequency. Comparing with single-phase TM boost PFC, both the input and output current ripples of the proposed PFC can be reduced if the equivalent inductance of the coupled inductor equals the inductance of single-phase TM boost PFC. Therefore, both the power-factor value and the power density are increased. The proposed topology is capable of sharing the input current and output current equally. The advantages of a TM boost PFC, such as quasi-resonant (QR) valley switching on the switch and zero-current switching (ZCS) of the output diode, are maintained to improve the overall conversion efficiency. 8. A Modified High-Efficiency LLC Converter with Two Transformers for Wide Input Voltage Range Applications Abstract: A modified LLC converter with two transformers in series, which has four operation configurations, covering the range of four times the minimum input voltage. To optimize the proposed LLC converter in an attempt to achieve good efficiency, a numerical method is developed based on the LLC converter’s steady-state equations. In order to minimize the magnetizing current and thus minimize the conduction and core losses, an optimal objective is proposed to find the maximum magnetizing inductance. 9. High-Efficiency Asymmetrical Half-Bridge Converter without Electrolytic Capacitor for Low-Output-Voltage AC–DC LED Drivers Abstract: Due to their high reliability and luminous efficacy, high-brightness lightemitting diodes are being widely used in lighting applications, and therefore, their power supplies are required to have also high reliability and efficiency. A very common approach for achieving this in ac–dc applications is using a two-stage topology. The power factor corrector boost converter operating in the boundary conduction mode is a Speak to: +91-9940798943 Write to me: coretronixprojects@gmail.com www.facebook.com/coretronix -3-
    • www.coretronix.org very common converter used as first stage. It is normally designed without electrolytic capacitors, improving reliability but also increasing the low-frequency ripple of the output voltage. The asymmetrical half-bridge (AHB) is a perfect option for the second stage as it has very high efficiency, it operates at constant switching frequency, and its output filter is small. 10. Decoupling Capacitor Selection in DCM Flyback PV Micro-inverters considering Harmonic Distortion Abstract: Electrolytic capacitors as a decoupling reservoir restrict the lifetime of photovoltaic (PV) micro-inverters. This has led to the development of several improved decoupling circuits that can reduce the capacitor value to allow the use of non-electrolytic types. The minimum decoupling capacitor value for the proper operation of discontinuous conduction mode fly back PV micro-inverters is analyzed by taking into account the total harmonic distortion (THD) and PV power utilization ratio. A decoupling capacitor selection method for single-stage and two-stage fly-back inverters is proposed. 11. A Bridgeless Boost Rectifier for Low-Voltage Energy Harvesting Applications Abstract: A single-stage ac–dc power electronic converter is proposed to efficiently manage the energy harvested from electromagnetic microscale and mesoscale generators with low-voltage outputs. The proposed topology combines a boost converter and a buckboost converter to condition the positive and negative half portions of the input ac voltage, respectively. Only one inductor and capacitor are used in both circuitries to reduce the size of the converter. 12. Design and Implementation of a Unity Power Factor Fuzzy Battery Charger using an Ultrasparse Matrix Rectifier Abstract: A novel unity power factor fuzzy battery charger conception based on an ultrasparse matrix rectifier (USMR). The advantages of the proposed converter are low harmonic distortion in absorbed currents and nearly unity power factor over a wide operating output power range. Its circuit has only three switching components and lowenergy-conversion loss. This reduces the cost and enhances the system’s efficiency for Speak to: +91-9940798943 Write to me: coretronixprojects@gmail.com www.facebook.com/coretronix -4-
    • www.coretronix.org high voltage battery. Thus, the proposed fuzzy logic controller improves the line power quality and delivers admissible output power to the battery. 13. Novel Zero-voltage and Zero-current Switching (ZVZCS) PWM Three-level DCDC Converter Using Output Coupled Inductor Abstract: A novel zero-voltage and zero-current switching (ZVZCS) pulse-width modulation (PWM) half-bridge (HB) three-level (TL) dc/dc converter is proposed. Compared with traditional ZVZCS PWM TL dc/dc converters, this converter does not include auxiliary resonant circuits. It can achieve zero-voltage switching (ZVS) for the leading switches and approximate zero-current switching (ZCS) for the lagging switches with the aid of the transformer parasitic inductance, Snubber capacitors and tappedinductor type smoothing filter. This converter can reduce the voltage and current spikes of the power switches as well as the primary circulating current loss effectively. The operation principle of the novel converter and the soft-switching implementation condition are analyzed according to equivalent circuits under different stages. 14. An Integrated Boost Resonant Converter for Photovoltaic Applications Abstract: Mobile applications necessitate nowadays huge digital resources. Power management of a digital systems-on-chip is based on dynamic voltage scaling. DC/DC converters used to supply the digital system-on-a-chips are facing stringent constraints with respect to load transients, line transients, and reference tracking. Hysteretic control is known as the most convenient control scheme with a fair tradeoff between transient performances, analog implementation and power consumption. Fixed-switching frequency hysteretic control has been experimented as well as full sliding mode control. Transient performances are reduced due to latencies introduced in the switching frequency control. A new analog implementation of the sliding-mode control is presented here with switching frequency control using a particular analog phase-locked loop but preserve transient performances. The dc/dc converter is implemented in CMOS 130 nm. The switching frequency range has been voluntarily limited and excludes the possible integration of passive components. Speak to: +91-9940798943 Write to me: coretronixprojects@gmail.com www.facebook.com/coretronix -5-
    • www.coretronix.org 15. High-Efficiency Single Switch Single- Input Multiple-Output DC–DC Converter Abstract: The aim of this study is to develop a high-efficiency single-input multipleoutput (SIMO) dc–dc converter. The proposed converter can boost the voltage of a lowvoltage input power source to a controllable high-voltage dc bus and middle-voltage output terminals. The high-voltage dc bus can take as the main power for a high-voltage dc load or the front terminal of a dc–ac inverter. Moreover, middle-voltage output terminals can supply powers for individual middle-voltage dc loads or for charging auxiliary power sources (e.g., battery modules). In this study, a coupled-inductor based dc–dc converter scheme utilizes only one power switch with the properties of voltage clamping and soft switching, and the corresponding device specifications are adequately designed. 16. A Modified Single-Phase Quasi-Z-Source AC–AC Converter Abstract: A modified single-phase quasi-Z-source ac–ac converter is proposed in this paper. The proposed converter has the main features in that the output voltage can be bucked or boosted and be both in-phase and out-of-phase with the input voltage. The input voltage and output voltage share the same ground, the size of a converter is reduced, and it operates in a continuous current mode. A safe-commutation strategy for the modified single-phase quasi-Z-source ac–ac converter is used instead of a Snubber circuit. 17. Improved Trans-Z-Source Inverter with Continuous Input Current and Boost Inversion Capability Abstract: This paper deals with a new family of high boost voltage inverters that improve upon the conventional trans-Z-source and trans-quasi-Z-source inverters. The improved trans-Z-source inverter provides continuous input current and a higher boost voltage inversion capability. In addition, the improved inverter can suppress resonant current at startup, which might destroy the device. In comparison to the conventional trans-Zsource/-trans-quasi-Z-source inverters, for the same transformer turn ratio and input and output voltages, the improved inverter has a higher modulation index with reduced voltage stress on the dc link, lower current stress flow on the transformer windings and diode, and lower input current ripple. In order to produce the same input and output voltage with the same modulation index, the improved inverter uses a lower transformer turn ratio compared to the conventional inverters. Thus, the size and weight of the transformer in the improved inverter can be reduced. Speak to: +91-9940798943 Write to me: coretronixprojects@gmail.com www.facebook.com/coretronix -6-
    • www.coretronix.org 18. A High Step-Up Three-Port DC–DC Converter for Stand-Alone PV/Battery Power Systems Abstract: A three-port dc–dc converter integrating photovoltaic (PV) and battery power for high step-up applications is proposed in this paper. The topology includes five power switches, two coupled inductors, and two active-clamp circuits. The coupled inductors are used to achieve high step-up voltage gain and to reduce the voltage stress of input side switches. Two sets of active-clamp circuits are used to recycle the energy stored in the leakage inductors and to improve the system efficiency. The operation mode does not need to be changed when a transition between charging and discharging occurs. Moreover, tracking maximum power point of the PV source and regulating the output voltage can be operated simultaneously during charging/discharging transitions. As long as the sun irradiation level is not too low, the maximum power point tracking (MPPT) algorithm will be disabled only when the battery charging voltage is too high. 19. Analysis of Half-Wave Class DE Low dv/dt Rectifier at Any Duty Ratio Abstract: Class DE low dv/dt rectifiers realize high-frequency high-efficiency rectification and low-diode voltage stress which is no more than the output voltage. Halfwave Class DE low dv/dt rectifier, which is one of the Class DE rectifiers, realizes the common ground between the input port and the output port. The half-wave Class DE low dv/dt rectifier is analyzed for any diode-ON-duty ratio. The equations of the waveforms, the input and output powers, the current and voltage transfer functions, the current and voltage stresses, the power-output capability, and the power conversion efficiencies are obtained. The characteristics of the normalized output power, the normalized input resistance and capacitance, the current and voltage transfer functions, and the poweroutput capability are clarified as functions of the diode-ON-duty ratio. 20. An Analytical Steady-State Model of LCC type Series–Parallel Resonant Converter with Capacitive Output Filter Abstract: A piecewise analytical function is proposed and applied to investigate the steady-state behavior of series–parallel resonant converter operated in a discontinuous current mode. The converter shows two sequences of the equivalent circuits alternatively operated in the discontinuous current mode with different output voltages. To get the response time of current in one resonance, a successive solving process based on the state-space method is presented analytically in each sequence. This solving process can Speak to: +91-9940798943 Write to me: coretronixprojects@gmail.com www.facebook.com/coretronix -7-
    • www.coretronix.org describe the complicated behavior resulting from the load rectifier, which makes the output capacitor appear or disappear several times in one switching period. By introducing the output voltage coefficient and the principle of energy transmission balance, the steady-state model is deduced afterward. This model is accurate and simple, making it helpful to design and optimize the converter conveniently. POWER SYSTEMS 1. Simulation of Transient Skin Effect of DC Railway System Based on MATLAB/Simulink Abstract: This technique for simulation of transient skin effect of the dc railway system based on MATLAB/Simulink. The classic calculation of skin effect based on frequency domain is not suitable for time-domain simulation. To develop a time-domain calculation method which can be realized in MATLAB/Simulink, through the analysis of the step series algorithm, results are applied to the calculation of frequency voltage signal and compared with skin effect impedance of frequency. Accurate simulation of the transient skin effect produces accurate modeling of the remote fault current. This is important for the dc railway protection researchers to develop techniques for discriminating remote short-circuits currents from locomotive starting currents. 2. A Sliding-Mode Duty-Ratio Controller for DC/DC Buck Converters with Constant Power Loads Abstract: Incorporating a medium-voltage DC (MVDC) integrated power system is a goal for future surface combatants and submarines. In a MVDC shipboard power system, DC/DC converters are commonly employed to supply constant power to electric loads. These constant power loads have a characteristic of negative incremental impedance, which may cause system instability during disturbances if the system is not properly controlled. This paper proposes a sliding-mode duty-ratio controller (SMDC) for DC/DC buck converters with constant power loads. The proposed SMDC is able to stabilize the DC power systems over the entire operating range in the presence of significant variations in the load power and input voltage. The proposed SMDC is validated by both simulation studies in MATLAB/Simulink and experiments for stabilizing a DC/DC buck converter with constant power loads. Speak to: +91-9940798943 Write to me: coretronixprojects@gmail.com www.facebook.com/coretronix -8-
    • www.coretronix.org 3. A Combination of Shunt Hybrid Power Filter and Thyristor Controlled Reactor for Power Quality Abstract: A combined system of a Thyristor-Controlled Reactor (TCR) and a Shunt Hybrid Power Filter (SHPF) for harmonic and reactive power compensation. The SHPF is the combination of a small rating Active Power Filter (APF) and a 5th harmonic tuned LC Passive Filter. The tuned passive filter and the TCR form a Shunt Passive Filter (SPF) to compensate reactive power. The small rating APF is used to improve filtering characteristics of SPF and to suppress the possibility of resonance between the SPF and line inductances. A PI controller was used and a triggering alpha was extracted using a look up table to control the TCR. A nonlinear control of APF was developed for current tracking and voltage regulation. The later is based on a decoupled control strategy, which considers that the controlled system may be divided into an inner fast loop and an outer slow one. Thus, an exact linearization control was applied to the inner loop and a nonlinear feedback control law was used for the outer voltage loop. 4. Stability Enhancement of a PMSG-Based Offshore Wind Farm Fed to a MultiMachine System through an LCC-HVDC Link Abstract: Adaptive-network-based fuzzy inference system (ANFIS) is an adaptation and robustness method since it combines the advantages of artificial neural network (ANN) and fuzzy logic controller (FLC). Besides, ANFIS is also a nonlinear controller that can be used to improve stability of the studied system under different operating points. This paper presents the stability-improvement results of an offshore wind farm (OWF) fed to a multi-machine system through a high-voltage direct-current (HVDC) link based on linecommutated converter (LCC). An effective control scheme using a designed ANFIS damping controller at the inverter station of the HVDC link to achieve damping improvement of the studied system is proposed. A frequency-domain scheme based on Eigen value and root-loci technique is carried out to compare the effectiveness of the proposed ANFIS control scheme and a modal-control designed PID damping controller. 5. Dynamic Averaged and Simplified Models for MMC-Based HVDC Transmission Systems Abstract: Voltage-source converter (VSC) technologies are rapidly evolving and increasing the range of applications in a variety of fields within the power industry. Existing two- and three-level VSC technologies are being superseded by the new modular multilevel converter (MMC) technology for HVDC applications. The computational Speak to: +91-9940798943 Write to me: coretronixprojects@gmail.com www.facebook.com/coretronix -9-
    • www.coretronix.org burden caused by detailed modeling of MMC–HVDC systems in electromagnetic transient-type (EMT-type) programs complicates the simulation of transients when such systems are integrated into large networks. 6. Coordinated Control and Energy Management of Distributed Generation Inverters in a Micro-grid Abstract: A microgrid consisting of different distributed generation (DG) units that are connected to the distribution grid. An energy-management algorithm is implemented to coordinate the operations of the different DG units in the microgrid for grid-connected and islanded operations. The proposed microgrid consists of a photovoltaic (PV) array which functions as the primary generation unit of the microgrid and a proton-exchange membrane fuel cell to supplement the variability in the power generated by the PV array. A lithium-ion storage battery is incorporated into the microgrid to mitigate peak demands during grid-connected operation and to compensate for any shortage in the generated power during islanded operation. The control design for the DG inverters employs a new model predictive control algorithm which enables faster computational time for large power systems by optimizing the steady-state and the transient control problems separately. 7. Power Flow and Power Reduction Control Using Variable Frequency of Offshore AC Grids Abstract: An “integrated strategy” for connecting offshore wind farms to onshore grids, an offshore AC grid is formed by interconnecting offshore wind farms and point-to-point VSC-HVDC links using an AC network. The advantage of this strategy is that in the case of a DC fault, AC circuit breakers are used to isolate the faulted HVDC link without the need for DC circuit breakers. This paper presents a control system that regulates power sharing between the HVDC links by varying the operating frequency of the offshore AC grid. Primary and secondary power regulation controllers are designed to achieve automatic power flow coordination between HVDC links. Increase in the offshore AC grid frequency during onshore AC grid fault or DC fault signals power flow imbalance. This signal is used to suppress the transient DC over-voltage through the coordination control between the wind farm side converters of HVDC links and the power reduction control of wind turbines. 8. Dynamic Stability Improvement of Four Parallel-Operated PMSG-Based Offshore Wind Turbine Generators Fed to a Power System Using a STATCOM Speak to: +91-9940798943 Write to me: coretronixprojects@gmail.com www.facebook.com/coretronix - 10 -
    • www.coretronix.org Abstract: The stability-improvement results of four parallel-operated offshore wind turbine generators (WTGs) connected to an onshore power system using a static synchronous compensator (STATCOM). The operating characteristics of each of the four WTGs are simulated by a 5-MW wind permanent-magnet synchronous generator while the onshore power system is simulated by a synchronous generator (SG) fed to an infinite bus through two parallel transmission lines. A damping controller of the proposed STATCOM is designed by using a pole-assignment approach to render adequate damping to the dominant modes of the studied SG. A frequency-domain approach based on a linearized system model using Eigen value analysis is performed while a time-domain scheme based on a nonlinear system model subject to disturbances is also carried out. RENEWABLE/SUSTAINABLE ENERGY 1. High Step-Up, High Efficiency Interleaved Converter with Voltage Multiplier Module for Renewable Energy System Abstract: A novel high step-up converter, which is suitable for renewable energy system is proposed in this paper. Through a voltage multiplier module composed of switched capacitors and coupled inductors, a conventional interleaved boost converter obtains high step-up gain without operating at extreme duty ratio. The configuration of proposed converter not only reduces the current stress but also constrains the input current ripple, which decreases the conduction losses and lengthens the life time of input source. In addition, Due to the lossless passive clamp performance, leakage energy is recycled to the output terminal. Hence, large voltage spikes across the main switches are alleviated and the efficiency is improved. Even the low voltage stress makes the low-voltage-rated MOSFETs can be adopted for reductions of conduction losses and cost. 2. A Comparative Study on Maximum Power Point Tracking Techniques for Photovoltaic Power Systems Abstract: A comprehensive review of the maximum power point tracking (MPPT) techniques applied to photovoltaic (PV) power system. A good number of publications report on different MPPT techniques for a PV system together with implementation. But, confusion lies while selecting a MPPT as every technique has its own merits and demerits. Hence, a proper review of these techniques is essential. Unfortunately, very few attempts have been made in this regard, excepting two latest reviews on MPPT. Since, MPPT is an essential part of a PV system, extensive research has been revealed in recent Speak to: +91-9940798943 Write to me: coretronixprojects@gmail.com www.facebook.com/coretronix - 11 -
    • www.coretronix.org years in this field and many new techniques have been reported to the list since then. In this paper, a detailed description and then classification of the MPPT techniques have made based on features, such as number of control variables involved, types of control strategies employed, types of circuitry used suitably for PV system and practical/ commercial applications. 3. A New Hybrid Modular Multilevel Converter for Grid Connection of Large Wind Turbines Abstract: The trend towards multi-megawatt (multi-MW) wind turbines and the increasing interest in direct-drive variable-speed wind energy systems have made multilevel converters a promising candidate for large wind energy conversion systems. A new hybrid modular multilevel converter for interfacing a full-scale, permanent magnet synchronous generator (PMSG)-based direct-drive variable-speed wind energy conversion system (WECS). The proposed hybrid converter, which is used on the grid side of the system, consists of a three-level modular multilevel converter (MMC) in series connection with three H-bridge modules. The generator-side converter is based on a conventional three-level neutral-point-clamped converter. The proposed hybrid converter, as opposed to the existing full-scale multilevel converter-based wind energy systems, provides structural modularity and higher dc-bus voltage utilization. These formulate and analyze the internal dynamics of the proposed hybrid converter including the circulating currents and the capacitor voltage ripples. The ac components of the circulating currents, if not properly reduced, increase the amplitude of the capacitor voltage ripples, rating values of the converter components, and losses. Based on the analysis, closed-loop circulating current and capacitor voltage ripple reduction techniques are developed. The reduction of capacitor voltage ripples help reduce the capacitor value. 4. A Novel Operation and Control Strategy for a Standalone Hybrid Renewable Power System Abstract: A novel operation and control strategy for a renewable hybrid power system for a standalone operation. The proposed hybrid system consists of a wind turbine, a fuel cell, electrolyze, a battery storage unit, and a set of loads. The overall control strategy is based on a two-level structure. The top level is the energy management and power regulation system. Depending on wind and load conditions, this system generates reference dynamic operating points to low level individual subsystems. The energy management and power regulation system also controls the load scheduling operation during unfavorable wind conditions under inadequate energy storage in order to avoid a Speak to: +91-9940798943 Write to me: coretronixprojects@gmail.com www.facebook.com/coretronix - 12 -
    • www.coretronix.org system blackout. Based on the reference dynamic operating points of the individual subsystems, the local controllers control the wind turbine, fuel cell, electrolyses, and battery storage units. 5. Dynamic Modeling and Control of Interleaved Flyback Module Integrated Converter for PV Power Applications Abstract: For PV applications, the interleaved flyback module integrated converters (IFMIC) operating in continuous conduction mode (CCM) shows the advantages of high power density, low voltage and current stresses, and low electromagnetic interference, but demonstrates a difficult control problem compared to the discontinuous conduction mode (DCM). The control issues and presents detailed modeling, in-depth dynamic analysis, and a two-step controller design approach for IFMIC systems operating in CCM. The proposed modeling approach is based on the fourth-order system considering the dynamics of the output CL filter. This realistic fourth-order system modeling shows the presence of a resonant peak at a certain frequency, which can cause phase loss and constraints of system bandwidth. A decoupled two-step controller design approach is thus proposed to simplify the modeling and control synthesis in the IFMIC development. The decoupled controller consists of a PI controller followed by a lag term for mitigating the effect of the resonant peak. INDUSTRIAL ELECTRONICS 1. A New Interleaved Three-Phase Single-Stage PFC AC–DC Converter Abstract: A new interleaved single-stage ac–dc converter is proposed in this paper to reduce line current harmonics while achieving power factor correction (PFC). The proposed rectifier can produce input currents that do not have dead band regions with high PFC, operate with a continuous output current, and minimize the input electromagnetic interference filter size. 2. Cascade Cockcroft– Walton Voltage Multiplier Applied to Transformerless High Step-Up DC–DC Converter Abstract: This paper proposes a high step-up dc-dc converter based on the CockcroftWalton (CW) voltage multiplier without a step-up transformer. Providing continuous input current with low ripple, high voltage ratio, and low voltage stress on the switches, diodes, and capacitors, the proposed converter is quite suitable for applying to low-inputlevel dc generation systems. Moreover, based on the n-stage CW voltage multiplier, the proposed converter can provide a suitable dc source for an n + 1-level multilevel inverter. Speak to: +91-9940798943 Write to me: coretronixprojects@gmail.com www.facebook.com/coretronix - 13 -
    • www.coretronix.org In this paper, the proposed control strategy employs two independent frequencies, one of which operates at high frequency to minimize the size of the inductor while the other one operates at relatively low frequency according to the desired output voltage ripple. 3. A New ZCS-PWM Full-Bridge Dc-Dc Converter with Simple Auxiliary Circuits Abstract: A new soft-switching PWM full-bridge converter is proposed in this paper. The outstanding feature of the new converter is that it allows its main power switches to operate with zero current switching (ZCS) and with fewer conduction losses than conventional full-bridge converters. This is achieved by using two very simple active auxiliary circuits – one active, one passive. 4. High-Efficiency LED Driver without Electrolytic Capacitor for Street Lighting Abstract: High-brightness light-emitting diodes (LEDs) are considered as a remarkable lighting device due to their high reliability, chromatic variety, and increasing efficiency. As a consequence, a high number of solutions for supplying LED strings are coming out. One-stage solutions are cost effective, but their efficiency is low as they have to fulfill several purposes with only one converter: power factor correction (PFC), galvanic isolation (in some cases), and current regulation. Two-stage and three-stage solutions have higher efficiency as each stage is optimized for just one or two tasks, and they are the preferred option when supplying several strings at the same time. Nevertheless, due to their higher cost in comparison to one-stage solutions, they are used when high efficiency, high performance, and the possibility of supplying several strings are the main concerns. In addition, they are also used when high reliability is needed and electrolytic capacitors cannot be used. 5. A Modified Three-Phase Four-Wire UPQC Topology with Reduced DC-Link Voltage Rating Abstract: The unified power quality conditioner (UPQC) is a custom power device, which mitigates voltage and current-related PQ issues in the power distribution systems. In this paper, a UPQC topology for applications with non-stiff source is proposed. The proposed topology enables UPQC to have a reduced dc-link voltage without compromising its compensation capability. This proposed topology also helps to match the dc-link voltage requirement of the shunt and series active filters of the UPQC. The topology uses a capacitor in series with the interfacing inductor of the shunt active filter, and the system neutral is connected to the negative terminal of the dc-link voltage to avoid the requirement of the fourth leg in the voltage source inverter (VSI) of the shunt Speak to: +91-9940798943 Write to me: coretronixprojects@gmail.com www.facebook.com/coretronix - 14 -
    • www.coretronix.org active filter. The average switching frequency of the switches in the VSI also reduces; consequently the switching losses in the inverters reduce. 6. Analysis and Design of a Multi-output Converter Using Asymmetrical PWM Half-Bridge Flyback Converter Employing a Parallel–Series Transformer Abstract: A multi-output converter using an asymmetrical pulse width modulation halfbridge flyback topology employing a parallel–series-connected transformer. Compared to conventional multi-output topologies, the proposed converter operates using a singleoutput controller without the need for additional control loops and devices. In order to solve the cross-regulation problem, the output stages of the proposed converter are stacked in series. In addition, the voltage regulation of the proposed multi-output converter is improved through the analysis of its resonant characteristics under load variations and minimizing the secondary conduction loss. The proposed multi-output converter shows excellent performance in terms of its output regulation from no-load to full-load conditions and good cross regulation under high output currents. 7. Analysis and Design of Phase-Shifted Dual H-Bridge Converter with a Wide ZVS Range and Reduced Output Filter Abstract: A phase-shifted dual H-bridge converter, which can solve the drawbacks of existing phase-shifted full-bridge converters such as narrow zero-voltage-switching (ZVS) range, large circulating current, large duty-cycle loss, and serious secondaryvoltage overshoot and oscillation, is analyzed and evaluated. The proposed topology is composed of two symmetric half-bridge inverters that are placed in parallel on the primary side and are driven in a phase-shifting manner to regulate the output voltage. At the rectifier stage, a center-tap-type rectifier with two additional low-current-rated diodes is employed. This structure allows the proposed converter to have the advantages of a wide ZVS range, no problems related to duty-cycle loss, no circulating current, and the reduction of secondary-voltage oscillation and overshoot. Moreover, the output filter’s size becomes smaller compared to the conventional phase-shift full-bridge converters. 8. Closed-loop Control of DC-DC Dual Active Bridge Converters Driving SinglePhase Inverters Abstract: A solid state transformer (SST) is a high-frequency power electronic converter that is used as a distribution power transformer. A common three-stage configuration of Speak to: +91-9940798943 Write to me: coretronixprojects@gmail.com www.facebook.com/coretronix - 15 -
    • www.coretronix.org an SST consists of ac-dc rectifier, isolated dc-dc dual-active-bridge (DAB) converter, and dc-ac inverter. This work addresses the controller design issue for a dc-dc DAB converter when driving a regulated single-phase dc-ac inverter. Since the switching frequency of the inverter stage is much higher than that of the DAB stage, the single-phase inverter is modeled as a double-line-frequency current sink. The effect of 120-Hz current by the single-phase inverter is studied. The limitation of a PI controller, low gain at 120 Hz, is investigated. Two methods are proposed to improve the regulation of the output voltage of DAB converters. 9. A Novel Flyback-Based Input PFC Stage for Electronic Ballasts in Lighting Applications Abstract: An electronic driver for public lighting systems. The input stage is based on the integration of two flyback converters with different polarities, in order to avoid the use of the input diode bridge rectifying stage. The output stage is a boost converter with an output current control. The proposed circuit is introduced and analyzed, and a design example for a 50-W light-emitting diode lamp is presented. The most relevant simulation and experimental results are also shown, in order to validate the idea. A comparison in terms of efficiency for the input stage is carried out between the proposed topology and the conventional flyback converter, showing an efficiency enhancement in the proposed converter. However, the most important advantage of the proposed converter is outlined in the final part of this paper. This advantage comes from the avoidance of the input diode bridge, thus enabling the bidirectional power flow at the input stage. Therefore, the topology can be used to deliver energy into the power grid. In recent lighting applications, the use of micro renewable generators in lighting points has made the use of special electronics to handle the energy flows in the ballast necessary. 10. A Novel Integrated Buck–Flyback Non-isolated PFC Converter with High Power Factor Abstract: A novel integrated buck–flyback non-isolated power factor (PF) correction (PFC) converter is proposed in this paper. This new converter is an inherent integration of a buck converter and a flyback converter, which operates in either flyback mode or buck mode according to whether the input voltage is lower or higher than the output voltage. In this way, the dead zones of ac input current in traditional buck PFC converter are eliminated. Therefore, the proposed integrated buck–flyback non-isolated PFC Speak to: +91-9940798943 Write to me: coretronixprojects@gmail.com www.facebook.com/coretronix - 16 -
    • www.coretronix.org converter can achieve high PF under universal ac input range, and its input current harmonics can easily meet the limits. 11. A High Frequency Dual-Channel Isolated Resonant Gate Driver with Low Gate Drive Loss for ZVS Full-Bridge Converters Abstract: As switching frequency increases, to reduce the gate drive loss combined with the Zero-Voltage-Switching (ZVS) technique is meaningful for the widely used FullBridge (FB) converters. A dual-channel isolated Resonant Gate Driver (RGD) is proposed in this paper. The proposed RGD is able to provide two isolated complementary drive signals for a pair of power MOSFETs in one bridge leg. The proposed RGD reduces about 79 % gate drive loss compared to the conventional Voltage Source Driver (VSD). In addition, the negative gate drive voltage provided by the proposed RGD prevents the false trigger problem in the FB converters. 12. Zero-Voltage Switching Multi-Output Flyback Converter with Integrated Auxiliary Buck Converter Abstract: A new multi-output converter. It consists of half-bridge inverter in primary side, and flyback rectifier which is integrated with auxiliary buck converter in secondary side. The primary switches control the main output voltage and the secondary synchronous switches control the auxiliary output voltage. The main advantages of the proposed converter are that the transformer size can be reduced due to the lower magnetizing offset current, all the switches including synchronous ones can achieve the zero-voltage switching (ZVS). ELECTRICAL MACHINE DRIVES 1. An Adjustable Speed PFC Bridgeless Buck-Boost Converter Fed BLDC Motor Drive Abstract: A PFC (Power Factor Corrected) BL (Bridgeless) buck-boost converter fed BLDC (Brushless Direct Current) motor drive as a cost effective solution for low power applications. An approach of speed control of BLDC motor by controlling the DC link voltage of VSI (Voltage Source Inverter) is used with a single voltage sensor. This facilitates the operation of VSI at fundamental frequency switching by using the electronic commutation of BLDC motor which offers reduced switching losses. A Speak to: +91-9940798943 Write to me: coretronixprojects@gmail.com www.facebook.com/coretronix - 17 -
    • www.coretronix.org bridgeless configuration of buck-boost converter is proposed which offers elimination of DBR (Diode Bridge Rectifier), thus reduces the conduction losses associated with it. 2. Digital Control Strategy for Four Quadrant Operation of Three Phase BLDC Motor with Load Variations Abstract: Brushless DC (BLDC) motor drives are becoming more popular in industrial, traction applications. This makes the control of BLDC motor in all the four quadrants very vital. This paper deals with the digital control of three phase BLDC motor. The motor is controlled in all the four quadrants without any loss of power; in fact energy is conserved during the regenerative period. 3. A Driver for the Single-Phase Brushless DC Fan Motor with Hybrid Winding Structure Abstract: A novel driver for a single-phase brushless dc fan motor with a hybrid series/parallel winding structure. The winding symbols and directions of the hybrid motor stator structure are defined, and the winding steps for the proposed series/parallel winding are explained. An adequate inverter driving circuit, which is capable to simultaneously obtain the advantages of the hybrid structure, is also discussed. At last, the overall system of this hybrid brushless dc motor with the proposed driving circuit is then implemented to verify the performance of the proposed driver and structure. Speak to: +91-9940798943 Write to me: coretronixprojects@gmail.com www.facebook.com/coretronix - 18 -