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A multi-level boost topology based on a flying capacitor is compared in this work with the hybrid, multi-level, partial power processing topology already presented in the literature for use as a highly efficient and compact dc/dc stage in 1500-V, two-stage, grid-connected PV systems. Different variations of the resonant stage of the hybrid topology are analyzed and compared in terms of losses, volume and complexity. Full multivariable optimization is conducted for the multi-level boost topology with different number of levels and for all the analyzed variations of the resonant stage of the hybrid topology. Appropriately rated new classes of 650-V and 900-V WBG devices are included in the optimization algorithm. It is concluded that due to the dominant conduction losses and gap in the voltage rating of the commercially available WBG devices between 650V and 200V, increase of the number of levels over 4 leads to the deteriorated loss and volume performances. All the analysis related to the resonant stage of the hybrid topology is confirmed by detailed and comprehensive measurements of two prototypes of 4kW of nominal and 7kW of maximal power. Additionally, all the loss models applied in the optimization algorithms presented in this paper are confirmed by detailed measurements, thermal calibration and finite element thermal simulations of the wide bandgap devices and inductor designs employed in this work. [ABSTRACT FROM AUTHOR]

The successful mission of CubeSat require reliable and fault-tolerant electrical power system (EPS) that powers all the other subsystems and payloads. Several studies have shown that EPS failure has been one of the main contributors for the CubeSat mission failure. The main objective of this paper is to enhance the lifetime of CubeSats EPS by proposing a distributed EPS architecture and power-down mode. The distributed architecture consists of independent converters for maximum power point tracking operation of photovoltaic (PV) panels. This is possible by using gallium nitride field-effect transistors to reduce the converter footprint and placing the converters on the back-side of the PV panels. Also, single-inductor based $N$ -1 redundant converters for generation and load-side are proposed to provide uninterrupted operation during component failures. Thus, the proposed distributed architecture not only improves the reliability but also facilitates placement of redundant converters to achieve the fault-tolerant capability. To further reduce the electrical and thermal stresses on the semiconductor devices and thus, improve the EPS life span, a novel power-down mode is proposed for the power converters. In this mode, semiconductor devices are switched-off whenever the power processed is below the threshold level and/or no-load operation. Reliability block diagrams are illustrated to demonstrate the reliability improvement and calculations shows that the proposed distributed architecture has higher reliability than the conventional EPS architecture. All the proposed concepts are validated using a prototype developed based on the specifications of MYSAT-1, which is an 1U CubeSat launched by Khalifa University. [ABSTRACT FROM AUTHOR]

Conventional PI controllers are vulnerable to changes in parameters and are difficult to tune. In this work, an artificial neural network (ANN) based controller is developed for the robust operation of a single-phase modified packed U-cell five-level inverter (MPUC-5) for solar PV application under variable insolation conditions. An MPUC-5 is a converter with a main and an auxiliary dc link of equal magnitude; although five-level operation is also still feasible with different voltages also. The maximum power point (MPP) of a PV array changes with the variation in the solar insolation. This results in a variable voltage at the output of the boost converter while maintaining the load line at the MPP. Consequently, the fundamental value of the output of the MPUC-5 also tends to change. Thus, it is required to produce angles that commit to an ac output voltage with a constant fundamental value and constrained to a minimum total harmonic distortion along with a third-order harmonic mitigation as per the grid codes, irrespective of the change in the dc-link voltages. A genetic algorithm is employed for this purpose. A large dataset is prepared for two-angle and four-angle operation of MPUC-5 under various dc-link voltages and constraints with which an ANN-based controller is trained. A neural network with a hidden layer is trained with the backpropagation technique; and once a correlation is developed, the network can be operated for a wide range of operating conditions. The robustness of the controller is verified through simulation in MATLAB/Simulink environment and validated by experimental emulation in an hardware in loop environment. [ABSTRACT FROM AUTHOR]

This article presents a new hybrid three-phase cascaded modular multilevel inverter developed with a reduced switch count concept for harvesting renewable energy. The basic module of the proposed inverter consists of six switches, three asymmetric dc links, and two blocking diodes. The inverter can generate six positive voltage states, which are negatively polarized by the end-side H-bridge unit. As a result, a higher number of voltage levels are obtained with a minimum number of switches that ensure reduced total harmonic distortion in the grid current. Additionally, the proposed inverter can operate at a comparatively lower switching frequency, which decreases the switching losses. Most of the switches in each individual module conduct for a small period resulting in low conduction losses. The reduced switch count with the low switching and conduction losses increases the compactness and the efficiency of the proposed inverter. Multiple high-frequency magnetic links are utilized for the dc sources required for the proposed inverter to achieve inherent dc-link voltage balancing ability and galvanic isolation. The performance of the proposed inverter is validated by simulation and experimental investigations. [ABSTRACT FROM AUTHOR]

This work studies a multilevel inverter topology composed of two MPUC7s cascaded connected fed by only one dc power source by using a high-frequency link (HFL). This topology can provide up to 49 voltage levels by using four asymmetrical dc links, 12 power switches, and an HFL system. The dc link with higher voltage is fed by a dc source. The other dc links, with lower voltage, are supplied from the main one via high-frequency transformer with unidirectional power flow that processes up to 33% of the load power. A nearest-level control, analysis of power distribution among each dc link, and the HFL system design are presented in detail. Besides, comparisons with other multilevel topologies using HFL are carried out. Experimental results are presented to validate the theoretical studies. [ABSTRACT FROM AUTHOR]

Nowadays, the three-level T-type inverters (3LT2Is) are widely employed in applications with high-performance requirements. The 3LT2Is commonly suffer from neutral point voltage (NPV) unbalance and common-mode voltage (CMV) variation. The medium vector pulse width modulation (MVPWM), which generates the reference voltage using medium and V0[OOO] zero voltage vectors, eliminates the CMV variation in 3LT2Is. However, it cannot keep the NPV balance, negatively affecting power quality. This article proposes a hybrid method to simultaneously eliminate CMV variation and guarantee the NPV balance without topological change or extra hardware. The proposed method uses MVPWM when NPV is balanced, eliminating CMV variation. If NPV goes unbalanced, it utilizes novel high/low triangle PWM (H/LPWM) and MVPWM in a hybrid manner to balance the NPV. The H/LPWM, similar to MVPWM, synthesizes voltage using medium and V0[OOO] voltage vectors to maintain the CMV elimination advantage during the NPV balancing process. However, the difference between H/LPWMs and MVPWM switching patterns adjusts the average neutral point current to balance the NPV. Noteworthy that the proposed method provides NPV balancing ability for the entire power factor range. As a result, it is usable for various applications of 3LT2I, such as photovoltaic inverters and motor drives. The proposed method is carrier-based, which reduces the execution time and simplifies the practical implementation. The simulation study and experimental evaluation have been accomplished, and their results demonstrate the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

Modular multilevel converters (MMC) are increasingly gaining its importance in HVDC, drive applications due to several attributes such as modularity, scalability, low device stress, excellent output voltage waveform. For MMC operations, it is important to accurately measure the voltages across the individual capacitors of submodules (SMs). These voltage sensors, while upgrading for high voltage applications, may cause a few concerns in terms of cost, complexity, and data acquisition system. To avoid all these, a discrete time adaptive observer (DTAO) is proposed in this article to observe the voltages across the capacitors of the SMs and use the observed values for closed-loop operation of the MMC. The proposed observer is designed by considering the parametric uncertainty in the MMC and its convergence is proved mathematically. Moreover, the DTAO is compared with existing observation techniques for MMC SM capacitor voltages. The efficacy of the proposed observer is shown through simulation and validated using an experimental setup. [ABSTRACT FROM AUTHOR]

This article proposes and analyzes a two-stage isolated dc–dc converter for electric vehicle charging applications, where high efficiency over a wide range of battery voltages is required. It employs a first preregulation stage and a second half-bridge LLC stage, integrated with the first. The second stage is always operated at resonance, ensuring high efficiency. The first preregulation stage is responsible for the desired input-to-output voltage conversion ratio and the zero-voltage switching operation of all the switches. This allows low conversion losses even with voltages that may vary over a wide range. The article presents the conversion structure, the converter analysis, the design of the magnetic elements, and demonstrates the converter operation considering an experimental prototype interfacing a ${750\text{-}} \mathrm{V}$ dc-link with an output bus with nominal voltage range ${250} \mathrm{}$ – ${500}\, \mathrm{V}$. The implemented module is rated ${5}\,\text{kW}$ and achieves a peak efficiency of $\boldsymbol{98.0\%}$ at ${3\text{-}} \text{kW}$ output power. [ABSTRACT FROM AUTHOR]

This article investigates the functional link neural network assisted deadbeat predictive current control for an onboard charger (OBC) of an e-rickshaw with multistep charging capability. This control algorithm is presented for wide load operation of OBC since a multistep charging scheme is introduced to reduce the electricity consumption by OBC in the course of the peak load hours. The presented grid-connected OBC topology has two stages interconnected with the dc link capacitor. The first stage is a front-end converter to regulate the voltage at the dc link capacitor. Moreover, it regulates the power quality within the IEEE-519 standard. Furthermore, a dc–dc converter to regulate the charging current is the second stage of the OBC. Keeping this in view, a bidirectional interleaved isolated single ended primary inductor converter (SEPIC) converter topology is utilized. To analyze the performance of the OBC under distinct operating conditions such as grid voltage variations, an experimental prototype of the bidirectional OBC, is developed. Furthermore, the efficacy of the bidirectional operation of the designed system is analyzed through the vehicle to grid operation. [ABSTRACT FROM AUTHOR]

The integration of distributed photovoltaic and new energy vehicles could further aggravate the over-voltage, over-load, and three-phase voltage unbalance in distribution networks. Multistation integrated system (MSIS) can resolve the aforementioned power quality issues. In this article, a new topology for a MSIS is proposed, which uses soft open point as the key equipment of the system and adopts the hierarchical power supply mode for a data center, electric vehicle charging pile, and other function stations. Based on the topology of the MSIS and smooth switching of the converter control mode, a coordinated control strategy is proposed to control the working mode of each function station and further optimize the system operation conditions. The small signal model of the MSIS is derived, which can provide theoretical support for the stable operation of the system. The simulation results of two different application scenarios verify that the proposed topology of the MSIS and coordinated control strategy effectively improve the voltage level of the distribution network, enhance the reliability of sensitive load power supply, and ensure safe and reliable operation of the MSIS. Finally, the fusion and integration functions of the MSIS are tested and verified. The on-site demonstration indicated a mutual win–win situation for the power supply company, energy supplier, equipment provider and users. [ABSTRACT FROM AUTHOR]

This article presents a new device named flexible step-voltage regulator (FSVR) based on a multiwinding transformer for unbalanced distribution networks. While the traditional step-voltage regulator (SVR) can be used to control the voltage magnitude only, the proposed device can be used to control both voltage magnitude and phase angle for each phase independently. This allows greater flexibility during voltage control in unbalanced distribution networks. A mathematical model of the FSVR is derived for implementation in unbalanced power flow analysis. Simulation studies for IEEE 13 bus and IEEE 34 bus test networks demonstrate the effectiveness of the FSVR over the traditional SVR in reducing real power losses and voltage imbalance in the distribution network. A scaled-down model of the FSVR is designed in the lab to demonstrate the proof of concept. [ABSTRACT FROM AUTHOR]

Unlike VSIs, the single-stage inverters (SSIs) from the family of Z-converters are capable of boosting input dc to a desired ac voltage. The Z-network of these converters consists of a symmetric X-shaped network or a combination of inductors and capacitors. The basic Z-source converter (ZSC), connected in X-shaped fashion is modeled as a fourth-order system. This can be further modeled as a second-order system to reduce the sensor count but this may lead to an unstable system if there is an asymmetry in network parameters. Also, the source current of SSIs contains second-order ripple current (SRC) component, which oscillates at twice the supply frequency and has detrimental effects on sources. To alleviate the above problems, a parametric uncertainty compensation and ripple mitigation (PUCRM) control methodology is proposed. PUCRM control can be used to maintain stability and achieve desired performance during parametric uncertainties in the dc–dc stage and to reduce SRC propagating to the sources while feeding ac loads. PUCRM consists of a nominal dual-loop PI controller, which regulates the SSIs to achieve desired performance and a nonlinear integral sliding mode component that mitigates the uncertainties and ripple component. The proposed method is verified using simulation and experimentation. [ABSTRACT FROM AUTHOR]

With the increasing demand for high-performance power electronic systems, the semiconductor device utilization has gained significant importance. This article proposes the Si/SiC devices based active neutral-point-clamped converter comprising SiC-based H-bridge structure. A novel pulsewidth modulation (PWM) scheme is also proposed that results in an effective utilization of the switching devices. In the proposed converter, the Si devices are soft-switched for all power-factor loading conditions. Therefore, high efficiency can be obtained even at high switching frequency operation with wide range of power factor values. Further, the conduction losses of the SiC mosfets are minimized by strategically selecting the switching states in such a way that the SiC mosfets conduct in parallel conduction paths during the null state operation. This leads to further enhanced efficiency. This article presents the detailed operating principle of the proposed topology operated with the presented PWM scheme. Moreover, a device loss analysis is presented to evaluate the conduction and switching losses of the proposed topology. The presented experimental results validate the performance parameters of the proposed topology with the proposed PWM scheme. Finally, the proposed PWM scheme is compared with the existing PWM schemes using efficiency values of the proposed and some of the prominent existing converter configurations. [ABSTRACT FROM AUTHOR]

Acquisition of the accurate phase currents is indispensable for the control and protection of switched reluctance motor (SRM) drives for electric transportation applications. Existing phase current reconstruction techniques for SRM are implemented under the current control techniques, which generate large torque pulsations. Therefore, the direct torque control (DTC) method can be adopted to minimize torque pulsations and to enhance transient performance in electrified vehicles. However, the existing current estimation methods cannot be applied to DTC strategies due to the simultaneous conduction of all phases at any switching instant. Furthermore, it offers a lower torque per ampere ($T/A$) ratio and draws a high source current. This article addresses the aforementioned concerns by proposing a cost-effective phase current reconstruction method with an improved DTC strategy for a 4-kW four-phase SRM drive. This method employs a 16-sector partition method with a new voltage vector selection by detecting zero-current regions of each phase. As a result, the long-tail currents can be avoided, thereby limiting the simultaneous conduction of all phases. The simulation and test results show that the proposed DTC has minimal torque pulsations, high $T/A$ ratio, low converter losses, and lower source current ripple in comparison to the existing DTC schemes under various operating conditions. Also, the proposed phase current estimation method effectively reconstructs the phase currents under both steady-state and transient operating conditions. [ABSTRACT FROM AUTHOR]

At the energy consumption level, buildings are currently the largest sector, therefore, the energy efficiency of these structures, assumes a priority role in refurbishing projects. The “building automation” as well as the redesign of the electrical and thermal system of a structure can offer significant contributions in terms of energy saving, comfort, and functionality. Recent policies introduced the nearly zero-energy building (nZEB) qualification. The challenge we are facing is to work on the refurbishment of existing buildings by identifying a model that on the one hand allows nZEB qualification and on the other hand applies to existing buildings with all the technical and economic constraints. The goal of this article is to present possible redevelopment projects, thanks to the use of software, applicable to the historical university department located in the center of Rome to compare the parameters and reference indices for calculating the performance of an nZEB included in the ministerial decree (DM) June 26, 2015. The building automation and the redesign of the thermal electrical system of the structure is one of the most important aspects to obtain nZEB evaluation but it is also important to change opaque vertical and horizontal structures and transparent envelopes. [ABSTRACT FROM AUTHOR]

In this article, a sliding mode control (SMC) is applied to regulate the delivered power of a symmetrical six-phase induction generator. For this, the SMC strategy associated to the field-oriented control strategy is used in order to adjust the inner current loops of a squirrel cage six-phase induction generator (SC6PIG). In this way, the control algorithm switches between positive and negative feedback according to the position of the operating point in the phase plane. This technique guarantees the robustness of the SC6PIG in case of the loss of one to three stator phases or machine converter legs. The switching line slope and the initial operating point have been set so that the system starts with a negative feedback, then it continuously switches back and forth to positive feedback in order to maintain the desired trajectory of the system. The simulation and experimental results demonstrate the effectiveness and the robustness of this technique since the delivered power of the SC6PIG presents the same dynamics in healthy or faulty modes with one to two phase losses. [ABSTRACT FROM AUTHOR]

This article presents the design of an electric vehicle (EV) battery charger isolation stage for minimizing switching frequency variation with the proposed duplex control. Traditionally, the realization of an EV charger with a resonant power conversion stage involves extreme frequency variation in the constant voltage (CV) mode resulting in switching losses, imposes severe constraints on the optimal design of magnetics, and presents control complexities due to secondary resonance and degraded pulsewidth modulation resolution. In this context, reported hybrid control strategies are complex and entail the simultaneous variation of control variables. In order to simplify control complexity and design constraints, the EV charger isolation stage with the quadruple rectifier and employing the proposed duplex control is presented with notable frequency reduction. Furthermore, the effect of high-frequency transformer nonidealities on the soft-switching range is delineated. The proposed duplex control contributes to the efficiency enhancement of the EV charger over a comprehensive range during CV charging, ensures soft switching, and prevents secondary resonance. It also offers continuous resonant current to overcome the underutilization of the transformer arising from high-frequency distortions. To validate the presented analysis, a 1.25-kW hardware prototype is designed and tested in the laboratory, and experimental results are presented. [ABSTRACT FROM AUTHOR]

In the research process of very fast transient overvoltage (VFTO), the accuracy of the switching arc model largely determines the calculation results of VFTO. How to more accurately simulate the arc striking and extinguishing process of the arc during the action of the disconnector is the key issue in the study of the arc model. In this article, the ATP-EMTP electromagnetic transient program was used to simulate arc damping with a series connection of a fixed-value resistance and a time-varying inductance, and the built-in MODELS module was used for programming to simulate the reignition and extinguishing process of the arc based on the gaseous dielectric theory and the energy balance theory. The model was applied to a 1000 kV gas insulated substation (GIS) test circuit. The relationship between the arc damping and arc voltage and current was analyzed, and the arc reignition law during opening and closing is studied. The arcing law obtained is compared with the experimental results of the existing literature, and the accuracy of the simulation model is verified. Simultaneously, the influence of the opening speed of the disconnector on VFTO was analyzed by simulation. The results show that when the opening speed is less than 0.7 m/s, the maximum value of VFTO in the test circuit increases with the increase in opening speed. After the VFTO amplitude reaches the maximum and continue to increase the opening speed, the VFTO amplitude decreases. This law is consistent with the experimental results of the existing literature, which proves that the arc model built in this article has a certain engineering application value. [ABSTRACT FROM AUTHOR]

In this article, a multioutput-based transformerless hybrid solar inverter (TLHSI) with no right half-plane zero (RHPZ) and reduced common-mode leakage/ground current is presented for photovoltaic (PV) based microgrid applications. In the proposed multioutput TLHSI, two magnetically coupled inductor coils are placed between the input and dc output sides along with a dc-link capacitor to continuously provide the stored energy to the dc load so that the RHPZ is eliminated and, thus, makes it a minimum phase system. Furthermore, a hybrid unipolar sinusoidal pulsewidth modulation technique is established to nullify the high-frequency components of common-mode voltage across the PV to ground stray capacitor. Also, it normalizes both dc and ac loads at the same instant from a single dc input during each operating state of the proposed TLHSI. The shoot-through issue is resolved in the proposed TLHSI, which increases the system reliability. Furthermore, as the deadtime is not required in between the switching pulses, the quality of the inverter output voltage improves. The performance analysis of the proposed TLHSI is compared with the existing topologies. To validate the performance of TLHSI, a scaled down 340 W laboratory prototype is developed. [ABSTRACT FROM AUTHOR]

A modular model-predictive control (MPC) method for a nonisolated three-phase $LCL$ grid-connected converter is proposed with zero-sequence voltage control and regulated third-harmonic injection capabilities. The control method is proposed with the combination of a modified three-phase $LCL$ converter topology to stabilize the common-mode voltage. The control mechanism consists of two layers: 1) the central-level control of $dq$ -sequence output current control cascaded with 2) the local-level control of zero-sequence voltage three-phase inductor current/capacitor voltage MPC. No grid-side inductance value is needed for the two-layer cascaded control structure, which both improves the dynamic performance from the inner MPC loop and avoids the MPC parametric error caused by the uncertainty of grid-side inductance. With the zero-sequence MPC, the common-mode voltage and leakage current can be attenuated without a bulky isolation transformer. A regulated third-harmonic injection (RTHI) method is designed based on the zero-sequence voltage control and the proposed modified converter topology to improve the dc bus utilization and avoid the overmodulation issue. Compared with the conventional third-harmonic injection methods, no extra harmonics are injected to the grid, and there is no need for a specialized grid total harmonic distortion optimization algorithm with the proposed zero-sequence-controlled RTHI. The stability and robustness of the proposed RTHI method are also improved with the zero-sequence MPC regulation. In addition, the modular concept of the local MPC module enables the extensibility for the power converter control with a flexible number of phases. The dynamic performance, leakage current attenuation, dc bus utilization, and grid-connection power quality of the proposed MPC method with RTHI have been validated experimentally. [ABSTRACT FROM AUTHOR]

In this article, an improved soft-switching quadratic boost converter is proposed. Instead of inserting an additional active clamp or auxiliary zero-voltage transition circuit at the switching node, the proposed topology connects the high-voltage switching node to the input diode node by replacing one of the input diodes with a low-rated switch. The proposed topology can attain soft-switching condition for all the switches and input diode turns-off under zero-current switching (ZCS). The operation of input-side switch not only aids zero-voltage switching (ZVS) turn-on for the main switch but also helps in reducing the conduction loss. Also, the input-side switch operates under ZCS turn-on and ZVS turn-off, making it a loss economical solution. An adaptive timing scheme for driving the input switch is proposed, which can ensure soft-switching condition under varying gain and load range. The detailed operational modes, analysis, and design considerations of the proposed topology are presented. A 250 W hardware prototype is built to validate the performance of the proposed converter operating at 100 kHz switching frequency. Results with adaptive soft-switching scheme shows that the converter is modulated to achieve its best efficiency condition under various system conditions. A peak efficiency of 96.1% at 155 W and efficiencies above 95.75% over a wide load range are achieved using all Si devices. [ABSTRACT FROM AUTHOR]

This article evaluates the performance of a relatively new pulsewidth modulation (PWM) method i.e., 240 $^\circ$ -clamped space vector PWM (240CPWM), in three-phase grid-connected photovoltaic (PV) converters under various grid voltage conditions. 240CPWM is a minimum switching loss PWM method that reduces the switching loss by 85% at unity power factor and has better total harmonic distortion (THD) as compared to conventional space vector PWM. A unique six-pulse dynamically varying dc-link voltage is required for 240CPWM. Typically, a three-phase grid-connected PV system consists of a dc–dc stage followed by a dc–ac stage. In this article, the dc–dc stage is operated in closed-loop control to shape the dynamic dc-link voltage required for 240CPWM. The dc–ac stage is operated in the current control mode using a proportional–integral controller along with a harmonic compensator to ensure sinusoidal grid currents along with maximum power point tracking. The modulation index of the dc–ac stage is uncontrolled and fixed at the maximum value, and the primary control mechanism changes the magnitude, phase, and wave shape of the dc-link voltage. The coordinated control of dc–dc and dc–ac stages is ensured for better dynamic performance and grid support functions. Finally, the performance of the grid-connected PV converter with 240CPWM is validated using a three-phase 3-kW 208-V hardware prototype under nonunity power factors, voltage unbalance, and voltage sag/swell conditions for the first time. The implemented control with 240CPWM achieves smooth operation under nonunity power factor and grid voltage disturbance conditions with THD as low as 3.5% and peak combined efficiency of dc–dc and dc–ac stages as 96.4%. [ABSTRACT FROM AUTHOR]

In this article, a 13-level switched capacitor multilevel inverters (SC-MLI) based single-phase inverter is proposed in which desired levels of output ac voltage are realized with reduced number of switch counts. The proposed inverter requires 12 switches, three diodes, one input dc source, and three capacitors. The requirement of less number of switches reduces the requirement of gate drivers, which enhances power density of converter. The second challenge in SC-MLI is to maintain self-voltage balancing across the capacitors. The self-voltage balancing capability becomes poor at low values of modulation index. The capacitors connected in proposed SC-MLI are capable to maintain the self-voltage balancing without requiring auxiliary circuits or complex control strategies. The operation of capacitors is self-balanced at all regions of modulation index values. The comparison of the proposed SC-MLI is carried out with state-of-art SC-MLIs discussed in the literature using the parameters like peak inverse voltage and total standing voltage. The switches connected in the proposed 13-level SC-MLI undergoes less voltage stress as compared to the SC-MLI configurations discussed in the literature. The proposed SC-MLI is highly competent to achieve good power quality and is capable to ensure voltage balancing of capacitors even at low values of modulation index. The validation of the proposed inverter topology is carried out using a laboratory prototype. The efficiency of the converter claimed using the simulation results is observed to be 96.2% while the efficiency evaluated using the experimental results is 94.1% at 500 W. [ABSTRACT FROM AUTHOR]

In this article, two kinds of finite control set-model predictive voltage control (FCS-MPVC) methods have been proposed for linear induction machine to eliminate the cumbersome selection of the weighting factor (WF), achieve lower ripples of both thrust and flux, and reduce the heavy calculation steps. The first method, FCS-MPVC I, uses one voltage vector (VV) during the whole control period, and the second method, FCS-MPVC II, uses two VVs. Moreover, the proposed methods use a single cost function without any WF. This function consists of the errors between primary voltage references with their predicted values in the αβ-axis. Depending on the distance between the reference VV (RVV), as calculated using the deadbeat control method, and all candidate VVs (CVVs), the first proposed method, FCS-MPVC I, can select the nearest VV to the RVV as the optimal VV (OVV), which can reduce the redundant evaluation work greatly. Meanwhile, the second proposed method, FCS-MPVC II, applies two VVs, active VV and null VV, to adjust the duty ratio effectively. To avoid the iterated evaluation for all CVVs, one simplified search order excluding unsuitable CVVs has been proposed to determine the optimal OVV, which selects only one active VV from the two adjacent active VVs in the sector owning the RVV. Afterward, based on a prototype of 3-kW arc induction machine with a large radius, extensive simulation and experiments have fully demonstrated that the proposed methods can get much lower thrust ripples and less calculation steps effectively, compared with those of conventional finite control set-model predictive thrust control strategy. [ABSTRACT FROM AUTHOR]

Common mode voltage (CMV) reduction in a traditional H6 (six switch) 3-φ inverter usually demands additional power semiconductors to avoid poor harmonic performance. However, apart from tending to the CMV related issues, these extra switches do not add any other capability to the inverter. To address this limitation, in this article, a novel H8 inverter configuration is proposed which not only reduces the CMV by 66.6%, the phase current total harmonic distortion (THD) is also improved. The proposed H8 inverter employs two additional power semiconductor devices along with the conventional H6 inverter in a manner that it can generate 15 space vectors (SV). By considering the CMV attribute of each SV, a unique sector configuration is proposed where the SV diagram is divided into 18 asymmetrical sectors and three distinct SV sequences are identified. A special pulsewidth modulation scheme is devised to operate the proposed topology to achieve reduced CMV and improved harmonic performance. A comparison study reveals that the proposed topology offers better phase current THD, low CMV, low losses, and low semiconductor requirement. Simulation and experimental results are included to justify the various claims. [ABSTRACT FROM AUTHOR]

Three-phase (3-φ) induction motor drives operated with switched capacitor (SC) inverter circuits offer superior harmonic performance and voltage boosting. The SC network, however, generally requires additional circuitry to precharge the capacitor(s) to prevent inrush current. To obviate the requirement of the extra circuit, an innovative SC precharging scheme is presented, which utilizes the winding inductance of the motor. The inverter circuit is so operated that the motor winding inductance first stores electrical energy from the input dc source and then releases it to the SC. These two actions are continued till the SC is precharged to a voltage equal to the magnitude of the input dc source. The circuit operation during the precharging is similar to the operation of a conventional buck-boost type dc–dc converter. The precharging action is so designed that the voltage of the SC cannot increase further. Therefore, the proposed scheme does not need any voltage sensor. The operation of the circuit during precharging is analyzed extensively to develop a mathematical background for the given method. It is shown that by manipulating the switching frequency during the precharging the precharging time can be controlled as per the user requirements. Various claims are validated using computer simulations and experiments. All the results are presented. [ABSTRACT FROM AUTHOR]

A single-stage high power factor (HPF) improved power quality charging solution for light electric vehicles (LEVs) is presented in this work. The charger topology comprises a bridgeless isolated modified SEPIC (BIMSEPIC) HPF ac–dc converter, to accomplish various charging modes with high performance at the supply side. Unlike conventional bridgeless SEPIC topologies, the presented topology ensures zero circulating current through the antiparallel diode of the switch, utilizes a single switch structure, and requires simple gate drive circuitry. Further, the discontinuous conduction mode operation of the charger significantly simplifies the control complexities and associated cost of implementation. Additionally, the magnetic component's volume and switching losses are reduced considerably. Finally, the presented topology is designed, simulated, and implemented to verify its efficacy for the LEVs charging applications. A comprehensive analysis is carried out at various operating conditions, and the relevant test results are demonstrated for the performance verification. Moreover, a comparative analysis with existing chargers verifies the excellent performance of the presented charger topology. [ABSTRACT FROM AUTHOR]

An isolated multilevel bidirectional dc–dc converter is presented in this article to interface the low-voltage (LV) battery and the high-voltage (HV) propulsion inverter in electric vehicles. The proposed topology achieves a HV step-up ratio in the motoring mode by reconfiguring two split capacitor half-bridge circuits in series/parallel through the symmetrical modulation of a voltage bidirectional, two quadrant switch. This reconfiguration generates a high-frequency multilevel voltage output at the dc-bus side of the inverter, which reduces the output filter volume. The dc-bus voltage is regulated by the duty cycle modulation of the intermediary switch in the motoring mode, simplifying the sensing and control. During regenerative braking, the converter is operated with phase shift modulation between the HV half bridges and the LV full bridge to regulate the battery voltage. The presented modulation strategies achieve zero voltage switching for the full-bridge devices over a wide load range. A comprehensive analysis of the proposed multilevel converter in motoring and braking modes along with the design constraints and soft switching boundary conditions is presented in this article. Detailed experimental results on a 1.5-kW laboratory prototype are presented to verify the design approach and illustrate the converter performance. [ABSTRACT FROM AUTHOR]

One of the major challenges in evacuating power from the offshore renewable energy source is reducing the number of equipment involved in the energy conversion process. In the strategy presented in this article, the output of a permanent magnet synchronous generator coupled with a wind turbine is converted to a low voltage DC by an AC–DC converter and then directly connected to a Medium Voltage Direct Current (MVDC) corridor using a new fault tolerant soft switched high gain DC–DC converter. During the fault in the MVDC corridor, the DC–DC converter is blocked forcing the fault current to zero, the faulty MVDC corridor is bypassed using the simple DC disconnectors, and then the DC–DC converter is connected to the healthy MVDC corridor. In this article, the efficacy of the proposed scheme is discussed in detail and substantiated through extensive simulation studies done in PSCAD/EMTDC. The theoretical and simulation analysis is also verified by experimental results. [ABSTRACT FROM AUTHOR]

In this article, a detailed analysis of fast output sampling (FOS)-based multirate output feedback (MROF) technique is done in the context of discrete time sliding mode control (DTSMC) based on nonswitching reaching law. In addition, for better performance and improved robustness, the relative degree of the sliding variable is chosen as two instead of one. Quantitative analysis of robustness in terms of ultimate band for the relative degree two (RD2) approach is done and compared with that of relative degree one (RD1) approach. First, only RD1 and RD2 approaches are proposed for speed tracking of a dc motor under parametric uncertainty. Then the same task is done using MROF-based RD1 and RD2 approaches. The proposed work is validated experimentally and is used for tracking a reference speed of a dc motor. [ABSTRACT FROM AUTHOR]

1500-V photovoltaic (PV) configuration is the standard design in the solar PV industry. Extending the maximum dc voltage from 1000 to 1500 V can reduce the installation cost of the entire power plant. However, it may affect the reliability of the corresponding 1500-V PV inverters, due to the increased loading stresses, i.e., voltage stress and thermal loading of power devices. In this context, this article proposes a solution to the reliability enhancement of silicon carbide-mosfet-based 1500-V PV inverters with variable gate resistance. This solution offers a possibility to adaptively adjust the switching speed to make a compromise between the switching power loss and voltage overshoot during commutation, thus enhancing the reliability. The evaluation results based on the mission profile of a 125-kW 1500-V PV system installed in Denmark indicate that the PV inverter with the proposed design, i.e., variable gate resistance, can improve reliability performance compared to the fixed gate resistance solution while ensuring a safer operating voltage margin. [ABSTRACT FROM AUTHOR]

A photovoltaic based distribution static compensator (PV-DSTATCOM) is one of the leading approaches to deal with the energy demand shortage and power quality issues in the modern power system. This article achieves the improved performance of PV-DSTATCOM to establish the grid integration and power quality enhancement. In the proposed system, during the PV-DSTATCOM state, photovoltaic array power is used to maintain the dc-link voltage by extracting the maximum power based on the perturb and observe algorithm and supplying the excess power into the grid. During the DSTATCOM state, a reference dc-link voltage control scheme is proposed based on the connected load on the point of common coupling, which thus regulates the dc-link voltage and enhances the PV-DSTATCOM performance. The control signals for the voltage-source inverter are generated based on the modified synchronous reference frame control scheme. The effectuality of the proposed system is validated by the MATLAB simulation results. A hardware prototype is developed to verify the usefulness of the proposed system compared to the control technique in the literature. Finally, the results presented in this article convey how the improved performance of PV-DSTATCOM has been accomplished while guaranteeing power quality improvement and grid integration. [ABSTRACT FROM AUTHOR]

Maximum power point tracking (MPPT) plays a significant role in a photovoltaic (PV) system's optimal performance. Bypass diodes create multiple peaks on the power–voltage curve during partial shading conditions (PSCs), reducing the PVs overall power extraction capability. This article proposed a new hybridized architecture for switched inductor and switched capacitor circuit based voltage equalizer (VE) topology with reduced switch count to prevent the multiple peaks and increase the energy yield during PSCs. The proposed VE operates with a fixed duty cycle and frequency. The MPPT controller with PSC detection is also proposed to operate VE only when the PSC is detected to avoid unwanted switching and conduction losses. The proposed system's effectiveness for ten modules connected in series has been determined compared with other modular state-of-the-art VEs. The proposed topology can be extended with a smaller number of control switches. On average, the experimental results showed a 30.42% improvement in energy yield in comparison with the conventional systems. Furthermore, the proposed controller offers the MPPT efficiency of 99.28% with a tracking time of 0.10 s for uniform shaded conditions and 0.692 s for PSCs on average. [ABSTRACT FROM AUTHOR]

This work extends the wavelet modulation (WM) technique for operating three-phase ($3\phi$), five-level (5L) power electronic converters (PECs). The WM technique is extended by resolution segmentation of the synthesis scale-based linearly combined wavelet functions, which are used as switching signals. The resolution segmentation is created based on the dilation property of synthesis scale-based linearly combined wavelet functions. Each leg of the $3\phi$ VS, 5L dc–ac PEC is operated by two sets of resolution-segmented synthesis scale-based linearly combined wavelet basis functions to produce the voltage of one phase. The extended WM technique is implemented for performance testing, when operating $3\phi$ VS, 5L, diode-clamped and flying-capacitor dc–ac PECs. In this article, Part I, simulation test results are presented and compared with results obtained using the level-shifted pulsewidth modulation, phase-shifted PWM, and space vector modulation. Test results show significant reductions of output harmonics, along with improvements in fundamental components of output voltages and PEC efficiency. [ABSTRACT FROM AUTHOR]

This article presents the implementation and experimental testing of the wavelet-modulation technique for three-phase ($3\phi$) 5-level (5L) power electronic converters (PECs). This version of the wavelet modulation technique is structured as a multiresolution analysis that can support a redundant nonuniform recurrent sampling-reconstruction of three reference-modulating signals. The reconstruction of reference-modulating signals is achieved by sets of resolution-segmented scale-base linearly combined synthesis wavelet basis functions, which are used as switching signals to activate the switching elements of a $3\phi$ , 5L, VS dc–ac PEC. The presented wavelet-modulation technique is implemented in real time using a digital signal-processing board. Switching pulses generated by the extended wavelet-modulation technique are used to operate $3\phi$ , 5L, VS, diode-clamped and flying-capacitor dc–ac PECs. Experimental performance of the tested 5L dc–ac PECs is evaluated, when operated by the presented wavelet modulation, level-shifted pulsewidth modulation (PWM), phase-shifted PWM, and space vector modulation techniques. Experimental tests are conducted for linear, dynamic, and nonlinear loads fed by the tested 5L PECs. Test results show that magnitudes of output voltage fundamental components can be significantly increased, and harmonic distortions can be effectively reduced using the wavelet-modulation technique. These features are further demonstrated by performance comparisons with other techniques under similar operating conditions. [ABSTRACT FROM AUTHOR]

For variable frequency induction motor drive application, conventional modular multilevel converter (MMC) faces some issues, like high capacitor voltage ripple at low frequency, high circulating current, and high component count. This article proposes a novel configuration to address these issues, where a six-pulse thyristor-based controlled rectifier is combined with a waveshaper-based MMC (WS–MMC). Each phase of the converter consists of a WS and director valve, and then the phases are connected in series to create a common dc-link. The use of a thyristor-based controlled rectifier as a front-end converter increases reliability and reduces component count to a large extent. Unlike conventional MMC, circulating current does not exist in this converter, and the capacitor voltage ripple does not depend on the operating frequency. As a consequence, the current rating of the switching devices is reduced for the same power output, and capacitor voltage ripple at low frequency stays within the specified limit. Besides this, the component count of the proposed configuration is far less than the MMC-based topologies available so far. The operation principle, relevant control techniques, and analysis of the converter are discussed in detail in this article. The complete system is simulated in MATLAB/SIMULINK, and the performance of the control methods has been validated at different operating frequencies with various load torques. The results show satisfactory performance. [ABSTRACT FROM AUTHOR]

The five-level active neutral-point-clamped (5L-ANPC) inverter has been applied to increase the power capacity of photovoltaic (PV) systems. However, this type of configuration requires to balance neutral point (NP) voltage and flying capacitor (FC) voltage properly. For the operation of the transformerless five-level inverter, another requirement is to suppress the leakage current associated with the common-mode voltage (CMV) vectors. Due to the mutually coupled issues, the conventional model predictive control (MPC) methods reported so far cannot deal with them properly at the same time. To address these problems, a novel double-vector MPC (DV-MPC) strategy with zero CMV vector is proposed in this article. First, 19 voltage vectors with zero CMV are implemented as candidate vectors. Then, for the purpose to reduce output current ripples, two voltage vectors are penalized by the cost function without weighting factors to track the reference voltage. In addition, the dwell times are optimized to further mitigate current ripples. Finally, to avoid the sharply increasing computational burden of the online iteration caused by the introduction of the second vector and its corresponding redundant switching states, a voltage-balance strategy is presented for the DV-MPC method, which can determine the suitable switching combinations directly and adapt them to the selected vectors to balance the voltages of the NP and FCs together. The effectiveness of the proposed method is verified by the simulation and experiment at the end of this article. [ABSTRACT FROM AUTHOR]

A novel single-stage ac/dc isolated onboard charger with modular stacked switches structure utilizing interleaved control is proposed in this article for high-voltage (HV) battery systems in electric vehicles (EVs). In the proposed converter, modular interleaved bridgeless ac/dc boost converters are integrated with modular CLL resonant circuits through sharing the two legs of stacked switches. With this configuration, the voltage stress across each switch is reduced to half of the dc-link voltage, which makes the circuit applicable for HV battery system (such as 800 V) in EVs. In the proposed design, the integrated interleaved boost circuit modules allow low input current ripple to be achieved. Two step-up resonant circuit modules are then connected to the two interleaved legs with their outputs connected in series at the input of a current-fed high-frequency rectifier. Soft-switching commutation is achieved for all switches and diodes in the proposed converter. The descriptions of the proposed converter and its operating principles will be discussed in this article. A silicon-carbide-based hardware prototype with a rated power of 2.4 kW, 90–135 Vac/800 Vdc system has been tested in the laboratory. Results confirmed that a power factor of 0.97 and a peak efficiency of 97.9% were achieved. [ABSTRACT FROM AUTHOR]

A nonisolated integrated multiple output synchronous buck converter is proposed in this article to cater the auxiliary power supply requirements of e-mobility. The converter provides independently controlled multiple outputs with reduced switch count as compared to conventional separate buck converters as well as conventional synchronous buck converter. The operating principle and working of the proposed converter are discussed in detail for better understanding. As the dynamic behavior of the converter is similar to the conventional buck converter, a simple controller is designed and implemented in this work. The converter is simulated in MATLAB-Simulink. A laboratory prototype of single input–quadruple output (SIQO) converter is developed and operated under closed loop condition to validate and demonstrate its advantages. The prototype is developed by designing two inductors on a single core for increased compactness and reduced cost of the converter. Each output of the converter can be independently controlled by varying the duty ratio of the related switch, thereby eliminating the effective cross regulation problem. The efficiency of the proposed SIQO converter is 93.6%, with four output ports, which is higher than its category of converters reported earlier. A significant improvement in the calculated efficiency is observed with the replacement of conventional switches and diodes of the converter by SiC switches (96.1%). [ABSTRACT FROM AUTHOR]

Rapid widespread vehicle electrification has incentivized fast chargers to improve their performances. In this article, an integrated-magnetic-based differential-mode Ĉuk rectifier (IM-DMCR) as a universal battery supercharger is introduced. The design challenges associated with the high-power operation of IM-DMCR are outlined, and optimized solutions are presented. A SiC-based full-scale 60-kW experimental prototype for the IM-DMCR is built and tested to verify the design. [ABSTRACT FROM AUTHOR]

This article presents a new Scott-ternary solar multilevel converter (ST-MLC)-based solar photovoltaic (PV) system for medium voltage applications. This system employs a single solar PV array as an input source and two voltage source converters (VSCs) to feed a three-phase grid. Solar power is fed from a two-phase to a three-phase medium voltage grid with balanced grid currents. The legs of VSCs are cascaded to form a two-phase system. The multiwinding transformers are connected in a Scott manner to develop a nine-level three-phase power conditioning system. The turn ratios of the transformers have ternary progression for the generation of higher levels. The modeling of the system is presented, and a closed-loop nearest level control strategy is incorporated to have minimum losses. Simulation results show the performance of the solar PV system under steady-state and dynamic irradiance. Varying solar profile is considered on basis of the daily average global solar irradiance from the geographical information system for New Delhi, India. The harmonic performance is analyzed for the converter voltage and grid current. Moreover, a detailed comparative analysis is covered for the ST-MLC to evaluate its superiority over its existing counterparts. Performance validation is done in a real-time test bench to validate the control and operation of the large-scale solar PV system. [ABSTRACT FROM AUTHOR]

This article introduces a novel electrical variable capacitor (EVC) circuit for use in the impedance matching circuits employed by 13.56 MHz RF plasma systems. The proposed design employs a turn-on/off using bias current and voltage condition technology, reducing the number of active components necessary for the EVC to operate. Experiments comparing the proposed EVC to state-of-the-art alternatives confirmed that the proposed design successfully operated with the reduced number of active components. Proposed EVC of automatic bias action by the power semiconductor switch may improve the impedance matching circuits used in high-power and high-frequency RF plasma system. [ABSTRACT FROM AUTHOR]

An analytical approach to size a dc-link capacitor for a three-phase current-controlled voltage-source inverter used for a permanent magnet synchronous motor is presented in this article considering the dc-link ripple voltage and capacitor ripple current. The analytical method derived in this article shows the variation of the dc-link voltage ripple with the change of the power factor and the modulation index. This analysis can be applied to determine the maximum possible ripple voltage for a given capacitor or the minimum capacitance needed to keep the voltage ripple under a limit. Then, current ripple analysis is used to determine the root-mean-square capacitor ripple current taking account of the thermal duty cycles of the application. Finally, capacitor life estimation analysis is used using the operating condition, thermal duty cycle, and ripple current to determine the capacitor end life for a given application. The research presents a sequential process to select a dc-link capacitor accounting for the electrical and thermal requirement of the system. The analysis is verified by simulation and experimental results, where the effect of components’ parasitic on the voltage and current ripple is presented. [ABSTRACT FROM AUTHOR]

In this article, we proposed a discrete-time sliding mode load thrust observer to reduce the influence of load thrust mutation on the linear motor and improve the antiinterference ability and speed tracking performance of the system. First, the electrical and dynamic models of linear motor are established, and the limitation of conventional double-closed-loop control based on proportional integral (PI) algorithm is analyzed. Second, the extended state equation of velocity and load thrust is given and an improved sliding mode reaching law is designed to establish the discrete-time load thrust observer. Based on Lyapunov theory, the stability of the observer is proved. The observed load thrust is compensated to the controller in the form of feedforward. Finally, a series of comparative experiments were carried out. The experimental results show that compared with the PI control, the maximum speed fluctuation of this method is reduced by about 18.1% when the load changes between no-load and rated load. This means that the method in this article can effectively improve the antidisturbance ability of the system. [ABSTRACT FROM AUTHOR]

This article presents an active neutral point clamped (ANPC)-based parallel dual-active bridge (DAB) architecture which combines dv/dt cancellation and power sharing in order to reduce electromagnetic interference (EMI) caused by common-mode (CM) current. High dv/dt associated with wide bandgap devices causes high CM current mainly due to parasitic capacitances. The corresponding conducted EMI can remarkably reduce the reliability of power converters and other onboard systems. This issue becomes worse due to higher dc bus voltage trend in electric vehicles (EV) and other dc systems. Conventional techniques struggle to provide attenuation in a wide frequency range. The problem can also be severe in soft-switched DAB converters as they operate at relatively higher frequencies. In this article, initially, an in-depth theoretical analysis is provided to understand the complimentary dv/dt events. Various factors causing nonideal dv/dt cancellation are discussed in detail together with possible solutions. Detailed experimental results are obtained from a 1100 V–150 V parallel DAB system including both the high and low voltage sides at different dv/dt rates. dv/dt cancellation at lowered dv/dt rates facilitated by power sharing and small snubbers provide up to 25 dBuA reduction in CM conducted EMI. A comparison with CM chokes is also presented to validate improved attenuation in a wide frequency range. [ABSTRACT FROM AUTHOR]

This article illustrates a method for sensorless control of a switched reluctance motor. The detection of the time instants for switching between the working phases is determined based on the evaluation of the switching frequency of the hysteresis current controllers for appropriately selected sensing phases. This enables a simple and cost efficient implementation. The method is compared with a pulse injection method in terms of efficiency and resolution. [ABSTRACT FROM AUTHOR]

This article proposes a single dc source-based hybrid three-phase thirteen-level inverter suitable for medium voltage applications. The multilevel structure is composed of a three-level T-type neutral point clamped (NPC), half-bridge, and three-level Flying capacitor converter with optimal switch count and high dc bus voltage utilization as high as 0.63 times the dc-link voltage. This requires a special attention to a novel capacitor balancing method using redundant switching states in order to operate at any power factor under grid-connected mode. A unified common-mode voltage is injected in the carrier based pulse width modulation (PWM) technique to maintain the voltage balance in dc-link capacitors as well as floating capacitors. Simulation results are presented under different operating conditions that include unity power factor operation with passive load as well as grid-connected inverter mode. The performance of the proposed multilevel inverter in the grid-connected mode is also validated with experimental results using a lab prototype. [ABSTRACT FROM AUTHOR]

This article presents a new topology for a single-stage nine-level (9L) switched-capacitor inverter. The structure of the proposed topology is not only simple but also compact. The proposed topology is developed with self-voltage balancing and a low number of power components. The output voltage (vo) gain is four times higher than the input voltage (vin). Each mode of operation is discussed with a detailed current path. The conventional sinusoidal pulsewidth modulation technique is used to generate the gate pulses. Next, the experimental results are obtained from a 1 kW prototype setup. The proposed topology is tested under different scenarios such as load change, input voltage changes, and modulation variations. Both simulation and experimental results have good agreement in terms of efficiency. Finally, a detailed comparative study is performed with other recent 9L inverters to prove the merits of the proposed topology. [ABSTRACT FROM AUTHOR]

Adjustable-speed drives (ASDs) generate current harmonics due to their nonlinear characteristic and switching function. These current harmonics could pass through a network and deteriorate the power quality, create resonances, and increase network power loss. Higher order 2–9 kHz harmonics, among them, have become a new challenge for drive manufacturers, as these harmonics will be covered in the forthcoming IEC standards (standardization committee SC77A). To address the existing gaps, this article explores 2–9 kHz current harmonics for a common ASD type that has a diode-bridge rectifier (DR) and a dc-link filter. Through the analytical study and experimental results presented in this article, it is shown that the main source of 2–9 kHz current harmonics at the grid side of this type of ASD is its front-end DR. Moreover, it is found out that the amplitude of these current harmonics can be significantly affected by the operation power of the other ASDs in the network. Furthermore, it is analyzed that these interactions increase the 2–9 kHz current harmonics at an ASD when the other ASDs operate at different load values. [ABSTRACT FROM AUTHOR]

A switching capacitor-based boost converter topological evolution is proposed in this article. Switching capacitor with dual-switch configuration is the basis for the topological evolution with common ground feature. The topologies evolved are capable of yielding high-voltage transformation ratio at smaller duty ratios like in Z-source dc–dc converter topologies. The front-end structure provides a voltage gain of 1/(1 − 2D) while the upstream circuit structure is compatible for embedding the voltage multiplier cells and thus gain enhancement becomes an easier task. On this basis, four different enhanced gain boost topologies with common ground feature [dual-switch-based switching-capacitor converter (DSSCC) Type-1 and -2, and dual-switch-based switching-capacitor fourth-order converter (DSSCFO) Type-1 and -2] are introduced in this article. In all these topologies, a small adjustment in the duty cycle is sufficient enough to ensure load voltage regulation even if the input supply voltage varies over wide ranges. Among these four proposed topologies, DSSCC Type-1 and DSSCFO Type-2 exhibit low source current ripple content due to the presence of inductance at the source side. Of these two, DSSCFO Type-2 exhibits low source current ripples as well as high voltage gain at moderate duty ratios. In view of this, detailed analysis and experimental investigations are established for DSSCFO Type-2. A comprehensive comparison of the proposed topologies with other reported topologies is given, wherein they exhibit identical as well as closely following voltage gain. A 220 V, 120 W, 50 kHz prototype is constructed for performance verification. Measurement results are provided to demonstrate the enhanced gain boosting along with low source current ripple features. [ABSTRACT FROM AUTHOR]