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Switched capacitor multilevel inverters with low input DC voltage sources and voltage boost capability are very attractive to producing a high voltage levels in the output. The paper introduces a modified switched capacitor multilevel inverter with voltage boost capability. The suggested topology can be extended into symmetric and asymmetric configurations. Nearest-level modulation method is employed to generate high-quality output waveforms. The presented multilevel inverter is compared with the similar configurations by considering various criteria. Finally, to confirm the operation of the suggested topology, a laboratory scale of the suggested inverter is implemented and the results are given. [ABSTRACT FROM AUTHOR]

Background and Objectives: Increasing environmental problems and challenges have led to increased use of renewable energy sources such as photovoltaic or PV system. One of the attractive research fields is power electronic converters as interfaces for renewable energy sources. Multilevel inverters can operate as such interfaces. This paper introduces modified topologies of switched-capacitor multilevel inverters, designed to overcome constraints of low voltage renewable energy sources such as PV. Methods: Configuration of topologies utilize a single DC source with series or parallel connection of capacitors to produce 7-level, 9-level, and 11-level voltage in the converter load side. The paper presents the converter operation principle, elements voltage stress analysis, and capacitor sizing calculations. Also, operation analysis of suggested inverter topologies is validated using implemented set up. Results: Comprehensive comparative analysis reveals that the proposed topologies have merits and superior performance compared to existing solutions regarding component number, voltage boost factor, and voltage stress. The experimental measurement results confirm the accuracy of multilevel output voltage waveforms and the self-balancing of capacitor voltages, as predicted by theoretical analysis. Conclusion: The suggested switched-capacitor multilevel inverters, moreover the superiority over previously presented topologies, show great potential for application in photovoltaic systems and electric vehicle battery banks. [ABSTRACT FROM AUTHOR]

This article proposes a novel 9L-switched capacitor inverter circuit with a voltage-boosting feature. The presented circuit uses fewer energy-stored capacitors, which reduces the size and cost. The conventional Active Neutral Point Clamped (ANPC) inverter output voltage is half of the input voltage, i.e. dc-link voltage requirement is double the output voltage which leads to several challenges such as high dc-link capacitor size and voltage ratings, front-end DC-DC boost converter, etc. These issues are eliminated in the proposed topology due to boosting features, but a soft-charging method is required to suppress the inrush current. A detailed comparison between the proposed and existing SC-based 9L- inverter is presented. To validate the proposed circuit, the simulation is carried out using MATLAB/Simulink tool and the same is verified in a prototype setup for 0.8 kW and its efficiency is 97.02% which is superior than the other topologies relating to this research work.

This paper introduces a novel Multi-Level Inverter (MLI) design which utilizes a single input and leverages capacitor voltages source to generate a four-fold increase in output voltage as the main problem that stays with the inverters is their low boost ability and efficiency while maintaining power quality at the same time. One capacitor is charged to match the input voltage magnitude, while the other two capacitors store twice this magnitude. Through a series-parallel combination with switching operations, all capacitors are effectively charged and discharged within each cycle, ensuring natural voltage balance. A comprehensive comparative analysis is conducted to highlight the advantages of this innovative approach, particularly in terms of component reduction and mitigation of voltage stress. Detailed assessment of power losses within the proposed circuit is undertaken, simulation studies are first carried out while extensive experimentation verifies its operational efficiency under diverse conditions such as varying modulation indices, loads, and supply-side fluctuations with an impressive maximum efficiency of 96.9 % at a 200 W power rating, our research contributes to advancing compact power converters, addressing crucial challenges in modern power electronics applications, and paving the way for enhanced performance and reliability in such systems.

In this paper, a novel structure of self-voltage balanced switched-capacitor-based seven-level inverter (SVB-SCSLI) is proposed for asymmetrical input energy source applications. SVB-SCSLI develops a seven-level staircase waveform with a minimum number of semiconductor devices compared to existing multilevel inverters (MLIs). The proposed converter is more suitable for the solar PV system where unequal DC voltage sources are available. The SVB-SCSLI also resolves the main difficulty of connecting many inverters in parallel to achieve staircase voltage. Besides, it attains voltage balancing capability at DC-link by holding constant capacitor voltage at every cycle. The detailed loss and steady-state analysis of the SVB-SCSLI are examined. Furthermore, the proposed converter's efficiency improves with better power quality than other topologies reported in the literature. Finally, a prototype is fabricated, and experimental results are presented to validate the feasibility of SVB-SCSLI. [ABSTRACT FROM AUTHOR]

This paper introduces a novel Multi-Level Inverter (MLI) design which utilizes a single input and leverages capacitor voltages source to generate a four-fold increase in output voltage as the main problem that stays with the inverters is their low boost ability and efficiency while maintaining power quality at the same time. One capacitor is charged to match the input voltage magnitude, while the other two capacitors store twice this magnitude. Through a series-parallel combination with switching operations, all capacitors are effectively charged and discharged within each cycle, ensuring natural voltage balance. A comprehensive comparative analysis is conducted to highlight the advantages of this innovative approach, particularly in terms of component reduction and mitigation of voltage stress. Detailed assessment of power losses within the proposed circuit is undertaken, simulation studies are first carried out while extensive experimentation verifies its operational efficiency under diverse conditions such as varying modulation indices, loads, and supply-side fluctuations with an impressive maximum efficiency of 96.9 % at a 200 W power rating, our research contributes to advancing compact power converters, addressing crucial challenges in modern power electronics applications, and paving the way for enhanced performance and reliability in such systems. [ABSTRACT FROM AUTHOR]

This work proposes, analyzes, designs, and validates superior topologies of UHGH converters that are capable of supporting extremely large conversion ratios up to ∼2000× and output voltage up to ∼4-12 kV for future mobile soft robots from an input voltage as low as the range of a 1-cell battery pack. Thus, the converter makes soft robots standalone systems that can be untethered and mobile. The extremely large voltage gain is enabled by a unique hybrid combination of a high-gain switched magnetic element (HGSME) and a capacitor-based voltage multiplier rectifier (CVMR) that, together, achieve small overall size, efficient operation, and output voltage regulation and shaping with simple duty-cycle modulation. With superior performance, power density, and compact size, the UHGH converters prove to be a promising candidate for future untethered soft robots.

ABSTRACT This paper proposes an improved single‐source switched‐capacitor inverter that can operate either as 7 or 9‐level inverter based on its capacitors' charging scenario. The proposed inverter utilizes single DC supply, two capacitors, ten switches (all unidirectional) and a single diode to provide a triple/quadruple boosting factor in its seven/nine‐level operation mode. In 7‐level (7 L) operation mode, both the capacitors are charged to identical voltage value (equal to the source voltage), but in 9‐level (9 L) mode, the capacitors are charged to different voltages. Any load type with variety of power factors can be supplied by the proposed inverter. The capacitors' impulsive charging current issue has been solved by employing compact (small‐inductor based) and low‐cost soft‐charging L‐D cells. The reliability assessments have also been performed on the proposed 7/9‐level inverter. The superiority of the proposed inverter over its similar counterparts have been verified by comprehensive comparative analysis. The experimental outcomes have also been provided to make sure of correct performance of proposed inverter.

This study presents a novel topology for a high-gain Cuk converter without isolation, leveraging switched-inductor (SL) and switched-capacitor (SC) networks tailored for renewable energy sources. Unlike traditional Cuk converters that perform negative-to-positive boost DC-DC voltage conversion, this innovative design offers a significantly enhanced voltage-boosting capacity. They evolve from the conventional Cuk converter by integrating an SL instead of the singular inductor and substituting the energy-transferring capacitor with an SC. The standout benefits of the modified Cuk converters include a remarkable voltage conversion ratio and minimized voltage stress on the primary switch, allowing a low-voltage-rated switch for greater efficiency. Comparatively, the proposed designs surpass the classical Cuk and a few modified Cuk converters in voltage gain and reduced switch voltage stress. The converter also avoids the need for transformers or coupled inductors, resulting in minimized volume, loss, and expense. The converters' operation in continuous conduction mode is rigorously analyzed in this study. After deriving all the relevant equations, they are validated against outcomes. The proposed Cuk converter topology was simulated using the MATLAB/Simulink tool, and the findings are deliberated. The performance of the proposed converter is compared with the other converters, and the proposed converter's superiority is proved through the obtained results. [ABSTRACT FROM AUTHOR]

This paper proposes a single-phase, transformer-less, seven-level inverter that utilizes eight switches, three capacitors, and two diodes to produce seven voltage levels with triple boosting ability. The availability of the common-ground point eliminates the leakage current in PV applications. The proposed Transformer-Less Triple-Boosting Seven-Level Inverter (TLTB7LI) has the ability to feed different types of loads from non-unity to unity power factors. The voltage balancing of capacitors takes place naturally without the need for auxiliary circuits and complicated control strategies. This paper investigates the appropriateness of the proposed TLTB7LI for grid-connected application. The Peak Current Controller (PCC) is employed to generate the switching pulses and regulate the active/reactive power transfer between the converter and the output, which guarantees the high quality of injected current to the output. Moreover, the operational principles, its control technique, as well as the design procedure of the key components of the proposed inverter have been presented. The superiority of the proposed inverter over existing counterparts has been verified through comparative analysis. The simulation and experimental analysis validated the proper operation of the proposed TLTB7LI. [ABSTRACT FROM AUTHOR]

Transformerless inverters have been extensively deployed in photovoltaic (PV) applications, owing to features such as high efficiency, high power quality, and low cost. However, the leakage current in such inverters due to the absence of galvanic isolation has resulted in several topological modifications. This paper introduces a single-input switched-capacitor (SC)-based multilevel inverter (MLI) that is capable of eliminating the leakage current due to its common-ground structure. Also, the proposed inverter has the capability of single-stage voltage boosting, which is essential in PV systems. The series–parallel switching facilitates the self-balancing of SCs, which, in turn, assists in voltage boosting. Moreover, the proposed MLI synthesizes a seven-level output using only eight switches. Following an in-depth analysis of the circuit operation, modulation scheme, and power losses, a detailed comparison among recently developed seven-level MLIs is carried out, which verifies the design's superiority. Extensive simulation and experimental results are presented to validate the prominent features of the seven-level MLI under dynamic operating conditions. [ABSTRACT FROM AUTHOR]

Soft robots have the potential to fundamentally change interactions between robots and the surrounding environment, and between robots and animals, and robots and humans in ways that today's hard robots are incapable of doing. However, to realize this potential, soft robot actuators require extremely high voltage supplies of more than 4 kV. The electronics that can satisfy this need currently are either too large and bulky or unable to achieve the high power efficiency required for mobile systems. To meet this challenge, this paper conceptualizes, analyzes, designs, and validates a hardware prototype of an ultra-high gain (UHG) converter that can support extremely large conversion ratios up to ∼1000× to provide up to 5 kV output voltage from an input voltage of ∼5-10 V. This converter is demonstrated to be able to drive HASEL (Hydraulically Amplified Self-Healing Electrostatic) actuators, a promising candidate to realize future soft mobile robotic fishes, from an input voltage range of a 1-cell battery pack. The circuit topology employs a unique hybrid combination of a high-gain switched magnetic element (HGSME) and a diode and capacitor-based voltage multiplier rectifier (DCVMR) to enable compact magnetic elements, efficient soft-charging in all flying capacitors, and adjustable output voltage capability with simple duty-cycle modulation. Achieving an efficiency of 78.2% at 15 W output power, while providing 3.85 kV output from 8.5 V input, the proposed UGH converter proves to be a promising candidate for future untethered soft robots.

Abstract This paper presents a new structure for switched-capacitor multilevel inverter with octuple voltage gain capability. The proposed inverter utilizes three capacitors, 13 semiconductor switches, three diodes, and an input voltage source to achieve a 17-level output voltage. The switched capacitors naturally achieve voltage balancing without the need for sensors or additional circuits, indicating the ease of control of the proposed structure. To control the inrush current of the switched capacitors, a charge limiting inductor has been utilized in the charging path of the capacitors. This not only reduces the inrush current of the capacitors and the input source current but also enables faster capacitor charging and extends their lifetime. The switches used in the proposed structure can withstand a maximum of 4 times the input voltage value or the half of the maximum output voltage, which is a significant advantage for the proposed structure. A detailed comparison with similar structures is provided to examine the advantages and disadvantages of the suggested inverter. The procedure of self-voltage balancing of the capacitors and the functional modes of the proposed topology has been explained in detail. The proposed structure is suitable for applications such as renewable energy sources transfer to load or grid. The performance of the proposed topology under different conditions is confirmed through simulation in the Matlab\Simulink software and the implementation of the laboratory sample.

Abstract Among different types of transformerless photovoltaic inverters, multi‐level inverters based on switched‐capacitors (SC) are the burning topic of recent decades due to their potential advantages, such as, single source requirement, voltage boosting capability, and high power density. However, for a seven level output voltage, a conventional SC based inverter architecture uses more than two units of SC, a large amount of power switches, which then lead to capacitor voltage balancing problems. This paper presents a seven‐level switched‐capacitor transformerless inverter (SCTI), which is structured with only two SC units, ten power switches, and a single DC source. The proposed SCTI ensures voltage boosting capability, self‐voltage balancing, and low power semiconductor losses. Apart from these, a modified sinusoidal pulse width modulation (MSPWM) is also proposed in this work, which guarantees better thermal performance and low inverter output voltage THD for the proposed SCTI. The proposed SCTI along with the MSPWM is simulated in MATLAB/Simulink and PLECS computer simulation environments. A reduced scale laboratory prototype is also built and tested to ensure the feasibility of the proposed SCTI.

This paper presents a new structure for switched-capacitor multilevel inverter with octuple voltage gain capability. The proposed inverter utilizes three capacitors, 13 semiconductor switches, three diodes, and an input voltage source to achieve a 17-level output voltage. The switched capacitors naturally achieve voltage balancing without the need for sensors or additional circuits, indicating the ease of control of the proposed structure. To control the inrush current of the switched capacitors, a charge limiting inductor has been utilized in the charging path of the capacitors. This not only reduces the inrush current of the capacitors and the input source current but also enables faster capacitor charging and extends their lifetime. The switches used in the proposed structure can withstand a maximum of 4 times the input voltage value or the half of the maximum output voltage, which is a significant advantage for the proposed structure. A detailed comparison with similar structures is provided to examine the advantages and disadvantages of the suggested inverter. The procedure of self-voltage balancing of the capacitors and the functional modes of the proposed topology has been explained in detail. The proposed structure is suitable for applications such as renewable energy sources transfer to load or grid. The performance of the proposed topology under different conditions is confirmed through simulation in the Matlab\Simulink software and the implementation of the laboratory sample. [ABSTRACT FROM AUTHOR]

Among different types of transformerless photovoltaic inverters, multi‐level inverters based on switched‐capacitors (SC) are the burning topic of recent decades due to their potential advantages, such as, single source requirement, voltage boosting capability, and high power density. However, for a seven level output voltage, a conventional SC based inverter architecture uses more than two units of SC, a large amount of power switches, which then lead to capacitor voltage balancing problems. This paper presents a seven‐level switched‐capacitor transformerless inverter (SCTI), which is structured with only two SC units, ten power switches, and a single DC source. The proposed SCTI ensures voltage boosting capability, self‐voltage balancing, and low power semiconductor losses. Apart from these, a modified sinusoidal pulse width modulation (MSPWM) is also proposed in this work, which guarantees better thermal performance and low inverter output voltage THD for the proposed SCTI. The proposed SCTI along with the MSPWM is simulated in MATLAB/Simulink and PLECS computer simulation environments. A reduced scale laboratory prototype is also built and tested to ensure the feasibility of the proposed SCTI. [ABSTRACT FROM AUTHOR]

Abstract Today, multilevel inverters are widely utilized in various applications. Reducing the number of components in the design of these converters is one of the crucial goals so that they have less volume and cost. This paper presents a single‐source structure for a multilevel switched‐capacitor inverter with voltage boost capability. The proposed structure can generate 25 sinusoidal‐like step voltage levels with a six times amplitude increase compared to the input. This converter uses only one direct current (DC) power source, 14 switches, and four capacitors. The nearest level control switching method has been used to control the converter, create voltage levels, and select the switching modes. A comprehensive comparison has been made with other recently presented structures to demonstrate the efficiency of the proposed structure. The advantages of the proposed structure include using only one DC voltage source, the ability to increase the output voltage six times compared to the input, the use of fewer power electronics components compared to the number of voltage levels, proper efficiency, self‐balancing of capacitors, and as a result, the lower cost. The performance accuracy of the proposed converter has been simulated in the MATLAB Simulink environment and then evaluated by a laboratory prototype.

A fully integrated ultra-low-power step-down DC-DC converter in 65nm is presented. The purpose of this converter is to convert battery voltage levels, in the range of 2.5-3V, to digital and mixed-signal voltage levels for low-power always-on domains. A down-conversion with a ratio of 5:1 is employed to provide a digital voltage level near the threshold voltage (Vth), which ranges from 0.55-0.6V. Higher voltage levels, such as 1.2V and 1.8V, are also made available for analog circuits. To achieve high-speed regulation at low power, an inverter-based comparator is utilized. Silicon results indicate an Efficiency-Enhancement-Factor (EEF) of 66% and a power density of 2.56 mW/mm2 at an output power of $100\mu $ W. These parameters represent the state-of-the-art for this level of power. The DC-DC converter exhibits a fast transient response, leading to minimal droops and overshoots, even for a 50pF output capacitor.

Two types of asymmetric switched-capacitor five-level single-phase DC-AC inverters are presented based on the clamping half-bridge circuit and the output half-bridge circuit. Furthermore, the switches of the two proposed circuits can be driven by half-bridge gate drivers and can be modularized. Moreover, the detailed analysis of the operation principle, design of clamping capacitor and output filter of these two inverters are presented. Finally, the feasibility and validity of the proposed structures are verified by PSIM-simulated results and experimental results using FPGA as the control kernel, respectively. [ABSTRACT FROM AUTHOR]

Today, multilevel inverters are widely utilized in various applications. Reducing the number of components in the design of these converters is one of the crucial goals so that they have less volume and cost. This paper presents a single‐source structure for a multilevel switched‐capacitor inverter with voltage boost capability. The proposed structure can generate 25 sinusoidal‐like step voltage levels with a six times amplitude increase compared to the input. This converter uses only one direct current (DC) power source, 14 switches, and four capacitors. The nearest level control switching method has been used to control the converter, create voltage levels, and select the switching modes. A comprehensive comparison has been made with other recently presented structures to demonstrate the efficiency of the proposed structure. The advantages of the proposed structure include using only one DC voltage source, the ability to increase the output voltage six times compared to the input, the use of fewer power electronics components compared to the number of voltage levels, proper efficiency, self‐balancing of capacitors, and as a result, the lower cost. The performance accuracy of the proposed converter has been simulated in the MATLAB Simulink environment and then evaluated by a laboratory prototype. [ABSTRACT FROM AUTHOR]

A feature known as high-voltage gain conversion is necessary for a number of applications, including photovoltaic (PV) connected systems, UPS, SMPS, and some inverter applications, specifically for the power processing of low-voltage renewable sources. This article makes a suggestion for an ultra-gain boost converter based on a switched-inductor switched-capacitor (SISC) network. Ultra-voltage gain (> 15) and lower voltage stresses across the switches are the main benefits of the proposed converter. Additionally, compared with other high-gain topologies, the number of components decreases. This paper presents a systematic analysis of the proposed ultra-gain boost DC–DC converter along with a comparison to other topologies that have been previously published in the literature. The simulation model confirmed that the efficiency of the proposed topology is 95.23%.

A voltage reference is indispensable in Integrated Circuits. To improve the limited linear output voltage range and energy efficiency of a voltage reference, we innovatively propose a switched-capacitor-based programmable voltage reference scheme employing inverter-based OTAs to reduce the power consumption, simultaneously using a novel Correlated Level Shifting (CLS) technique (without active overhead) to enhance the OTA's DC gain and integral gain. Experimented with SMIC 180 nm CMOS technology, a scheme-based voltage reference realizes a programable output voltage range from 266 to 995 mV at −30 to 120 °C, and the corresponding temperature coefficient (TC) ranges from 82.4 to 99.5 ppm/°C. The power consumption is 976 nW. Furthermore, comparative experiments and evaluations with other schemes have unequivocally verified the superiority of our proposed scheme, characterized by its high energy efficiency and wide output voltage range. The scheme can be suitably deployed in a multitude of novel edge-data processing systems. [ABSTRACT FROM AUTHOR]

This work proposes, analyzes, designs, and validates superior topologies of UHGH converters that are capable of supporting extremely large conversion ratios up to ∼2000× and output voltage up to ∼4–12 kV for future mobile soft robots from an input voltage as low as the range of a 1-cell battery pack. Thus, the converter makes soft robots standalone systems that can be untethered and mobile. The extremely large voltage gain is enabled by a unique hybrid combination of a high-gain switched magnetic element (HGSME) and a capacitor-based voltage multiplier rectifier (CVMR) that, together, achieve small overall size, efficient operation, and output voltage regulation and shaping with simple duty-cycle modulation. With superior performance, power density, and compact size, the UHGH converters prove to be a promising candidate for future untethered soft robots. [ABSTRACT FROM AUTHOR]

Transformerless grid-connected inverters have attained a lot of research interest in renewable energy interface applications, due to certain promising properties like greater efficiency, light weight, affordable price, and tolerable power density. Among various types of transformerless grid-tied photovoltaic (PV) inverters, multilevel inverters (MLIs) are mostly popular due to their ability to transmit reactive power, small filter size for reducing total harmonic distortion (THD) and their common-ground (CG) configuration to mitigate the detrimental leakage current due to the parasitic capacitances of the PV array. Again, among different types of MLIs for PV systems, switched-capacitor (SC) based multilevel inverter topologies are the burning topic in current decades due to their single source requirements for producing multilevel output voltage. However, for mostly used single-phase five-level inverters, most of the existing SC based topology requires at least two SCs for power conversion. In this paper, a five-level transformerless inverter based on a single SC is proposed, requiring only seven switches, no diode, a single capacitor, and one dc voltage source. The proposed transformerless MLI also has auto-boosting capability. Notably, the number of power switches operating at high frequency is limited to three, which lowers down the switching losses of the inverter. Rather than a new single SC based five-level transformerless inverter topology, a control scheme is also presented to inject a precisely regulated current into the grid that can govern both the active and reactive power support modes. In-depth comparisons between the proposed and cutting-edge MLIs are also provided. All these claims are validated through MATLAB/Simulink and PLECS computer simulation environments. A laboratory-scaled prototype is also built and tested to support the simulated claims further and validate the effectiveness and feasibility of the proposed five-level transformerless inverter topology.

In this work, two new topologies of single-phase hybrid multilevel inverters for symmetrical and asymmetrical configurations are presented for use in drives and control of electrical machines and the connection of renewable energy sources. The proposed topology uses 2 dc sources, 12 switches, 1 flying capacitor, and 3 diodes to generate boosted 13-levels and 17-levels for symmetric and asymmetric configuration, respectively. Self-voltage balancing of its capacitor voltage regardless of load type, load dynamics, or modulation index is a key advantage of the suggested design. The higher performance of proposed topologies in terms of the total number of switches, TSV, THD, switch stress, and dc sources are demonstrated by comparing those with recently published topologies. In addition, a widely employed nearest level control modulation approach is used to provide output voltage levels with low THD. Finally, experiments were undertaken to validate the performance of the suggested topology.

This paper introduces a new topology of three-level quasi-switched boost F-type inverter (3L-qSBFTI) to improve voltage gain compared to traditional impedance-source inverters (ISIs). This topology uses a switched-capacitor (SC) structure to increase the boost factor to twice that of traditional ISIs. Unlike any conventional SC circuits, the currents through capacitors when they are connected in parallel are limited by inductor current. Hence, there is no inrush current through capacitors and semiconductor devices in this operating state. Furthermore, this SC structure helps to obtain self-balanced neutral-point-voltage. The lower-shoot-through (LST) state, which is inserted into P-type small vectors, is used to boost the DC-link voltage. This insertion helps to increase modulation index utilization. As a result, the component voltage rating of the introduced inverter is significantly improved. The comparison study, simulation, and experimental validations have been presented to verify the proposed inverter.

This paper presents a non-isolated bidirectional dc-to-dc converter (BDDC) topology employing a switched inductor switched capacitor (SISC) module. The bidirectional power flow capability aid to its application mainly in microgrids and electric vehicles. The switched inductor (SI) and switched capacitor (SC) cells in combination assist in the generation of high gain voltage without using a bulky transformer. The theoretical analysis of the proposed converter, its gain calculation, and small signal analysis are analyzed in detail. It benefits from having a wide voltage-gain range and less voltage stress across the power switches. Also, the proposed (SISC-BDDC) can operate both in boost and buck modes. Simulations are carried out for both the modes using MATLAB/Simulink platform. A 200 prototype is also developed to operate with $V_{\mathrm {in}}$ = 12 V and $V_{\mathrm {out}}$ = 160-200V. Using the dSPACE1104 control platform, the maximum efficiency of 95.25% of the converter is justified in steady and transient operating conditions.

This paper proposes an analytical model for the optimized design of a switched-capacitor programmable voltage reference (SC-PVR). This PVR topology guarantees a straightforward design, easy portability across different technology nodes, and does not require any special technology option. The developed model allows the study of the trade-offs and the a priori evaluation of the system performance. The circuit design optimization is carried out with MATLAB, and it permits SC-PVR to achieve current consumptions of few tens of nanoampere, with a voltage ripple specification of 500 μ V. An SC-PVR has been designed in 65-nm CMOS technology, with a sizing extracted by the model optimization. Transistor-level simulation results are aligned with MATLAB results and confirm that the investigated architecture is suitable for ultra low-power applications. • A model for the design of a switched-capacitor programmable voltage reference (SC-PVR) is proposed. • The model allows the study of trade-offs and a priori evaluation of system performance. • Design optimization with MATLAB permits to SC-PVR an ICC of few tens of nA and low ripple. • Transistor level design from the model confirms that SC-PVR can be ultra low-power. [ABSTRACT FROM AUTHOR]

This article proposes a single-stage, seven-level (7L), switched-capacitor-based grid-connected inverter architecture with a common ground feature. This topology has the ability to boost the output voltage up to three times the input voltage. The proposed topology can diminish the leakage current in grid-connected photovoltaic (GC-PV) applications, and its capacitor voltages are self-balanced without any additional control strategies. The different operating modes are described in detail with their related mathematical expressions. The design of passive components and a detailed power loss analysis are presented. The merits of the proposed structure are demonstrated using a detailed comparative assessment. The grid-connected operation of the proposed inverter structure is simulated in the MATLAB/Simulink environment, and the results are presented. The laboratory prototype of 935 W is built and analyzed to validate the performance of the proposed structure. [ABSTRACT FROM AUTHOR]

The switched-capacitor of boost seven-level active neutral-point-clamped inverter has the large voltage ripple due to its inherent long discharging interval. Aiming at reducing the switched-capacitor voltage ripple and subsequently the capacitance, this article proposes a flexible third harmonic voltage modulation method. In specific, the long discharging interval can be divided into short intervals or even avoided by flexibly regulating the amplitude and phase-angle of third harmonic voltage based on various modulation indexes and power factors. An offline particle swarm optimization algorithm is employed to find the corresponding optimal amplitude and phase-angle of third harmonic voltage, which will further be put into the online look-up table to simplify the real time implementation. Experimental results verified the performance of the proposed modulation method. [ABSTRACT FROM AUTHOR]

In switched-capacitor (SC) based multilevel inverters (MLIs), capacitors are usually replenished by a dc voltage source or other capacitors, inrush charging current are found at switching instants. In order to solve this issue, this article presents a new type of step-up MLIs, which is implemented by using a front-side quasi-Z-source unit to feed SC-based multilevel circuits. As a result, the charging current variation of capacitors is effectively limited by the quasi-Z-source impedance. Moreover, the charging voltage can be regulated by controlling the duty ratio of shoot-through states of the quasi-Z-source unit, and the total voltage gain of the new MLI is enhanced as both SC and quasi-Z-source units have boost capability. Structurally, the two units share a common switch network so that the new MLI has simple structure. Topologies for single- and three-phase configurations, operation, and modulation, as well as the parameter design are analyzed in detail. Finally, the feasibility of the new MLI is verified experimentally by a downscale three-phase prototype. [ABSTRACT FROM AUTHOR]

This paper presents research results related to the concept of a high-voltage-gain DC-DC converter with a low input current ripple. In the proposed topology, a low-volume DC-DC switch-mode boost converter operates in parallel with a switched-capacitor voltage multiplier (SCVM). The overall converter achieves a four-fold voltage gain, but the voltage stress of the transistor and the diode of the boost converter is only half of the output voltage. This is achieved by applying the specific topology of the proposed converter. Furthermore, the boost part uses a low-volume choke as it operates in the discontinuous conduction mode (DCM). The parallel operation of the boost converter and the SCVM decreases the current stress in some components of the multiplier. This paper presents a concept of the hybrid converter, an analytical model for the selection of components and switching parameters, an efficiency model, and the verification of the converter operation through simulation tests and experiments.

To use fewer components to construct a multilevel inverter (MLI) with more levels and high quality of the output voltage, a hybrid MLI is developed by combining a double-mode switched-capacitor (SC) unit with a T-type unit fed by flying capacitors (FCs). The SC unit is used to boost the amplitude of the output voltage to twice the dc input voltage, while the T-type unit is responsible for increasing the number of output levels. A total of ten transistors, four capacitors, and two diodes are used to generate 17 different levels. As two of the four capacitors are charged by a single dc source directly and the other two operate as FCs, there is no capacitor voltage ripple accumulation (CVRA) problem, resulting in high-quality output voltage. In addition to topology, a voltage balance controller of the FCs is developed to cooperate with the APOD-PWM strategy. Compared with other single-phase SC-based MLIs, the proposed inverter has a lower cost per level. Finally, to verify the feasibility of the proposed inverter, both the simulation model and experimental prototype are established. The results show that the proposed inverter has high-quality output voltage waveform and good dynamic response. The measured efficiency is above 96.5 for a wide range of loads, and the maximum value is up to 98.36.

This multilevel inverter type summarizes an output voltage of medium voltage based on a series connection of power cells employing standard configurations of low-voltage components. The main problems of cascaded switched-capacitor multilevel inverters (CSCMLIs) are the harmful reverse flowing current of inductive loads, the large number of switches, and the surge current of the capacitors. As the number of switches increases, the reliability of the inverter decreases. To address these issues, a new CSCMLI is proposed using two modules containing asymmetric DC sources to generate 13 levels. The main novelty of the proposed configuration is the reduction of the number of switches while increasing the maximum output voltage. Despite the many similarities, the presented topology differs from similar topologies. Compared to similar structures, the direction of some switches is reversed, leading to a change in the direction of current flow. By incorporating the lowest number of semiconductors, it was demonstrated that the proposed inverter has the lowest cost function among similar inverters. The role of switched-capacitor inrush current in the selection of switch, diode, and DC source for inverter operation in medium and high voltage applications is presented. The inverter performance to supply the inductive loads is clarified. Comparison of the simulation and experimental results validates the effectiveness of the proposed inverter topology, showing promising potentials in photovoltaic, buildings, and domestic applications. A video demonstrating the experimental test, and all manufacturing data are attached.

High voltage gain DC-DC boost converters are widely used in grid-connected applications through integration with the Renewable Energy Sources (RESs). Photovoltaic (PV) arrays or Fuel Cells (FCs) generate a limited value of the DC voltages and then for high power and high voltage applications, at the first stage, these voltages should be increased. This study presents a high gain, single-switched, and efficient DC-DC boost converter using the switched-capacitor and switched-inductor cells. These blocks easily can enhance the voltage and present an input current with the least values of the ripples. This will be done through replacing the location of the input inductors and by applying a switched-inductor block. Magnetizing in parallel and demagnetizing in series for the inductors present the smaller input current stresses. A single switch is used for the proposed boost converter that directly decreases the complexity of the control circuit for obtaining a fixed DC voltage at the output side for flexible input voltages or loads. More voltages will be presented by the used switched-capacitor cell simply by adding several diodes and capacitors. A deep and detailed mathematical analysis will be presented for continuous (CCM) and discontinuous conduction modes (DCM) and a 200 W laboratory-scaled prototype is presented. The results of the hardware tests confirm the correctness of the theoretical analysis and simulation results.

Multilevel inverters (MLIs) with switched-capacitor (SC) combinations are widely recognized to improve the power quality and efficiency of the renewable energy and high-frequency power distribution systems. Self-balancing of SCs and voltage boosting ability are the salient features of the recently developed SC MLIs. This work presents a new SC MLI structure using a reduced number of switches and two dc sources. For increasing the voltage levels, the basic units of the proposed MLI can be extended without increasing the number of dc sources. By suitable charging-discharging patterns, the SCs are self-balanced and voltage boosting is achieved. Comparative analysis with prior-art MLIs demonstrates the merit of topological advancement. Further, extensive simulation and experimental results confirm the feasibility of the proposed MLI under different loading and dynamic operating conditions.

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

This paper demonstrates a high-efficiency modular multilevel resonant DC-DC converter (MMRC) with zero-voltage switching (ZVS) capability. In order to minimize the conduction loss in the converter, optimizing the root-mean-square (RMS) current flowing through switching devices is considered an effective approach. The analysis of circuit configuration and operating principle show that the RMS value of the current flowing through switching devices is closely related to the factors such as the resonant tank parameters, switching frequency, converter output voltage and current, etc. A quantitative analysis that considers all these factors has been performed to evaluate the RMS current of all the components in the circuit. When the circuit parameters are carefully designed, the switch current waveform can be close to the square waveform, which has a low RMS value and results in low conduction loss. And a design example based on the theoretical analysis is presented to show the design procedures of the presented converter. A 600 W 48 V-to-12 V prototype is built with the parameters obtained from the design example section. Simulation and experiments have been performed to verify the high-efficiency feature of the designed converter. The measured converter peak efficiency reaches 99.55% when it operates at 200 kHz. And its power density can be as high as 795 W/in3.

High-voltage and efficient power converter topologies equipped with the simple and practical controller circuits are necessary, especially for integration between the low-power and low-voltage renewable energy sources (RESs) like the photovoltaic (PV) arrays and the grid. These converters can be used widely in electrical vehicles (EVs) or charging stations, aquatic, medical, transportation application and other cases. This study proposes a switched capacitor (SC)-based quadratic boost converter (QBC) structure that provides high-voltage gain at low duty cycles equipped with the fuzzy logic control (FLC) technique. The output gain of the proposed converter is higher than a second-order step-up converter or a conventional QB circuit thanks to the presented switched-capacitor topology and the manipulation of the switches in conventional QBC. By using the second switch to the conventional QBC, the voltage stress across the main power switch will decrease that enhance the reliability and long-life of the converter. Since the SC block acts as an intermediate layer between the QB and load through the capacitors and diodes of this block, the voltage and current stresses of the power switches and diodes on the QB side are less than stresses for semiconductors for classical QB and boost converter. In this study, the proposed QBC and controller system are analyzed mathematically in detail and in MATLAB/SIMULINK environment. A 200 W prototype was developed in the laboratory to validate the proposed converter and computerized analysis. Finally, the theoretical and experimental results were compared and verified. [ABSTRACT FROM AUTHOR]

Nonisolated high-voltage gain soft-switching dc–dc converter is an ideal candidate for distributed generation system converters. This article proposes a high-voltage gain soft switching quasi-Z-source dc–dc converter. The converter integrates a coupled inductor and switched capacitor into a quasi-Z-source network. Soft switching is achieved for all active devices in the converter by controlling the auxiliary switch Sa. By inheriting the advantages of the quasi-Z-source network and coupled-inductor/switched-capacitor, the converter has high voltage gain, high efficiency, low input current ripple, low voltage spike of main switch, and common ground. In addition, the efficiency of the converter is improved by recycling the energy of leakage inductance, resulting from an inherent active clamp of the main switch. The steady-state operation, voltage relationship, current/voltage stress, and power dissipation of each component of the converter have been analyzed and derived in detail. The properties of the proposed converter are verified by designing a 200 W prototype in the laboratory. When the input voltage is 48 V and the output voltage is 380 V, the converter efficiency reaches 96.92%, while the efficiency is 93% in a hard switching. The key waveforms of the converter obtained from the experiment agree well with the theoretical analysis results. [ABSTRACT FROM AUTHOR]

In this article, high step-down dc–dc converters are widely employed in data center applications. Due to the higher step-down conversion ratio in the new generation 48 V voltage regulator module, a conventional buck converter is not suitable for such applications. To conquer this problem, a novel dc–dc converter is proposed in this article to achieve an ultrahigh step-down voltage conversion ratio for data centers. The nonisolated topology can be optimally designed to integrate both the switched-capacitor and coupled inductor techniques, which allows zero-voltage-switching (ZVS) of all active switches to be achieved and improves high efficiency. In addition, the converter presents the advantages of lower voltage stress, ultrahigh voltage gain, common ground, and simple control strategy. A comprehensive analysis of the steady-state analysis, derivation of voltage gain, voltage stress, and ZVS condition is presented in detail. Finally, a 30 W, 48-to-1 V experimental prototype is built and tested, which validates the ultrahigh step-down voltage gain and soft-switching characteristic of the proposed converter. The maximum efficiency of the prototype is 89.1% and the efficiency is 81.4% in full-load condition. [ABSTRACT FROM AUTHOR]

A cost-effective three-phase triple-gain switched-capacitor (SC) inverter topology is proposed in this paper. The proposed topology structural design comprises a single source and can generate a seven-level line-to-line output voltage waveform with minimum switching components. The proposed topology comprises a pair of switched capacitors per phase leg with an inherent capacitor voltage balancing property. Structural description, operation principle, power losses analysis, and level shift-pulse width modulation strategy have been described. A fair comparative study has been presented to prove the merits of the proposed work with the recent topologies. The simulation and experimental results demonstrate the feasibility and verification of the proposed topology. [ABSTRACT FROM AUTHOR]

DC-DC converters are widely applied in different industrials such the Renewable Energy Sources (RESs) utilizations, Electrical Vehicle (EV) applications and power transmission technologies. Different topologies are presented for these converters including the modified Buck, Boost or Buck-Boost converters, switched-inductors and switched-capacitor-based structures and circuits with transformers. A DC-DC converter is needed to transmit and make the voltage applicable to the grid or home applications to use the different levels of the generated voltage by different voltage sources. In this study, a switched-inductor-based converter is presented to operate in low or high-power utilizations. One application of the proposed converter is aiming to supply the necessary voltages to the devices requiring low voltage, such as mobile phones and computers, and transmit the obtained voltage to the electricity grids that can be categorized at the high-voltage applications. Based on the load voltages level, there is a need to obtain a high-gain converter, which can operate as a buck and boost converter. Since electrical energy must be transmitted as lossless as possible, the converter must be highly efficient. In the proposed converter, the number of the components are optimized and only one power switch is used. The main advantage of the converter is that it can be controlled simply since it contains only one power switch. Also, three diodes are used in the proposed structure that only one of them is activated at the time intervals that the switch is on ON-state and the other two diodes are activated for the OFF-state of the switch. All these features can help for obtaining smaller dynamic and switching losses through the power transmission process. Both inductors are charged in the ON-state and discharged in the OFF-state operational modes that can guarantee a Continuous Conduction Mode (CCM) working conditions for the converter. Also, a capacitor is used to transfer the voltage between the input and output sides during the switching process.

A nonisolated bidirectional dc–dc converter is proposed for energy storage systems in this article. The proposed converter is composed of three active switches, two synchronous rectifiers, two clamping capacitors, and two inductors. The proposed converter has advantages of being a simple structure, a fewer number of components, a common ground, lower voltage stress, and wide voltage gain range. Compared with the conventional buck converters, the novel converter triples the effective duty cycle and lowers voltage stresses across the active switches. A 300-W/500-kHz GaN-based experimental prototype is built and tested to verify the correctness and validity, demonstrating a peak efficiency of 94.54% in step-down mode and a peak efficiency of 94.88% in step-up mode. [ABSTRACT FROM AUTHOR]

The reset noise sampling feedforward (RNSF) technique is proposed in this paper to reduce the noise floor of the readout circuit for micro-electromechanically systems (MEMS) capacitive accelerometer. Because of the technology-imposed size restriction on the sensing element, the sensing capacitance and the capacitance variation are reduced to the femto-farad level. As a result, the reset noise from the parasitic capacitance, which is pico-farad level, becomes significant. In this work, the RNSF technique focuses on the suppression of the parasitic-capacitance-induced noise, thereby improving the noise performance of MEMS capacitive accelerometer. The simulation results show that the RNSF technique effectively suppresses the thermal noise from the parasitic capacitance. Compared with the traditional readout circuit, the noise floor of the readout circuit with the RNSF technique is reduced by 9 dBV. The presented circuit based on the RNSF technique is fabricated by a commercial 0.18- μ m BCD process and tested with a femto-farad MEMS capacitive accelerometer. The physical measurement results show that, compared with the readout circuit without the RNSF technique, the RNSF technique reduces the noise floor of the readout circuit for MEMS capacitive accelerometer from −72 dBV to −80 dBV. Compared with other similar works, the proposed readout circuit achieves better F o M   (F o M = (p o w e r × n o i s e   f l o o r) / s y s t e m   b a n d w i d t h = 490   μ W · μ g / Hz) among the switched-capacitor readout circuits. [ABSTRACT FROM AUTHOR]

This work demonstrates a RISC-V vector microprocessor implemented in 28 nm FDSOI with fully integrated simultaneous-switching switched-capacitor DC-DC (SC DC-DC) converters and adaptive clocking that generates four on-chip voltages between 0.45 and 1 V using only 1.0 V core and 1.8 V IO voltage inputs. The converters achieve high efficiency at the system level by switching simultaneously to avoid charge-sharing losses and by using an adaptive clock to maximize performance for the resulting voltage ripple. Details about the implementation of the DC-DC switches, DC-DC controller, and adaptive clock are provided, and the sources of conversion loss are analyzed based on measured results. This system pushes the capabilities of dynamic voltage scaling by enabling fast transitions (20 ns), simple packaging (no off-chip passives), low area overhead (16%), high conversion efficiency (80%-86%), and high energy efficiency (26.2 DP GFLOPS/W) for mobile devices.

This work demonstrates a RISC-V vector microprocessor implemented in 28 nm FDSOI with fully integrated simultaneous-switching switched-capacitor DC-DC (SC DC-DC) converters and adaptive clocking that generates four on-chip voltages between 0.45 and 1 V using only 1.0 V core and 1.8 V IO voltage inputs. The converters achieve high efficiency at the system level by switching simultaneously to avoid charge-sharing losses and by using an adaptive clock to maximize performance for the resulting voltage ripple. Details about the implementation of the DC-DC switches, DC-DC controller, and adaptive clock are provided, and the sources of conversion loss are analyzed based on measured results. This system pushes the capabilities of dynamic voltage scaling by enabling fast transitions (20 ns), simple packaging (no off-chip passives), low area overhead (16%), high conversion efficiency (80%-86%), and high energy efficiency (26.2 DP GFLOPS/W) for mobile devices.