Showing papers on "Voltage multiplier published in 2023"

A New High Efficiency High Step-Up DC/DC Converter for Renewable Energy Applications

Abstract: This article introduces a new nonisolated soft-switching coupled-inductor (CI) step-up dc/dc converter. The presented topology utilizes a three-winding CI (TWCI) along with a voltage multiplier circuit to increase the voltage conversion ratio without needing a high duty cycle. Using this circuit, a high voltage gain can be achieved without requiring a large number of turns ratio in the CI. The input current ripple of the introduced converter is very low, which is very desirable for renewable energy sources applications. The TWCI also creates an additional design freedom to increase the voltage gain, which indicates more circuit flexibility. Additionally, the voltage stress across the single power switch is limited with the help of a regenerative clamp capacitor. The leakage inductor of the CI is used to create a resonant tank to reduce power losses further. The leakage inductances help provide the zero-current switching conditions for the single power switch and decrease the reverse-recovery issues for all diodes, leading to an efficiency improvement. The operation principle, steady-state analysis, and design considerations are discussed thoroughly. Finally, the theoretical analysis is validated through experimental results obtained from a 200 W prototype with 250 V output voltage.

Coupled Inductor-Based Single-Switch Quadratic High Step-Up DC–DC Converters With Reduced Voltage Stress on Switch

Abstract: In this article, two single-switch quadratic boost converters based on a three-winding coupled inductor (CI) are proposed. These converters provide a high voltage gain in a low duty cycle, reduced voltage stress on the power switch, continuous input current with a low di/dt, higher design flexibility, and limited current falling rate on the voltage multiplier diodes to minimize the reverse recovery loss. Moreover, the first proposed converter has two capacitors in the output reducing the need for a bulky output capacitor, while the second proposed converter has higher utilization of the CI and is able to provide a higher voltage gain. The operation principle and theoretical analysis, such as voltage stress, current stress, effect of leakage inductances on the voltage gain, and design considerations are presented in this article. Furthermore, the superiority of the proposed converters over the competitive high step-up quadratic converters are justified through a comparison study. Finally, a 300-W, 30- to 400-V laboratory experimental setup is implemented to validate the theoretical analysis.

Unidirectional Step-Up DC–DC Converter Based on Interleaved Phases, Coupled Inductors, Built-In Transformer, and Voltage Multiplier Cells

Abstract: This article proposes a unidirectional high step-up dc–dc converter. The study approaches principle of operation, analysis, guide design, and experimental validation. The high-voltage gain is reached using coupled inductors and voltage multiplier cells (VMC). An interleaved structure of two phases is employed to provide a low-current ripple in the input side. The current balance between the phases occurs due to the insertion of a built-in transformer, which also contributes to increasing the voltage gain. The energy from the leakage inductances is reused, reducing voltage spikes across the semiconductors. Additionally, the proposed converter provides an input–output common ground, which is a requirement for many applications. To verify the proposed converter, a 1-kW prototype, 48–800 V, and 16.67 of voltage gain, was designed and tested. The maximum peak efficiency reached was 94.89% and the rated power efficiency was 93.86%.

High Step-Up SEPIC-Based Trans-Inverse DC–DC Converter With Quasi-Resonance Operation for Renewable Energy Applications

Abstract: This article proposes a new single switch trans-inverse high step-up converter applicable in sustainable sources of energies such as photovoltaic (PV) and fuel cell (FC). Through developing a single-ended primary-inductor converter by a three-winding built-in transformer (BIT) mixed with a switched-capacitor voltage multiplier cell, high voltage gains as well as low voltage stress across the mosfet can be achieved to reduce the required duty cycle and the conduction losses. The third winding of the BIT acts in a trans-inverse manner whose turns ratio should be lower than unity. Hence, with a lower number of windings the voltage gain can also be improved. Furthermore, the quasi-resonance operation of the proposed converter, reduces the associated switching losses of the mosfet and also guarantees zero current switching of diodes through the whole switching cycle. Meanwhile, low input current of the proposed converter serves as an interesting feature to maintain PV and FC lifetime. The detailed steady-state analysis of the proposed high-efficiency converter is presented with an extensive performance comparison to explore its advantages. Finally, a 200-W prototype with 20–250-V voltage conversion is developed in the laboratory to examine the carried steady-state analysis.

A Novel Non-Isolated High-Gain Non-Inverting Interleaved DC–DC Converter

Abstract: High-gain DC–DC converters are being drastically utilized in renewable energy generation systems, such as photovoltaic (PV) and fuel cells (FC). Renewable energy sources (RES) persist with low-level output voltage; therefore, high-gain DC–DC converters are essentially integrated with RES for satisfactory performance. This paper proposes a non-isolated high-gain non-inverting interleaved DC–DC boost converter. The proposed DC–DC converter topology is comprised of two inductors and these are charging and discharging in series and parallel circuit configurations. The voltage multiplier technique is being utilized to produce high gain. The proposed topology is designed to operate in three modes of operation. Three switches are operated utilizing two distinct duty ratios to avoid the extreme duty ratio while having high voltage gain. Owing to its intelligent design, the voltage stress on the switches is also significantly reduced where the maximum stress is only 50% of the output voltage. The proposed converter’s steady-state analysis with two distinct duty ratios is thoroughly explored. Furthermore, a 160 W 20/400 V prototype is developed for performance analysis and validation. The converter topology can generate output voltage with a very high voltage gain of 20, which is verified by the prototype. Moreover, a high efficiency of 93.2% is attained by the proposed converter’s hardware prototype.

Analysis and Design of a New High Voltage Gain Interleaved DC–DC Converter with Three-Winding Coupled Inductors for Renewable Energy Systems

Abstract: In this article, a new non-isolated interleaved DC–DC converter is proposed to provide a high voltage conversion ratio in renewable energy systems. The converter configuration is composed of a two-phase interleaved boost converter integrating a voltage-lift capacitor and three-winding coupled inductor-based voltage multiplier modules to achieve high step-up voltage conversion and reduce voltage stresses on the semiconductors (switches and diodes). The converter can achieve a high voltage conversion ratio when working at a proper duty ratio. The voltage stresses on the switches are significantly lower than the output voltage, which enables engineers to adopt low-voltage-rating MOSFETs with low on-state resistance. The switches can turn on under zero-current switching (ZCS) conditions because of the leakage inductor series reducing switching losses. Some diodes can naturally turn off under ZCS conditions to alleviate the reverse–recovery issue and to reduce reverse–recovery losses. The input current has small ripples due to the interleaved operation. The leakage inductor energy is recycled and voltage spikes on the switches are avoided. The proposed converter is suitable for applications in which high voltage gain, high efficiency and high power are required. The principle of operation, steady-state analysis and design considerations of the proposed converter are described in detail. In addition, a closed-loop controller is designed to reduce the effect of input voltage fluctuation and load change on the output voltage. Finally, a 1000 W laboratory prototype is built and tested. The theoretical analysis and the performance of the proposed converter were validated by the experimental results.

Three-Terminal Gain Cells Based on Coupled Inductor and Voltage Multiplers for High Step-Up Conversion

Abstract: A generalized methodology for creating gain cells with three terminals is proposed in this brief. The gain cells are based on inductor coupling and voltage multiplier techniques and are applied to the classical dc-dc Boost converter. When compared with conventional gain cells already described in the literature, the proposed ones are able to provide higher step-up gains with the same number of components. Additionally, they also require lower magnetizing inductances to ensure their operation in continuous-conduction mode, which may reduce the volumes of the coupled inductors. To illustrate the application of the proposed gain cells, an example of high step-up dc-dc converter is created and its operation principle is analyzed. A 200-W prototype concerning to this converter is built and tested, validating the proposal.

A Novel High-Voltage Gain Step-Up DC–DC Converter with Maximum Power Point Tracker for Solar Photovoltaic Systems

Abstract: In order to generate electricity from solar PV modules, this study proposed a novel high-voltage gain step-up (HVGSU) DC–DC converter for solar photovoltaic system operation with a maximum power point (MPP) tracker. The PV array can supply power to the load via a DC–DC converter, increasing the output voltage. Due to the stochastic nature of solar energy, PV arrays must use the MPPT control approach to function at the MPP. This study suggests a novel HVGSU converter that uses the primary boost conversion cell and combines switched capacitors and voltage multiplier cells. The proposed topology is upgradeable for high-voltage gain step-up and can be incorporated as well. A clamp circuit reuses the energy that leaks out so that the switch voltage stress and power loss are kept to a minimum. One thing that makes it stand out is that the voltage stress on the diodes and switch stays low and constant even as the duty cycle changes. Additionally, the inductor greatly reduces the diodes’ reverse recovery losses. There is a lot of information about steady-state analyses, operation principles, and design guidelines. A prototype circuit is built to test the maximum power point tracking operation with voltage conversion from 20–40 V to 380 V at 150 W. The results of the experiments support the theoretical analysis and claimed benefits. The proposed converter has the ability to track the maximum power point and a high conversion efficiency over a wide range of power. A weighted efficiency of 90–96% is shown by the prototype.

A High Step-Up Cost Effective DC-to-DC Topology Based on Three-Winding Coupled-Inductor

Abstract: Owing to the low voltage level that renewable energy sources like solar panels frequently provide, and limited capability of simple boost converter, need for high gain step-up dc-to-dc converters are increased. In this article a single switch high step-up dc-to-dc topology with high efficiency is developed. To obtain high voltage gain, the described step-up dc-to-dc topology employs three windings coupled inductor and voltage multiplier cell method. To get the high voltage gain, this innovative converter does not require to work at a high duty cycle state by increasing the turns ratio of the coupled inductor. The suggested converter's working modes and theoretical model are investigated, and finally, a prototype setup is used to verify the theoretical and simulation analyses' correctness.

CMOS Radio Frequency Energy Harvester (RFEH) with Fully On-Chip Tunable Voltage-Booster for Wideband Sensitivity Enhancement

Abstract: Radio frequency energy harvesting (RFEH) is one form of renewable energy harvesting currently seeing widespread popularity because many wireless electronic devices can coordinate their communications via RFEH, especially in CMOS technology. For RFEH, the sensitivity of detecting low-power ambient RF signals is the utmost priority. The voltage boosting mechanisms at the input of the RFEH are typically applied to enhance its sensitivity. However, the bandwidth in which its sensitivity is maintained is very poor. This work implements a tunable voltage boosting (TVB) mechanism fully on-chip in a 3-stage cross-coupled differential drive rectifier (CCDD). The TVB is designed with an interleaved transformer architecture where the primary winding is implemented to the rectifier, while the secondary winding is connected to a MOSFET switch that tunes the inductance of the network. The TVB enables the sensitivity of the rectifier to be maintained at 1V DC output voltage with a minimum deviation of −2 dBm across a wide bandwidth of 3 to 6 GHz of 5G New Radio frequency (5GNR) bands. A DC output voltage of 1 V and a peak PCE of 83% at 3 GHz for −23 dBm input power are achieved. A PCE of more than 50% can be maintained at the sensitivity point of 1 V with the aid of TVB. The proposed CCDD-TVB mechanism enables the CMOS RFEH to be operated for wideband applications with optimum sensitivity, DC output voltage, and efficiency.

Development of 80-kW High-Voltage Power Supply for X-ray Generator

Abstract: This article describes the development of an 80-kW high-voltage power supply (HVPS) to drive an X-ray tube. Since the developed HVPS is based on an LCC resonant converter with a symmetrical bipolar voltage multiplier (SBVM), it shows many superior features such as soft switching capability and low voltage imbalance among stages. In addition, the proposed circuit has high power density because a series resonant capacitor is removed by using a method converting the SBVM into capacitors and the full-wave rectifier. Furthermore, a suggested transformer achieves high insulation performance and effective winding area utilization by applying half of the output voltage to the core. The detailed design based on the fundamental harmonic approximation is presented for the practical use of the LCC resonant converter with the SBVM in high voltage and high power applications. Also, some significant issues in the implementation are addressed. The performance of the developed HVPS is verified by simulations and experimental results.

ZVS–ZCS High Step-Up/Step-Down Isolated Bidirectional DC–DC Converter for DC Microgrid

Abstract: A soft-switched isolated bidirectional dc–dc converter is proposed for distributed generation systems. Dual coupled inductor-based flyback energy conversion circuit achieves high-voltage step-up/down ratio and high efficiency at lowered duty cycle and, attributes the galvanic isolation. Active switch-based capacitor multiplier cell appreciably reduces voltage stresses on low-voltage (LV) and high-voltage (HV) stage mosfets , thereby allowing LV rating devices (small $R_{ds(ON)}$ ). Active-voltage-clamping type circuit extensively suppresses the voltage spikes across LV-switches caused by leakage inductance. Indeed, this clamp circuitry is formed without any additional switches/diodes, thus, reduces clamp device count. By availing of quasi-resonance, thus, without needing the HV stage snubber, switching voltage spikes are substantially alleviated. Furthermore, this clamp along with quasi-resonance achieves zero-voltage (ZVS) and zero-current (ZCS) switching, over wide-load range, for all switches in both step-up and step-down operations. Reduced voltage stresses, minimized clamp device count, diminished conduction losses, and bidirectional soft-switching performance collectively enhances the efficiency. A 600-W laboratory built set-up working at 75 kHz verifies the viability of the design concept. Measured peak efficiencies in boost and buck stages are 96.65% and 96.58%, respectively.

Dynamic Neural-based Model Predictive Voltage Controller for an Interleaved Boost Converter with Adaptive Constraint Tuning

Abstract: in recent years, interleaved current-fed boost dc converters consisting of a voltage multiplier and an active clamp circuit have been interested because of their good features like low input currents, and output voltages ripple high voltage-gains. Then developing more effective modeling and control techniques is important to increase their performance. In modeling section, it has been tried to estimate system model using the real data and dynamic neural networks with reducing number of variables. In control section there are constraints on control signal and its changing rate and in the proposed dynamic neural-based model predictive control (NMPC) controller, control signal changes constraint has been calculated adaptively. The proposed NMPC has been applied on system in online form and experimental results have been compared to the basic NMPC and a PI controllers. The output voltage have been specified for two loads with different input voltage. The experimental results show that their current transient response has smaller current peak and output voltage has smaller overshoot when load and voltage change. Output voltage steady-state response also has smaller oscillations about 2 volts for using proposed NMPC.

Performance Analysis of Low Power Radio Frequency Micro Energy Harvester using MEMS Antenna for Wireless Sensor Networks

Abstract: Recently, there has been a growing tendency of interest from researchers to use ambient energy to power electronic equipment using various energy harvesting techniques. Micro energy harvesting is a potential technique to convert ambient energy from the environment to electrical energy. The wireless sensor network requires a constant source of electrical energy to activate it and the radio frequency (RF) ambient energy source that always exists in the environment is very suitable for use. Therefore, the designed and developed RF micro energy harvester consisting of an impedance matching circuit, a voltage multiplier and a rectifier circuit does not require an external energy source to activate it. This RF micro energy harvester circuit is constructed and simulated using PSPICE software by connecting a 1 MΩ load resistor. At an input power of -20 dBm or 10 μW captured by the MEMS antenna, the values of the output voltage and current produced in this energy harvester circuit are 2.36 V and 1.7 mA, respectively. Meanwhile, the maximum efficiency percentage of the entire RF micro energy harvester circuit is 55.7%. The output power value of 40.12 mW is higher than the input power value of 10 μW. This RF micro energy harvester is capable of activating a wireless sensor network with a minimum input current requirement of 1 mA. An integrated circuit layout using 180 nm CMOS technology for a multiplier circuit has been successfully developed with a very small size of 22.48 x 56.96 μm2 as proof that the circuit can be fabricated as an integrated circuit chip.

A modified configuration of high step‐up non‐isolated DC‐DC converter with low voltage stress: Analysis, design, and implementation

Abstract: This study develops a novel DC-DC converter with an extremely high voltage conversion ratio that utilizes just one switch, a voltage multiplier circuit (VMC), and a coupled-inductor. Two diodes and two capacitors comprise the VMC, employed to reach high voltage gain. Consequently, the conduction loss is minimized by using a low voltage rated switch with lower RDS(on). Due to the coupled inductor's leakage inductance, the output diodes' reverse recovery trouble is solved. Moreover, the passive clamp technique stores and recycles leakage energy at the output. The proposed DC-DC converter features are high conversion ratio, low maximum voltage on semiconductors, remarkable efficiency, the existence of only one active low voltage switch, and simple circuit topology with common ground between the input and the output. This paper outlines CCM, BCM, and DCM's operating concept and steady-state analysis in great detail. Furthermore, the suggested structure's capability is indicated by mathematical analysis and comparative findings with other earlier structures. Eventually, experimental findings with 210 W output power and 25 kHz switching frequency demonstrates that the proposed converter can be used successfully.

WPT-Based Voltage Equalizer for Scalable Cell-String Charging

Abstract: Wireless power transfer (WPT)-based voltage equalizer (VE) shows unique advantages due to its physical isolation. Meanwhile, the markets of high-power fast charging have imposed significant needs for high-voltage wireless charging systems. However, a WPT-based charging equalizer cannot support a large-scale cell-string. This paper proposes a wireless charging VE with modularity to balance cascaded cell-strings automatically using multiple coils. The WPT system's intrinsic high-frequency power is used to power the voltage multiplier (VM). Only two diodes and one capacitor are required for an extra cell, which enables fewer components and a simple structure. Circuit analysis and a one-transmitter-two-receiver charging equalization experiment validate the system's operating principles. The voltage gaps among eight ultra-capacitor (UC) cells are equalized from 1.1 V to 0.01 V, with an overall efficiency of 76.5% under a 35.2 V output. Non-ideal conditions with coupling mismatch and frequency shifts are also analyzed to reveal the system's characteristics. It contributes several ways to providing general modular wireless charging equalization solutions for large-scale cell-string with lower cost and higher scalability.

Analysis and Suppression of Capacitor Voltage Ripple for Hybrid MMCs Under Boosted AC Voltage Conditions

Abstract: Capacitor voltage ripple suppression is significant for hybrid modular multilevel converters (MMCs) to reduce the capacitance, footprint and cost. However, the existing voltage ripple suppression methods are mainly intended for half-bridge submodule (HBSM)-based MMCs, and not applicable to the hybrid MMC due to its special configuration of mixed half-bridge and full-bridge submodules (FBSMs). Therefore, this article aims to reduce the capacitor voltage ripple for hybrid MMCs under boosted ac voltage conditions. The analysis of charging and discharging behaviors of FBSMs and HBSMs with boosted ac voltage is conducted first to obtain the maximum energy ripple in SM capacitors, which is equivalent to peak-to-peak value of voltage ripple. Then, the effect of modulation index and power factor angle on the capacitor voltage ripple is investigated in detail to find the possible ways to suppress the fluctuation. Consequently, the optimal modulation index that minimizes the capacitor voltage ripple is derived. Furthermore, this article proposes a circulating current injection method to suppress the capacitor voltage ripple under various operating points. In this method, the capacitor voltage ripple amplitude is taken as the direct suppression object to ensure the effect of voltage ripple minimization. Finally, the validity of the proposed method is proved under different operating conditions by simulation and experimental results.

An Extendable Voltage Multiplier Based Multi-Input DC/DC Converter with Soft-Switching Operation

Abstract: In this paper, an extendable multi-input (MI) non-isolated resonant dc-dc converter is proposed by using current-fed voltage multiplier (VM) cells for renewable energy application. The input sources have continuous currents with low ripples, which reduce the input filters volumes and costs. Furthermore, zero voltage switching (ZVS) turn on of its switches, as well as zero current switching (ZCS) of diodes, are realized and the reverse recovery problem of the diodes is effectively eliminated. By using the VM cells, the voltages stresses of the components are reduced, so low voltage-rating components can be used, which reduces conduction losses and costs and increases efficiency of the converter. Also, by increasing the number of the VM cells, voltage gain can be improved, without using extremely high duty cycles values. The given topology, its operation principles, as well as its steady-state analysis and characteristics, are discussed, in detail. Finally, the proposed converter has been designed and simulated at 1 kW output power with 50 V input voltage and 800 V output voltage to validate the given analysis and advantages of the proposed converter.

Dual-Input, Single-Output Step-Up DC/DC Power Electronic Interface for Energy Harvesting Systems

Abstract: In this paper, a new Energy Harvesting Power Electronic Interface (EHPEI) is proposed. The proposed EHPEI is suitable for low-power, low-voltage energy harvesting applications. It is a combination of two boost and also has a modular structure using a voltage multiplier cell (VMC). The output voltage can be regulated under variable inputs by tuning duty-cycles of both switches. Since the EHPEI is combined from two sources and both sources supply power to load either standalone or simultaneously together, it is beneficial to improving reliability and stability in energy harvesting applications. In addition, with implying VMC, voltage stress on switches and diodes are decreased. The operation principle and steady-state analysis of continuous conduction mode (CCM) are used to determine voltage gain. The simulation results are used to verify the performance and validity.

Advanced DC–DC converter topologies for solar energy harvesting applications: a review

Abstract: In this study, the advanced topologies of a DC–DC converter for applications involving the harvesting of solar energy are discussed. This work’s primary contribution is a guide for choosing the most effective topology for a DC–DC converter when developing solar energy collection systems. Several topologies of a DC–DC converter for solar energy harvesting applications are compared in terms of the range of power levels they can oversee, the complexity of the underlying hardware, the cost of implementation, the tracking efficiency and the overall efficiency of the converter. This article explains five innovative approaches for adapting boost converters to function as standard DC–DC converters to capture solar energy, consisting of (i) voltage-multiplier cell, (2) coupled inductor, (3) coupled inductor and switch capacitor, (4) cascaded topology and (5) voltage-lift technique. Because of the boost converter’s restrictions, it is necessary to deliver high performance. The comparison findings demonstrate that the voltage-lift-based boost-converter topology performs more effectively than the alternatives. In conclusion, the information presented in this paper can be utilized when developing solar energy collection systems to determine the sort of direct current to direct current converter that will be most effective.

A Novel Switched Hybrid-Voltage Doubler High Gain DC-DC Converter for Renewable Energy Applications

Abstract: In renewable energy system applications, the power converter is essential for transferring energy into the load centre. The AC network voltage is much higher than the renewable energy source voltage; therefore, a transformer is commonly used to step up the voltage. However, the size and cost of the system are larger due to the presence of a bulky transformer, and also the efficiency is deteriorated due to PWM voltage being applied to the transformer. To eliminate the requirement of the transformer, DC link voltage is boosted up to a higher level using a high-gain converter. Various DC-DC converters have been proposed in recent studies; however, the involvement of the active switches is high to produce higher voltage gain, which reduces efficiency. In order to overcome this limitation, this particular paper proposes a novel switched hybrid-voltage doubler high gain DC-DC converter, which helps to achieve higher gain with a minimum number of components count compared to other reported converters. It also reduces the device's stress, thereby increasing its efficiency. This paper describes the detailed operational studies along with CCM and DCM modes. The mathematical analysis under each operating state is reported in this paper. A detailed comparative study on the performance merits of the proposed converter, along with other recently reported converters, is presented. Finally, the simulation results are presented to validate the operation of the proposed converter. Furthermore, a 500 W laboratory setup is developed to verify the operation details and practical feasibility of the converter through experimental results and presented in this paper. From the measured results, it is concluded that the proposed converter can play the most promising role in the transmission phase in renewable energy system implementations since it boosts the voltage to the adequate point as required by the system.

Design high voltage gain DC converter based on maximum power point resistance for photovoltaic applications

Abstract: Due to the nonlinear properties of photovoltaic (PV) modules, the design of the high-gain direct current (DC) converter for maximum power point tracking (MPPT) is complicated. In this paper, the design of a new step-up DC converter for MPPT applications is proposed. The proposed converter is structured of two symmetrical reverse-parallel DC-DC boost converters. This structure is supported by voltage multiplier cells equipped to increase output voltage and decrease voltage stress on semiconductor switches. To simplify the high-gain DC converter design, the PV module's maximum power point is treated as resistance by using the incremental conductance (INC) method. The MPPT boost converter's inductance, input capacitance, and output capacitance are calculated using the derived equations using nine parameters. The results showed that the proposed DC converter simulation meets the necessary requirements. The size of the input capacitor, inductor, and output capacitor have been decreased. When the proposed converter is compared to a traditional converter, there is less voltage stress, low current ripple, and an increase in voltage gain. This has led to an improvement in the overall converter efficiency.

A High Step-Up Resonant Converter Based on Current-Fed Voltage Multiplier Technique

Abstract: An extendable non-isolated resonant dc-dc converter based on current-fed voltage multiplier (VM) technique is proposed in this paper for high step-up applications. These VM cells capacitors participate in a resonant network; therefore, no additional elements are required to provide a resonant tank circuit to realize soft switching conditions for power switches. Zero voltage switching (ZVS) and zero current switching (ZCS) conditions are realized here for switches and diodes, respectively. Consequently, MOSFETs dominant switching losses and the diodes reverse recovery problems are well overcome. Furthermore, the input source current waveform is continuous. Also, using the VM cells reduces the power devices voltage stresses. Accordingly, low voltage rating devices can be used, which reduce conduction losses and cost, and improve the converter efficiency. Also, by using more VM cells, the proposed converter can be used for high-voltage applications, without using extremely high duty cycle values to regulate the output voltage. The operation principles, steady-state analysis, design guidelines, and main characteristics of the proposed converter are given here, in detail. Finally, an 800 W prototype converter, with 80–100V input voltage and 2 kV output voltage, has been implemented to validate the given analyses, simulation results, as well as to show the proposed converter main advantages.

High Step-Up DC–DC Converter with Quartic Voltage Gain

Abstract: This paper depicts a high gain DC–DC converter designed for PV applications. The proposed converter is synthesized to yield a voltage gain that is quartic (power of 4) times the voltage gain of a conventional boost converter (CBC). The proposed converter is synthesized in two stages. The first stage is derived from a classical interleaved boost converter (IBC) and uses a voltage-lift capacitor. In the second stage, the voltage gain is further extended by employing a cubic cell structure which is developed by using one coupled inductor along with diode-capacitor combinations. The switches in the IBC structure are operated at a duty ratio of 0.5 and 180° phase-shift to cancel out the input current ripple. The switches in stage-1 of the proposed converter are subjected to voltage stress of 9% of VO, while the third switch in stage-2 experiences voltage stress which is the same as VO. The prototype is simulated using PSIM software to verify the proposed voltage gain concept. The converter specifications are as follows: 18 V input, 400 V output, 50 kHz switching frequency, and 250W power rating. The efficiency of the prototype is 94.14%. Further, under closed-loop conditions, a regulated output voltage of 400 V is obtained.

CNTFET-based design of low power charge pump technique-based voltage multiplier

Abstract: This study presents an effective approach for designing voltage multiplier using CNTFET devices based on charge pump and low power consumption for devices used in renewable energy systems. This method has been developed analytically and evaluated using experimental measurement and the simulation through 32nm CNTFET technology. The technique allows to the designers to determine the number of stages that improves performance of the given input voltage and reduces the power consumed during conversion. In the proposed work, the applied input voltage is 97 mV, and the resultant output voltage is 1000 mV, which is almost 10 times better than the applied input voltage resulting in a highly optimum multiplier result. The power consumed for conversion is 5.631 nW, which is extremely low in contrast to earlier studies, and the produced output is significant through the use of CNTFET devices.

Maximizing Energy Harvesting in a Miniaturized Implant with an Integrated Coil Receiver

Abstract: In this work, a fully integrated energy harvester employing an on-chip coil and a voltage multiplier rectifier is proposed. The differential, multi-stage rectifier is optimized recurring to a genetic algorithm with the objective of maximize the power delivered to the load (W power transfer level) while minimizing area and start-up voltage. The rectifier is one of the most critical components in wireless-powered systems, generating a stable DC supply voltage, its efficiency is the main limiting factor in the achievable power budget. When implemented inside an implant, the circuit should occupy the minimum possible area and present a low start-up power as in the context of most applications, the amount of energy that reaches the receiver is extremely small. Simulation results show that the proposed circuit performs with an efficiency of 38% delivering a stable 1.16 V DC voltage to a 100 kΩ load, providing an output power of 14.9 W and solely occupying an area of 8750 m. Post-fabrication experimental results are presented, where a small inductive link employing a fully integrated receiver coil is used with the rectifier. A maximum power transfer of 12.5 W is achieved, with the inductive link operating at 915 MHz.

A Nonisolated Single-Switch Coupled Inductor-Based DC-DC Converter with High Voltage Gain for Renewable Power Generation Systems

Abstract: This article proposed a new structure of nonisolated high step-up DC-DC converter based on a three-winding coupled inductor and voltage multiplier cells (VMCs) for renewable energy systems applications such as PV power generation. Continuous input current with low ripple, common ground between output and input ports, low voltage stress across semiconductors, low number of components, high voltage gain, and high efficiency are the main advantages of the proposed converter. In order to further increase the output voltage, the windings of the coupled inductor are combined with VMC. The combination of coupled inductor and VMC technique leads to a high voltage gain with low duty cycle, and therefore the conduction loss of power switch is reduced. Additionally, the diodes’ reverse recovery currents are reduced which improve the presented topology’s efficiency. On the other hand, the used VMCs clamp the voltage, and the peak voltages across power switch are decreased. The operational modes, steady-state, and efficiency analysis are discussed. Also, to demonstrate the performance of the recommended converter, an experimental prototype with 580 W output power and 400 V output voltage with the switching frequency of 25 kHz is built and the experimental results are presented. Also, another 1 kW, 400 V with the switching frequency of 50 kHz has been implemented and tested.

Performance Analysis of Various Rectifier Topologies for 2.45 GHz RF Energy Harvesting Applications

Abstract: This paper aims to evaluate and compare the performance of three basic configurations of RF energy harvesting rectifier, the series, the voltage doubler, and the voltage multiplier. To achieve this goal, different parameters affecting the performance of the rectifier were analyzed in the 2.45 GHz ISM band. When the simulated series rectifier, voltage doubler and voltage multiplier are perfectly matched, a conversion efficiency of 77.18 %, 75.29 % and 66.6 % is reached, respectively, at an input power of 15 dBm. While, the DC output voltage at the same input power level is 6.5 V, 5.29 V, and 7.59 V.

Dickson voltage multiplier with 1 to 6 stages for dual-band rectifiers (2.45/5.8 GHz) with low input power

Abstract: This paper presents the design of highly efficient rectifiers that can operate at WiFi frequencies (2.45 GHz and 5.8 GHz) and match low input power. The designed dual-band rectifiers use multi-stage dickson voltage multipliers (DVM) (from 1 to 6 stages), and the main idea of this paper is to find the number of stages that offers the best performance and that can be used by applications that operate within the same constraints (operating frequencies, input power). The efficiency and the output voltage (Vout) are the parameters studied to analyze the designed rectifiers. The results showed that as the number of DVM stages increased, the efficiency curves for both frequencies shifted to the higher input power range, even when using the same diode (SMS7630) and the same load (5 KΩ). We concluded that the rectifier with 1-stage DVM is the most suitable to be used for low input power at the selected frequencies since it provides an efficiency of 57.734% at 0 dBm for 2.45 GHz and 36.225% at 1 dBm of input power for 5.8 GHz.