High DC Output Voltage Research Articles

Augmented SPWM based Hybrid Output Converter for Renewable Energy and Nano-Grid Application

This study suggests a novel Augmented Sine PWM(ASPWM) based Hybrid Output Converter that can concurrently power AC and DC loads. Two boost converters are used in this configuration, and the AC voltage is the differential voltage tapped between the two source nodes (of the MOSFETs) of the individual converters. This converter plays a different role in providing power to AC and DC loads than conventional boost converter. Conventional boost requires a minimum of two stages to step up output DC voltage and inverter stage to convert DC to AC power. This novel hybrid output converter (HOC) skips all stages of boosting the output voltage and next stage of inverter also. HOC consists of two boost converts pumped by two VM(voltage multiplier) stages to get high voltage DC output. This HOC has two inputs, supplied by renewable like solar PV cells and has two outputs to supply AC and DC loads simultaneously. This dual input HOC integrates two renewable inputs for standalone nano grid application. The principle of operation of HOC is augmented sinusoidal pulse width modulation with AC reference signal is shifted by 1800for individual boost converter and augmented by dc offset. The circuit has been extensively simulated in PSIM’22 Matlab Simulink and an experimental prototype of 110W is tested in the laboratory.

High gain coupled inductor SEPIC based boost inverter using extended SPWM

This research work designs a high gain coupled inductor SEPIC (CI-SEPIC) based boost inverter. This topology presents low switching voltage stress, high output DC and AC voltage and highly efficient system, which makes it suitable for renewable energy applications. A seventh order system is obtained through dynamic modelling of the CI-SEPIC converter for which PID controller is designed to track the reference value. The extended sine-wave pulse width modulation (ESPWM) has maintained the high gain without compromising the efficiency and ensured low voltage stress on the switching devices. Simulation and experimental results validated that CI-SEPIC based boost inverter with ESPWM achieved high dc gain of 15.98, boost factor of 25, exceptional dc-ac coupling with minimum possible capacitance of 3.3uF, decreased device stress by 33% and smaller size of the complete system.

Perancangan Dan Implementasi Half Bridge Dc – Dc Converter Dengan Kendali Arus Hysteresis

DC-DC Converter is a direct voltage (DC) power supply device that is produced by converting DC input voltage into a lower or higher DC output voltage. In its development, the application of DC-DC Converter allows an electronic device to function with a small energy source, where the output voltage can be varied as needed. DC-DC Converters have been widely developed because they have various advantages, including: simpler form and has high efficiency. In this thesis, an Arduino Mega 2560-based current controller will be implemented. The type of current controller implemented is hysteresis current control with the well-known, tested and proven considerations. Current control works if the inductor current rises from the lower limit of the hysteresis band to the upper limit then the switch will be turned off (inductor current above the upper reference Ip.Ref) and if this current drops from the upper limit to the lower limit the switch will be turned on (current inductor under low frequency Iv.Ref). This current control also has advantages in overcurrent protection such as when there is a short circuit in the load.

Modular Three-Phase Diode Rectifier With High-Frequency Isolation and Selective Harmonic Elimination Modulation

This article proposes a modular three-phase diode rectifier with high frequency isolation and selective harmonic elimination in input currents. The proposed system consists of modular ac–ac converters with 20 kHz transformer isolation on the primary side followed by a three-phase diode rectifier to produce a high quality dc output voltage. A new hybrid pulsewidth modulation scheme is proposed that combines the high frequency 20 kHz transformer operating frequency with a low frequency selective elimination of 5th, 7th, 11th, and 13th current harmonics in the 60 Hz input currents resulting in near sinusoidal waveform.Therefore, high quality input current is achieved in open loop. The secondary side consists of a three-phase diode rectifier with high quality output, suitable for ev-charging/switch mode power supplied in data centers etc. The output dc voltage is shown to be regulated via a simple duty cycle control of the high frequency (20 kHz) without affecting the harmonic elimination features in the input currents. The proposed approach is modular and can adapt to higher input voltages. Simulation results are discussed, which explore all the features of the proposed high performance ac to dc rectifier. Select results are verified experimentally on a 120 V rms line-to-line, three-phase, 1 kW laboratory prototype system. <xref ref-type="fn" rid="fn1" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">¹</xref> <fn id="fn1" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><label>¹</label> This article is the updated version of [1] and include more details about the output DC voltage regulation, the design of input (AC) and output (DC) filter, additional experimental results among other changes </fn>

Performance Analysis of a Relift Luo Converter-Derived Dual-Output DC to DC Converter for Microgrid Applications

A microgrid typically maintains multiple voltage bus bars with AC or DC or both. The various subsystems participating in the microgrid are connected to the appropriate voltage bus bars. Renewable energy sources like the wind energy or the solar photovoltaic energy may also be integrated to the microgrid. A battery-based energy storage system is also usually required. In this work, a dual-output DC to DC converter derived from the double lift or the relift Luo converter is proposed and validated. The proposed system uses a solar photovoltaic source and delivers a high-voltage DC output to deliver power to the high-voltage DC bus bar. A battery of medium voltage is connected across the second output of the dual-output converter. The proposed idea is validated using modeling and simulations in the MATLAB Simulink environment and an experimental prototype.

A high step-up DC–DC converter based on ASL and VMC for renewable energy applications

In this paper, a new high step-up non-isolated DC–DC converter has been proposed and analyzed. The proposed topology provides a high DC output voltage, which is adjustable by two different duty cycles. Moreover, low voltage stress across the power switches can be marked as another advantage of this structure. The inequality of the switches’ duty cycles helps obtain high output voltage with moderate duty cycles in this converter. Four inductors based on two magnetic cores, four capacitors, two diodes, and three switches make up the converter’s components. Operational modes of the proposed topology are investigated under steady-state analysis in continuous conduction mode (CCM), discontinuous conduction mode (DCM), and boundary condition mode (BCM). In addition, mathematical calculations of voltage, current, and efficiency are provided in this paper. In addition, a comparison study of the proposed converter and other related structures is conducted to determine the advantages it offers. The proportion of losses and efficiency calculation are analyzed. Finally, a (500 W, 50 kHz) laboratory prototype is assembled and analyzed to validate the analytical findings in this paper.

Three Port Isolated AC/DC Converter with Power Factor Correction

1: : This paper proposes a converter with three ports with isolated output and higher output power and voltage levels. The converter has two input ports, connecting an AC source and the solar PV source. The third port acts as an output port to supply the desired load. The proposed topology can supply the high dc output voltage with isolation while maintaining a high input power factor. A single-stage conversion is used, which helps in reducing the switching devices and the bulky electrolytic capacitor while integrating a Solar PV. As there is no intermediate stage of conversion in the proposed converter, thus it is well suited for the standalone PV based application such as remote light electric vehicle chargers. The simulation verification of the proposed converter is obtained in the MATLAB/SIMULINK and the experimental results are obtained using control algorithm implemented using FPGA based Typhoon HIL 402. Background: To implement the proposed novel converter and study the switching operations Objective: Conventionally, a two-stage conversion is required for providing isolated DC output Methods: Verification of control method in simulation with hardware validation Results: Justified the control method and working of topology Conclusion: The desired operation of the converter is achieved

Design of LLC resonant converter with silicon carbide MOSFET switches and nonlinear adaptive sliding controller for brushless DC motor system

Introduction. The high voltage gain DC-DC converters are increasingly used in many power electronics application systems, due to their benefits of increased voltage output, reduced noise contents, uninterrupted power supply, and ensured system reliability. Most of the existing works are highly concentrated on developing the high voltage DC-DC converter and controller topologies for goal improving the steady state response of brushless DC motor driving system and also obtain the regulated voltage with increased power density and reduced harmonics, the LLC resonant DC-DC converter is implemented with the silicon carbide MOSFET switching devices Problem. Yet, it facing the major problems of increased switching loss, conduction loss, error outputs, time consumption, and reduced efficiency. Also the existing works are mainly concentrating on improving the voltage gain, regulation, and operating performance of the power system with reduced loss of factors by using the different types of converters and controlling techniques. The goal of this work is to obtain the improved voltage gain output with reduced loss factors and harmonic distortions. Method. Because, this type of converter has the ability to generate the high gain DC output voltage fed to the brushless DC motor with reduced harmonics and loss factors. Also, the nonlinear adaptive sliding controller is implemented to generate the controlling pulses for triggering the switching components properly. For this operation, the best gain parameters are selected based on the duty cycle, feedback DC voltage and current, and gain of silicon carbide MOSFET. By using this, the controlling signals are generated and given to the converter, which helps to control the brushless DC motor with steady state error. Practical value. The simulation results of the proposed LLC silicon carbide MOSFET incorporated with nonlinear adaptive sliding controller controlling scheme are validated and compared by using various evaluation indicators.

Soft Switching Control of Power Factor Correction for Distribution System

A boost Power Factor Correction (PFC) front end converter followed by a full bridge transformer-isolated dc/dc converter is popular in offline dc power supply. In this configuration switching losses are high and overall efficiency is reduced. For solving this problem individual soft-switching techniques are required for both the converters. A dc power supply system that uses a new Zero-Voltage Switching (ZVS) strategy to get ZVS function is proposed here. A soft-switching dc power supply system with high input power factor and stable dc output voltage is presented with simple and compact configuration. The proposed circuit is not only operated at constant frequency, but all semiconductor devices are operated at soft switching without additional voltage stress. A significant reduction in the conduction losses is achieved, since the circulating current for the soft switching flows only through the auxiliary circuit and a minimum number of switching devices are involved in the circulating current path, and the rectifier in the proposed converter uses a single converter instead of the conventional configuration composed of a four-diode front-end rectifier followed by a boost converter. An average-current-mode control is employed in proposed dc power supply system to synthesize a suitable low-harmonics sinusoidal waveform for the input current.

Single switch Z source/quasi Z source DC-DC converters

&lt;span&gt;This paper analyzes a family of high step up single switch switched capacitor boost converters and Z-source/quasi Z-source dc-dc converters to provide high output dc voltage gain, a proper choice for photovoltaic applications. The operating principles, parameters design guideline of these converters are presented along with simulation results.&lt;/span&gt;

Parallel-charge series-discharge inductor-based voltage boosting technique applied to a rectifier-fed positive output DC-DC converter

The conventional power electronic boost converters have inherent limitations that they are not able to increase the low DC input voltage level into sufficiently high DC output voltage level. This is because of the fact that (1). the inductor used in the converter has certain amount of internal resistance, and (2). the power devices used in the converter are subjected to high potential stress which led to damage of the devices. A configuration of a non-isolated step-up rectifier-fed positive output power converter capable of converting low DC voltage into high DC output voltage-based on the concept of parallel-charge series-discharge inductors is proposed in this paper. The proposed converter is fed by an uncontrolled diode bridge rectifier to which an input sinusoidal AC voltage of magnitude 30 V (rms) is given. The converter is configured such that the input AC voltage of 30 V (rms) is stepped-up to around 900 V (DC) at the output of the converter, with extremely low duty ratio. The proposed converter configuration employs only two high power semiconductor switches with reduced complexity of control. In this work, the converter topology is presented, and its steady state behavior and dynamic modeling are discussed for continuous inductor current mode operation. Further, it is revealed that the voltage gain of the converter is influenced by the variation of the duty cycle of the power switches. The effectiveness of the converter is better understood through simulation in MATLAB/SIMULINK platform. The results demonstrate that the converter is able to maintain higher constant output voltage profile with significantly reduced overshoot and settling time. &#x0D; &#x0D;

Design and Model of Series-Connected High-Voltage DC Multipliers

The generation of high dc voltages is necessary for feeding many technical applications and testing the insulation material of high-voltage dc transmission lines and ac power cables with long lengths. The article proposes a modular multiplier high-voltage dc generator with integrated Cockcroft-Walton (CW) circuits. In this new topology, CW circuits are connected in series to produce a high dc output voltage with low regulation factor (<; 2%) and a negligible ripple factor without the need for costly filters to produce a nearly constant output voltage. The modules are fed by low input ac voltage sources that have the same magnitude and frequency. Numerical simulations using MATLAB/Simulink confirm the viability of the proposed generator. The generator is finally validated by experimental tests on a kV-size prototype.

5.8 GHz High-Efficiency RF-DC Converter Based on Common-Ground Multiple-Stack Structure.

This paper presents a 5.8 GHz RF–DC converter for high conversion efficiency and high output voltage based on a common-ground and multiple–stack structure. An RF isolation network (RFIN) for the multiple-stack RF–DC converter is proposed to combine the DC output voltage of each stack without separating its RF ground from the DC ground. The RFIN is designed using micro-strip transmission lines on a single-layer printed circuit board (PCB) with a common ground for the bottom plate. A 4-stack RF–DC converter based on a class-F voltage doubler for each stack was implemented to verify the proposed RFIN for the multiple-stack and common-ground structure. The performances of the implemented 4-stack RF–DC converter were evaluated in comparison to the single-stack converter that was also implemented. The size of the implemented 4-stack RF–DC converter using bare-chip Schottky diodes is 24 mm × 123 mm on a single-layer PCB. For an input power of 21 dBm for each stack of the RF–DC converter with a load resistance of 4 kΩ, a high efficiency of 73.1% and a high DC output voltage of 34.2 V were obtained.

Operating principles and practical design aspects of all SiC DC/AC/DC converter for MPPT in grid-connected PV supplies

A 20 kW, 20 kHz high frequency (HF) link maximum power point tracking (MPPT) converter for a grid-connected PV supply, based on all silicon carbide (SiC) power semiconductors, is presented. In the developed converter, SiC power MOSFETs are used in the low-voltage PV panel side and SiC Schottky diodes on the high-voltage DC output, in order to maximize the power conversion efficiency and the power density. Operating principles of the resulting dual H-bridge MPPT converter and the practical aspects of the converter design and its circuit layout, are described in detail. The implemented converter performance is compared with that of a classical Si-IGBT and hybrid-IGBT based MPPT converter in terms of efficiency. This configuration can compete with the non-isolated MPPT converter topologies, such as the boost converter commonly used in grid-connected PV systems, since it allows the possibility of using a conventional two-level, three-phase grid-connected inverter. This is due to the enhanced common-mode EMI performance as compared to non-isolated MPPT topologies, resulting in a competitive high efficiency PV converter design with galvanic isolation. It has been shown that the converter size can be shrinked up to a power density of 1.6 kW/lt, with a DC-DC converter full-load efficiency of 98%. The resulting compact and highly efficient SiC power MOSFET based HF link MPPT converter is suggested to be a part of grid-connected, multi-string PV supplies with simple inverter topologies in the future.

The Design of Operational Amplifier for Low Voltage and Low Current Sound Energy Harvesting System

The objective of this paper is to design a combination of an operational amplifier (op-amp) with a rectifier used in an alternate current (ac) to direct current (dc) power conversion. The op-amp was designed to specifically work at low voltage and low current for a sound energy harvesting system. The goal of the op-amp design with adjustable gain was to control output voltage based on the objectives of the experiment conducted. The op-amp was designed for minimum power dissipation performance, with the means of increasing the output current when receiving a large amount of load. The harvesting circuits which designed further improved the power output efficiency by shortening the fully charged time needed by a supercapacitor bank. It can fulfil the long-time power demands for low power device. Typically, a small amount of energy sources were converted to electricity and stored in the supercapacitor bank, which was built by 10 pieces of capacitors with 0.22 F each, arranged in parallel connection. The highest capacitance was chosen based on the characteristic that have the longest discharging time to support the applications of a supercapacitor bank. Testing results show that the op-amp can boost the low input ac voltage (∼3.89 V) to high output dc voltage (5.0 V) with output current of 30 mA and stored the electrical energy in a big supercapacitor bank having a total of 2.2 F, effectively. The measured results agree well with the calculated results.

Three-Port Rectifier-Based AC–DC Power Converters With Sigma Architecture and Reduced Conversion Stages

Novel ac–dc power converters with sigma architecture and three-port rectifier (TPR) are proposed in this paper. The TPR is composed of an ac input port, a low-voltage dc output port, and a high-voltage dc output port. The low voltage dc port, whose voltage is lower than the peak line voltage of the ac port, is connected to the dc load so that the input power can be directly fed to the dc load through the TPR within single-stage power conversion. The TPR is responsible for line current regulation and dc load voltage control, while another dc–dc converter is used to regulate the high-voltage dc port of the TPR. The proposed sigma ac–dc converter has the merits of reduced conversion stages and lower switching losses because of the single-stage power conversion and three voltage-level characteristics of the TPR. Furthermore, the power rating of the down-stream dc–dc converter is reduced significantly because only partial power needs to be processed by the dc–dc converter. The operation principles and characteristics of the proposed ac–dc converter are analyzed in detail. A 2-kW prototype is built and tested to verify the effectiveness and advantage of the proposed method.

Performance analysis of a new high gain dc–dc converter interfaced with solar photovoltaic module

This work presents a new single switched high gain dc–dc converter which can be used in PV systems, in which the low DC output voltage of PV module is converted into high dc output voltage. The proposed converter utilises a single switch, an inductor and a capacitor to transfer the inductive and capacitive energy simultaneously, achieving a high boost ratio. The voltage gain of the dc–dc converter is obtained as 10. The state space model of the converter is presented and all the performance parameters of the proposed converter are analysed when coupled with a PV module. A practical solar module BPSX150S is designed using manufacturer's datasheet by MATLAB program/.m files. Different MPPT algorithms like P&O, Incremental Conductance and Modified Perturb and Observe algorithm are used to find the maximum power point and extract the maximum power. The complete PV system is modelled using the proposed converter interfaced with the designed PV module with MPPT to keep the output voltage constant. The proposed converter is implemented in hardware for the experimental verifications and the experimental results are presented. All the simulations are done using MATLAB program/.m files and SIMULINK.

Single Switched Non-isolated High Gain Converter

&lt;p&gt;This paper presents a new single switched inductor- capacitor coupled transformer-less high gain DC-DC converter which can be used in renewable energy sources like PV, fuel cell in which the low DC output voltage is to be converted into high dc output voltage. With the varying low input voltages, the output of DC-DC converter remains same and does not change. A state space model of the converter is also presented in the paper. This constant output voltage is obtained by close loop control of converter using PID controller. High voltage gain of 10 is obtained without use of transformer. All the simulations are done in MATLAB-SIMULINK environment.&lt;/p&gt;

Enhanced Antenna Design for Rectenna Application in the 2.45 GHz ISM Band

In this paper a two layers microstrip antenna design at 2.45 GHz ISM band with Harmonic rejection filter embedded on the ground plane is presented. The two roger substrates with relative permittivity of 2.2 are separated by an air gap which enhances the antenna gain. The design is simulated using Computer Simulation Technology (CST) Studio Suite 2015. Different aperture couplings slots such as rectangular and triangular aperture coupling slots are studied and compared. It is found that the antenna with triangular aperture coupling slot enhances the antenna performance by suppressing 2 nd and 3 rd harmonics at 5 GHz and 8 GHz, respectively, increasing the antenna gain and providing a better circular polarization behavior. The simulated antenna design achieves a gain of 9 dB, return loss of -23.6dB, axial ratio of 1.27dB and axial-ratio bandwidth of 40.8% (2 ~ 3 GHz). The proposed antenna shows an enhancement in the antenna performance which makes it a suitable candidate for rectifying antenna or rectenna application as it can increase the total conversion efficiency resulting in a high output DC voltage used to power low power electronic and electrical devices such as wireless sensor.

Maximum Power Point Tracking with Dichotomy and Gradient Method for Automobile Exhaust Thermoelectric Generators

In this study, a direct-current/direct-current (DC/DC) converter with maximum power point tracking (MPPT) is developed to down-convert the high voltage DC output from a thermoelectric generator to the lower voltage required to charge batteries. To improve the tracking accuracy and speed of the converter, a novel MPPT control scheme␣characterized by an aggregated dichotomy and gradient (ADG) method is proposed. In the first stage, the dichotomy algorithm is used as a fast search method to find the approximate region of the maximum power point. The gradient method is then applied for rapid and accurate tracking of the maximum power point. To validate the proposed MPPT method, a test bench composed of an automobile exhaust thermoelectric generator was constructed for harvesting the automotive exhaust heat energy. Steady-state and transient tracking experiments under five different load conditions were carried out using a DC/DC converter with the proposed ADG and with three traditional methods. The experimental results show that the ADG method can track the maximum power within 140 ms with a 1.1% error rate when the engine operates at 3300 rpm@71 NM, which is superior to the performance of the single dichotomy method, the single gradient method and the perturbation and observation method from the viewpoint of improved tracking accuracy and speed.