High Output Voltage Gain Research Articles

Quasi Z source direct matrix converter based K- to three-phase wind energy conversion system using maximum constant boost current control modulation technique

The conversion system for wind energy has no restriction on the number of output phases. K numbers of output phases can be converted into standard grid-connected three-phase supply using a quasi-Z source direct matrix converter (QZSDMC). The obtained input supply may be five phases from the wind energy conversion system with continuously variable frequency as well as variable terminal voltages. Using the proposed QZSDMC converter with maximum constant boost current control modulation technique constant three-phase voltages as well as frequency can be maintained at the grid side. Additionally, the energy conversion system has high output voltage gain. The proposed converter as well as the modulation technique produces the maximum voltage transfer ratio of 1.05. The output voltage gain reached nearly 1.99 compared with the traditional power converters. The voltage THD and current THD are maintained within the acceptable limit of 5.3 and 3.6 respectively. The power factor have been maintained nearly unity throughout the all mode of operations. To stabilize the grid frequencies and grid voltages additional control blocks are used. This research article presents simulation results for the proposed QZSDMC converter with a maximum constant boost current control modulation technique. Also, the proposed scheme has been validated with suitable experimental results.

An Improved Series 36-Pulse Rectifier Based on Dual Passive Pulse-Doubling Circuit on the System DC Side

The series-type 12-pulse rectifier generates a large amount of harmonics in the AC side current due to the strong nonlinearity of its rectifying diodes, causing serious harmonic pollution to the power grid. This article proposes a series 36-pulse rectifier based on a DC side dual passive frequency-doubling circuit to suppress the AC side current harmonics of a 12-pulse rectifier. The rectifier uses two symmetrical passive pulse multiplication circuits to regulate the circulation in the DC side circuit, increasing the output voltage and current state of the rectifier bridge, thereby increasing the number of pulses in the rectifier from 12 times to 36 times. Firstly, the working principle of the rectifier and the working mode of the dual passive frequency-doubling circuit were analyzed. Secondly, the harmonic suppression mechanism of the rectifier input current was revealed, and the frequency-doubling characteristics of the load voltage were analyzed. Finally, the correctness of the theoretical analysis was verified through a semi-physical platform. The verification and comparison results show that under the optimal conditions of the injecting transformer turns ratio, the DPPC can not only reduce the THD value of the input current by about 1/3 (from 14.87% to 4.78%) but can also increase the fluctuation frequency of the load voltage by 3 times (from 12 to 36), while improving the power quality of the AC/DC side rectifier and achieving the low harmonic operation of the rectifier. The proposed 36-pulse rectifier can effectively suppress harmonics; it has the advantages of simple structure, strong robustness, and high output voltage gain, and it is suitable for medium-voltage and high-voltage high-power rectification applications.

Investigation of a power factor correction converter utilizing SEPIC topology with input current switching

The single-ended primary-inductor converter (SEPIC) is a popular converter topology that can be employed in diverse application fields where the needed output voltage is greater or lesser than the input voltage. The non-inverted output voltage of a SEPIC converter provides additional advantages when compared to a buck-boost or Ćuk converter. Furthermore, the position of the capacitor in the SEPIC converter provides inherent isolation and circuit safety. One drawback in the conventional bridge-diode SEPIC AC-DC converter is the lack of controllability which can be overcome by adding extra active switch(es) or by replacing the passive diode(s) with active switch(es). However, introducing more active switches increases the control complexity and may increase the requirement for additional driver circuits. To address this trade-off, this article proposes a single-phase AC to DC modified SEPIC converter with input current-switching capability without adding any extra active switch(es). The existing active switch of the DC-DC SEPIC converter was shifted towards the input side and thus no additional switch has been introduced. This allows the option of input-current switching without any additional complexity in the control or driver circuit. The circuit topology, principles of operation, and ideal voltage gain equations for the suggested circuit have been derived and included in this research work. The proposed circuit has been simulated in both open-loop conditions and closed-loop control with varying duty cycles and output load. Results from the simulation show that the proposed converter provides better efficiency (∼90 %) and lower total harmonic distortion (THD) (10 %) for varying duty cycles when compared to a conventional converter. The converter also shows good dynamic response. A low-power 15V hardware prototype has been built to experimentally validate the performance of the proposed converter. Experimental results illustrate that the suggested converter can improve the power factor by up to 0.968 while operating at an efficiency above 75 %. This converter topology can be suitable for applications where high output voltage gain, high power factor, and lower THD are needed without isolation requirements.

Improving Performance of Solar Array Fed BLDC Drive Using Firefly Algorithm Based High Gain Converter

The improved transient response of PID controller for improved Luo converter supplied Brushless DC (BLDC) motor using solar energy source is extensively investigated. The BLDC drive uses a hybrid PV system and battery-based power generation as a power source to assure continuous power supply to pump water regardless of solar insolation. The PV system serves as the main energy source, and the battery providing as a backup source that discharged its power only during inclement weather or at night if the photovoltaic panel is insufficient to operate the centrifugal pump. The solar panel feeds power into the battery, whenever water to the field is not required, thus there is no need for an extra power source to charge the batteries. The high output voltage gain DC-DC converter does not make any discomfit to the system performance in regards to irradiance variation, switching loss, or power loss by converter or motor side respectively. Moreover, current sensor, voltage sensor, and control circuits are completed excluded which enhance performance and the cost of the system get reduced effectively. A bidirectional charging control allows a bi-directional converter to alter the battery operation mode automatically. The overall system performance is validated using simulation and experimental setup.

An enhanced gain non-isolated quadratic boost DC-DC converter with continuous source current

In this paper, a non-isolated quadratic boost DC-DC converter has been proposed. The proposed converter provides high output voltage gain with a lower component count on the structure. In addition, the input side inductor provides continuous source current and the output voltage is positive. Since the proposed topology possesses the continuous source current, it simplifies the filter design at the input side further making the converter suitable for photovoltaic applications. Another important feature of this converter includes the utilization of the same switch ground that omits the additional control power supply in the system design. The detailed mathematical modeling of the proposed topology including the steady state analysis for different modes of operations, voltage stress calculations of the components, and power loss calculations have been precisely demonstrated in this work. The simulation has been carried out in Matlab/Simulink software. Finally, a 250 W experimental prototype has been developed and tested in the laboratory environment and the peak efficiency of the proposed topology has been found 92% at 50% duty cycle, which validates the correctness of the theoretical and simulation outcomes of the proposed work.

Contribution to the Development of a Smart Ultrasound Scanner: Design and Analysis of the High-Voltage Power Supply of the Transmitter

A smart ultrasound scanner plays an important role in the transition to point-of-care imaging. DC–DC bipolar converters are essential in the generation of the ultrasound burst signal as they power the piezoelectric transducer. The conventional bipolar converter has minimal output gain and high-voltage stress, and the longer duty cycle on the semiconductors produces high conduction losses and reduces the efficiency of the system. The transmitter supply voltage is minimal, necessitating the use of high-gain bipolar converters. This proposed study is concerned with the development of an improved high-output voltage gain symmetric bipolar DC–DC converter topology which may be suitable for applications such as powering a smart ultrasound scanner transmitter. The proposed converter combines the conventional single-ended primary inductor converter (SEPIC) with a voltage multiplier cell (VMC) to improve voltage gain, transistor duty cycle, efficiency, and reliability. The present study describes the working principle of the proposed converter. The analysis of the voltage gain is carried out in continuous current mode (CCM) and discontinuous current mode (DCM), taking into account the nonidealities of the device. The simulation of the proposed system is carried out in the numerical environment Matlab/Simulink in order to verify its characteristics. A prototype model is realized and the experimental study presented validates the theoretical arguments and simulations. Due to the advantages of continuous input current, self-balancing bipolar outputs, and small component size, the proposed converter is a suitable choice for smart ultrasound transmitters.

Performance Analysis and Evaluation of Multiphase Split-Source Inverters

Due to their many advantages over their counterparts, such as Z-source inverters (ZSIs), split-source inverters (SSIs) have recently received much attention as single-stage boost inverters. This paper discusses a multiphase version of the SSI topology for the first time. Among multiphase systems undergoing a revolution in the research area, five-phase motor drives are a relatively practical selection in industrial applications. Therefore, this paper focuses on a five-phase SSI as an example. The topology, operating principles, modulation techniques, and performance analysis of the analyzed topology are introduced. A modified space-vector modulation (MSVM) scheme is developed to eliminate low-frequency ripples in the input current. There is also a detailed analysis and graphical evaluation of the output currents ripples using the space-vector approach. It is evident that multiphase SSI is suitable for motor drives, especially when a high-output voltage gain is required. In addition to having a nearly identical ripple in output current to a conventional VSI, it has the benefit of performing the boosting action in a single stage with fewer passive components and a low ripple in input current. Finally, the simulation and experimental results have been conducted to demonstrate the viability of the multiphase SSI studied in the theoretical study and analysis.

Power Factor Correction Application Based on Independent Double-Boost Interleaved Converter (IDBIC)

In this paper, a Power Factor Correction (PFC) application, based on the novel power stage topology named Independent Double-Boost Interleaved Converter (IDBIC), has been analyzed. The novelty of the proposed PFC rectifier is based on the sum of capabilities, such as supplying three independent output voltage levels with interleaved operation at the input and high voltage gain. The hardware used within this application consists of an AC input L-C-L filter, a single-phase bridge rectifier, the IDBIC power stage, output capacitors group and a group of variable high-power rheostats (resistors) group as DC load. The main purpose of the carried study was to highlight the advantages and disadvantages of the novel power stage topology in the context of a green and modern AC to DC conversion solution. Nowadays, a high level of the efficiency and power factor have become a mandatory feature for the AC to DC conversion solutions to satisfy the international electrical standards. Thus, considering the modern electrical standards and recommendations, the current study tries to better depict the working steps and principles of the modern power stage topology within an AC to DC conversion application. The behavior of the considered power stage described in different detailed working steps (such as the Discontinuous Conduction Mode and Continuous Conduction Mode) may help understand how the energy conversions process of AC to DC becomes more efficient. The high output voltage gain of the considered power stage is the key feature in the Power Factor Correction process. With such a feature, the AC to DC conversion solution/application can also operate at lower input AC voltages (such as 90 [V] and 110 [V]). The proposed solution can be successfully used in the electric vehicle (automotive field) and high-power electrical traction (e.g., trains, high power electrical machines and drives). The same solution can also be used successfully in fast battery charging applications and chemical electrolysis processes.

High gain DC/DC converter with continuous input current for renewable energy applications

In this paper, a new design of a non-isolated high-voltage gain DC/DC converter that operates at a reasonable duty cycle, by merging the dual boost converter with the switched inductor structure, is presented as a solution for the high-conversion ratio requirement. The proposed converter operates in discontinuous-current mode (DCM) with zero current switching for all switches and diodes. Wide duty cycle range operation, high output voltage gain, low switching stress, small switching losses, and high efficiency are achieved efficiently. Operating the converter in DCM can support a wide range of the duty cycle operation, maintain lower voltage stress of all devices, ensure the same current sharing among inductors, make it easy to control, provide more stability, and require a smaller inductor which reduces size and weight of the proposed converter. Moreover, the converter operates with a continuous input current. These features make the converter a good choice for many applications such as photovoltaic, x-ray, fuel cells, etc. To prove the converter’s effectiveness, theoretical analysis, project specifications, and operation principles are presented and studied. Experimental results in an open and closed-loop, and a comparison with other recent converters are also introduced to confirm the validity of the proposed converter.

Non‐isolated high step‐up DC/DC converter for low‐voltage distributed power systems based on the quadratic boost converter

AbstractDistributed energy resources have been broadly developed in recent years for supporting DC and AC microgrids. Unfortunately, most of them produce low output DC or AC voltages, and interfacing converters are required. These are implemented either in single‐stage or dual‐stage configurations. Step‐up converters are the essential section in dual‐stage designs, which their producing gain is important. Improving the boost factor and efficiency as well as decreasing the number of required components and electrical stresses on power components are the most critical challenges in designing such topologies. Continuing past efforts, this paper proposes a new non‐isolated step‐up DC/DC converter that can be used in low‐voltage distributed power systems and many other applications requiring step‐up DC/DC conversion. The topology requires only one power switch located on the converter's low voltage (LV) side. Hence, it can be easily selected from LV ratings, low on‐resistance power semiconductors. Besides, the converter operates with a continuous input current, which is a valuable feature in connection with current‐sensitive voltage resources. Compared with the recently proposed topologies, the topology provides better conversion gain and efficiency. In this article, the operating principle of the introduced converter is comprehensively investigated. Also, in order to examine the converter performance, experimental results will be presented and analyzed. For this purpose, a 400 V/400 W prototype has been designed and built. Results confirm the above claims and show that the converter efficiency equals 96.1%, and it produces high output voltage gain about 12 times.

A new generalized cross-connected switched capacitor multilevel inverter topology with high output voltage gain for single phase solar PV unit

Switched capacitor multilevel inverters are gaining much attention these days due to their merits like voltage boosting and voltage balancing characteristics. A Cross Connected Switched Capacitor Multilevel Inverter (C2SC-MLI) topology is proposed in this work. It can synthesize thirteen levels in the terminal voltage waveform and with a voltage boost ratio of 1:3. The topology is extendable by adding additional “n” modules in series. The number of levels (NLevel) and the voltage gain can be increased up to 4i+9 and 1:(i+2) respectively by connecting ‘i’ such ‘n’ modules. The topology also has inherent voltage balancing ability. To prove the advantage of proposed topology it is compared with recent switched capacitor multilevel inverter topologies and conventional multilevel inverter topologies in terms of number of power electronic components required, cost and voltage gain. The performance of proposed topology is validated using simulation in MATLAB and with an experimental prototype rated 0.1 kW fed by a solar PV emulator under steady state and dynamic loading conditions.

High Output Voltage Gain DC/DC Boost Converter Suitable For Renewable Energy Applications

High-voltage gain DC–DC boost converter is very important because it is required in many industrial applications, and therefore becomes the focus of all researches nowadays. Conventional topologies is used to obtain high gain due to its advantages such as simple structure, simple control, and low cost but it must be operated at extreme duty cycle in order to obtain high voltage gain which leads to high semiconductors voltage stress, high switching loss, and diode reverse recovery problems that degrades the system performance, and cause a significant efficiency reduction. Using of Cascaded boost converter and switched inductor converter solve some of the problems appeared with conventional boost converter as they have higher voltage gain without working with high duty cycle like conventional one, but they have some problems such as higher losses, and lower efficiency that also degrades the system performance. This study presents a new non-isolated high voltage gain DC DC boost converter operating with a reasonable duty cycle by integrating dual boost converter with switched inductor structures. The presented converter operates with soft-switching ZVS mode for all switches, high voltage gain, and high efficiency. In order to prove the converter effectiveness, the theoretical analysis, operation principle, and simulation results are presented.

Evaluation of DC-DC converter using renewable energy sources

This work analyses and evaluates the performance of renewable energy sources-based converters using Intelligent techniques. The objective of the research is to maintain the reliability of the converters such that it decreases the switching losses, high duty cycle and recycles the leakage energy. To accomplish the high output voltage gain converters are designed with different intelligent methods. Due to heavy demands, the cost of fossil fuel has gone up.so the need for the time is identifying and developing renewable energy sources along with developing new technologies for energy saving in renewable energy system to fight the issues plaguing the environment.

A Generalized Multilevel Inverter Based on T-Type Switched Capacitor Module with Reduced Devices

Conventional multilevel inverters have problems in terms of their complicated expansion and large number of devices. This paper proposes a modular expanded multilevel inverter, which can effectively simplify the expansion and reduce the number of devices. The proposed inverter can ensure the voltage balancing of the voltage-dividing capacitors. The cascading of the T-type switched capacitor module and the step-by-step charging method of the switched capacitors enable the inverter to achieve high output voltage levels and voltage gain. In addition, the inversion can be achieved without the H-bridge, which greatly reduces the total standing voltage of the switches. The nine-level inverter of the proposed topology can be realized with only ten switches, obtaining a voltage gain that is two times larger. The above merits were validated through theoretical analysis and experiments. The proposed inverter has good application prospects in medium- and low-voltage photovoltaic power generation.

Performance Analysis of Modular Forward Converter in Input Parallel Output Series (IPOS) Architecture Using PI and Fuzzy Logic Controller

This paper investigates the performance of modular dc–dc forward converter in Input Parallel Output Series (IPOS) configuration which is controlled by an effective controller. This IPOS topology facilitates the converter to have high output voltage gain. The role of controller is crucial in ensuring the power sharing between the converters. Fuzzy controller, known for its versatility, is employed in this research work. The fuzzy controller feeds appropriate pulse width modulated control signals for appropriate input and load regulation. The performance of the fuzzy controller is analyzed by comparing it with proportional integral controller and a advanced neural network controller. The proposed IPOS system has been analyzed using MATLAB/Simulink environment and hardware prototype. The simulation and hardware results reveal that the suggested topology with fuzzy controller is very effective compared to its counterparts.

Design, analysis, and implementation of a multiport DC–DC converter for renewable energy applications

This study studies a two-input boost DC/DC converter with high-output voltage gain. The presented converter has several advantages such as high step-up capability, continuous input current, bidirectional power flow from one of the ports, and its simple and low-cost structure. The presented converter can achieve a high-output voltage gain without using a coupled inductor or a transformer in its structure. Coupled inductors can cause voltage spikes on the main power switch, so active/passive clamp circuits are additionally required to eliminate the voltage spikes. The continuous input current of the presented converter makes it suitable for renewable energy sources such as photovoltaic panels and fuel cells. An energy storage source such as a battery pack can be used in the presented converter. Charging and discharging of the energy storage source is possible using the presented converter. Pulsating charging current of the battery can improve the lifetime of the battery. In addition, discharging of the battery can be done without any constraints in the duty cycles. The thorough analysis and design of the proposed converter are discussed. A 300 W prototype of the presented converter is also used to verify the feasibility and proper operation of the converter.

Extended Switched-Boost DC-DC Converters Adopting Switched-Capacitor/Switched-Inductor Cells for High Step-up Conversion

This paper proposes a family of switched-boost dc–dc converters for the high stepup voltage conversion applications, such as renewable energy power generation, uninterruptible power supply, and automobile high-intensity discharge headlamps. Compared with other dc–dc converters, the proposed switched-boost converter, which combines the traditional switched-boost network with the switched-capacitor/switched-inductor cells, has the following features: higher output voltage gain, a fewer passive components such as inductors and capacitors, and lower voltage stress across the output diode and power switches. Another advantage of the proposed topology is its expandability. If a higher voltage conversion ratio is required, additional cells can be easily cascaded by adding one inductor and three diodes. The structure, operating principle analysis, parameter design, and comparison with other dc–dc converters are also analyzed. Finally, both simulations and experimental results are presented to verify the effectiveness of the proposed converter.

High step-up quasi-Z-source DC\u2013DC converters with single switched capacitor branch

Aiming to integrate the respective merits of the switched-capacitor converter and the quasi-Z-source converter. An novel high step-up quasi-Z-source DC–DC converter with a single switched-capacitor branch is proposed. Compared to other high boost DC–DC converters, the proposed converter can provide higher output voltage gain, lower current stress across the switches, and lower voltage stress across the output diodes by using the same or similar passive and active components. Therefore, the efficiency and reliability of the converter can be improved. The topological derivation, operating principle, parameter selection, and comparison with other DC–DC converters are presented. Finally, both simulations and experimental results are given to verify the characteristics of the proposed converter.

A Novel High Controllable Voltage Gain Push-Pull Topology for Wireless Power Transfer System

Wireless Power Transfer (WPT) is commonly used to transmit power from a transmitting coil to various movable power devices. In the WPT system, due to a resonant tank inherent characteristic, the system cannot achieve a high output voltage gain. This paper proposes a novel current-fed push–pull circuit to realize high output voltage gain by adding a bi-directional switch between the resonant network and inverter. To obtain a high voltage gain, this paper proposes energy storage and energy injection mode to realize an energy boost function. A duty cycle control method for mode switching is also proposed. The proposed method allows the converter to operate with a variable voltage gain over a wide range with high efficiency. Experimental validation shows that the system gain of a proposed circuit can achieve a variable gain from 2 to 7 of which the converter can be two times higher than the classical system with the same condition.

A New Dual Boost DC/DC Converter With a High Voltage Gain

This paper proposes a new boost DC-DC converter with a high voltage conversion ratio for the renewable energy source. To get a high voltage gain, the proposed converter consists of the new two stage cascaded structure and has two voltage conversion processes. Due to the new structure and voltage conversion process, it has the higher output voltage gain at the same duty cycle than the conventional boost converter. To verify the performance and effectiveness the proposed circuit was analyzed and tested by the PSIM simulator. The calculated power efficiency of the proposed circuit was 90.5% and the proposed circuit had the 3.5 times higher conversion ratio at the half duty cycle than the conventional boost converter. Therefore, the superior voltage conversion ability of the proposed circuit is proved from the simulation results.