High DC Gain Research Articles

PV-Fed Micro-Inverter with Battery Storage for Single Phase Grid Applications

Nowadays, micro-inverters are trending due to the latest features consisting in PV technology. However, integration of a high-gain boost converter is needed to improve the low rating output voltage of PV modules to meet the load demand. A high-gain converter with less component count is required for grid integration systems. This article proposes a new quasi z-source based high-gain DC–DC converter with reduced components, cost, and size. The proposed converter is integrated with the micro-inverter for single-phase grid applications along with battery storage. A radial basis function network algorithm is utilized for a PV system to track the maximum power point, an efficient hysteresis current controller is applied for the full-bridge inverter for the robust regulation of current and the energy can be stored through the bidirectional dc/dc converter to supply the power to grid when the sources are drained conditions. An efficient PV extraction, low total harmonic distortion and achieves unity power factor which is perfectly suitable for grid-connected PV systems. The operating modes in every aspect and analysis of the proposed configuration have been investigated in detail. The implementation of control strategies is discussed in detail. Simulation of the proposed micro-inverter is designed in MATLAB/SIMULINK tool to validate the efficiency under variable operating conditions. With the successful implementation of the proposed technique, total harmonic distortion is reduced to 2.05% and efficiency is enhance to the 98%.

Comparative assessment of high gain boost converters for renewable energy sources and electrical vehicle applications

Abstract Due to greenhouse gas emissions and the energy crisis, the conventional way of generation of electricity using fossil fuels is being substituted with Renewable Energy Sources (RES) like solar photovoltaics (SPV), fuel cells, wind, etc. The voltage produced by RES is very small in magnitude; therefore, the choice of DC–DC converter is critical for regulating and improving the output of RES to its maximum level. To meet the power requirement for the utility grid and electric vehicles (EV), the voltage must be enhanced. So far, various types of high-gain DC–DC boost converter (HG-BC) topologies have been suggested. An overview of HG-BC topologies for RES and EV applications is presented in this paper, which provides a unique, extensive, perceptive, and comparative analysis of HG-BC topologies. The mathematical modeling and operating principles of each converter topology have been analyzed and discussed. The boost factor (B) and component count for various HG-BC are thoroughly compared for a 0.5 duty cycle using the MATLAB/Simulink tool.

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

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.

A Novel Multilevel DC–DC Flyback Converter-Fed H-Bridge Inverter

The objective is to produce a high-gain DC to DC flyback boost converter integrated with a multi-level converter for inverter applications. It has two stages: the first one is flyback multilevel converter, and another level comprises level controller and H-Bridge Inverter. The addition of voltage multiplier cells enhances the commercial flyback converter with multiple voltage outputs producing high voltage gain. These multiple outputs are fed to an H-bridge inverter for producing a multilevel output in an inverter. This DC-to-DC converter steps up the DC supply, but it also decreases the switches, diodes, and capacitors. This kind of converter not only reduces the switch count but also reduces the voltage stress, and total harmonic distortion. To increase the number of levels in the converter, the number of capacitors and diodes in the DC-to-DC converter without disturbing the main circuit must be increased to achieve the required output voltage. The number of power switches for the proposed topology is compared to comparable topologies in the current literature. The results of the simulation are communicated via the MATLAB/ Simulink domain, and the recommended converter’s functionality is demonstrated.

A design and optimization of CMOS ECG amplifier applied to medical monitoring system

ECG amplifier is widely used in medical monitoring system as a part of the transceiver circuit and sensors. For those who suffer from cardiovascular diseases, an ECG signal can reflect their heart conditions. This paper makes a research mainly on the design purpose of the ECG amplifier which includes low power consumption and high CMRR, and then presents the active load differential amplifier design to restrain the noise and to implement the function of amplify. The design also displays how to maintain a balance between high DC gain and less distortion by setting the parameters. As is displayed in the figures, the ECG amplifier successfully removes the common-mode noise and achieves the ideal wave shape with the use of a software built-in calculator. The DC gain is about 60.55dB. When increases the DC gain with a fixed power consumption to 40dB, the wave shape will be a bit distorted. The design explains the application of the ECG amplifier into medical monitoring system in section 2 and proposes an example of ECG amplifier which can amplify and filter the original signal in section 3. Background knowledge, working process and measured results are given in this paper.

A new extended single-switch high gain DC–DC boost converter for renewable energy applications

High-gain DC/DC converters are considered one of the most important components of green energy systems. Large numbers of these converters are used for increasing the voltage gain by using an extreme duty cycle. However, it increases losses and the cost, degrades the system performance, and hence obtains a low efficiency. In this article, a new design of a high-gain DC/DC boost converter is proposed. This converter has the potential to be used in low input voltage applications that need a high voltage gain such as systems powered by solar photovoltaic panels and fuel cells. The new topology is characterized by its simplicity of operation, high voltage gain, better efficiency, continuity of the input current, reduced number of inductors and capacitors, and can be extended to get higher gains. The converter structure, principle of operation, and design consideration of inductors and capacitors are presented in detail. Derivation of power losses and efficiency is presented. A laboratory prototype is implemented, and various experimental tests are given. The achievement of the suggested design is confirmed and compared with other recent high-gain converters.

A 0.3V Rail-to-Rail Three-Stage OTA With High DC Gain and Improved Robustness to PVT Variations

This paper presents a novel 0.3V rail-to-rail body-driven three-stage operational transconductance amplifier (OTA). The proposed OTA architecture allows achieving high DC gain in spite of the bulk-driven input. This is due to the doubled body transconductance at the first and third stages, and to a high gain, gate-driven second stage. The bias current in each branch of the OTA is accurately set through gate-driven or bulk-driven current mirrors, thus guaranteeing an outstanding stability of main OTA performance parameters to PVT variations. In the first stage, the input signals drive the bulk terminals of both NMOS and PMOS transistors in a complementary fashion, allowing a rail-to-rail input common mode range (ICMR). The second stage is a gate-driven, complementary pseudo-differential stage with an high DC gain and a local CMFB. The third stage implements the differential-to-single-ended conversion through a body-driven complementary pseudo-differential pair and a gate-driven current mirror. Thanks to the adoption of two fully differential stages with common mode feedback (CMFB) loop, the common-mode rejection ratio (CMRR) in typical conditions is greatly improved with respect to other ultra-low-voltage (ULV) bulk-driven OTAs. The OTA has been fabricated in a commercial 130nm CMOS process from STMicroelectronics. Its area is about 0.002 <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">mm</i> <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , and power consumption is less than 35nW at the supply-voltage of 0.3V. With a load capacitance of 35pF, the OTA exhibits a DC gain and a unity-gain frequency of about 85dB and 10kHz, respectively.

High-Gain Step-Down DC–DC Converter Employed in a Battery Charging Application

High-Gain Step-Down DC–DC Converter Employed in a Battery Charging Application

Review on Unidirectional Non-Isolated High Gain DC–DC Converters for EV Sustainable DC Fast Charging Applications

Modern electrical transportation systems require eco-friendly refueling stations worldwide. This has attracted the interest of researchers toward a feasible optimal solution for electric vehicle (EV) charging stations. EV charging can be simply classified as Slow charging (domestic use), Fast charging and Ultrafast charging (commercial use). This study highlights recent advancements in commercial DC charging. The battery voltage varies widely from 36V to 900V according to the EVs. This study focuses on non-isolated unidirectional converters for off-board charging. Various standards and references for fast off-board charging have been proposed. Complete transportation is changed to EVs, which are charged by the grid supply obtained by burning natural fuels, contributing to environmental concerns. Sustainable charging from sustainable energy sources will make future EV completely eco-friendly transportation. The research gap in complete eco-friendly transit is located in interfacing sustainable energy sources and fast DC EV charging. The first step towards clean, eco-friendly transportation is identifying a suitable converter for bridging the research gap in this locality. A simple approach has been made to identify the suitable DC-DC converter for DC fast-charging EVs. This article carefully selected suitable topologies derived from Boost, SEPIC, Cuk, Luo, and Zeta converters for clean EV charging applications. A detailed study on the components count, voltage stress on the controlled and uncontrolled switches, voltage gain obtained, output voltage, power rating of the converters, switching frequency, efficiency obtained, and issues associated with the selected topologies are presented. The outcome of this study is presented as the research challenges or expectations of future converter topologies for charging.

Modelling and Real-time Validation of a Two–input High–gain DC–DC Converter with a Reduced Number of Switches

Modelling and Real-time Validation of a Two–input High–gain DC–DC Converter with a Reduced Number of Switches

Non-Isolated high gain DC to DC converter using sustainable energy

Solar energy, wind energy etc. are the main sustainable energy sources used around the world. These sustainable energy sources are used in day-to-day life in various forms for numerous purposes. One of the highly used sustainable energy sources is the solar energy which with the help of photovoltaic (PV) cells can be made use for the generation of electrical power. However, these sources generate less voltage values and thus it requires a high gain converter. In this paper, a modified Luo with flyback DC to DC converter is presented that assures high voltage gain, single switch, less stress across the components and less ripple current. Furthermore, the simulations along with the hardware prototype for the presented converter is carried out and presented in this paper.

A Single-Inductor Multi-Input Multilevel High Step-Up DC–DC Converter Based on Switched-Diode-Capacitor Cells for PV Applications

This article presents a single-inductor multi-input multilevel high gain dc–dc converter, which is suitable for exploiting arbitrary number of PV arrays to provide fixed voltage levels for multilevel inverters. The converter is capable of transferring power from each input to the output, at the same time. Additionally, the proposed structure provides outputs with same voltage levels that makes it appropriate for connecting to multilevel inverters. Due to the deployment of diode-capacitor cells, which have been extended from both nodes of the central capacitor, the output voltage ripple has been decreased, which leads to the employment of capacitors with smaller size. Also, the number of inputs and outputs can be chosen arbitrarily. In addition, because of the utilizing only one inductor, the cost, and total size of the converter has been reduced. The control approach of the converter is pulsewidth modulation and all switches can be turned <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</small> or <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">off</small> , simultaneously. The theoretical analysis and gain calculations of the converter has been investigated in this article. In order to design the converter, the voltage ripple across each capacitor has been calculated. Furthermore, a comprehensive comparison has been performed between the proposed converter and counterparts. Finally, a dual-input three-level prototype of the proposed converter with 300 W output power has been implemented to confirm the validity of the converter's performance.

Microwave-Irradiated Metal-Oxide Thin-Film Transistors With Recessed Gate Structure and Their Applications in Logic Circuits

The effects of a recessed gate structure on the device performance of sol-gel-based metal-oxide thin-film transistors (oxide-TFTs) consisting of aluminum oxide dielectric and indium-gallium-zinc oxide semiconducting films fabricated through effective microwave irradiation are investigated, as compared with elevated and non-patterned gate structures. Low-voltage operating oxide-TFTs with an optimized recessed gate structure exhibited improved device performance including OFF-state current of approximately <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$10^{-{11}}$ </tex-math></inline-formula> A and field-effect mobility of 3.4 cm2/V-s in the linear regime, compared with those with elevated (~ <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$10^{-{9}}$ </tex-math></inline-formula> A and 1.9 cm2/V-s) and non-patterned (~ <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$10^{-{10}}$ </tex-math></inline-formula> A and 2.8 cm2/V-s) gate structures. Furthermore, the charge transport mechanism responsible for improved device performance and operational stability against prolonged positive and negative gate bias stresses in the oxide-TFTs with the recessed gate structure is investigated through activation energy and velocity distribution that are determined from direct-current and time-domain non-quasi-static transient analyses, respectively. Finally, enhancement-load-type nMOS inverters operating at 5 V are developed for logic circuits, which exhibit a relatively high dc gain of 32.2 in the recessed gate structure, compared with that of 17.1 and 27.1 in the elevated and the non-patterned gate structures, respectively.

Dynamic Analysis of Extendable Hybrid Voltage Lift DC–DC Converter for DC Microgrid

This paper proposes a novel non-isolated high voltage gain dc–dc converter with a boost2 (B2) technique. The derived single-switch hybrid voltage-lift topology generates a higher voltage conversion ratio with less component counts than traditional voltage-lift converters. Furthermore, to show its superiority, the proposed topology is compared with other recent non-isolated dc–dc converters in terms of the number of power components such as inductors, capacitors, diodes, and switches. Moreover, the voltage stress across the power switch is less than the output voltage, which results in using low-rated components and reducing the converter cost. The steady-state analysis of the proposed topology is carried out with the operating modes in continuous and discontinuous conduction modes. The critical inductance for the proposed converter is derived for design considerations. Compared to the other traditional step-up converters, the stresses across the power diodes are highly reduced. The analysis related to the addition of an expander cell with the topology is performed concerning boundary conditions. An efficiency model with loss calculation is presented. Furthermore, the reliability analysis is performed with the military handbook to determine the failure rate of the converter’s components. Finally, the simulation and 50 W prototype model for experimental validation prove the strength of the proposed topology.

Non-isolated high voltage gain DC to DC converter based on the diode a capacitor switches

&lt;p&gt;&lt;span&gt;Many researchers have put great endeavor to develop DC converter’s designs, into studying how to increase voltage gain with low switching stress and low ripple current. This paper has proposed a circuit to boost the voltage with a high gain conversion ratio. It is a combined adverse parallel two boost conversion. Two inductors are connected on both sides of the input source to decrease the current-ripple of the input current and output sides utilizing the interleaving technique. The proposed converter integrated with an active-network circuit is based on multiplier cells and two output capacitors. The voltage gain and voltage stresses across power semiconductors have been determined using a steady-state analysis. In addition, the input current- ripple and output voltage-ripple are analysis have been reported. This converter's inductors operate in a continuous conduction mode (CCM). The designed converter is capable of achieving significant voltage gain while maintaining a low duty ratio. Furthermore, the active switches and output diodes are under low voltage stress. As a result, low voltage components can be used to decrease conduction loss and cost. Finally, this converter was simulated in MATLAB/Simulink software to verify the theoretical calculations.&lt;/span&gt;&lt;/p&gt;

A Modified Interleaved Capacitor Clamped DC–DC Converter With Non-Resonant Soft Switching

Since the solar panels and fuel cells have low output voltage, which need to be converted to the 400 V or higher dc bus voltage in the renewable energy power generation systems, where, the high gain dc–dc converter plays a key role. Furthermore, with the requirement of the converter in low cost and high efficiency, the soft-switching interleaved boost-type converters based on switched-capacitor and voltage multiplier cell as the high gain dc–dc converters have been widely applied. However, the above-mentioned soft-switching interleaved boost-type converters in literature have resonant spikes on the switches or there are coupled inductors, which will cause the high cost due to the large stresses of the switches or low efficiency due to the high core losses of the coupled inductors. To solve the above-mentioned problems, a modified interleaved capacitor clamped (MICC) dc–dc converter with non-resonant soft-switching (NRSS) is proposed, in which only an auxiliary inductor operating in discontinuous conduction mode with few μH is used to achieve the zero-current-switching for all switches and diodes. Furthermore, the operating principle of the proposed converter is given, the interleaved boost structure is used as the front stage of the proposed converter to reduce the input current ripple and lighten the current stress on all switches and magnetic components, the MICC structure with NRSS as the output stage is proposed as a voltage multiplier module to achieve the high voltage gain. Then, the circuit parameter design for this converter is presented. Finally, a 400 W experimental prototype is built to verify the correctness and the effectiveness of the proposed topology.

Family of Non-Isolated Quadratic High Gain DC–DC Converters Based on Extended Capacitor-Diode Network for Renewable Energy Source Integration

Many topologies in the area of non-isolated high-voltage gain dc–dc converter are reported for improving efficiency and voltage gain and to reduce the switch stress with the use of minimum number of components. A family of quadratic high-gain dc–dc converters using an extended capacitor–diode network is proposed in this article, and an extensive analysis has been conducted to assess their performances. The output voltage of the five proposed converters by considering the effect of parasitic elements is derived, and the analytical efficiency profiles are drawn. The proposed converters are designed for 650 V, 0.5 kW, and 50 kHz with a 48-V input source. The hardware prototypes are fabricated for the five converters, and the experimental results are presented. For the considered design, converters I and III give higher efficiency and lower voltage stress on the semiconductor devices. Converters IV and V are suitable for higher voltage gain applications. A dynamic model for converter I is derived and a controller is implemented for closed-loop operation. A suitable converter among the family can be selected according to the applications for the integration of renewable energy sources.

Design of Novel HG-SIQBC-Fed Multilevel Inverter for Standalone Microgrid Applications

The growth of distributed power generation using renewable energy sources has led to the development of new-generation power electronic converters. This is because DC–DC converters and inverters form the fundamental building blocks in numerous applications, which include renewable integrations, energy harvesting, and transportation. Additionally, they play a vital role in microgrid applications. The deployment of distributed energy resources (DERs) with renewable sources such as solar has paved the way for microgrid support systems, thus forming an efficient electric grid. To enhance the voltage of such sources and to integrate them into the grid, high-gain DC–DC converters and inverter circuits are required. In this paper, a novel single-switch high-gain converter (HG-SIQBC) with quadratic voltage gain and wide controllable range of load is proposed, the output of which is fed to a modified multilevel inverter for conversion of voltage. The overall performance of the newly designed converter and inverter is analyzed and compared with the existing topologies. A prototype of the investigated multilevel inverter is designed and tested in the laboratory. Development and testing of such novel topologies have become the need of the hour as the grid becomes smarter with increased penetration of distributed resources.

High gain chopper supplied from PV system to fed synchronous reluctance motor drive for pumping water application

Power generation for renewable energy sources increased rapidly during last few years. Similarly, the high gain dc–dc boost choppers are taking place of conventional power converters used for photovoltaic (PV) appliances. Researchers are developing different methods in order to provide high voltage gain, low ripple, reduced switch stress, low converter costs, and minimized variations of PV operating points. This study proposes a two-stage converter for a freestanding water pumping motor drive power by solar PV system. According to the proposed system, at first, a high gain (HG) cell and a DC-to-DC boost converter are combined to increase the PV voltage to high levels. Later on, the resulting dc voltage feds a three-phase synchronous reluctance motor drive that operates centrifugal pump load. The perturb and observe approach is utilized to get the maximum power out of the solar PV module. Moreover, indirect field-oriented control is implemented to accomplish smooth starting of synchronous reluctance motor. In order to validate the effectiveness of proposed technique, a MATLAB/Simulink environment-based simulation setup along with an experimental prototype is developed. Additionally, various cases are considered based on different operating conditions and irradiance levels to collect and analyse the results.

A High-Gain DC Side Converter with a Ripple-Free Input Current for Offshore Wind Energy Systems

Considering that the distance between offshore wind farms and onshore converters is getting farther and farther, dc transmission becomes increasingly more applicable than conventional ac transmission. To reduce the transmission loss, a feasible solution is using a high-gain dc/dc converter to boost the rectified output voltage to thousands of volts. Thus, a novel single-switch high-gain dc/dc converter with a ripple-free input current is presented in this paper. The structure consists of two cells—a coupled-inductor cell and a switched-capacitor cell. The coupled-inductor cell in the proposed converter provides a ripple-free input current. The switched-capacitor cell provides a high voltage gain. The converter has a simple control strategy due to the use of a single switch. Moreover, the output capacitor is charged and discharged continuously by a 180° phase shift to eliminate the output voltage ripple. A steady-state analysis of the converter is proposed to determine the parameters of the devices. In addition, a 240 W, 40/308 V laboratory prototype at 35 kHz switching frequency has been developed, in which the input current ripple is only 1.1% and a peak efficiency of 94.5% is reached. The experimental results verify the validity and feasibility of the proposed topology.