Non-isolated High Voltage Gain Research Articles

A Stacked Symmetrical Non-Isolated High Step-Up Voltage Gain Converter with High Efficiency and Low Voltage Stress on Components

This paper introduces a cascaded symmetrical non-isolated high step-up voltage gain converter with high efficiency and low voltage stress on components combining a non-isolated buck-boost converter and voltage doubler structure. In the proposed converter, the input source is connected in series to the output load; hence, a part of the source energy is directly delivered from source to load, not through the switching branch, improving efficiency. Furthermore, the appropriately stacked voltage doubler stage not only amplifies the high step-up voltage gain ratio but also considerably diminishes the voltage stress on all semiconductor devices and capacitors. As a result, the costless low internal resistance and low voltage components can be employed for higher efficiency, higher power density, and lower cost. To demonstrate the practicality of the proposed topology, the operating principle is outlined, and the steady-state characteristics are thoroughly analyzed. Furthermore, a 360 W prototype converter has been fabricated to confirm the efficiency of the proposed converter.

Implementation of non-isolated high-gain DC-DC converter for electric vehicle application

ABSTRACT This paper introduces a non-isolated high voltage gain DC-DC converter for electric vehicles (EVs). The proposed converter schematic is modelled to be operated on reasonable duty cycle by employing passive switched inductor (PSL) cell and voltage multipliers. Moreover, this structure is functioning on continuous conduction mode (CCM) with a wide range of operations. This structure offers high voltage gain, lower voltage stress across all the devices, low switching losses and high efficiency. Thus, simple proportional integral (PI) controller is adopted to regulate the output to the desired voltage of 200 V. The proposed converter is designed and simulated using MATLAB/Simulink platform and hardware prototype of 100 W/200 V is developed to examine the performance of the proposed circuit. Besides, the experimental results are recorded to prove its robustness over both source voltage and load power discrepancies. The efficiency of the presented configuration is around 91% and it acts as a good choice for EV applications.

A Non-Isolated High Voltage Gain DC–DC Converter Suitable for Sustainable Energy Systems

A non-isolated high gain DC–DC converter with magnetic coupling and a VM circuit is proposed in this study. By the use of the appropriate coupled inductor turn ratio, the output voltage of the recommended topology can be raised. The VM circuit is used to boost the voltage gain even further as well as to clamp the voltage spike across the switch, which results in a lower voltage on the switch. As a result, a MOSFET switch with a lower ON-state resistance (RDS-ON) is used which, in turn, causes the conduction losses to be reduced and the entire system efficiency to be raised. Another advantage of the proposed structure is the ZCS of the diodes, which reduces the voltage drop losses caused by the regenerative diodes. The function modes analysis and the theoretical equations are accomplished. A comparison survey with other prior works is being developed to investigate the competency of the proposed converter. Based on this, the higher voltage gain and efficiency as well as the lower voltage stress on the semiconductors can be achieved by the proposed converter compared to the other converters. The effectiveness of the proposed converter is confirmed by the experimental results at a laboratory-scale operating under 150 V output voltage with a 96% efficiency at the 150 W full load and a 25 kHz switching frequency.

A Coyote Optimization-Based Residual Attention Echo State Reactive Controller for Improving Power Quality in Grid-PV Systems

Improving the power quality and reactive injection capability of grid-PV systems represent the most demanding and crucial tasks in power systems. In the conventional works, many types of converters and regulating approaches have been designed for this goal. The multi-level inverter (MLI) is the best solution for grid-PV systems since it helps to improve power quality while reducing losses. However, the existing works face the key problems of the complex system model, increased components utilization, computational burden, presence of harmonics, and high switching frequency. Therefore, the proposed work aims to develop novel and advanced controlling techniques for improving the reactive power compensation ability and power quality of grid-PV systems. The original contribution of this paper is to implement an advanced soft-computing methodologies for developing the controlling mechanisms. At first, an ATOM search optimization (AOS) based MPPT controlling technique is used to extract the maximum electrical energy from the PV panels under changing climatic situations. Then, the output voltage of PV is effectively regulated with the help of a non-isolated high voltage gain DC-DC converter, which also supports the reduction of the switching loss and frequencies. In order to generate the switching pulses for operating the converter, a novel coyote optimized converter control (COCC) mechanism is developed in this work. Moreover, a residual attention echo state reactive controller (RaERC) is implemented for generating the controlling signals to actuate the switching components of the nine-level inverter. This kind of controlling mechanism could highly improve the power quality of grid system with less processing time. For assessment, the simulation and comparison results of the proposed controlling mechanisms are validated and tested using various parameters.

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.

Modified High Gain DC-DC Converter with APICs for Microgrid

This paper proposes a nonisolated high voltage gain DC-DC converter. The active–passive inductor cells (APICs) makes the converter topology expandable, and it also helps in providing a high gain quality at lower duty cycles. The proposed converter is suitable for high gain applications mainly necessitating microgrid as well as integration of renewable energy sources into the existing grid infrastructure. The merits of the converter can be attributed to the ability to achieve high gain and low current stress and switching losses on power electronic switches. The proposed converter is analyzed in both continuous and discontinuous modes of operation, the efficiency is calculated and simulation results substantiate the operation of the converter.

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

<p><span>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.</span></p>

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.

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.

Steady-State Performance Characteristics of a DC Motor fed by Quadratic DC-DC Boost Converter

This paper presents the analysis of steady-state performance of a DC motor fed by a non-isolated quadratic DC-DC boost converter. The proposed quadratic configuration based non-isolated high voltage gain DC-DC converter operating in continuous conduction mode employs one power switch and reduced number of diodes and passive components. Due to single power switch, the switching and conduction losses are reduced thereby improving the converter efficiency. A DC shunt motor of 5 HP power rating is used as load to the proposed converter. The proposed cost-effective converter-fed DC motor operating under no-load is simulated using MATLAB / SIMULINK tool. The steady-state performance characteristics, such as speed, torque, and armature current of the DC motor, are obtained for one particular value of duty ratio of the power switch. The results validate the superior performance of the suggested DC-DC converter-fed DC motor at moderate duty ratio.

Non-Isolated High Step Up in Voltage DC–DC Converter Topology for Renewable Applications

In the class of the boost converters, the conventional DC–DC boost converters are in common practice but their limited boost capabilities at higher duty ratios are one of the concerns. The isolated and non-isolated step-up DC–DC converters are one of the remedies of the above issue. The presence of switched inductor and switched capacitors in the circuit of non-isolated configuration can provide considerable step-up in voltage at the output, and also facilitate lower voltage stress on components. In this paper, work has been done to propose three non-isolated high-voltage gain DC–DC boost converter topologies. Along with the high voltage gain, the topologies also have lesser voltage stress across the active power switches and diodes used in topologies. The proposed topologies are suitable for low dc input levels like renewable sources, microgrid and grid-connected applications. A Matlab/Simulink 2017a environment is utilized to derive, design and simulate the proposed topologies for a 100-W load operation. The basic topology is also realized in hardware as a prototype circuit with 100-W resistive load, operated at 50[Formula: see text]kHz switching frequency.

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.

High step‐up single switch quadratic modified SEPIC converter for DC microgrid applications

A new non-isolated high-voltage gain single switch quadratic modified single-ended primary-inductor capacitor (SEPIC) DC-DC converter is proposed in this study. The proposed converter consists of a modified SEPIC converter along with a boosting module to obtain a high-voltage gain at a low-duty ratio. It has all advantages of the SEPIC converter such as continuous input current, which makes it applicable for renewable energy sources such as photovoltaic systems. The proposed converter is able to attain a higher voltage gain in comparison with similar previous transformer-less DC-DC converters. Also, unlike high-voltage transformer-based DC-DC converters, it does not suffer from leakage inductances. Also, the proposed converter presents low-voltage stress across the switch and output diode. The proposed converter is controlled through a single switch and there is no limitation for a range of duty ratios. The voltage gain analysis of the proposed converter is done in continuous conduction mode and discontinuous conduction mode, also comparative analysis is done with the existing topologies with similar features. The proposed converter is designed for 400 V DC microgrid applications. The theoretical analysis of the proposed converter is verified by the experimental investigation in the laboratory.

No-Isolated High Gain DC/DC Converter with Low Input Current Ripple Suitable for Renewable Applications

In this paper, a new non-isolated high voltage gain dc/dc converter with low input current ripple is proposed for renewable sources applications. The proposed converter combined SEPIC converter and voltage multiplier cells. In order to achieve high voltage gain, the proposed converter can increase the output voltage level using the voltage multiplier unit. The voltage stress across the semiconductors will be decreased compared to SEPIC, conventional boost converter. Therefore, using only one switch with lower resistance RDS(on), the overall efficiency of the proposed converter is increased significanly. In order to verify the theoretical analysis of the proposed converter and its accurate operation, a 150 W prototype operating at 25 kHz is built and tested.

Fault Diagnosis and Fault Tolerant Operation of A Non-Isolated High Voltage Gain Three Level Boost Converter

Fault Diagnosis and Fault Tolerant Operation of A Non-Isolated High Voltage Gain Three Level Boost Converter

Improved topology of high voltage gain DC-DC converter with boost stages

ABSTRACT In this letter, a novel topology of a non-isolated high voltage gain dc-dc converter is proposed. The topology is based on the diode-capacitor voltage multiplier stages, integrated with inductor-based boost stages at the input. Due to reduced voltage imbalance between the voltage multiplier stage capacitors the design features low spikes in the switch current. Consequently the switch current stress, as well as conduction and switching losses are reduced accordingly. The proposed converter can draw continuous current either as a multiport converter from two input sources or from a single source as an interleaved converter and achieves a voltage gain of 15 with two voltage multiplier stages. A 400 W prototype of the converter with Vin = 20 V and Vout = 300 V has been implemented to validate the enhancement.

Ripple-Free Input Current High Voltage Gain DC–DC Converters With Coupled Inductors

This paper presents three nonisolated high voltage gain dc–dc converters with ripple-free input current. The proposed converters combine coupled inductors and voltage-doubler structure (VDS) to achieve high step-up of input voltage. An active clamp circuit is used to suppress voltage spike of the switch caused by of the leakage inductor of the coupled inductor. VDS is placed in the secondary winding of the coupled inductor that clamps the diodes voltage stress. Working principle and design methodology of the proposed converters are presented in detail. Experimental results for a 300 W laboratory prototype, 48 V input voltage, and regulated output voltage of 400 V, are shown to validate the operation of proposed converters.

Non‐isolated high‐voltage gain dual‐input DC/DC converter with a ZVT auxiliary circuit

A non-isolated high-voltage gain dual-input DC/DC converter with a zero voltage turn-off (ZVT) auxiliary circuit has been presented. Two photovoltaic (PV) modules can be connected to the proposed converter with separate maximum power point tracking (MPPT). The cost of whole PV power generation system can be decreased significantly as a single converter is employed instead of two converters. All switches can achieve ZVT by an auxiliary circuit, and turn-off switching losses can be decreased and the efficiency of the converter can be improved. Working principle and performance characteristics of the proposed converter are analysed in detail, a dual-input maximum power point tracking control algorithm has been designed for the proposed converter. An 800 W experimental prototype has been built to verify the theoretical analysis.

Non‐isolated high step‐up three‐port converter with single magnetic element for photovoltaic systems

A new non-isolated high-voltage gain three-port converter for standalone photovoltaic systems is proposed. The magnetic element of this converter is only one coupled inductor. The primary winding of the coupled inductor is shared between battery charger circuit and main converter. Leakage inductance energy of the coupled inductor is either transferred to battery or is regenerated via the passive-clamp circuit. Using switched capacitor and voltage lift techniques, the voltage gain is significantly increased for both low-voltage ports. Single magnetic element, high-voltage gain with reasonable duty cycle, low-voltage stress on the switches, low winding turn ratio of coupled inductor and high efficiency are the merits of this converter. The operation principles and the steady-state analysis are described for the three modes of: single-input single-output, single-input dual-output and dual-input single-output. To verify the theoretical analysis, a laboratory prototype with 28 V input, 48 V battery voltage and 380 V output voltage is implemented and tested.

A modified high step-up non-isolated DC-DC converter for PV application

A non-isolated high voltage gain DC-DC converter has been presented in this paper. The boost, SEPIC and modified SEPIC converters were analyzed and their performance was compared with the proposed converter. The proposed converter has been designed for the input voltage of 15 V and an output voltage of 150 V with 100 W output power. The efficiency of the converter obtained was 92.5%, which is higher than that of the other converter models which were analyzed. Also, the proposed converter utilizes reduced input current and shows low switching voltage stress. The time response analysis conveys that the proposed converter settles to the steady state voltage and current faster than the other compared converters.