Dual-input Converter Research Articles

A Bipolar DC Grid-Interfaced Integrated Dual Input Converter with Reduced Overloading under Unbalanced Line Voltage Conditions

A Bipolar DC Grid-Interfaced Integrated Dual Input Converter with Reduced Overloading under Unbalanced Line Voltage Conditions

A Soft-Switched Current-Fed Dual-Input Isolated DC–DC Converter Topology

A soft-switched current-fed dual-input isolated dc-dc converter topology is proposed in this article. This converter integrates two low-voltage dc sources with similar transferred characteristics such as two PV panels or two batteries into a dc bus using a simple circuit topology and a minimum number of active and passive components. The energy transfer between the input and output ports is controlled by modulating the pulse-width of the control signals. Moreover, the soft-switching operations are discussed, and the smooth connection between the input-side inductor and the transformer leakage inductance is achieved. Furthermore, the operation of the converter in reverse power flow direction is presented to demonstrate the bidirectional operational capability of the converter. Finally, different operation modes of the proposed dual-input converter are verified by the experimental results obtained from a 250 W hardware prototype.

Implementation of a dual input DC-DC boost converter for solar and fuel cell integration with a smart grid

This research involves the implementation of a dual-input DC-DC boost converter for integrating solar and fuel cell energy sources with a smart grid. The growing demand for renewable energy sources necessitates the efficient utilization and integration of multiple energy systems. The proposed dual-input converter enables simultaneous extraction and management of power from solar panels and fuel cells, resulting in improved energy generation and utilization. The converter incorporates a smart grid interface, allowing bidirectional power flow between the energy sources and the grid. The design and control strategy of the dual-input converter are discussed in detail, with a focus on achieving high conversion efficiency, maximum power point tracking, and optimal power sharing between the solar panels and fuel cells. The control algorithm utilizes a combination of Perturb and Observe (P&O) and Incremental Conductance (IncCond) methods for Maximum Power Point Tracking (MPPT), ensuring efficient power extraction from the solar panels. Additionally, a Proportional-Integral (PI) controller is implemented to regulate power flow between the energy sources and the grid. Simulation and experimental results are presented to validate the proposed converter's performance under various operating conditions.

Systematic Synthesis of Multiple-Input and Multiple-Output DC–DC Converters for Nonisolated Applications

Multiple-input converters (MICs) and multiple-output converters (MOCs) are attractive solutions for interfacing various voltage levels. In order to reveal the intrinsic relationships among the diverse topologies and provide as many viable topologies as possible for practical applications, this article aims to analyze the topology construction principles and propose a systematic approach to derive MICs and MOCs. To begin with, the general principle of the topology derivation is analyzed according to circuit network theory. Inspired by the idea of design controllable inductor power-flow loops (IPFLs), five construction types are proposed to create multiple power-flow network (MPN) in MICs and MOCs. Then, four basic switching cells for the topology synthesis are proposed and a flow diagram for the optimal design procedure is provided to guide the topology derivation. As one example, a family of viable and optimized MICs and MOCs with various characteristics is derived from typical Buck converter. Based on the analysis of the derived converters in continuous conduction mode (CCM) and discontinuous conduction mode (DCM), the number of magnetic components is not increased at all so that they are promising candidates for applications requiring compact size and high integration. Besides, topology comparison and selection among a family of MICs is also conducted in view of practical specifications. Finally, one derived dual-input converter is analyzed in detail and experimentally verified to demonstrate the theoretical results.

Integration of Photovoltaic-Based Transformerless High Step-Up Dual-Output–Dual-Input Converter with Low Power Losses for Energy Storage Applications

The synchronous integration of numerous input and output loads is possible with multi-input (MI) and multi-output (MO) DC–DC converters. In this paper, the non-isolated DC–DC converter described, which has a high step-up capability and multiple ports for outputs and inputs for energy storage system (ESS) applications. The voltage level of the converter is changeable. The capacity to provide the large voltage increases with a low duty cycle portion, the ease with which each duty cycle can be controlled, and minimal power losses are all advantages of the proposed design. The proposed system offers advantages for applications requiring energy storage. In the continuous conduction mode (CCM), the operation principles, steady-state evaluation, and extracting of the voltage and current coefficients are performed. The supply sources can be inserted or withdrawn without causing a cross-regulation issue in the proposed converter. Ultimately, the functionality of the proposed structure is examined using simulation and the laboratory prototype that has been implemented. The proposed converter achieved 94.3% efficiency at maximum power. In addition, the proposed converter attained minimum losses with a difference of 28.5 W when compared to a conventional converter.

A New Converter Topology with PV/Battery Hybrid System with Energy Management Control Strategy

This Paper aimed at developing a standard procedure for the design of large-scale institutional grid-connected solar PV systems using the roofs of buildings and car parks. Grid-connect PV systems with battery back-up (sometimes referred to as uninterrupted power supply or hybrid solar PV systems) are becoming increasingly popular. Grid-connected systems do not need batteries which reduces considerably initial capital costs and energy costs. For a comparable load, grid -tied systems use smaller PV arrays than stand-alone systems. In order to address this issue, a two-stage stand-alone scheme consisting of a novel transformer coupled dual-input converter llowed by a conventional full-bridge inverter is proposed. The proposed converter can realize maximum power point tracking and battery charge control while maintaining the proper voltage level at the load terminal. A suitable control strategy for the proposed converter devised for manipulating the converter to realize the first two aforementioned objectives, while the third objective is achieved by employing a conventional proportional integral (PI) controller to control the output voltage of the five level inverter through sinusoidal pulse width modulation

Control Strategy to Generate PWM Signals with Stability Analysis for Dual Input Power Converter System

The prime role of a renewable resource based DC hybrid power system is, to maintain the output voltage constant with higher efficiency. In order to achieve this the duty cycles of the converter switches are dynamically controlled. Multiple input single output (MISO) converter uses separate controller for adjusting the duty cycle, this complicates the design and implementation of the system. Hence, to overcome this limitation a centralized controller is used. The control strategy depends on the pattern of gating signals given to the converter switches. When independent controller is employed, then gating signals of any pattern can be used to drive the switches. However, if a single controller is used, and then a definite pattern is very much essential otherwise, the output voltage and efficiency gets affected. In this paper, an attempt is made to validate and evaluate the performance parameters of MISO converter with two pattern of gating signals; they are synchronized and unsynchronized pulses at their rising edge. The control strategy focusses on the generation of these gating pulses. PID controller is tuned appropriately to determine the gains to achieve the stability of the proposed converter. The dual input power converter validated to show how the PWM pattern affects the efficiency, ripple and regulation of the converter. Using MATLAB SIMULINK platform the simulation of the proposed concept with dual input converter in closed loop is validated. Simulation results proves that synchronized pulses gives DC efficiency of 87% at designed output of 12V output. Converter with unsynchronized PWM pulses operates at lesser efficiency of 75% and the output voltage is of 10V.

Control Strategy to Generate PWM Signals with Stability Analysis for Dual Input Power Converter System

The prime role of a renewable resource based DC hybrid power system is, to maintain the output voltage constant with higher efficiency. In order to achieve this the duty cycles of the converter switches are dynamically controlled. Multiple input single output (MISO) converter uses separate controller for adjusting the duty cycle, this complicates the design and implementation of the system. Hence, to overcome this limitation a centralized controller is used. The control strategy depends on the pattern of gating signals given to the converter switches. When independent controller is employed, then gating signals of any pattern can be used to drive the switches. However, if a single controller is used, and then a definite pattern is very much essential otherwise, the output voltage and efficiency gets affected. In this paper, an attempt is made to validate and evaluate the performance parameters of MISO converter with two pattern of gating signals; they are synchronized and unsynchronized pulses at their rising edge. The control strategy focusses on the generation of these gating pulses. PID controller is tuned appropriately to determine the gains to achieve the stability of the proposed converter. The dual input power converter validated to show how the PWM pattern affects the efficiency, ripple and regulation of the converter. Using MATLAB SIMULINK platform the simulation of the proposed concept with dual input converter in closed loop is validated. Simulation results proves that synchronized pulses gives DC efficiency of 87% at designed output of 12V output. Converter with unsynchronized PWM pulses operates at lesser efficiency of 75% and the output voltage is of 10V.

Design and Development of Dual Input DC–DC Converter for Hybrid Energy System

In hybridization of energy sources with distinct voltage–current characteristics, power electronic converter plays crucial role for efficient and reliable energy diversification. In this paper nonisolated dual input converter is proposed for integration and diversification of energy from two different sources with distinct voltage–current characteristics. The proposed dual input converter (DIC) is proficient for energy diversification from two sources individually and concurrently with series and parallel combination of connected sources. The proposed topology can be operated in buck, buck-boost and boost modes of operation. It offers compact design, higher degree of reliability in operation, simplicity in control and flexibility in selection of input source voltage magnitude. Comprehensive analysis of the proposed converter and detailed comparison with existing literature has also been presented. The proposed concept has been simulated in MATLAB SIMULINK and validated experimentally using dSPACE 1103 real time digital signal controller.

Topological Comparison of Dual-Input DC-DC Converters

Dual input dc-dc converters have two input voltage sources or one input source and an energy storage system like ultra capacitor, PV, battery, super capacitors and a single output load. In order to process the power in hybrid energy systems using reduced part count, researchers have proposed several multi-input dc-dc power converter topologies to transfer power from different input voltage sources to the output. This paper compares non-isolated dual-input converter topologies topologically ,based on the components count, various fields of application and different modes of operation for hybrid systems mainly used in electric vehicles and renewable energy systems composed of energy storage systems (ESSs) with different voltage-current characteristics. Dual input dc-dc converter topologies considered in this paper are investigated using MATLAB and PSIM software and output voltage and inductor current waveforms are shown.

Independent MPPTracking Method of Hybrid Solar-Wind Power Conditioning Systems Using Integrated Dual-Input Single-PWM-Cell Converter Topology

This paper proposes the modeling and control strategy to track the MPPs of hybrid PV and Wind power systems, using a new dual input boost converter. The dual input power conditioning system with an independent MPPT control scheme is introduced with minimum number of circuit elements in order to reduce the switching loss, size and cost of the system. Since the operating conditions for the PV and Wind power systems are very distinct from each other, an efficient and superior control system is required to track the MPPs of both renewable sources with the use of a simply-structured single-ended single-inductor converter. The design of Power-Conditioning System (PCS) and detail control strategy are presented in this paper. To provide independent tracking of MPPs, a variable duty-cycle control strategy is employed for the wind system and a variable frequency strategy is employed for the PV system. Finally, the proposed dual-input converter for hybrid power conditioning system is implemented and the hardware test results are presented. From the hardware experiment, it is concluded that the proposed system successfully tracks the MPPs of both of the renewable power systems independently.

Design and control of a grid tied 6-switch converter for two independent low power wind energy resources based on PMSGs with MPPT capability

In this study, a novel three-phase six-switch dual input converter is proposed and employed as a rectifier to integrate two variable speed wind turbines based on permanent magnet synchronous generator (PMSG) into the utility grid. The proposed converter is derived by reducing the number of switches of nine switch converter. It is also noticeable that the proposed topology is cost-efficient especially in low power applications, due to the fact that the cost of IGBTs is nearly the same for the average ratings of switches. Utilized control method promises sinusoidal waveforms and obtains unity power factor in generators side. In order to enhance the efficiency of the system, a maximum power point tracking (MPPT) algorithm is also applied. MATLAB/SIMULINK is used as an aid to test the converter and the control scheme. Moreover, an experimental prototype of the proposed rectifier is implemented so as to evaluate analysis, control method and simulation results.

Two-Stage Solar Photovoltaic-Based Stand-Alone Scheme Having Battery as Energy Storage Element for Rural Deployment

Solar photovoltaic (PV)-based stand-alone systems have evolved as a promising solution to the issue of electrification in areas where the grid is not available. The major challenges in designing such systems are as follows: 1) extraction of maximum power from the PV array; 2) protection of the battery from overcharge and overdischarge; 3) dc to ac conversion; and 4) provision for adequate voltage boosting. As multiple objectives are required to be satisfied, the existing schemes for stand-alone systems require a minimum of three converter stages, leading to considerable reduction in the reliability and efficiency of the system. In order to address this issue, a two-stage stand-alone scheme consisting of a novel transformer-coupled dual-input converter (TCDIC) followed by a conventional full-bridge inverter is proposed in this paper. The proposed TCDIC can realize maximum power point tracking and battery charge control while maintaining the proper voltage level at the load terminal. The small signal mathematical model of the TCDIC is derived. A suitable control strategy for the proposed TCDIC is devised. The operation of the scheme is verified by performing detailed simulation studies. A laboratory prototype of the scheme is developed. Detailed experimental validation of the scheme utilizing the laboratory prototype is carried out to confirm the viability of the scheme.

Design and Implementation of a Power Converter to Process Renewable Energy for Step-down Voltage Applications

In this study a power converter to process renewable energy is proposed, which can not only process solar energy but deal with wind power. The proposed converter is derived from two series modified forwards to step down voltage for charger system or dc distribution application, so as called Modified-Forward Dual-Input Converter (MFDIC). The MFDIC mainly contains an upper Modified Forward (MF), a lower MF, a common output inductor and a DSP-based system controller. The upper and lower MFs can operate individually or simultaneously to accommodate the variation of atmospheric conditions. Since the MFDIC can process renewable power with interleaved operation, the ripple of output current is suppressed significantly and thus better performance is achieved. In the MFDIC only a common output inductor is needed, instead of two separated inductors, so that the volume of the converter is reduced significantly. To draw maximum power from PV panel and wind turbine, perturb-and-observe method is adopted to achieve the feature of Maximum Power Point Tracking (MPPT). The MFDIC is constructed, designed, analyzed, simulated and tested. Simulations and practical measurements have demonstrated the validity and the feasibility of the proposed dual-input converter.

High‐efficiency dual‐input converter with high‐voltage gain and internal charge function

In this study, a high-efficiency dual-input converter with an internal charge circuit is developed. The proposed coupledinductor- based converter can boost the voltages of two input power sources with different low-voltage levels to a controllable high-voltage DC bus. The high-voltage DC bus can be taken as the main power for a high-voltage DC load or the front terminal of a DC?AC inverter. The charge circuit inside the proposed dual-input converter can provide the redundant energy from the major source for the auxiliary power source (e.g. battery module) to save the manufacturing cost. According to the operation of power management, the operational states of the proposed dual-input converter can be divided into three situations including a standalone power-supply state, a charge state and a unify power-supply state. The techniques of voltage clamping and soft switching are employed in this converter, and the corresponding device specifications are adequately performed. Thus, the goal of high-efficiency dual-input power conversion with high-voltage gain can be achieved. Some experimental results via a 1.5 kW-level prototype are given to verify the effectiveness of the proposed dual-input converter in practical applications.

A Power Supply System with ZVS and Current-Doubler Features for Hybrid Renewable Energy Conversion

In this paper, a power supply system for hybrid renewable energy conversion is proposed, which can process PV (photovoltaic) power and wind-turbine energy simultaneously for step-down voltage and high current applications. It is a dual-input converter and mainly contains a PV energy source, a wind turbine energy source, a zero-voltage-switching (ZVS) forward converter, and a current-doubler rectifier. The proposed power supply system has the following advantages: (1) PV-arrays and wind-energy sources can alternatively deliver power to the load during climate or season alteration; (2) maximum power point tracking (MPPT) can be accomplished for both different kinds of renewable-energy sources; (3) ZVS and synchronous rectification techniques for the active switches of the forward converter are embedded so as to reduce switching and conducting losses; and (4) electricity isolation is naturally obtained. To achieve an optimally dynamic response and to increase control flexibility, a digital signal processor (DSP) is investigated and presented to implement MPPT algorithm and power regulating scheme. Finally, a 240 W prototype power supply system with ZVS and current-doubler features to deal with PV power and wind energy is built and implemented. Experimental results are presented to verify the performance and the feasibility of the proposed power supply system.

An Isolated Dual-Input Converter for Grid/PV Hybrid Power Systems

An isolated dual-input power converter for a grid/photovoltaic (PV) hybrid power indoor lighting system is proposed in this paper. The proposed converter can be operated in single power supply mode or hybrid power supply mode. While the available PV power is insufficient for the load demand, the proposed dual-input converter will automatically deliver the complement power from the grid. The power complementing is achieved by two independent control loops of the PV power and the grid power. Finally, a prototype for a 36W LED lighting module is constructed to verify the validity of the proposed converter. From the experimental results, it can be seen that a smooth 24V/1.5A output power for the LED lighting module can be provided even while the PV power is insufficient or unavailable.

A Review and Design of Power Electronics Converters for Fuel Cell Hybrid System Applications

This paper presents an overview of most promising power electronics topologies for a fuel cell hybrid power conversion system which can be utilized in many applications such as hybrid electrical vehicles (HEV), distributed generations (DG) and uninterruptible-power-supply (UPS) systems. Then, a multiple-input power conversion system including a decoupled dual-input converter and a three-phase neutral-point-clamped (NPC) inverter is proposed. The system can operate in both stand-alone and grid-connected modes. Simulation and experimental results are provided to show the feasibility of the proposed system and the effectiveness of the control methods.