Dual-output Converter Research Articles

Systematic Review of Bidirectional, Multiport Converter Structures and Their Derivatives: A Case Study of Bidirectional Dual Input Dual Output Converters

This study thoroughly compares multiple single bidirectional and multiport converters (MPCs), highlighting the significant role of MPCs in multi-input and multi-output (MIMO) systems. MPCs offer a more efficient and cost-effective solution than multiple single converters, especially in applications involving photovoltaic (PV), electric vehicles (EVs) with storage systems, and power grids. This research emphasizes the importance of multi-input converters (MICs) in integrating diverse voltage sources. It notes the rising popularity of multi-output DC-DC converters in portable electronics, owing to their reduced component count, lower costs, and compact design. This paper emphasizes comparisons based on diverse aspects and applications, shedding light on recent developments in basic bidirectional converters. Additionally, it delves into the advancements in MPC topologies, focusing on efficiency, reliability, and modularity improvements. These advancements are crucial for harnessing cost reduction, simplicity, and compactness. Furthermore, this paper introduces an innovative multiport DC-DC converter tailored for integrating and managing renewable sources. This new converter design enhances PV system and battery storage performance by reducing power conversion steps, using fewer components, and improving voltage-boosting capabilities. Its unique bidirectional buck-boost structure allows for versatile connections between sources and loads with varying voltage and power requirements. The performance of this novel converter is evaluated through MATLAB/Simulink simulations under different scenarios. Experimental studies further validate its effectiveness, marking a significant contribution to power conversion and management in integrating renewable sources such as DC microgrids.

Dependence of Continuous-Discontinuous Conduction Mode Boundary on Gate Pulse Shift in Coupled Inductor Single-Input Dual-Output Boost Converter

The coupled inductor single-input dual output (SIDO) converters can supply two different output voltages from one input voltage with reduced component counts, reduced losses, and increased efficiency. Inversely coupled inductors enhance the advantages by reducing the core and overall converter sizes. The CI-SIDO boost converters operate in three modes– continuous conduction mode (CCM), discontinuous conduction mode (DCM) and CCM/DCM boundary. Due to simple load-independent control, the CCM is preferred more for operating CI-SIDO converters. This paper introduces the method of lowering the CCM/DCM boundary, thus, widening the CCM range of the converter by shifting the gate pulse. The commonly used method of reducing the CCM/DCM boundary current is increasing the inductance values, which is not preferred due to the increased size of the core and the converter. The paper presents the shift of gate pulses to reduce the boundary current of the CI-SIDO boost without changing inductance or any other circuit element. The gate pulse shift where maximum reduction takes place is found analytically. The proposed method is experimentally verified for all possible voltages and coupled inductor parameters. The presented experiments observed the percentage reduction in CCM/DCM boundary current is up to 91.67%.

Fault-tolerant single-input dual-output converter with preserved output under fault operation

DC-DC converters have played an important role in the auxiliary power supply to electric vehicles, DC micro-grids, and portable electronic applications. To reduce the number of components and to improve the power density, multiport DC-DC converters have been recently proposed. Many multi-output converters are designed based on specific operational constraints on duty ratio or inductor currents. Further, simultaneous control of outputs is critical and involves cross-regulation issues. This paper proposes a single-input dual-output (SIDO) DC-DC converter with fault-tolerant circuit configuration to circumvent these challenges. The designed converter is helpful for the simultaneous control of loads by cross-regulation issues and has simple control without any control constraints on duty ratio or inductor currents. The topology proposed in this paper, can most significantly tolerate the failure during open-circuit for single and multiple switches and gives the preserved output voltage under fault case. The effectiveness and feasibility of the proposed configuration is validated using MATLAB/Simulink.

Comparative Analysis of Different Control Strategies for Relift Luo Converter

Dual-output DC to DC converters have drawn attention in the domestic, automobile, and industrial domains. A dual-output converter usually provides a voltage step-down channel and a voltage step-up channel. Typically, an automobile needs a battery charging unit, a traction motor drive, and several other applications. A typical application may require two channels of DC output with a low-voltage (LV) channel and a high-voltage (HV) channel. While the generic boost-derived and quadratic boost-derived dual-output converters are available in the literature, this article focuses on the control aspects of a relift type Luo converter-derived dual-output converter (LDDOC). A solar photovoltaic (SPV) source is the main power, and it charges a battery. The LV loads may be connected across the battery, and the relift stage delivers a regulated 48 V output. The regulation of the 48 V output using a PI controller, a fuzzy logic controller, an ANN-based controller, and a sliding mode controller (SMC) has been studied using simulations. The simulations reveal that the sliding mode controller is advantageous because of meeting out the required performance, easy implementation, and low cost. An experimental setup has also been developed to verify the performance of the sliding mode controller for the regulation of the HV channel output voltage at 48 V.

A novel method for hybridization of super lift luo converter and boost converter for electric vehicle charging applications

ABSTRACT The demand for electric vehicles (EVs) has increased dramatically in recent years, making it increasingly challenging to keep up with the demand for charging infrastructure. However, conventional power converters (DC–DC converters) have drawbacks such as a high component count, low voltage gain, low efficiency, and high cost. A new DC–DC multiport converter has been proposed to address these challenges by hybridizing a Super-lift Luo and Boost Converter (SLBC) with Photovoltaic (PV) and battery sources as dual inputs. The proposed Dual-Input Dual-Output (DIDO) converter offers significant advantages by super-lifting the input voltage while producing two step-up voltages, one by the Luo converter and another by the Boost converter. The SLBC uses simple structures without any additional electric circuits or transformers to generate high voltage gain and high power efficiency. To evaluate the performance of the proposed SLBC, the converter operation has been analyzed under steady-state and Continuous Current Mode conditions, and a comparison with other similar configurations has been conducted to demonstrate its benefits. Simulation and experimental results have shown that the proposed SLBC offers a considerable reduction in conduction losses compared to other SLBC converters in similar situations. Furthermore, the SLBC system provides 1.2 kW output at the charger side with 94.8% efficiency, making it a viable option for powering various EV components, including the charger, motor, lighting, and audio system, with variable voltages.

Computationally-Efficient Model Predictive Control of Dual-Output Multilevel Converter in Hybrid Microgrid

This paper presents a hybrid microgrid configuration with a flying capacitor dual-output (FCDO) converter. The output ports of the FCDO converter can directly interface ac sources/loads operating at different amplitudes and frequencies without additional ac/dc/ac converter units. Compared to the conventional configuration, the hybrid microgrid with the FCDO converter operates at multilevel voltages, reduced power conversion stages, less power switch count, and fewer control loops. The paper also presents a cascaded model predictive control (CMPC) algorithm for such configuration to control the variables, namely three-phase dual-output currents, ac/dc bus and FC voltages, and active/reactive power. The proposed CMPC sequentially executes multiple single-objective MPC units with adaptive dynamic reference (ADR) models to control the multivariable. The controller first obtains the optimum voltage vector for each output port by minimizing the output current errors, where the ADR model generates the appropriate references. Finally, the controller identifies the optimum state from the determined voltage vector pair by minimizing the FC voltage errors. Unlike conventional MPC, the CMPC algorithm reduces the computational burden of the controller and attains multivariable control without additional control loops and weighting factors. Furthermore, the converter's performance with CMPC algorithm is validated experimentally on a low-power hybrid microgrid.

An Adaptive Estimator Based Sliding Mode Control of Nonisolated Single-Input Double-Output Cuk Converter

This article presents an adaptive estimator based sliding mode control (AESMC) for a single-input dual-output (SIDO) converter used in applications requiring multiple regulated output voltages. The proposed SIDO converter is synthesized from the conventional Cuk converter by inserting an additional switch and inductor. However, the coupled capacitor present in the proposed converter topology leads to cross-coupling (CC) and cross-regulation (CR) issues, resulting in the instability of the converter. Furthermore, these issues increase the parameter design and control complexity of the converter. Therefore, this article proposes AESMC to address the CC and CR issues present in the converter. The adaptive estimator of AESMC facilitates the design of adaptive law for effectively estimating the system disturbances. Then, based on the estimated parameters, the input of the SMC is designed to generate switching pulses. Furthermore, the effectiveness of the AESMC in eliminating CC and CR effects is validated by comparing the results obtained with the decoupler+PI controller. Moreover, the system stability analysis with the proposed control technique is presented by considering the Lyapunov direct method. The effectiveness of the proposed control algorithm is evaluated in MATLAB/Simulink, and the obtained results are validated in a hardware prototype developed in the laboratory.

Design and implementation of a Fuzzy logic supervisory based on SMC controller for a Dual Input-Single Output converter

Multi-Input Converters (MIC) are an advancing technology suitable for sustainable energies, due to its ability to incorporate several Renewable Energy Sources (RES). Various structures and topologies of DC–DC converters are developed recently to ensure the highest performances of hybrid RES. The MIC are a typical coupling system which has several operating modes. Thus, their management system and controller design become complicated. This paper reports on the design, modelling, and control of a non-isolated double-input boost converter based on fuzzy supervision strategy. In fact, this work describes the design of a multi-input multi-output (MIMO) supervisor with power sharing abilities. The supervisor decides the percentage of the power for each input source. The studied converter is proficient for the integration of power sources individually or simultaneously. First, the state space model of the dual input single output converter based on the average model technique is presented. Second, an intelligent fuzzy management system is proposed. Meanwhile, the power control is based on sliding mode control (SMC). The stability of the system with the proposed SMC is proved via Lyapunov theory. Finally, a comparative study is conducted betweendifferent controllers in the supervised and non supervised modes, theses controllers (PI and SMC) have been used to control the voltage and the current loops. The validity of the suggested supervisor and its performances is tested experimentally on a laboratory prototype using dSPACE 1104 real time digital board. Experimental results demonstrate the robustness and the flexibility of the Fuzzy supervisor based on SMC (FSMC) compared to one which based on PI control(FPI) under different operating conditions.

A dynamic mismatch loss mitigation algorithm with dual input dual output converter for solar PV systems

A dynamic mismatch loss mitigation algorithm with dual input dual output converter for solar PV systems

Coupled Inductor Based Voltage Balancing in Dual-Output CLL Resonant Converter for Bipolar DC Distribution System

Bipolar dc distribution systems face imbalances in voltages when unbalanced loads are connected at the outputs. To address imbalances in bipolar voltage levels, dedicated voltage balancers are required. However, they add extra active and/or passive components; including, magnetics, capacitors, etc. This increases the cost, reduces the conversion efficiency, and power density of dual-output converters. Therefore, to tackle the imbalances in output voltages without adding any extra active and/or passive components, this article presents coupled inductor ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">CI</i> ) based voltage balancing in dual-output <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">CLL</i> resonant converter. The main features of the proposed method are as follows: since <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">CI</i> is the result of already present resonant inductors of <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">CLL</i> tank circuit, therefore, it does not require extra magnetic components to balance the output voltages; with no additional components, it does not increase the magnetic volume, component count, cost, and complexity of the converter; due to the direct coupling, a half of circuit inductances are integrated to achieve the respective resonant inductance of the tank circuit; and it can also avoid complex control schemes applied to voltage balancing. Besides, with the proposed <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">CI</i> , the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">CLL</i> converter maintains all of its good features including; zero-voltage and zero-current-switching (ZVZCS). The detailed analysis of the proposed <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">CI</i> with different load conditions is discussed. Moreover, <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LLC</i> or Type-12 resonant tank circuit is presented to validate ZVZCS operation in the reverse power flow condition. To verify the effectiveness of the proposed <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">CI</i> based voltage balancing, a 3.6-kW hardware prototype has been built and tested.

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

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

Unified Model of Peak Current Mode Controlled Coupled SIDO Converters

Coupled inductor single-input–dual-output (CI-SIDO) converters are promising converters used in the applications that demand multiple voltage supplies due to their high efficiency and small volume. However, this class of converters suffers from poor cross-coupling and cross-regulation issues, which affects the dynamic performance and stability. These issues can be suppressed with peak current mode control because of its faster dynamic response. To design the controller and study dynamic performance, a small-signal model of the system is essential, which consists of a converter model and current modulator model. However, developing the current modulator model for PCM controlled CI-SIDO converters is challenging because it consists of two reference current for two inductor currents each consisting of three slopes. No literature is available that derives a unified model of PCM controlled CI-SIDO converters. Therefore, this article proposes a unified small-signal model for PCM controlled CI-SIDO converters. The proposed model is applicable to three topologies of CI-SIDO converters, i.e., CI-SIDO buck, CI-SIDO boost, CI-SIDO boost and buck converter. The proposed unified model is a useful tool to study the dynamic performances, stability, and design outer controllers. Finally, the accuracy of the proposed unified model is verified by performing simulation and experiment of PCM controlled CI-SIDO converters considering inner-loops closed.

Partial Power Processing Multiport DC–DC Converter With Radial Module Connections

The partial power processing (PPP) concept has been extensively employed in many two-port converters to achieve high efficiency and high-power density by modifying one of the original converter ports to be connected in series between input and output. This is attractive but is confined to two-port applications, and how to extend it to multiport applications is not clear. Hence, this article aims to explore a generalized PPP multiport scheme by arranging the connection of the module rather than the converter. For a PPP single-input(output)- <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">N</i> -outputs(inputs) converter, one terminal of all <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">N</i> +1 modules is connected together to construct a radial structure, and another terminal is series/parallel connected with the input/output port. Each module only needs to process partial power caused by the voltage or current difference between input and output. Therefore, the required power rating of components is effectively reduced, contributing to low cost as well as low power loss. In this article, a PPP single-input dual-output converter with active bridge modules is also taken as an example to be introduced in detail, designed and experimented upon, which validates that high efficiency and high-power density can be achieved.

Synthesis and Implementation of a Multiport Dual Input-Dual Output Converter for Electric Vehicle Applications

In recent years, multiport DC-DC converters are seen in a variety of power converter applications in electric vehicles. The design of multiport converter architectures plays a major role in DC microgrids and electric vehicle applications. This research examines a modified multiport converter structure interface with dual inputs and dual outputs used in electric vehicles. The versatility of accommodating energy sources with varying voltage and current nature characteristics is the most notable feature of this converter. During operation, the proposed architecture can offer a boost as well as buck operations at the same time. The suggested dual input-dual output (DIDO) converter is built with fewer components and a simpler control technique which makes it more dependable and the converter is cost-effective. Furthermore, this structure allows the power to flow in both directions making it to be utilized in electric vehicle battery charging during regenerative braking. The converter’s steady-state and dynamic behavior are investigated, and a control strategy for regulating the power flow among the varied input energies is proposed. To develop the suggested converter, a small-signal model is modeled. MATLAB simulation and experimental findings are used for the verification of converter design and validated the performance behavior experimentally using a hardware setup.

A Single-Input Dual-Output DC-DC Converter for Powertrain of PEM Fuel Cell Vehicle

Multi-output converter plays a vital role in portable electronic and electric vehicle (EV) applications. In this regard, a new single-input dual output (SIDO) converter is proposed in this paper. Most of the single-input dual-output converter configurations presented by various researchers in the domain of multi-output converters function under particular assumptions about operational duty cycle and inductor current.Also, the issue of crossregulation is still prevalent while operating the loads in many SIDO converters.The proposed configuration generates two output voltages in boost and buck-boost modes without any constraints on the duty ratioor inductor currents. In addition, it doesn't encounter cross-regulation problems; subsequently, the output voltage V01 (V02) is not influenced by load changes in i02 (i01). To verify the feasibility and effectiveness of the proposed configuration, a 200 W prototype circuit is developed; simulation and experimental results are validated.

A Bi-Directional Dual-Input Dual-Output Converter for Voltage Balancer in Bipolar DC Microgrid

Bipolar DC microgrids (BDCMGs) have several issues related to the voltage and require numerous converters to supply power to both poles. To solve these issues, a bidirectional dual-input dual-output (DIDO) converter is proposed for the voltage balancer in BDCMG. The DIDO converter has dual-input sources and a dual-output port connected to the grid. Additionally, the DIDO converter simultaneously performs independent bidirectional power control and voltage balancing control. Based on the input voltages, this paper proposes modulation methods for three cases. The modulation method of the second case has a wide operating range and low balancing current ripple without increasing the switching frequency. Moreover, only voltage balancer mode without active input sources is proposed, considering the intermittent source. Therefore, it can operate as a voltage balancer under all conditions. The voltage balancing performance of the three cases was analyzed. Finally, the proposed modulation and control method of the DIDO converter were verified through experimental results.

Effect of Coupling on Discontinuous Conduction Mode of Coupled Inductor SIDO Boost Converter

A single-input dual-output (SIDO) converter with a coupled inductor is a widely used converter to generate two outputs from a single input. The analysis presented in the literature is for continuous conduction mode, where the converters are operating in heavily loaded conditions. While operating, the load may reduce, leading to the discontinuous conduction mode (DCM) of the converter. A coupled inductor SIDO (CI-SIDO) boost converter is analyzed in this article. As this converter combines two boost converters with a common input and a coupled inductor, the DCM operation of one boost affects the other. Due to coupling, it is found that the body diode of the <small>mosfet</small> turns <small>on</small> in the DCM operation of the CI-SIDO boost converter. This article finds the conditions to turn <small>on</small> body diode and its effect on the average values of the inductor current, diode current, and input current. The article also analyzes the CI-SIDO boost when the body diode is not turned <small>on</small>. This article finds the effect of change in input voltage, load current, and duty ratios on the DCM operation of the CI-SIDO boost. Simulations verify all the obtained conditions in MATLAB/Simulink and experiments using a laboratory prototype. This article is accompanied by a supplementary online document with additional illustrative diagrams and experimental results.

Unifying Inductor Current Ripples and Inductor Design in Coupled SIDO Converters by Forming Sectors of Duty Ratios

Single-input dual-output (SIDO) converters have a common input and two different outputs. An inversely coupled inductor (CI) makes the converter compact by reducing the core size. This article presents the coupled inductor SIDO (CI-SIDO) buck, boost, and buck–boost converters. It is found that numerous patterns of inductor currents are possible for these CI-SIDO converters depending on the coupled inductor parameters and duty ratios. The inductor current patterns also depend on the gate pulse patterns. With the change in the patterns, inductor current ripples change. It is difficult to analyze the numerous possibilities of inductor current patterns for all the CI-SIDO converters. This article presents an approach to unify inductor current patterns and inductor current ripples in CI-SIDO converters by forming sectors of duty ratios. In each sector, the inductor current patterns and the inductor current ripples are different from other sectors. The formation of sectors of duty ratios is valid for all three CI-SIDO converters. The article also proposes a unified coupled inductor design with reduced inductor current ripples and reduced flux in the core. Experiments verify the analysis using laboratory prototypes.

Single Coupled Inductor Converter With Simultaneous Step-Up and Step-Down Dual-Output Over Whole Load Range

Due to the advantages of small size and low cost, single-inductor dual-output converters are attractive choices to provide simultaneous step-up and step-down (SUSD) outputs in engineering applications. However, they also suffer from several limitations, including reverse port polarity, large number of conducting components, or limited output power range. Aiming to eliminate these undesired shortcomings, this article proposes a single coupled inductor dual-output converter, which can work in two modes depending on whether the secondary side of coupled inductor takes part into operation. With the mixed modes, the proposed converter cannot only provide SUSD outputs over whole load range since a new energy transfer pathway is added by using the coupled inductor, but also achieves low conduction losses owing to the reduced number of conducting components. Moreover, no additional magnetic component is required, and the negative terminals of input and outputs are connected together in the proposed converter. Its operation principle and small-signal model are also detailed introduced in the article, followed by the design of closed-loop control to improve the dynamic stability. Finally, a prototype circuit with 24 V input and 12, 48 V outputs is built to experimentally verify the converter performance.

A single input dual output converter with low cross regulation

Nowadays, many applications require multiple power supply voltages for various sub-functional modules, especially in consumer electronics. The single input dual-output (SIDO) converter contains less components is good scheme than adopt two single input single output (SISO) converters. However because of the outputs are coupled with same magnetic component, it would suffer cross regulation problem. This paper presents a cross regulation solution for the SIDO AC/DC converter. By the rectifier diode of upper output winding is replaced with a synchronous rectifier switch and the stacked design of two output windings. The energy of the two output windings can circulate with each other. Therefore cross regulation can be effectively improved. The operation principles, design procedure of the proposed solution are present and descripted. A prototype circuit was built to validate the feasibility of the proposed solution. The main advantages of proposed converter are implemented with low cost analog IC, the synchronous rectification has lower conduction loss, the stacked windings design have less total turns number and lower voltage stress for synchronous rectifier switch.