Single-input Dual-output Converter Research Articles

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.

Synthesis of Dual-Output DC−DC Converters With Coupled Inductor From a Generalized Output Branch

A generalized output branch with coupled inductor is proposed in this article, with which a diversity of single-input dual-output (SIDO) configurations can be synthesized through substituting it for the original inductor in the conventional single-input single-output (SISO) converters. Furthermore, for each configuration, multiple SIDO converters will be generated after realizing the auxiliary voltage source in the generalized output branch with two different nodes. Because the number of magnetic components remains unchanged in comparison with the SISO converter, high power density can be achieved in the derived SIDO converters with coupled inductor. Moreover, the cross-regulation problem is effectively alleviated, and soft-switching operation is realized for switches. Hence, both optimized steady-state and dynamic performance can be obtained. In this article, three example SIDO configurations based on buck, boost, and buck−boost converters are derived, and an example family of 12 SIDO converters from buck converter is demonstrated in detail. Afterwards, a unified operation principle and performance analysis suitable for all these 12 converters are also introduced, which is helpful for the topology comparison. Finally, experimental verification of the theoretical analysis is also conducted.

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.

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.

High‐gain single‐switch single‐input dual‐output DC‐DC converter with reduced switching stress

AbstractIn light‐emitting diode (LED) driver applications, as an alternative of employing two separate conventional DC‐DC converters, single‐input dual‐output converters (SIDO) have excellent performance over traditional topologies. However, SIDO has the limitation of more number switches required, which leads to higher switching losses and deteriorating efficiency. In order to overcome this drawback, this paper presents a novel of a single‐switch single‐input dual‐output DC‐DC converter with a high‐gain ratio. It attains the two boosted outputs with a high‐gain conversion ratio using a single switch by incorporating the switched‐capacitor technique. In addition, the bulkiness of the converter was reduced by utilizing only one inductor and switch. Moreover, it improves efficiency by reduced switching stress and cross‐regulation at output ends. Furthermore, the performance of the converter in continuous conduction mode (CCM) and discontinuous conduction mode (DCM) has been explained in this paper. Finally, a 120‐W hardware setup has been built and tested. The experiment results are presented to validate the merits of the proposed topology.

Analysis of single input dual output buck converter with reduced cross regulation using decoupled sliding mode control strategy

AbstractIn the present scenario, single input dual output (SIDO) converters are remarkably required for wide range of applications, as it is capable of handling two outputs with a single source. The general advantages of SIDO converters are reduced number of components in the topology; power rating can be increased or decreased depending on the application and it ease of control. However, it faces with a common problem of cross regulation occurring due to the change of load in anyone of the load terminals. This paper proposes a control technique for a SIDO buck converter (SIDO‐BC) to have a mitigated cross regulation scenario during load change. Decoupled sliding mode controller (D‐SMC) is developed for the SIDO‐BC by considering the boundary limits of the inductor current. The D‐SMC‐based SIDO‐BC provides better output regulation with mitigated cross regulation when compared to the conventional techniques. The topological small signal model derivation of the SIDO‐BC is firmly derived, and the controller is designed and developed in such way to provide a stabilized regulated output. The entire system is implemented in simulation and in experimental hardware to validate the performance.

SIDO coupled inductor‐based high voltage conversion ratio DC–DC converter with three operations

Here, a single-input, dual output (SIDO) coupled inductor-based high voltage conversion ratio DC–DC converter is proposed. The proposed converter has the capability of operating as a SIDO converter in a way that the terminal of the input voltage source is exchangeable among the three ports. Therefore, there are three different operation modes for the proposed converter. The voltage conversion ratios of the high voltage ports over the low voltage port can be improved by increasing the turn ratio of the coupled inductors. The main advantage of the proposed converter is achieving high voltage gains with lower number of components for the whole range of duty cycles comparing to the conventional multi-port high voltage gain converters. Moreover, two output voltages of the proposed converter can be simultaneously regulated on different constant levels with a good precision. In this study, the voltage conversion ratios, the inductors’ average currents, the voltage and current stress on the switches are calculated theoretically. Finally, an experimental prototype of 30 V input and 410, 260 V outputs with the power 510 W is implemented and the results are verifying the theoretical ones.

Derivation of Single-Input Dual-Output Converters With Simple Control and No Cross Regulation

The design of power converter circuits is highly dependent on the types of the input and output terminations. Conventional dc–dc converters assume the input termination being a voltage source, and the converter circuits so developed are voltage-source-mode (VSM) converters which generally consist in switching an inductor between the input and the output with two complementary switches. However, when dealing with an input current source, the counterpart current-source-mode (CSM) converters are much less known. This article derives all single-input dual-output (SIDO) converters that inherently achieves no cross regulation using both VSM and CSM buck and boost converters, and provides a detailed comparison of the different SIDO configurations in terms of step-up and step-down functions, connection type, number of ground-referenced drivers, number of inductors, number of capacitors, voltage stress, and current stress. The control requirements for independent regulation of the two outputs are discussed. For illustration purposes, one specific CSM SIDO converter is presented and its detailed operation and design considerations are discussed. Finally, experimental results are presented to verify the analytical findings.

DC–DC SIDO converter with low‐voltage stress on switches: analysis of operating modes and design considerations

In this study, a new DC–DC single-input–dual-output (SIDO) converter is proposed which is able to step up and share the input voltage between the output terminals with constant duty cycle for whole ranges of duty cycles. Due to the fact that the voltage stresses on the semiconductors of the proposed converter are considerably low, the proposed converter can be applied in both low- and high-power applications. This topology can be used instead of two boost converters, which have very improved conversion ratios in comparison with the recently presented step-up converters. The proposed configuration can be used in many applications such as renewable energy sources and diode-clamped inverter in the grid-tied systems. In this paper, steady-state and small-signal analyses of the SIDO converter are presented and the simulation and experimental results are extracted and compared. In practical applications that SIDO is needed, using single-input–single-output can be a solution, resulting high cost. To reduce the costs, this study proposes a novel topology, which has reduced components and can step up the input voltage into two separate ports. Finally, a prototype circuit with 42 V input and 510 V/372 W and 730 V/381 W outputs are built to validate the theoretical analysis.

Developing a super-lift luo-converter with integration of buck converters for electric vehicle applications

In this paper, a DC-DC multi-port converter is introduced by integrating a super-lift and a buck converter (SLBC). The proposed single-input dual-output (SIDO) converter has conventional positive output voltage super-lift advantages while simultaneously generating a step-up voltage by Luo-converter and a step-down voltage by the buck converter. In this structure, without utilizing electromagnetic components to generate a dual output, the ripple in output voltages is kept low. Meanwhile, the introduced SLBC has a simple structure and an appropriate control method providing a wide range of output voltages. Besides, to illustrate the advantages of the proposed SIDO converter, a comparison with other similar configurations is carried out. Also, simulation and experiment results indicate a considerable reduction in conduction losses compared to other SIDO converters in the same situations. The operation accuracy of SLBC is validated by performing several simulations in PSCAD/EMTDC software and testing a 150W prototype in the laboratory.

A Three-Switch-Based Single-Input Dual-Output Converter With Simultaneous Boost & Buck Voltage Conversion

With the increasing demand of applications that have two different output voltages, the single-input dual-output (SIDO) converter with fewer components is becoming the cost-effective option instead of employing two single-input single-output converters. However, the cross-regulation of different outputs is still a challenge in SIDO converters design. To save cost and obtain improved cross-regulation performance, a novel SIDO converter consisting of three active switches is proposed in this article. Owing to the use of a voltage multiplier circuit, a high step-up voltage conversion ratio is achieved with relatively low voltage stress of switches. Thanks to the independent power flow and two control variables, the cross-regulation performance is improved, and simultaneous buck as well as boost output voltages is realized. Additionally, all switches can achieve zero-voltage switching operation, which contributes to a significant switching loss reduction. The operation characteristics, design considerations, and control strategy of the proposed converter are analyzed. To verify the theoretical analysis and measure the power efficiency, a prototype circuit with 48 V input and 24 V/2 A, 200 V/1 A outputs is built.

Synthesis of Integrated Multiport DC–DC Converters With Reduced Switches

With the increasing demand of different voltage levels in industrial applications, multiport dc–dc converters have been widely employed owing to their low-cost merits. Aiming to provide more multiport topologies so that engineers can select out a preferred one for the specified application, this article proposes a novel principle to systematically implement topology derivation by replacing switches in original converters with pulsating current source cells. This principle is simple and effective, with which multiple new integrated multiport converters having a low number of switches are easily evolved. The advantage of reduced switches is very beneficial for the low-power applications with relatively less switches since the overall cost can be effectively improved. And in order to achieve a comprehensive understanding of the proposed converters, an example single-input dual-output converter that integrates the asymmetrical half-bridge flyback converter with the buck converter is analyzed in detail. It operates similarly with the two separate converters, but with favorable advantages of reduced switches and improved switching operation. Finally, an experimental prototype is built to verify the theoretical analysis.

A novel scheme for torque ripple minimization of BLDC motor used in solar air conditioner

The application of BLDC motor is constrained to certain areas due to its drawback of torque ripple. This paper presents a novel scheme of reducing the commutation torque ripple of BLDC motors by injecting additional voltage in the non-commutating phase of the motor. In this work, two independent output voltages with different magnitudes are provided by single-input dual-output (SIDO) converter. One of the voltages (Vdc1) is connected to voltage source inverter which runs BLDC motor. Another voltage (Vdc2) is added to the main voltage (Vdc1) as an additional voltage at the time of commutation between any two phases. The SIDO converter is fed from PV system incorporated with MPPT scheme. The proposed configuration is developed and simulated in MATLAB/Simulink. Results prove the effective utilization of solar power for running the BLDC motor with reduced torque ripple and applicability of the proposed scheme in solar-powered air conditioner.

A Novel Single-Input–Dual-Output Impedance Network Converter

A novel single-input–dual-output (SIDO) impedance network converter with only three switches is proposed in this paper. Due to the special features of impedance network, an artful design and some improvements are conducted on two Z-source half-bridge converters to form the proposed converter, the new designed converter can not only obtain all the advantages of Z-source half-bridge converters, but also realize dual outputs by reducing one fourth of components. The SIDO converter is potential for dual-outputs applications like electric vehicle systems for both driving the car and saving energy back. Therein, a detailed analysis of the proposed converter is conducted and the corresponding simulations are presented. Finally, the experimental results of a 100 W of implemented prototype can verify the effectiveness of the proposed converter.