Multiple-output DC-DC Converter Research Articles

Design of digital compensators for multi-output DC-DC converters with reduced cross-regulation

ABSTRACT In the recent times, a single multi-port DC-DC converter (MPC) is highly preferred over the multiple single output DC-DC converters. Single Input Dual Output (SIDO) Buck converter with Coupled Inductors (CI) are widely employed for the reduction of multiple outputs. In this paper, the prognostic procedures to monitor MPC operating with load dynamics are discussed. The occurrence of cross-regulation during the load dynamics is suppressed by an improved digital compensator, which was specifically designed to address the cross-regulation problem. The developed digital compensation circuit is employed in the CI-SIDO Buck converter with an input of 48 V and delivering outputs of 12 V/75Watts and 24 V/125 Watts. The occurrence of cross-regulation is controlled by decoupled dual loop digital PID controller with dynamical digital compensation. A meticulous Frequency Response Analysis (FRA) with bode plot is conducted exhaustively for the derived system transfer functions. The proposed design is verified in simulation and experiments, exhibiting an enhanced results with significant suppression in cross-regulation and stability.

Optimizing weighted voltage mode control for enhanced output cross-regulation in multi-output DC/DC converters

Weighted voltage mode control is a widely used method for regulating multiple output DC-DC converters, but inconsistent outcomes are often observed in design due to the complexity of the weighting variable optimization. This study proposes an optimization-based approach to accurately estimate the optimal weighting factors for improved output voltage regulation in multiple output forward DC-DC converters. Three optimization algorithms, the Imperialist Competitive Algorithm (ICA), Particle Swarm Optimization (PSO), and Ant Colony Optimization (ACO) are compared for their speed and accuracy in estimating the weighting factors. Additionally, a Fuzzy Logic Controller (FLC) is used to further reduce the overall steady-state error and improve transient characteristics. Simulations are performed using the MATLAB/Simulink software, and the results show that the proposed strategy significantly enhances output cross-regulation in multiple output forward DC-DC converters. The ICA-based weighting factor estimator is found to be the most effective algorithm among the three optimization algorithms tested. The main contribution of this study is to provide a more efficient and accurate method for estimating the weighting factors in multiple output forward DC-DC converters, which can lead to improved performance and reliability in various applications.

An efficient controller design of a PV integrated single inductor multiple output DC-DC converter for dynamic voltage and low power applications.

In this article, a Single Inductor Multiple Output (SIMO) DC-DC boost converter for driving independent three outputs of dynamic voltage and low power is proposed. Compared with the traditional SIMO DC-DC converter, the proposed work accomplishes (i) independent control of power at each output, (ii) small switch count, (iii) relatively better scalability with increasing output channel, (iv) fast response time, and (v) relatively better efficiency. The core aim of the current article is to implement an efficient controller design of the SIMO DC converter circuit operating in continuous conduction mode for dynamic voltage applications. The SIMO circuit comprises a photovoltaic (PV) array as a renewable energy harvesting source at the input. A hysteretic controller based on direct control with seamless transition control topology is implemented in this model for SIMO operation. This scheme is popular due to its less cost, simple, easy-to-use design architecture, and fast speed of close loop control. The configuration of the solar array is designed to deliver maximum power on the input of the SIMO DC-DC converter. For tracking the maximum power point, incremental conductance with integral control configuration is applied on the PV array with fast speed and efficiency. The MATLAB/Simulink environment is utilized for model configuration. The simulation results show that the proposed SIMO configuration with the PV array provided 100.5 W and 21.7 W for 1000 W/m2 and 250 W/m2, respectively.

Multiple Input-Single Output DC-DC Converters Assessment for Low Power Renewable Sources Integration

This paper presents a comparison of Isolated (Flyback) and non-Isolated (Buck) multiple input-single output (MISO) DC-DC converters. The analysis of DC-DC converters is based on pulsed voltage source cells (PVSC). The modeling of both converter types is detailed through their mathematical models and electrical simulations using Matlab/Simulink and PSIM. The comparison focuses on the sizing parameters, non-ideal output characteristics and efficiency. Results show that the output voltage of the MISO Buck converter exhibits a linear dependence on the duty cycles control signal and has slightly higher efficiency than the Flyback converter. To validate the operation of both converters, a scenario with two inputs (low-power hydroelectric and photovoltaic voltage sources) is considered. The modeling and control of both source systems are detailed and the MISO converter performance response is evaluated under sources changes and efficiency point of view.

SIMO DC-DC Converter with Low-Complexity Hybrid Comparator-Charge Control

A hybrid control method using a comparator and a charge control method is proposed for a single-inductor multiple-output (SIMO) DC-DC converter. SIMO DC-DC converters have the weaknesses relating to cross-regulation, as all the output channels share the energy stored in a single inductor. Although multiple control methods such as Time-Multiplexing Control (TMC) and Ordered Power Distributing Control (OPDC) have been proposed to prevent cross-regulation or to improve load capability, effective use of limited resources appears to have not yet been achieved. This paper introduces a hybrid control topology that (1) utilizes comparator-based regulations for most outputs and (2) uses a new charge control loop method for the last output to reduce cross-regulation with low hardware complexity. In addition, the proposed scheme efficiently reuses the system’s redundant energy by adaptively controlling the freewheeling switch that opens the path to the input battery to store the surplus energy resources again. The proposed SIMO DC-DC converter was designed and validated with a 0.18 μm 3.3 V CMOS process. The converter has four regulated outputs of 0.9, 1.2, 1.5, and 2.2 V, and as a result of the simulation, it was found that the cross-regulation was estimated to be 0.4 mV/mA when the output current changes by ~200 mA. In addition, estimated peak power conversion efficiency of 88.5% was achieved at a total output power of 405 mW.

Multiple output high gain DC-DC converter

Multiple output DC-DC converters with high gain are the most cost-effective development in improving renewable energy applications. The high gain DC-DC boost converters can convert low voltage from renewable energy sources to high DC bus voltage level. The multiple output high gain converter has advantage of multilevel outputs which eliminate the requirement of individual converters for each voltage level. The DC-DC boost converter with multiple outputs provides boost outputs with different gains at low duty ratios with higher efficiency. The non-isolated multiple output DC-DC converter works on switched-capacitor and switched-inductor technique with a wide input voltage range. The dual power switches are driven with a single PWM drive signal. The voltage stress across components is less than half of the main output voltage. The dual outputs with single input reduce size and cost of the high gain converters in modern power electronics. The operation of DC-DC converter analysed in continuous conduction mode. The performance study of the multiple output high gain DC-DC converter is carried out with MATLAB/SIMULINK R2017b for 100W/20kHz.

Minimal switching of multiple input multilevel output DC-DC converter

This paper proposes a minimal switching multiple input multilevel output (MS-MIMLO) DC-DC converter. Minimizing the cost of operation is an utmost priority of any electric circuit design. Thus, reduction number of switches that control and manage the operation of feeding power into the MIMLO DC-DC convertors is presented. The proposed MS-MIMLO DC-DC converter exerts many advantages, include high voltage transfer ratio with a small size inductor, reduced power losses and low voltage stress across the semiconductor devices. Beside the highly conversion ratio and efficiency, the characteristics of the proposed converter have a simple configuration with low number of components as well. The MATLAB/Simulink software was implemented to simulate the proposed topology in order to verify the performance of the MS-MIMLO DC-DC converter. The result of simulations demonstrated the benefits of reducing the number of switches without affecting the operation and performance of the MIMLO DC-DC converter circuit.

The Topologies of Multi-Input Single-Output Isolation-Free DC-DC Convertor for Hybrid Power Plants

Today it is an obvious fact that energy consumption tends to increase due to technological developments, population growth, and increasing living standards. In last two decades, renewable energy sources are accepted the most convenient way. However, most of these alternative systems are not considered sufficient to supply whole demand alone. But hybrid systems with some of alternative energy sources, such as solar, wind and biomass appear to be a solution to supply the energy needs in the future. In hybrid systems, the DC-DC converter structure is the main device when converting energy for the proper loads. Single / multiple input, single / multiple output DC-DC converter topologies vary in design according to the energy demand of the load. Particularly, topologies with bi-directional power flow and less circuit elements come to the fore. In this study, the simulation of multi-input single output (MISO) DC-DC converter topologies was performed in Matlab / Simulink software. Induction current and voltage, output current and voltage, as well as output power used in the determined topologies were analyzed. The mathematical equations given in the topologies were confirmed by simulation studies.

Single-Inductor Multiple-Input Multiple-Output Converter With Common Ground, High Scalability, and No Cross-Regulation

Single-inductor multiple-input multiple-output (SIMIMO) dc-dc converters can integrate different input sources and supply power to multiple output loads with fewer components. This article proposed a current-source-mode (CSM) SIMIMO dc-dc converter. By virtue of the constant inductor current, the proposed CSM SIMIMO dc-dc converter can avoid cross-regulation naturally and allow the use of much simpler control strategy. The proposed configuration has the advantage of all inputs and outputs sharing a common ground and ease of expansion. Moreover, the number of the main circuit components is reduced. A CSM single-inductor dual-input dual-output (SIDIDO) dc-dc converter is constructed for illustration. The two input sources can work independently in the event of the two input sources being disconnected. A detailed comparison of the different SIDIDO dc-dc converters is provided.

Design and implementation of multiple output forward converter with Mag-amp and LDO as post regulators for space application

Linear power supplies are commonly used power supplies for many applications. They have some drawbacks such as low efficiency, difficulty in thermal management and also in regulation of the output voltage. Some of these drawbacks can be overcome by Switch Mode Power Supplies (SMPS). One of the best-suited applications of SMPS is for space applications that require power supplies which are lighter, smaller, more efficient and highly reliable. Multiple-output DC-DC converters are an important topology of SMPS that can be used for space applications. But, in multiple output converters usually, only the master output is regulated and the other outputs are left unregulated and this can result in cross-regulation. In this paper, post regulators such as Magnetic amplifiers (Mag-amp) and Low DropOut regulator (LDO) are proposed to regulate each output and also to improve load regulation. In addition to this, the input voltage feed-forward control technique is proposed to control the duty cycle of the switch, which is dynamically faster and provides better line regulation when compared to the voltage feedback controller. Besides, over current protection circuit for the converter is discussed in detail.
 Keywords: Cross regulation effect, Mag-amp and LDO, multiple output forward converter, output over current protection, voltage feed forward control.

Non-isolated multiple input multilevel output DC-DC converter for hybrid power system

<p><span>The utilization of multisources of energy in a compact and an effective power system gains an essential role in power electronic industry. As such, the design and simulation of a new non-isolated Multiple Input Multilevel Output (MIMLO) DC-DC converter for hybrid power system is presented. The MIMLO DC-DC converter can be integrated in renewable energy, such as fuel cells, wind turbines and photovoltaic arrays etc, to get the best output voltages. The MIMLO DC-DC converter powers the load from renewable energy sources through the independence of the availability of other sources. The proposed topology has been simulated by using MATLAB/Simulink software to testify the performance control operation of the Multiple Input Multilevel Output DC-DC converter. The results of the carried-out simulation favor the usage of multi-input voltage, rather than a single input voltage. The MIMLO design has the advantages of a simple configuration, reduced number of switches, fewer components, high efficiency, and high conversion ratio. The Multilevel Output DC-DC converter provides high voltage transfer with low size inductors, reduction of losses, low stress voltage on switches and diodes. </span></p>

Multiple output dc-dc converter derived from Cock-Croft Walton voltage multiplier and SIMO converter

Multiple output dc-dc converter derived from Cock-Croft Walton voltage multiplier and SIMO converter

Fuzzy Controlled Multiple Output Dc to Dc Flyback Converter with Output Voltage Regulation

The aim of this paper is to design and closed loop control implementation of a DC to DC Flyback converter with multiple output features. DC-DC Conversion technology is the major subject area in the field of power electronics engineering and drives and has been under development form six decades. Most of the advance systems like telecommunication and computer systems use the single output DC-DC Converter for different levels of voltage in the same system, which limits the efficiency, power density and increases the cost of the whole system. To achieve the features like high efficiency and high density for advance systems Multiple Output DC-DC Converter (MODC) are gathering much attention, and most of the research work is going to get the regulated multiple outputs, for different application like computer, electric vehicles, aircrafts etc. A MATLAB/Simulink model of a Multiple Output Flyback Converter (MOFC) is developed to get the regulated multiple output voltage. Two different control techniques have been employed such as Proportional Integral Derivative Control (PIDC) and Fuzzy Logic Control (FLC), to achieve the same for normal and disturbances cases and its performance is then estimated in terms of various parameters like Rise Time (Tr), Settling Time (Ts) and Overshoot (OS). The comparative results clearly reveal the better response of the proposed approach.

Deadbeat Control for Single-Inductor Multiple-Output DC–DC Converter With Effectively Reduced Cross Regulation

This article presents a deadbeat-based control approach for the single-inductor multiple-output (SIMO) dc-dc converter. The proposed approach contributes to effectively solve the cross-regulation problem by independently regulating different output voltages based on independent load currents. Unlike conventional model-based methods, which require the measurement of load currents, the proposed approach employs output current observers to replace current sensors. Furthermore, it obtains an excellent dynamic and steady-state voltage regulation performances. Details of the proposed controller and output current observer are discussed. For verifying the validity of the proposed approach, simulation and hardware experiments are conducted on a single-inductor dual-output (SIDO) buck converter platform. The corresponding results are analyzed and compared with the performances of the start-of-art methods.

Multiple-Output DC-DC Converters with a Reduced Number of Active and Passive Components

Multiple-output converters have been widely used where individual outputs are required. Compared with conventional separate converters, the advantage of multiple outputs is to have a lower number of active and passive components. In this paper, first, a pulse-width-modulation (PWM)-pulse-frequency-modulation (PFM) method is used for two-output converters that have only one coil and one active switch. Secondly, three-output converter topologies are proposed where the third output is controlled by phase delay (PD). These converters need only two coils and two active switches to regulate three outputs. How to obtain PD at different switching frequencies is discussed next, and a PWM-PFM-PD controlled five-output buck converter is presented. The proposed solution uses only two active switches and two magnetic cores to adjust five-output voltages independently. A modeling and digital control method are proposed in order to regulate the five output voltages. A prototype circuit with independent 15 V/1.5 A, 12 V/1.5 A, 5 V/0.8 A, −5 V/0.6 A and 3.3 V/0.45 A outputs is assembled to validate the analysis, and it was proved that it regulates the output voltages at different loads.

A Single-Stage Dual-Output Tri-Mode AC-DC Regulator for Inductively Powered Application

This paper presents a one-stage AC-DC voltage regulator with dual-output for inductively powered applications. In order to maximize the circuit performances, more than one independent regulated output voltage is often required to cater for different sub-modules in a system. The typical two-stage implementation which consists of a rectifier and a multiple-output DC-DC converter limits the overall power conversion efficiency of the receiver. A new architecture which is able to rectify and regulate two or more output voltages simultaneously in a single-stage is proposed and thereby improving the overall power conversion efficiency substantially. In addition, an energy-efficient control scheme is adopted to control the multiple switches in the architecture. Since no inductor is required in the proposed one-stage conversion structure, the cross-regulation problem that used to exist in a multiple-output switching converter has been eliminated. Apart from this, it is easier to be integrated with a system-on-chip (SoC) due to its minimized footprint. The tri-mode dual-output design was fabricated in standard $0.18~\mu \text{m}$ CMOS process. It delivers a maximum output power of 114mW. The measured peak power conversion efficiency is 91.7% at dual regulated output voltages of 1.8V and 2V.

Single‐inductor multiple‐output DC–DC converter with duty‐cycle‐constrained comparator control

An auto-buck-boost single-inductor multiple-output (SIMO) dc-dc converter with duty-cycle-constrained comparator control is presented in this Letter. Combined both comparator-based and duty-cycle-constrained controllers enable the dc-dc converter attaining fast transient response and low cross-regulation (CR). The proposed algorithm is independent of the precision of current sensor and suppresses CR robustly with the proposed tri-feedback loop control of comparator-based voltage control, duty-cycle-constrained distribution and average current control. The proposed scheme is suitable for auto-buck-boost SIMO dc-dc converter design for dynamic voltage scaling applications.

An Adaptively Controlled 10-Output Reconfigurable Dual-Bus SIMO System With Group Allocator for Diversified Load Condition

Portable electronic devices require multiple supply voltages with relatively large differences in load currents, causing serious regulation, EMI, and efficiency problems when adopting a single-inductor multiple-output (SIMO) dc-dc converter. To resolve these issues, this paper presents a reconfigurable SIMO system with ten-output having two buses, one for heavy-load and one for light-load outputs. The converter maintains the load current condition so that each bus is well balanced even when the load currents are diversified by using the proposed group allocator, which properly assigns a bus for each output depending on its load current. Due to this load balancing function, regulation issues that could occur under diversified load conditions are resolved, and high efficiency is achieved over a wide load current range. The test chip was fabricated in 1P4M 0.18 μm CMOS process. The system has ten independently regulated outputs with an output voltage ripples below 25 mV, and greater than 81% efficiency is achieved across a wide load range (0-300 mA).

Power quality improvement in switched mode power supplies using two stage DC-DC converter

This paper deals with an improved power quality multiple output switched mode power supply (SMPS) using two stage DCDC converter. A non-isolated buck-boost DC-DC converter is used as the first stage whereas single ended primary inductance converter (SEPIC) is used in the second stage. The first stage of buck-boost converter is designed in discontinuous conduction mode (DCM) for inherent power factor (PF) correction. Design and simulations of the two stage DC-DC converter with load variations on the SMPS are performed in MATLAB software to demonstrate the effectiveness of the multiple output DC-DC converter to have a stiff voltage regulation and negligible ripple.Keywords: DC-DC converter; Two stage; PFC; THD; Buck-boost converter; SEPIC; SMPS; Power quality

Robust decentralized controller for minimizing coupling effect in single inductor multiple output DC-DC converter operating in continuous conduction mode

This paper describes a novel robust decentralized control design methodology for a single inductor multiple output (SIMO) DC-DC converter. Based on a nominal multiple input multiple output (MIMO) plant model and performance requirements, a pairing input-output analysis is performed to select the suitable input to control each output aiming to attenuate the loop coupling. Thus, the plant uncertainty limits are selected and expressed in interval form with parameter values of the plant model. A single inductor dual output (SIDO) DC-DC buck converter board is developed for experimental tests. The experimental results show that the proposed methodology can maintain a desirable performance even in the presence of parametric uncertainties. Furthermore, the performance indexes calculated from experimental data show that the proposed methodology outperforms classical MIMO control techniques.