Non-inverting Buck-boost Converter Research Articles

Stability analysis for an ad-hoc model predictive control in DC/DC converters with a constant power load

This paper presents a stability analysis for a horizon-one continuous control set model predictive control (MPC) for DC/DC converters connected to a constant power loads (CPLs). Different MPC approaches have been previously presented, each tailored to a specific type of converter but without a formal stability proof, failing to ensure robust performance across various operating conditions. Unlike previous works in the scientific literature, our approach is general and applicable to any second-order DC/DC converter, including the Buck, Boost, Buck-Boost, and non-inverting Buck-Boost converters. A formal stability analysis was conducted using the proposed approach, initially for the open-loop system and subsequently for the closed-loop system. The trace-determinant or triangle criterion was employed for discrete-time systems in R2. Three analyses were conducted to evaluate the performance of the proposed MPC, showing the stability issues of DC/DC converters with CPLs in open loops. This work proposes solutions using the suggested technique. Numerical simulations utilizing the Boost and Buck-Boost converters demonstrate that, in open-loop operation, even minor perturbations in the CPL value can destabilize the behavior of electrical variables. In addition, simulations show that, for the Boost converter, the settling time was about 1.5ms. Meanwhile, in the Buck-Boost case, it was about 5ms. Standardized control indicators, such as the integral absolute error criterion (IAE), the integral of the time-multiplied absolute error criterion (ITAE), and the integral of the time-multiplied square error criterion (ITSE), confirm the effective performance of the proposed one-step MPC. The values range between 1.521×10−2 and 4.591×10−6 for the Boost converter, and between 6.607×10−3 and 3.366×10−6 for the Buck-Boost topology.

Model Predictive Control With Stability Guarantee for Second-Order DC/DC Converters

This paper proposes a continuous-control-set model-predictive control (CCS-MPC) designed explicitly for second-order dc/dc converters such as the boost, buck, buck-boost, and non-inverting buck-boost converters. These converters share a bilinear dynamic structure that allows designing a generalized control. In contradistinction to the conventional finite-control-set approach, the proposed control uses a pulse-width modulation that allows a continuous control set with constant switching frequency. The modulation index's saturation is considered an inequality constraint in the optimization model. The proposed control guarantees stability in the sense of Lyapunov. This property is proven by using the passive structure of these converters. Experimental results on the four converters mentioned above show the superior performance of the proposed control in terms of robustness, offset, computation time in the central processing unit and, of course, stability.

Dead-Time Evaluation With Switching Frequency for GaN-Based Non-Inverting Buck-Boost DC–DC Converter Using FPGA-Based High-Frequency Control

Dead-Time Evaluation With Switching Frequency for GaN-Based Non-Inverting Buck-Boost DC–DC Converter Using FPGA-Based High-Frequency Control

Design of Stable Digital V2 Controllers for the Synchronous Noninverting Buck–Boost Converter

The non-inverting buck-boost converter is suitable for battery powered applications as it can operate in buck, buck-boost, and boost modes. Traditional current mode and voltage mode controllers are generally employed to control it in closed loop. It is well established that a peak V <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> controller provides superior load-transient performance compared to conventional current mode and voltage mode controllers. However, a peak V <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> controller cannot be applied to the non-inverting buck-boost converter during boost and buck-boost modes because of its non-minimum phase behavior. This paper proposes a digital peak V <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> controller which can work effectively during all the modes. The proposed controller samples both the inductor current and output voltage at the rate of the switching frequency. Thus, digital implementation of this controller does not need high-speed ADCs. Unlike traditional peak V <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> controllers, the proposed controller does not depend on effective series resistance (ESR) of the output capacitor. An average model-based small-signal model of the proposed controller is presented. Analysis shows that a sufficient current loop gain can make the system behave like a first order system. This enables the designer to employ a PI controller to achieve superior transient performance in all the modes. Furthermore, fast-scale stability analysis of the controller is carried out using approximate discrete-time models to derive an analytical stability boundary of slope compensation. A non-inverting buck-boost converter prototype is fabricated and the proposed controller is implemented using an FPGA platform. Experimental results show close correlation with the analysis.

Performance Analysis and Comparison of Non-Inverting Buck-Boost Converter Using PI, OCC, and Hybrid OCC-PI Control

The study compares and analyses the performance of the one-cycle control (OCC), hybrid one-cycle-proportional integral control (OCC-PI), and the conventional PI control method applied to the non-inverting buck-boost converter. The hybrid OCC-PI control method combines the OCC and PI control techniques to provide a hybrid non-linear closed-loop control technique for regulating the buck-boost converter. The MATLAB/Simulink equivalent system model was simulated with design parameter variations using a wide input voltage range of 9 – 36 V, a nominal output voltage of 28 V, and a fixed switching frequency of 250 kHz to validate the control response speed, reliability, and robustness of the proposed control technique. The simulation results due to input voltage, output voltage, and load variations were carried out whiles recording the settling time, overshoots, efficiency, output voltage, and inductor current ripples due to each applied control technique. The simulation results indicated that the Hybrid OCC-PI control provides better response speed and a lower output voltage overshoot relative to the PI. It also provides better reference voltage tracking compared to the OCC control method.

A PID control scheme with enhanced non-dominated sorting genetic algorithm applied to a non-inverting buck-boost converter

A PID control scheme with enhanced non-dominated sorting genetic algorithm applied to a non-inverting buck-boost converter

An Analog Multiplier Controlled Buck-Boost Converter

This brief presents an analog multiplier based controller for a noninverting buck-boost (NIBB) converter, in which the controller can work for both buck and boost modes of the NIBB converter, thus simplifying the design and saving the power and area for the controller. Moreover, it can obtain good line regulation and load regulation performances. The analog multiplier based controller can automatically change over between the buck and boost modes according to the input and output voltages. This brief, fabricated in 65-nm CMOS process, exhibits a core area of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${1}.{67}{\times }{0}.{64}{mm}^{2}$ </tex-math></inline-formula> . It outputs a stable 0.9 V when the input voltage changes from 0.7-1.4 V, with a maximum output load current of 200 mA.

Direct Model Predictive Control of Noninverting Buck-boost DC-DC Converter

In this paper, direct model predictive control (DMPC) of the noninverting buck-boost DC-DC converter with magnetic coupling between input and output is proposed. Unlike most of the other converters, the subject converter has the advantage of exhibiting minimum phase behavior in the boost mode. However, a major issue that arises in the classical control of the converter is the dead zone near the transition of the buck and boost mode. The reason for the dead zone is practically unrealizable duty cycles, which are close to zero or unity, of pulse width modulation (PWM) near the transition region. To overcome this issue, we propose to use DMPC. In DMPC, the switches are manipulated directly by the controller without the need of PWM. Thereby, avoiding the dead zone altogether. DMPC also offers several other advantages over classical techniques that include optimality and explicit current constraints. Simulations of the proposed DMPC technique on the converter show that the dead zone has been successfully avoided. Moreover, simulations show that the DMPC technique results in a significantly improved performance as compared to the classical control techniques in terms of response time, reference tracking, and overshoot.

A Coupled-Inductor-Based Soft-Switching Noninverting Buck–Boost Converter With Reduced Auxiliary Component Count

This letter proposes a coupled-inductor-based soft-switching noninverting buck–boost converter (NIBBC) with reduced auxiliary component count. Instead of using multiple auxiliary passive components to achieve soft switching, the proposed coupled-inductor-based NIBBC uses the coupled inductor as the main inductor, and the auxiliary current generated by the magnetic coupling effect is used to obtain the soft switching for all switches. With simple pulsewidth modulation under fixed frequency, full-load range zero-voltage switching can be obtained under a wide voltage range. Unlike the conventional method utilizing the coupled inductor only to generate nonactive power, the coupled inductor of the proposed converter also takes participant in the power transmission. Besides, the added diode can achieve zero current turn- <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">off</small> that avoids the diode recovery issue. The operating principle, the soft switching, and the parameter designs are analyzed in this letter. Finally, experimental results have verified the effectiveness of the proposed solution.

An Efficient Non-Inverting Buck-Boost Converter with Improved Step Up/Down Ability

In this article, a new non-inverting buck-boost converter with superior characteristics in both bucking and boosting is presented. The proposed converter has some distinct features, such as high step-up/-down ability and low voltage/current stress on its switching devices. The voltage gain of the proposed converter is double the reported value for the traditional buck-boost converter. Although it has three switches, the three switches operate simultaneously, hence no dead-time is required. Two out of the three switches are under voltage stress equal to half of the output voltage. The overall efficiency of the system is promising because of the ability to select devices with low voltage drops. Converter analysis and steady-state performance in both continuous conduction mode (CCM) and discontinuous conduction mode (DCM) are presented in detail. A 1 kW hardware prototype of the converter was implemented in the laboratory; with a step-up ratio of 3.5 and 1 kW power, the measured efficiency is above 95.4%, and with step-up ratio 8, it is around 91.5%.

Comparison of DC-DC converters for solar power conversion system

This paper covers the comparison between four different DC-DC converters for solar power conversion. The four converters are buck converter, buck-boost converter, boost converter, and noninverting buck-boost converter. An MPPT algorithm is designed to calculate battery voltage, current of PV array, the voltage of PV array, power of PV array, output power. It is observed that the non-inverting buck-boost converter is the finest converter for solar power conversion. The final circuit design has the results of 12.2V battery voltage, 0.31A current of PV array, 34V voltage of PV array, 23mW power of PV panel, and 21.8mW of output power. The efficiency of this system is nearly 95%. All four circuits are simulated in MATLAB/Simulink R2020b.

Mixed-Ripple Adaptive On-Time Controlled Non-Inverting Buck-Boost DC-DC Converter With Adaptive-Window-Based Mode Selector

A mixed-ripple adaptive on-time controlled non-inverting buck-boost dc-dc converter with novel adaptive-window-based mode selector is proposed, and no compensator is required in the control circuits. For achieving high conversion efficiency, the non-inverting buck-boost dc-dc converter only works in the buck or boost modes, not the buck-boost mode. Moreover, with the proposed mode selector, smooth transition between buck mode and boost mode can be achieved. Besides, it makes the efficiency reach its maximum when the input voltage approaches the output voltage. The proposed chip was implemented by using a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.35~\mu \text{m}$ </tex-math></inline-formula> CMOS 2P4M 3.3V/5V mixed-signal polycide process. The input voltage may range from 2.5 to 5.0 V, and the output voltage is regulated at 3.3V. According to the measured results, the maximal conversion efficiency is 97.8%.

Linear Quadratic Regulator and Fuzzy Control for Grid-Connected Photovoltaic Systems

This work presents a control scheme to control a grid-connected single-phase photovoltaic (PV) system. The considered system has four 250 W solar panels, a non-inverting buck-boost DC-DC converter, and a DC-AC inverter with an inductor-capacitor-inductor (LCL) filter. The control system aims to track and operate at the maximum power point (MPP) of the PV panels, regulate the voltage of the DC link, and supply the grid with a unity power factor. To achieve these goals, the proposed control system consists of three parts: an MPP tracking controller module with a fuzzy-based modified incremental conductance (INC) algorithm, a DC-link voltage regulator with a hybrid fuzzy proportional-integral (PI) controller, and a current controller module using a linear quadratic regulator (LQR) for grid-connected power. Based on fuzzy control and an LQR, this work introduces a full control solution for grid-connected single-phase PV systems. The key novelty of this research is to analyze and prove that the newly proposed method is more successful in numerous aspects by comparing and evaluating previous and present control methods. The designed control system settles quickly, which is critical for output stability. In addition, as compared to the backstepping approach used in our past study, the LQR technique is more resistant to sudden changes and disturbances. Furthermore, the backstepping method produces a larger overshoot, which has a detrimental impact on efficiency. Simulation findings under various weather conditions were compared to theoretical ones to indicate that the system can deal with variations in weather parameters.

Multimode Smooth Transition Technique for Three-Level Cascaded Noninverting Buck–Boost DC–DC Converter

In this article, a new three-level cascaded noninverting buck-boost converter (TL-CNIBB) is proposed, which has a superior adaptation for a wide-range voltage input of renewable energy access. Firstly, the operation principle is analyzed for TL-CNIBB and it is mainly divided into four modes, namely buck mode with the voltage ratio below or above 0.5, boost mode with the voltage ratio below or above 2. Due to multilevel and multimode features, several fundamental issues are required to be settled, such as a dead zone between buck mode and boost mode, capacitor voltage unbalance on both sides, and subharmonics at the edge of modes. For dead zone and capacitor voltage balance problems, a systematic control strategy is proposed, and four kinds of smooth transition technologies are proposed to deal with different cases. Furthermore, to avoid the chattering and subharmonics at the edge of modes, a modified hysteretic transition method is proposed. Finally, a prototype of TL-CNIBB system is constructed, and the experiments are carried out to verify the performance of the proposed system with high viability and flexibility.

A two‐phase non‐inverting buck‐boost converter for an RL load

There is an increase in renewable energy sources, which are regarded as current sources, where DC-DC converters are widely used which require more suitable loads for driving current type loads. This paper uses a duality approach to show that the converter circuit can apply to the current type loads without too much voltage variation. It illustrates the derived steps for a conventional buck converter by using graph formation. To validate the duality approach, five original switching converters are detailed. A current source with an R-L load (CSRL) converter is used for current-based applications, such as electrical motors, electromagnetic relays, or light-emitting diodes (LEDs). This study proposes a two-phase non-inverting buck-boost converter with an R-L load which is suitable for driving current-based applications. The design procedure and steady-state analysis are presented. SIMPLISTM software is used to simulate the topologies. This method for operation mode and formula derivation is like in voltage type circuit structures, and this study has sufficient mathematical analysis capabilities. For demonstration, a 650 W VSRL converter is implemented to verify the feasibility of the method. The corresponding circuit topology of the conventional circuit can be illustrated by using the duality approach rapidly.

Sensorless Adaptive Voltage Control for Classical DC-DC Converters Feeding Unknown Loads: A Generalized PI Passivity-Based Approach.

The problem of voltage regulation in unknown constant resistive loads is addressed in this paper from the nonlinear control point of view for second-order DC-DC converters. The converters’ topologies analyzed are: (i) buck converter, (ii) boost converter, (iii) buck-boost converter, and (iv) non-inverting buck-boost converter. The averaging modeling method is used to model these converters, representing all these converter topologies with a generalized port-Controlled Hamiltonian (PCH) representation. The PCH representation shows that the second-order DC-DC converters exhibit a general bilinear structure which permits to design of a passivity-based controller with PI actions that ensures the asymptotic stability in the sense of Lyapunov. A linear estimator based on an integral estimator that allows reducing the number of current sensors required in the control implementation stage is used to determine the value of the unknown resistive load. The main advantage of this load estimator is that it ensures exponential convergence to the estimated variable. Numerical simulations and experimental validations show that the PI passivity-based control allows voltage regulation with first-order behavior, while the classical PI controller produces oscillations in the controlled variable, significantly when the load varies.

DC Voltage Sensorless Predictive Control of a High-Efficiency PFC Single-Phase Rectifier Based on the Versatile Buck-Boost Converter

Many electronic power distribution systems have strong needs for highly efficient AC-DC conversion that can be satisfied by using a buck-boost converter at the core of the power factor correction (PFC) stage. These converters can regulate the input voltage in a wide range with reduced efforts compared to other solutions. As a result, buck-boost converters could potentially improve the efficiency in applications requiring DC voltages lower than the peak grid voltage. This paper compares SEPIC, noninverting, and versatile buck-boost converters as PFC single-phase rectifiers. The converters are designed for an output voltage of 200 V and an rms input voltage of 220 V at 3.2 kW. The PFC uses an inner discrete-time predictive current control loop with an output voltage regulator based on a sensorless strategy. A PLECS thermal simulation is performed to obtain the power conversion efficiency results for the buck-boost converters considered. Thermal simulations show that the versatile buck-boost (VBB) converter, currently unexplored for this application, can provide higher power conversion efficiency than SEPIC and non-inverting buck-boost converters. Finally, a hardware-in-the-loop (HIL) real-time simulation for the VBB converter is performed using a PLECS RT Box 1 device. At the same time, the proposed controller is built and then flashed to a low-cost digital signal controller (DSC), which corresponds to the Texas Instruments LAUNCHXL-F28069M evaluation board. The HIL real-time results verify the correctness of the theoretical analysis and the effectiveness of the proposed architecture to operate with high power conversion efficiency and to regulate the DC output voltage without sensing it while the sinusoidal input current is perfectly in-phase with the grid voltage.

State-of-the-Art Review on Soft-Switching Technologies for Non-Isolated DC-DC Converters

The soft-switching technology is widely used in DC-DC converters, DC-AC inverters, and AC-DC rectifiers. Soft-switching non-isolated DC/DC converters (Buck, Boost, and Buck-Boost) are the most active research area of the soft-switching technology, and fruitful results are achieved. However, there is currently no comprehensive review for the soft-switching technology of non-isolated DC/DC converters. This paper introduces soft-switching topologies for non-isolated DC/DC converters, and presents classification and characteristic of all kinds of soft-switching technologies. Some soft-switching technologies of derivative converters (non-inverting Buck-Boost converters and multiphase converters) are also presented. Finally future trends and generalized constitution methods of the soft-switching topology for non-isolated DC/DC converters are concluded. The soft-switching theory and constitution methods summarized in this article are expected to be able to guide the proposing of new soft-switching technologies for DC-DC converters.

Alternative Control Approach to Achieve Fast Load-Transient Responses in DC–DC Converters

This article proposes a controller for dc-dc converters to achieve fast load-transient responses. The controller is developed for both continuous conduction mode (CCM) and discontinuous conduction mode (DCM) of operation. The main idea is developed for buck converters, but it is shown that the proposed controller can be applied to other topologies, such as the noninverting buck-boost converter. The controller derivation, analysis, and experimental verifications are provided in both CCM and DCM, and its performance is compared with other methods. The main advantage of the proposed controller is that it minimizes the recovery times associated with load-transient responses in dc-dc converters while maintaining component sizes and other system parameters within the acceptable range. The proposed controller can be used to minimize load transients in electronic portable devices and electric vehicle charging.

A Soft-Switching Synchronous Rectification Noninverting Buck–Boost Converter With a New Auxiliary Circuit

In this article, a new soft-switching auxiliary circuit structure for the synchronous rectification noninverting buck-boost converter (NIBBC) is proposed. This new auxiliary circuit, which contains a fully coupled inductor (or a transformer), a snubber inductor, a capacitor, and a power diode, will provide zero voltage switching (ZVS) turn-ON conditions for all power transistors of the proposed NIBBC. In addition, waveform ripples in the auxiliary circuit of the output side are reduced, and then the output current ripple is also reduced. Meanwhile, the current across the main inductor is not affected by the auxiliary circuit. In order to analyze the proposed NIBBC, operating principles, soft-switching implementation conditions, and main characteristics of the proposed NIBBC are presented in this article. Finally through building a 400-W experimental prototype, key waveforms and measuring efficiency curves are obtained. Experiment result shows that all transistors of the new NIBBC operate under ZVS conditions. The efficiency of the proposed NIBBC is improved by comparing to the triangular current mode soft-switching NIBBC.