Buck Converter System Research Articles

Experimental Evaluation of the Robust Controllers Applied on a Single Inductor Multiple Output DC-DC Buck Converter to Minimize Cross Regulation Considering Parametric Uncertainties and CPL Power Variations

This paper presents two control design strategies for voltage regulation in a single inductor dual-output DC-DC buck converter system. Based on a nominal multiple input multiple output plant model and performance requirements, both a Linear Quadratic Regulator and a Decoupled PI control law are designed to control the power converter system under parametric uncertainties such as voltage source variation, constant power load variation, and load resistance variation. Therefore, the converter can cascade operation, which may cause the undesired effects of voltage oscillation and reduce the system’s stability margin. The control performance was assessed under both the uncertainties of resistive loading and the power variation in a constant power load. A single inductor dual-output DC-DC buck converter board was developed for experimental tests. The experimental results show that the Linear Quadratic Regulator strategy, compared to the PI strategy, presented a robust performance in the presence of parametric uncertainties in the resistive load-bearing; however, it was sensitive to uncertainties due to the presence of constant power loads.

Disturbance rejecting PID-FF controller design of a non-ideal buck converter using an innovative snake optimizer with pattern search algorithm

The optimal design of a proportional-integral-derivative controller with two cascaded first-order low-pass filters (PID-FF) for non-ideal buck converters faces significant challenges, including effective disturbance rejection, robustness to parameter variations, and the mitigation of high-frequency signal noise, with existing approaches often struggling and leading to suboptimal performance in practical applications. This study addresses these challenges by introducing a constraint on the open-loop crossover frequency to mitigate high-frequency noise and ensuring the controller prioritizes maintaining constant output voltage and robust responsiveness to input voltage and load current variations. This study also introduces an innovative metaheuristic algorithm, the opposition-based snake optimizer with pattern search (OSOPS), designed to address these limitations. OSOPS enhances the Snake Optimizer (SO) by integrating opposition-based learning (OBL) and Pattern Search (PS), thereby improving its exploration and exploitation capabilities. The proposed algorithm design includes a crossover frequency constraint aimed at counteracting high-frequency noise and ensuring robust performance under diverse disturbances. The efficacy of the OSOPS algorithm is demonstrated through rigorous statistical box plot analysis and convergence response comparisons with the original SO algorithm. Additionally, we systematically compare the performance of the OSOPS-based PID–FF–controlled non-ideal buck converter system against systems utilizing the original SO algorithm and the classical pole placement (PP) method. This evaluation encompasses transient and frequency responses, disturbance rejection, and robustness analysis. The results reveal that the OSOPS-based system outperforms the SO- and PP-based systems with 14.21 % and 32.10 % faster rise times, along with 15.38 % and 84.95 % faster settling times, respectively. The OSOPS and SO systems also exhibit higher bandwidths, exceeding the PP-based system by 18.74 % and 17.03 %, respectively. By addressing the key challenges in PID-FF controller design for non-ideal buck converters, this study provides a substantial advancement in control strategy, promising enhanced performance in practical applications.

Investigation on the Effect of Parasitic Elements on PID Control of DC-DC Buck Converter

DC-DC converter circuits are used in many electronic devices to adjust the voltage to a certain level such as Electric Vehicle. DC-DC Buck converters, which are the most used type of DC-DC converters, reduce the input voltage and keep the output voltage constant at a desired reference voltage value. In this study, the effect of parasitic elements in Buck DC-DC converters is examined on the PID controllers. Parasitic elements cause a non-linear effect on the Buck converter system model. Studies in the literature generally control the output voltage by designing controllers on the Buck converter model without parasitic elements. Alternatively, linear controllers such as PID are designed according to the linearizing model, taking into account the effect of parasitic elements. In addition, nonlinear controllers are designed on the full model with the effect of parasitic elements. In this study, the effect of parasitic elements on linear controllers, especially PID, is examined.

A novel opposition-based hybrid cooperation search algorithm with Nelder–Mead for tuning of FOPID-controlled buck converter

This paper introduces a novel metaheuristic algorithm named the opposition-based cooperation search algorithm with Nelder–Mead (OCSANM). This enhanced algorithm builds upon the cooperation search algorithm (CSA) by incorporating opposition-based learning (OBL) and the Nelder–Mead simplex search method. The primary application of this algorithm is the design of a fractional-order proportional–integral–derivative (FOPID) controller for a buck converter system. A comprehensive evaluation is conducted using statistical boxplot analysis, nonparametric statistical tests and convergence response comparisons to assess the algorithm’s performance and confirm its superiority over CSA. Furthermore, the FOPID-controlled buck converter system based on OCSANM is compared with two top-performing algorithms: one using a hybridized approach of Lévy flight distribution with simulated annealing (LFDSA) and the other employing the improved hunger games search (IHGS) algorithm. This comparison encompasses transient and frequency responses, performance indices and robustness analysis. The results reveal the notable advantages of the proposed OCSANM-based system, including 25.8% and 8.7% faster rise times, 26% and 8.8% faster settling times compared with the best-performing approaches, namely LFDSA and IHGS, respectively. In addition, the OCSANM-based system exhibits a 34.7% and 9.6% wider bandwidth than the existing approaches-based systems. Incorporating voltage and current responses of the buck converter’s switched circuit with the OCSANM-based FOPID controller further underscores the algorithm’s effectiveness. To provide a comprehensive assessment, the paper also compares the proposed approach’s time and frequency domain responses with those of 17 other state-of-the-art approaches attempting to control buck converter systems similarly. These findings affirm the effectiveness of the OCSANM in designing FOPID controllers for buck converter systems.

Design and Optimization of Voltage Mode PWM Control of DC-DC Buck Converter with a PI-Lead Compensator Using the Simulated Annealing Algorithm

This paper presents a method for improving the performance of DC-DC Buck Converter Systems using voltage mode Pulse Width Modulation (PWM) control. We explore the effectiveness of Proportional-Integral (PI) and Lead Compensator controllers in enhancing system stability, minimizing voltage fluctuations, and improving load response. The system is modeled through transfer functions, and the controllers' impacts are analyzed both individually and in tandem. A key contribution of this work is the optimization of the PI-Lead Compensator parameters utilizing the Simulated Annealing Algorithm, which is fine-tuned to improve phase margin, gain crossover frequency, and steady state error. These parameters are critical for optimizing the system’s output performance. Through MATLAB simulations, we demonstrate the iterative process of parameter optimization and validate the algorithm's efficacy in managing the DC-DC Buck Converter. The results highlight the enhanced performance achieved with the optimized parameters, providing a viable solution for effective control of DC-DC Buck Converter Systems.

FOPID Controller Design for a Buck Converter System Using a Novel Hybrid Cooperation Search Algorithm with Pattern Search for Parameter Tuning

This research introduces a novel metaheuristic algorithm, OCSAPS, representing an upgraded cooperation search algorithm (CSA) version. OCSAPS incorporates opposition-based learning (OBL) and pattern search (PS) algorithms. The proposed algorithm's application aims to develop a fractional order proportional-integral-derivative (FOPID) controller tailored for a buck converter system. The efficacy of the proposed algorithm is assessed by statistical boxplot and convergence response analyses. Furthermore, the performance of the OCSAPS-based FOPID-controlled buck converter system is benchmarked against CSA, Harris hawk optimization (HHO), and genetic algorithm (GA). This comparative analysis encompasses transient and frequency responses, performance indices, and robustness analysis. The outcomes of this comparison highlight the distinctive advantages of the proposed approach-based system. Moreover, the proposed approach's performance was compared with six other approaches used to control buck converter systems similarly regarding both time and frequency domain responses. Overall, the findings underscore the efficacy of the OCSAPS algorithm as a robust solution for designing FOPID controllers in buck converter systems.

Mismatched disturbance compensation enhanced robust H∞ control for systems with nonvanishing uncertainties/disturbances

AbstractThis article proposes a robust control method based on disturbance observer techniques for systems subject to mismatched uncertainties/disturbances. In the existing composite robust control methods with disturbance compensation, only matched uncertainties/disturbances, that is, the uncertainties/disturbances acting on the same channels as the control inputs, are feedforward compensated, while the mismatched ones are only attenuated in a conservative manner. It should be highlighted that if the mismatched uncertainties/disturbances are nonvanishing, the controller generally requires excessive control energy to suppress the effects of uncertainties/disturbances, where the control gains must be designed to ensure robust properties at the expense of sacrificing nominal tracking and/or stabilization performances. To address this problem, this article further introduces the compensation of mismatched uncertainties/disturbances into the robust control. Moreover, to attenuate the effects of observation errors, sufficient conditions for the asymptotic and robust stability of error systems are established. Finally, the proposed controller is applied to a DC–DC buck converter system feeding constant power load. Experimental results confirm its feasibility and efficiency.

An Objective Holographic Feedback Linearization Based on a Sliding Mode Control for a Buck Converter with a Constant Power Load

As a typical load, the constant power load (CPL) has negative impedance characteristics. The stability of the buck converter system with a mixed load of CPL and resistive load is affected by the size of the CPL. When the resistive load is larger than the CPL, the buck converter with the output voltage as an output function is a non-minimum phase nonlinear system, because its linear approximation has a right-half-plane pole. The non-minimum phase characteristic limits the application of many control techniques, but the objective holographic feedback linearization control (OHFLC) method is a good control strategy that can bypass the non-minimum phase system and make the system stable. However, the traditional OHFLC method, in designing the controller, generally uses a linear optimal quadratic design method to obtain a linear feedback control law. It requires a state quantity component with a one-order relative degree to the system. But it is not easy to find such a suitable state quantity with a one-order relative degree to the system. In this paper, an improved OHFLC method is proposed for Buck converters with a mixed loads of CPL and resistive loads, using the sliding mode control (SMC) theory to design the controller, so that the output state quantity components with different relative degrees to the system can be used in the holographic feedback linearization method. Finally, the simulation and experimental results also demonstrate that this method has the same, or even better, dynamic response performance and robustness than the traditional OHFLC method.

Enhanced Tracking of DC-DC Buck Converter Systems Using Reduced-Order Extended State Observer-Based Model Predictive Control

Enhanced Tracking of DC-DC Buck Converter Systems Using Reduced-Order Extended State Observer-Based Model Predictive Control

An Extended-State Observer Based on Smooth Super-Twisting Sliding-Mode Controller for DC-DC Buck Converters

This paper designs a novel smooth super-twisting extended-state observer (SSTESO)-based smooth super-twisting sliding-mode control (SSTSMC) scheme to promote the robust ability and voltage-tracking performance of DC-DC buck converters. First, an SSTESO is proposed to estimate the unknown lumped disturbance and compensate for the estimation of the voltage controller. The SSTESO is realized by constructing a novel smooth function to replace the nonlinear sign function in STESO, which can provide a faster convergence speed and higher estimation accuracy. The SSTSM controller is designed by adopting a similar smooth function to further suppress chattering and improve dynamic response. Comprehensive simulation results demonstrate that the proposed SSTESO-based SSTSMC scheme can improve the robustness and transient response of a DC-DC buck converter system in the presence of external disturbance and parameter uncertainties.

Immersion and invariance based adaptive command filtered backstepping control design for a class of SISO uncertain nonlinear systems in strict-feedback form

In this article, an immersion and invariance based adaptive command filtered backstepping control method (I&I ACFBC) is proposed for a class of single-input and single-output (SISO) uncertain nonlinear systems in strict-feedback form. The problem of the explosion of complexity inherent to the traditional adaptive backstepping control design is solved by applying the proposed adaptive control technique, and the compensating signals are constructed to reduce the effect of the known filtering errors produced by the command filters. The adaptive laws are achieved by an immersion and invariance method. The Lyapunov stability theory is utilized to ensure the boundedness of all the signals in the closed-loop system. The feasibility and validity of the proposed adaptive control scheme are demonstrated by the simulation and experimental results on a DC-DC buck converter system.

Enhanced performance of hysteresis controlled single phase Ac/Dc buck converter system using cubic boron arsenide semiconductor material

This paper presents a single phase AC-DC buck converter using Hysteresis controller in order to provide superior response. As an alternative to the DC grid, the single phase AC/DC buck converter is getting prominence. The rectifier's AC output is fed into a Buck converter (BC) and then filtered with a filter. Higher order harmonic components are present in the power drawn by nonlinearandunbalancedloads,whichinturn raises the supply current’s totalharmonicdistortionlevel. In comparison to other controllers, hysteresis current controllers are well known for their robustness, faster error tracking, greater dynamic response and simplicity of implementation. In this study, a single phase buck converter system with a Proportional Integral controller (PIC) and a Hysteresis controller is modelled and simulated (HC). The findings of comparing the performance of buck converters with PIC and HC are presented. The outcomes show that an HC controlled Buck Converter responds more quickly. Because of improvements in material science and a desire for higher performance, wide band-gap semiconductors are used in switching circuits. This paper also discusses the cubic boron arsenide semiconductor material, which is used to create the power electronic switches used in AC-DC converters and has good thermal conductivity and high manoeuvrability for electrons and holes.

Robustness enhancement of DRL controller for DC–DC buck convertersfusing ESO

Recent application studies of deep reinforcement learning (DRL) in power electronic systems have successfully demonstrated its superiority over conventional model-based control design methods, stemming from its adaption and self-optimisation capabilities. However, the inevitable gap between offline training and real-life application presents a significant challenge for practical implementation, owing to its insufficient robustness. With this in mind, this paper proposes a novel robust DRL controller by fusing an extended state observer (ESO) for the DC–DC buck converter system feeding constant power loads (CPLs). To be specific, the mismatched lumped terms are reconstructed by an ESO in real time, and then fed forward into the agent's action, aiming to improve the adaptability to parameter variations of the real-life converter systems. By carefully conducting simulation and experimental tests, the robustness enhancement ability of the proposed framework compared with model-free DRL and conventional PI controllers are clearly verified.

Simple formula for designing the PID controller of a DC-DC buck converter

This paper proposes a simple way to design a proportional integral derivative proportional integral derivative (PID) controller for a DC-DC buck converter. This work concerns getting the formula to calculate Kp, Ki, and Kd parameters from a PID controller easily. The main advantage of this formula is that the tuning process of the K<sub>P</sub>, K<sub>I</sub> and K<sub>D</sub> parameters of the PID controller will be simplified just by entering the R, L, and C component values of the buck converter into the formula. The synthesis process of the formula is explained step by step. State space analysis is used to model the equations and transfer functions of the buck converter. The transfer function of the PID controller and buck converter was analyzed to obtain the Buck Converter system's closed loop transfer function. The formula for calculating the parameters K<sub>P</sub>, K<sub>I</sub> and K<sub>D</sub> of the PID controller is derived from the closed loop transfer function of the buck converter system. Numerical simulations are provided to confirm the effectiveness of the proposed PID controller. The performance of the buck converter controlled by the proposed PID controller was tested under various load conditions.

ELM-Based Adaptive Practical Fixed-Time Voltage Regulation in Wireless Power Transfer System

This paper proposes an extreme learning machine (ELM)-based adaptive sliding mode control strategy for the receiver-side buck converter system in the wireless power transfer system subjecting to the lumped uncertainty. The proposed control strategy utilizes a singularity-free fixed-time sliding mode (FTSM) feedback control, which ensures a fixed-time convergence for both the sliding variable and voltage tracking error. An ELM-based uncertainty bound estimator is further designed to learn the uncertainty bound information in real-time, which opportunely loosens the constraint of bound information requirement for sliding mode control design. The global stability of the closed-loop system is rigidly analyzed, and the good performance of the proposed control strategy is validated by comparison experiments which exhibit ideal overshoot elimination, 45.70–51.72% reduction of settling time, and 13.65–36.96% reduction of the root mean square value for voltage tracking error with respect to different load types.

A novel-enhanced metaheuristic algorithm for FOPID-controlled and Bode’s ideal transfer function–based buck converter system

The search for a better approach to design a convenient controlling scheme is one of the main challenges of the research field related to power converters. This paper brings forward a significant contribution as part of this challenge. In this regard, novel approaches have been proposed for both controller scheme and tuning algorithm. In terms of controlling scheme, a fractional-order proportional–integral–derivative (FOPID) controller was used alongside the Bode’s ideal transfer function to achieve optimum performance of a buck converter system. To achieve a greater performance of the FOPID controller, a novel metaheuristic algorithm, which consists of a balanced structure in terms of explorative and exploitative phases, has also been developed by hybridizing the hunger games search algorithm with simulated annealing technique. The proposed hybrid algorithm helped tuning the FOPID controller optimally. The proposed algorithm and controlling scheme have been proved to be a better approach for controlling a buck converter system in terms of time and frequency domains along with disturbance rejection. To further verify the effectiveness of the proposed hybrid algorithm–based controlling scheme, it was compared with other reported and capable approaches which have also confirmed the greater performance of the proposed approach.

Fixed-Time Sliding Mode Control for DC/DC Buck Converters With Mismatched Uncertainties

In this paper, the fixed-time control problem of DC-DC buck converter systems with mismatched disturbances is investigated. Firstly, the sliding mode fixed-time observers are constructed to estimate the matched and mismatched disturbances of the systems. Secondly, a novel segmented terminal sliding mode control (TSMC) variable considering the mismatched disturbance of the system is designed based on the observations. To improve the tracking performance, a new second-order fixed-time reaching law is proposed. Then, in order to make the DC-DC buck converter systems with mismatched disturbances achieve accurate control in a fixed-time independent of the initial state, a novel fixed-time nonsingular TSMC based on the fixed-time observers is proposed. Finally, comparative experiments are conducted to verify the effectiveness and practicality of the proposed control strategy.

Advanced discrete-time sliding mode control with fast output sampling and its application to buck converter

In this paper, a relative degree two (RD2) sliding variable based discrete time sliding mode control (DTSMC) is designed for a linear time invariant system when output sampling is done faster than control input computation. The RD2 framework has been established for better performance and improved robustness of the discrete time sliding mode control system. The paradigm of fast output sampling (FOS) is utilized since it allows control computation using only the sampled output information, which is important from the implementation perspective making the design practical. A formal analysis is presented to establish the range of the controller parameters for this novel combination of DTSMC with RD2 sliding variable in the FOS framework. Also, a quantitative analysis of robustness in terms of ultimate band for the RD2 approach is done and compared with that of the RD1 approach. The theory is validated in a test bench application of a buck converter for tracking voltage references utilizing the FOS paradigm. The FOS paradigm had previously not been tested in any practical system with DTSMC, and this is the first time it is presented for the dc–dc buck converter system.

A Revisit to Model-Free Control

Starting from Fliess's model-free control (MFC) technique developed 15 years ago, this article aims to provide a systematic framework for characterizing, benchmarking, and generalizing this emerging control technique, with a particular focus on power electronics (PE). It examines the performance of MFC in terms of dynamic response, stability, and robustness, using the classical control theory as a basic tool. A theoretical comparison is conducted with the conventional linear control techniques on dynamic response and performance robustness. A generalized MFC theory and means to enhance its robustness performance are also highlighted. This article suggests that MFC, in contrast to the conventional understanding based on model-independent error dynamics, is practically a model-based control technique. Such model dependence characteristics under MFC become more severe for PE systems. However, following a new design principle, MFC is found possible to possess extraordinarily robust performance against model variations as compared to most existing model-based control methods. On top of that, stability margin is found to be the key bottleneck hindering the performance robustness of the existing MFC techniques. A new MFC with greater stability margin and performance robustness is proposed in this article. Comprehensive Pareto fronts analysis, simulations, and experiments are conducted on a buck converter system to verify the new understandings and conclusions drawn from the framework. With the new design principle and the new MFC, the system is able to demonstrate an almost constant dynamic response despi <bold xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">te</b> 25-fold circuit parameter ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">R, C</i> , and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">L</i> ) variations and 1.85-fold input voltage variations.

Modeling and Performance of a Buck Converter Based on ‘Fuzzy Logic Soft Computing Technique’ for Low Voltage Operations

This present paper details a ‘fuzzy logic soft computing technique’ of designing a controller for a buck converter operating at low voltages. The dc – dc buck converters find applications in solar energy technologies where they are used in solar control charging systems, battery charging systems, drones, in the automotive industry where there is integration of the engine and dc-dc motor drives resulting in hybrid electric drives or vehicle’s. Conventional controllers that is the proportional derivative control (pid) have dominated the control engineering field from the time of invention, however, these controllers present increased overshoot and a long time to achieve steady-state conditions. In this regard since fuzzy logic has intelligent capabilities, then a fuzzy logic soft computing-based controller is proposed in this paper. A mathematical analysis of the dc-dc buck design is also given and the modeling of the fuzzy logic control algorithms that avoids mathematical analysis is also discussed. Fuzzy control is one of the soft computing tools that consists of the observation made by people and their decision based on non-numerical information is also discussed. The performance analysis of the fuzzy controller is determined under constant load and variable decreasing voltage conditions. The analysis and simulation of the dynamic response in closed-loop frequency response are conducted in the Simulink platform in Matlab. The proposition of control is executed on a dc-dc step down converter for an input of 12V. This proposed fuzzy logic control technique provides a dc – dc buck converter system with increased overall operating efficiency and a very stable output.