Controlled DC-DC Buck Converter Research Articles

Self-Organizing Fuzzy Neural Nonsingular Fast Terminal Sliding Mode Control of DC-DC Buck Converter

Self-Organizing Fuzzy Neural Nonsingular Fast Terminal Sliding Mode Control of DC-DC Buck Converter

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.

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.

Reinforcement Learning-Based Control of DC-DC Buck Converter Considering Controller Time Delay

Reinforcement Learning-Based Control of DC-DC Buck Converter Considering Controller Time Delay

ESO-based Backstepping Control of DC-DC Buck Converter Under Mismatched load Disturbance

The DC–DC power converter play a critical role to provide stable DC output voltage, however which is subject to various uncertainties and disturbance in supplying the sensitive loads. This paper propose a composite backstepping control strategy with extended state observer (ESO) for buck converter. Firstly, a backstepping control function is constructed to derive an inner current loop reference assuming load disturbance is known, which renders global stability of the system. An ESO is designed to estimate the mismatched load current and feedforward it to the backstepping controller to obtain disturbance rejection. Quantitative selection of control and observer gains are provided under highly nonlinear relationship of system dynamics. Rigorous stability of proposed scheme are poved with analysis of robustness. Finally, simulation results illustrate the effectiveness of the proposed control scheme in the presence of load disturbance and uncertainties

Control of DC–DC Buck Converters Using Robust Composite Backstepping and Integral Terminal Sliding Mode Approaches

This paper proposes a new composite scheme to design a robust voltage controller for DC-DC buck converters in which the composite structure combines the recursive backstepping approach with an integral terminal sliding mode controller (ITSMC). In this work, the proposed ITSMC is designed to overcome the one-degree limitation of existing ITSMCs and difficulties for the finite time convergence in standard sliding mode controllers (SSMCs) as it incorporates a quick reaching law. Moreover, the singularity problem in existing SSMCs is tackled using a modified integral sliding surface. The backstepping strategy is used to ensure the voltage monitoring with a higher degree of accuracy. The robustness of the proposed composite approach is ensured by capturing the variations in parameters, input voltage, and mismatch in the model; as all these factors are included in the dynamical model of the DC-DC buck converter based on which the proposed composite controller is designed. The robustness and stability of the proposed composite controller are simultaneously analyzed using the concept of the Lyapunov stability theory. The theoretical and analytical findings for the proposed composite robust backstepping ITSMC (RBITSMC) are further verified through extensive simulation studies in the MATLAB/Simulink platform. Performance comparisons of the proposed RBITSMC are also presented against an existing adaptive nonsingular fast terminal sliding mode controller (ANFTSMC). Finally, experimental results from the application of the proposed control strategy on a laboratory prototype are presented to justify its application on the practical system.

Design, implementation and performance evaluation of different digital control techniques for current controlled DC-DC Buck converter

The paper presents modelling, control architecture, analysis and design of digital compensators for single feedback-loop voltage mode control as well as two feedback-loop average current mode control and peak current mode control of current controlled DC-DC Buck converter operating in continuous conduction mode with output current as control variable. The compensators are derived using digital redesign approach, simulated on MATLAB, implemented as control algorithms on Texas Instruments' 32-bit TMS320F28069M microcontroller platform, and experimentally validated by testing with a laboratory prototype of current controlled Buck converter. Simulation and experimental results are discussed, compared and evaluated for converter output current performance in tracking reference current signal as well as in regulation against input voltage and load disturbances. Salient features of each control technique are identified and described to determine its suitability in applications of DC-DC converters requiring controlled output current.

Learning-Based Model Predictive Control of DC-DC Buck Converters in DC Microgrids: A Multi-Agent Deep Reinforcement Learning Approach

This paper proposes a learning-based finite control set model predictive control (FCS-MPC) to improve the performance of DC-DC buck converters interfaced with constant power loads in a DC microgrid (DC-MG). An approach based on deep reinforcement learning (DRL) is presented to address one of the ongoing challenges in FCS-MPC of the converters, i.e., optimal design of the weighting coefficients appearing in the FCS-MPC objective function for each converter. A deep deterministic policy gradient method is employed to learn the optimal weighting coefficient design policy. A Markov decision method formulates the DRL problem. The DRL agent is trained for each converter in the MG, and the weighting coefficients are obtained based on reward computation with the interactions between the MG and agent. The proposed strategy is wholly distributed, wherein agents exchange data with other agents, implying a multi-agent DRL problem. The proposed control scheme offers several advantages, including preventing the dependency of the converter control system on the operating point conditions, plug-and-play capability, and robustness against the MG uncertainties and unknown load dynamics.

LADRC Based Digital Control DC-DC ASIC Design

The Internet of Things (IoT) systems require power management modules to have the characteristics of low power consumption, high conversion efficiency, high integration, stable output, and good dynamic response. Due to its ease of tuning and superior control performance, linear active disturbance rejection control (LADRC) is an attractive design option. Yet, to date, due to its high complexity, LADRC has been used in software systems, while little effort has been made in its hardware implementation. In this work, we investigate and explore efficient hardware implementation of the LADRC algorithm. A fully integrated digital LADRC controller for DC-DC Buck converters is synthesized with UMC 55 nm CMOS process. Its input voltage is 5V, stable output voltage is 2V, and rated operating current is 100mA. To our best knowledge, this is the first work to implement LADRC algorithms in hardware. Simulation results show that the LADRC controller is superior to the PID controller in the terms of start-up time, line regulation, load regulation.

Design, Implementation and Performance Evaluation of Different Digital Control Techniques for Current Controlled DC-DC Buck Converter

Design, Implementation and Performance Evaluation of Different Digital Control Techniques for Current Controlled DC-DC Buck Converter

Determination of Different Types of Controller Parameters Using Metaheuristic Optimization Algorithms for Buck Converter Systems

The steady-state operation with low error and the fast dynamic response in transient of the DC-DC converter circuits depend on the controller design. The performance of the controller used in DC-DC converters, which vary the level of DC voltage depends on the controller coefficients. Although classical methods are often used to determine these coefficients in controller design, various modern optimization methods have been recently used. In this study, the DC-DC buck converter control simulation is performed with FOPID, PID and TID controllers. Aquila Optimizer, African Vultures Optimization Algorithm and Hunger Games Search optimization algorithms are used to determine the coefficients of these controllers in the literature. However, Fitness-Distance Balance Based Runge Kutta is employed first time for PID controller in buck converter in this study. The performance indices integral absolute error, integral square error, integral time absolute error, and integral time squared error are employed to assess the outcomes. When the results obtained are examined, the FOPID controller gives the best results in the control of the buck converter. These results are obtained by using the coefficients determined by the Fitness-Distance Balance Based Runge Kutta (FDBRUN) optimization algorithm. It has better performance than the other algorithms.

Electromagnetic Interference Characteristics and Reduction Using CISPR11 for a Medical Light Emitting Diode Drive DCDC Buck Converter

Recently, many low-power LED (Light Emitting Diode) lighting fixtures that can contribute to a low-carbon society have been installed in clinical settings. However, since Alternating Current (AC) voltage cannot be used directly for LED devices, Direct Current (DC) voltage must be applied LED devices. For this reason, it is necessary for the LED equipment to install an ACDC power converter. A buck converter as an ACDC power converter is applied to the LED equipment, but Electromagnetic Interference (EMI) radiated from it has a strong influence on the wireless communication of a medical place. In particular, EMI radiated emission to medical telemeter systems using wireless communication becomes a significant problem of biomedical signal discontinuations. To investigate the EMI radiated strength, it must be measured using CISPR11 medical equipment international standard (International Special Committee on Radio Interference) on Limits and methods of measurement. This paper is focused on the LED drive DC power converter EMI radiated emission. The CISPR11 measurement EMI disturbance characteristics when a buck type current control DCDC buck converter circuit is used for the lighting of an LED device are shown. It is reported experimental results of EMI radiated emission characteristics improvement by changing the input and output circuit constants of the proposed circuit. Moreover, it is shown that can reduce to the floor noise level (background noise) when an output capacitor is inserted without an input filter.

A fast transient RBAOT controlled DC-DC buck converter with dual-loop DC offset cancellation technique and constant switching frequency

A fast transient ripple-based adaptive on-time (RBAOT) controlled DC-DC buck converter is presented in this paper. Firstly, for improving the output DC accuracy while keeping the fast transient response, a dual-loop DC offset cancellation technique is proposed. The fast loop ensures fast transient response, and the slow loop to compensate for the output DC offset introduced by ripple injection. Secondly, considering the parasitic resistances of the devices, the proposed switching frequency compensation technique reduces the frequency variation in steady state regardless of the input output voltage and load current condition. The proposed buck converter has been fabricated using 0.18-μm CMOS process. Measurement results show that the proposed converter has an outstanding output DC accuracy, the output offset is less than 2 mV. Moreover, the switching frequency is centered at 2 MHz with less than 1.5% variation for an output of 1.8 V and inputs ranging from 2.1 to 3.6 V. The maximum conversion efficiency is up to 94.6%, and the transient response times are 2 and 3 μs at rising and falling edges, respectively.

Design and development of realistic PV emulator adaptable to the maximum power point tracking algorithm and battery charging controller

In this paper, PV emulator is developed using double loop PI controlled DC-DC buck converter. Ambient environmental conditions such as irradiance, temperature and wind speed are considered for creating PV reference model in the PV emulator. The simulation model of the proposed PV emulator is created and tested using MATLAB Simulink package. To validate the effectiveness of the proposed PV emulator, it is tested with different operating conditions such as varying irradiance, temperature and wind speed. The current–voltage and power-voltage characteristic of the PV emulator is compared with PV reference model. The suitability of the PV emulator is tested with MPPT algorithm and battery charging controller in addition to number of objectives. Real time testing of the proposed PV emulator is done experimentally and also corresponding results are discussed. The proposed Solar PV emulator has the following properties: (1) higher bandwidth DC-DC buck converter, (2) extremely reliable performance with lower response time, and (3) lower output voltage and current ripple.

Linear Observer Based Linearizing Control of DC-DC Buck Converter

In this article; we process DC-DC buck converter by linearizing control (non linear control INPUTOUTPUT). As one observes at the same time the inductor current not measurable by a linear state observer proposed. This method can control the system by varying the output voltages, input voltage and load resistance. The proposed method has a stable response capable of reaching the model reference smoothly.

Auto-Tuning of DC-DC Buck Converters Through the Modified Relay Feedback Test

This paper presents the design and application of the modified relay feedback test (MRFT) auto-tuning method to the PID voltage-mode control of dc-dc buck converters. The proposed method, which also includes a set of tuning rules, does not require knowledge of the converter or load parameters, and produces a controller with near-optimal dynamic performance for virtually any dc-dc buck converter. The proposed MRFT auto-tuning also guarantees a specified phase margin. An important feature of the MRFT auto-tuning is that it is non-complex and thus practical, consisting of a simple test stage and a quick tuning stage. In the test stage oscillations are excited using the MRFT algorithm, and the frequency and amplitude of these oscillations are measured. In the tuning stage, these measurements are used with the pre-designed tuning rules to calculate PID controller parameters. The designed MRFT auto-tuning is evaluated experimentally by using it to auto-tune four different dc-dc buck converter designs, where in each case parameters of the converter are unknown to the auto-tuning algorithm. The experimental results show good performance of the MRFT auto-tuned controller in all cases. A mathematical proof that the MRFT auto-tuning guarantees a specified phase margin is also provided.

Design and experimental implementation of a new robust observer-based nonlinear controller for DC-DC buck converters

DC-DC buck converters are extensively used in many industrial and end-user applications where significant attention highlights their power-conversion efficiency and robustness to load and source disturbances. This paper considers the problem of DC-DC buck converter control for Maximum Power Point (MPP) and voltage trajectory tracking applications in renewable energy systems. A new nonlinear robust controller is proposed for fast and robust output voltage tracking in the DC bus of the power source. New states are augmented in the design of a novel composite sliding mode controller. Furthermore, a nonlinear state observer is incorporated in the design for current estimation. Parameters of the overall approach are tuned using Particle Swarm Optimization (PSO) algorithm with an objective to ensure a good balance between fast transients, robustness, and dynamic performance in practical implementations. This novel strategy is cost-efficient and accounts for the switched and nonlinear aspects of the problem in addition to disturbances. The stability of the closed-loop system is analyzed and guaranteed through Lyapunov stability theory. The low complexity of the presented controller grants it a remarkable advantage for higher reliability in physical realization. Moreover, comparative simulation tests and experimental results from multiple scenarios show significant trajectory-tracking improvements in terms of faster convergence rate with short transients and effective disturbance rejection performance compared to the optimally tuned Proportional Integral (PI) controller that is widely adopted in industrial applications.

Comparison analysis of chattering in smooth sliding mode controlled DC-DC buck converter using constant plus proportional reaching law and proposed reaching laws

This paper presents a comparative analysis of chattering in sliding mode controlled DC-DC buck converter for chattering suppression using constant plus proportional reaching law and proposed reaching laws. A smooth SMC is used for chattering suppression in buck converter. The different switching functions are used in proposed reaching laws and constant plus proportional reaching law applied to SMC buck converter, the tan hyperbolic reaching law, sigmoid reaching law and constant plus proportional rate reaching law. The proposed method tan hyperbolic gives less switching loss among the reaching laws and stable output voltage. Inturn, performance of the buck converter increases, tanhyperbolic reaching law is more sensitive to matched, mismatched disturbance and parameter uncertainties. Loading conditions are also applied to the buck converter to measure the disturbances and parametric variations. The results are verified by MATLAB/Simulink.

Universal finite-time observer based second-order sliding mode control for DC-DC buck converters with only output voltage measurement

DC-DC buck converters are widely used in industrial applications. Practically, there are parametric uncertainties, external disturbances and nonlinear unmodeled dynamics affecting the control performance of the DC-DC buck converters. Worse still, the current sensor may fail to work normally in practice. Taking the factors aforementioned into account, this paper proposes a universal finite-time observer (UFTO) based second-order sliding mode controller with only output voltage measurement in a simple structure for buck converters subject to mismatched disturbances. Firstly, a universal finite-time observer is designed to give the estimations of unmeasurable states including the current inductor and lumped disturbances. Secondly, introducing the estimations, a second-order sliding mode controller is proposed and a rigorous stability of the whole system is presented. Under the proposed finite-time controller, the system obtains a better convergence property and a better disturbance rejection ability comparing with the asymptotic control method. Moreover, the controller has a simple structure, providing convenience for engineers. As a by-product, only voltage sensor is needed, which reduces the cost and improves the fault tolerant ability for the system. Simulation and experimental results are investigated to validate the effectiveness of the proposed control approach.

Sliding Mode Controlled DC-DC Buck Converter using Traditional and Proposed Reaching Laws

Comparison analysis of sliding mode controlled dc-dc buck converter for chattering suppression with traditional and proposed reaching laws. A proposed reaching laws and traditional reaching law applied to SMC DC-DC buck converter, the proposed reaching law effectively reduces the chattering, because switching devices are existing in the model, it reduces the switching losses in the switching devices of the dc-dc buck converter. The results of proposed reaching law are compared with traditional reaching law. Proposed method gives less switching losses, in turn efficiency of the buck converter increases, more chattering mitigation by proposed reaching laws as compared to traditional reaching law. And very less sensitive in line and load variation. Simulation done in MATLAB.