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According to the operating modes of three‐phase line‐voltage cascaded boost high power factor rectifier topology, the operating characteristics of the rectified output voltage of each module and the characteristics of the topology for automatically balancing the input current under the unbalanced grid are analyzed in this article. Based on the analysis to the unique feature, a simple dual‐loop PI control strategy in the rotating coordinate system is designed with no need to deal with the negative sequence component of grid voltage. In response to the issue of unbalanced DC‐link capacitor voltage of each module caused by unbalanced grid, injection of the zero‐sequence voltage component is adopted in the designed control system, which make the output power of each module be able to be independently regulated, so that the balancing control to the DC‐link capacitor voltage of each module is realized. At the same time, the three‐phase input currents always remain in balance automatically operating under unity power factor. Simulations and experiments have verified the superiority of the topology structure and the feasibility of the control strategy. [ABSTRACT FROM AUTHOR]

This paper presents challenges in the control of 5GDHC networks and proposes an approach for the robust control design of these networks. Temperatures are low and temperature differences are small in 5GDHC networks, in order to minimise heat losses in the distribution network and directly utilise low-temperature heat sources. Therefore, the robust control design of substations is crucial for stable and efficient operation of 5GDHC networks. We proposed the key steps to obtain a consistent control design that can be verified and tested prior to commissioning of the building substations and network. The design approach was elaborated in a case study in an existing neighbourhood in Haarlem, the Netherlands, constructed in the 1930s to 1970s. This neighbourhood will become independent of natural gas using PVT-rooftop panels, individual heat pumps (HP), a 2-pipe, bi-directional energy flow network operating at ultra-low temperatures and ATES system as a seasonal and daily storage facility. [ABSTRACT FROM AUTHOR]

The linear power amplifier (LPA) suffers from low power supply utilization in the DC power supply mode, leading to reduced output efficiency. This paper constructs an efficient power supply mode based on closed‐loop dynamic power supply system (CLDPSs). The CLDPSs can generate a pair of bipolar dynamic power supplies based on a predetermined signal to provide power to LPA, which can maintain a small voltage drop between the power supply and the output of LPA, thereby improving the power supply utilization of LPA. In addition, the study also focuses on the conflicting relationship between the output ripple and the dynamic performance of the CLDPSs, for which a new parametric design of the LC filter circuit is proposed, aiming to achieve a balance between these two aspects. Finally, a voice coil motor driving platform is constructed for experimental testing. The results demonstrate that the output ripple and dynamic performance of the CLDPSs can be balanced. In comparison to the DC power supply mode, the CLDPSs power supply mode can enhance the efficiency of LPA by 2 times while the driving accuracy of voice coil motor is basically unchanged. [ABSTRACT FROM AUTHOR]

Given the presence of various non‐ideal conditions, such as detection errors, converter non‐linearity, noise, and parameter mismatches, the flux model experiences the introduction of DC bias and high‐frequency harmonics, which subsequently deteriorate the accuracy of flux estimation. To dispose these issues, an improved non‐linear flux observer (FOIFFO) using a second‐order generalised integrator as an in‐loop filter is proposed for the sensorless control of permanent magnet synchronous motors. The observer demonstrates robust performance in eliminating DC bias and having a strong filtering ability for high‐order harmonics even without amplitude and phase compensation to accurately estimate the rotational speed and rotor position. The performance of the method is analysed by transfer functions and bode plots, while the discretisation method of the FOIFFO is proposed. Finally, the new sensorless control strategy is verified by synthesising the experimental results. [ABSTRACT FROM AUTHOR]

Abstract This article presents an intelligent stability monitoring and improvement method for the grid‐connected converter system. The model of grid‐connected converter, based on the weighted average current feedback (WACF) and weighted average voltage feedforward (WAVF) control, is first established. Then, the time‐varying grid impedance and parameter perturbation of LCL‐filter are precisely identified by artificial neural network (ANN) module in real time. Furthermore, the control parameters are adaptively tuned by certain rules based on the predicted parameters to increase the high‐frequency stability margin of converter system. Simulation and experimental results are given to validate the proposed identification and parameter tuning method. The proposed method is able to monitor the real‐time operation state of the grid‐connected converter and improve the self‐adaptivity of the grid‐connected converter system against parameter perturbation.

Abstract The multivariable process plays a significant role in industrial applications, and designing a controller for the Multi-Input Multi-Output process is challenging due to dynamic process changes and interactions between system variables. Traditionally, the PI family of controllers has been used for its simple design, easy tuning, and quick deployment. However, these processes require complex control actions due to multiple loops in process plants. Thus, this paper proposes an Iterative Learning Controller Dead-time compensating PI, which utilizes the newly developed hybrid Simulated Annealing-Ant Lion Optimization algorithm for Single-Input Single-Output process simulation and real-time experimentation on the Quadruple Tank System. To validate the effectiveness of the developed controller, Machine Learning techniques such as regression and ensemble trees are used to accurately predict the actual system response using error values from respective processes. The simulation and experimental results demonstrate that the proposed controller achieved better performance. The regression and ensemble tree algorithm models effectively predicted the actual response. The obtained data shows that the proposed controller improved system stability and robustness by minimizing nearly half of the overshoot and improving settling time, with an average of 29.9596% faster than the other controller in the SISO process and 14.6116% in the MIMO process.

Abstract A vast number of mass flow controllers (MFCs) are used in semiconductor industry. For the stable supply, an efficient production method of MFC is required. The gain tuning of the proportional-integral (PI) control to realize a setting flow rate is essential for efficient mass production. The gains are tuned to meet the specifications required for evaluation indices of response time and overshoot amount in a step response waveform. The tuning is complicated especially for the case of pressure-based MFCs. In this paper, we propose a simple method for the PI gain tuning using the Gaussian mixture model (GMM) and the direct inverse analysis applicable to the pressure-based MFCs’ production. The relationship between the gains and evaluation indices for a standard unit of the MFC is modeled as the GMM. The direct inverse analysis calculates the difference between the standard and a test unit. Under the assumption that the difference can be compensated by a simple shift, gains likely to meet the specifications for the test unit are searched. We applied the method to seven test units. The result showed that the gains of all the test units were tuned within only a few iterations whose numbers were much less than the conventional manual tuning method, and there was no untunable unit.

Abstract This paper proposes an improved two‐degree‐of‐freedom active disturbance rejection controller for the coupling problem of asynchronous motor vector system. To simplify the analysis process and accommodate observers of different types, a unified expression based on different controllers for the system output is developed. The closed‐loop transfer function generated by the reference input and load disturbance is given. For the coupling problem of motor output speed and immunity, the structure of a higher‐order extended state observer is reconstructed. The extended state observer estimates both the output speed and the total system disturbance, which serve as feedback and feed‐forward compensation quantities. Compared to the PI controller and traditional active disturbance rejection controller, the proposed controller achieves decoupling of output response speed and immunity, simplifies the process of parameter tuning. Finally, simulation and experiment results verify the feasibility and effectiveness of the algorithm in this paper.

This paper compares the performance of a Sliding Mode Control (SMC) and Proportional-Integral (PI) controller under different voltage and load conditions. The study's findings underscore the need to account for load variations in system designs and to continuously seek system optimization irrespective of the controller type chosen. PI controller demonstrates effectiveness under certain circumstances. However, significant drops in voltage and current during abrupt load changes are obtained. On the other hand, SMC enables superior adaptability, efficiently managing voltage transients and load variations without any electrical disturbances, thereby maintaining system stability. A comparative analysis further emphasizes the SMC's superior time response and robustness against reference voltage changes. Consequently, SMC is proven to be a preferable choice over the PI controller in systems experiencing frequent voltage and load variations. However, both controllers achieve the potential for further response time optimization and stability. [ABSTRACT FROM AUTHOR]

This paper proposes an improved two‐degree‐of‐freedom active disturbance rejection controller for the coupling problem of asynchronous motor vector system. To simplify the analysis process and accommodate observers of different types, a unified expression based on different controllers for the system output is developed. The closed‐loop transfer function generated by the reference input and load disturbance is given. For the coupling problem of motor output speed and immunity, the structure of a higher‐order extended state observer is reconstructed. The extended state observer estimates both the output speed and the total system disturbance, which serve as feedback and feed‐forward compensation quantities. Compared to the PI controller and traditional active disturbance rejection controller, the proposed controller achieves decoupling of output response speed and immunity, simplifies the process of parameter tuning. Finally, simulation and experiment results verify the feasibility and effectiveness of the algorithm in this paper. [ABSTRACT FROM AUTHOR]

A vast number of mass flow controllers (MFCs) are used in semiconductor industry. For the stable supply, an efficient production method of MFC is required. The gain tuning of the proportional-integral (PI) control to realize a setting flow rate is essential for efficient mass production. The gains are tuned to meet the specifications required for evaluation indices of response time and overshoot amount in a step response waveform. The tuning is complicated especially for the case of pressure-based MFCs. In this paper, we propose a simple method for the PI gain tuning using the Gaussian mixture model (GMM) and the direct inverse analysis applicable to the pressure-based MFCs' production. The relationship between the gains and evaluation indices for a standard unit of the MFC is modeled as the GMM. The direct inverse analysis calculates the difference between the standard and a test unit. Under the assumption that the difference can be compensated by a simple shift, gains likely to meet the specifications for the test unit are searched. We applied the method to seven test units. The result showed that the gains of all the test units were tuned within only a few iterations whose numbers were much less than the conventional manual tuning method, and there was no untunable unit. [ABSTRACT FROM AUTHOR]

This article presents a buck converter in which the inductor has been replaced by a transmission line. This approach would be practically conceivable if the power supply and load had a greater spatial distance. Alternatively, the model derived in this way could also be regarded as an intermediate model in order to replace a power coil via discretization with a larger number of smaller coils and capacitors. In the time domain, this new converter can be described by a system of coupled partial and ordinary differential equations. In the frequency domain, a transcendental transfer function is obtained. For comparison with an equivalently parameterized conventional converter, Padé approximants are derived. A linear controller is designed for the converter topology under consideration. [ABSTRACT FROM AUTHOR]

Conical tanks have a high application rate in industrial processes, especially in colloidal mills, chemical processes, and food processing. The use of conical tanks presents significant benefits because they contribute to sedimentation and reduce the accumulation of impurities compared to conventional cylindrical tanks. However, level control of a conical tank due to its shape requires advanced strategies to guarantee efficient control. In this research, a model predictive control (MPC) method was designed and implemented for the level control of a conical tank on a laboratory scale. To evaluate the performance of the controller, it was compared with a traditional proportional–integral (PI) controller, and the rise time, settling time, overshoot, and error in the steady state were analyzed when different set point changes were tested. In addition, the system was subjected to disturbances, and the MPC demonstrated better performance in a transient state, as well as smooth and stable action controls that allowed for an increase in the useful life of the actuator. In addition, an interactive graphical interface was developed that allowed a dynamic response in a real plant to be experienced; this provides an academic tool for designing control strategies before implementation in a real process. [ABSTRACT FROM AUTHOR]

Abstract Wireless power transfer (WPT) is a promising technology and has attracted many researchers’ attention due to its inherent advantages such as reliability, safety, flexibility, and low maintenance costs. For WPT systems, the output voltage varies according to the variable loads and the coupling coefficient conditions, affecting system stability and efficiency. In this regard, this study is concerned with the tracking control problem of WPT systems based on fuzzy supervisory proportional–integral (PI) controller and a phase shift modulation technique, which is for the first time proposed by this paper. By introducing appropriate fuzzy rules, the proposed control scheme not only can track the desired output voltage but also has better robust behaviour to deal with the problem of variations of circuit elements and coupling coefficients. That is, the proposed fuzzy supervisory PI control scheme can perform better than the traditional PI controller. Analysis of the designed control method and simulation results validate the superiority of the proposed method over the traditional PI controller in all conditions, which can make it a suitable choice for the applications of electric vehicle charging systems. The analysis is supported by experimental measurements.

Abstract This paper extends the characteristic ratio approach using novel inequalities to ensure zero/low overshoot for linear‐time‐invariant systems with zeros. The extension provided by this paper is based on the maximally‐flatness property of a transfer function, where the square‐magnitude of the transfer function is ensured to be a low‐pass filter. In order to be able to design low‐order/fixed structure controllers, a partial pole‐assignment approach is used instead of the full pole‐assignment used in the Characteristic Ratio Assignment (CRA) method. The developed inequalities and additional stability conditions are combined into an optimization problem using time domain restrictions when necessary. Although the method given in the paper is general, particular inequalities are developed for PI and PI‐PD controller cases, due to their frequent use in industrial applications. Similarly, First‐Order‐Plus‐Delay‐Time (FOPDT) and Second‐Order‐Plus‐Delay‐Time (SOPDT) systems are considered specifically, since most of the practical systems can be approximated by one of these types. The study is extended to plants with uncertainties where a theorem is developed to decrease computation time dramatically. The benefits of the proposed methods are demonstrated by several examples.

Even though the energy penalties and solvent regeneration costs associated with amine-based absorption/stripping systems are important challenges, this technology remains highly recommended for post-combustion decarbonization systems given its proven capture efficacy and technical maturity. This study introduces a novel centralized and decentralized hybrid control strategy for the post-combustion carbon capture plant, aimed at mitigating main disturbances and sustaining high system performance. The strategy is rooted in a comprehensive mathematical model encompassing absorption and desorption columns, heat exchangers and a buffer tank, ensuring smooth operation and energy efficiency. The buffer tank is equipped with three control loops to finely regulate absorber inlet solvent solution parameters, preventing disturbance recirculation from the desorber. Additionally, a model-based controller, utilizing the model predictive control (MPC) algorithm, maintains a carbon capture yield of 90% and stabilizes the reboiler liquid temperature at 394.5 K by manipulating the influent flue gas to the lean solvent flowrates ratio and the heat duty of the reboiler. The hybrid MPC approach reveals efficiency in simultaneously managing targeted variables and handling complex input–output interactions. It consistently maintains the controlled variables at desired setpoints despite CO2 flue gas flow disturbances, achieving reduced settling time and low overshoot results. The hybrid control strategy, benefitting from the constraint handling ability of MPC, succeeds in keeping the carbon capture yield above the preset minimum value of 86% at all times, while the energy performance index remains below the favorable value of 3.1 MJ/kgCO2. [ABSTRACT FROM AUTHOR]

Wireless power transfer (WPT) is a promising technology and has attracted many researchers' attention due to its inherent advantages such as reliability, safety, flexibility, and low maintenance costs. For WPT systems, the output voltage varies according to the variable loads and the coupling coefficient conditions, affecting system stability and efficiency. In this regard, this study is concerned with the tracking control problem of WPT systems based on fuzzy supervisory proportional–integral (PI) controller and a phase shift modulation technique, which is for the first time proposed by this paper. By introducing appropriate fuzzy rules, the proposed control scheme not only can track the desired output voltage but also has better robust behaviour to deal with the problem of variations of circuit elements and coupling coefficients. That is, the proposed fuzzy supervisory PI control scheme can perform better than the traditional PI controller. Analysis of the designed control method and simulation results validate the superiority of the proposed method over the traditional PI controller in all conditions, which can make it a suitable choice for the applications of electric vehicle charging systems. The analysis is supported by experimental measurements. [ABSTRACT FROM AUTHOR]

The metal manufacturing industry employs the reversible cold rolling mill, which is a machine used to process and shape various metal products such as steel sheets, aluminum sheets, and copper sheets. High accuracy control of web velocity and web tension is essential in the manufacturing process for preventing the web from bending or breaking during the entire manufacturing process. In this work, we introduce a control law design method using PI control with unknown parameters for the web winding system to ensure that the final product will not be affected by deformation or breakage. In the first step of the adaptive backstepping procedure, the integral action is obtained by adding the integral of the tracking error to the error considered. The stability of the control design is ensured by the Lyapunov stability theorem. It verifies that the trajectory dynamics are asymptotically stable. To illustrate the effectiveness and performance of the proposed controllers, simulation studies using the MATLAB/Simulink environment are presented. [ABSTRACT FROM AUTHOR]

This study numerically investigates mixed convective cooling in a two‐dimensional horizontal channel containing periodically heated blocks by applying proportional (P), proportional‐integral (PI), and proportional‐integral‐derivative (PID) controllers. Three different controller configurations regulate the amount of cold air entering the chamber. The air's non‐dimensional temperature is continuously monitored at the set point to compare the controllers' performance, and the percentage of overshoot and the steady‐state error are analysed. The investigated chamber comprises one inlet and two exit ports, a temperature sensor, and two heated blocks that are isotherm heat sources. The Galerkin finite element approach computationally solves the equations of continuity, momentum, and energy to analyse the thermo‐fluid phenomena occurring within the chamber. Parametric simulation is carried for different values of the proportional gain (Kp = 0.005, 0.010, 0.050 m s−1 K−1), the integral gain (Ki = 0.05, 0.10, 0.15 m s−2 K−1), the derivative gain (Kd = 10−5, 10−4, 10−3 m K−1) to achieve a consistent and expeditious response. Variations of Reynolds, Richardson, and mean Nusselt numbers with time are plotted to compare the system's performance. The investigation indicates that the PI controller produces a comparable level of performance with the PID controller, reducing the necessity to add a derivative controller. [ABSTRACT FROM AUTHOR]

This paper extends the characteristic ratio approach using novel inequalities to ensure zero/low overshoot for linear‐time‐invariant systems with zeros. The extension provided by this paper is based on the maximally‐flatness property of a transfer function, where the square‐magnitude of the transfer function is ensured to be a low‐pass filter. In order to be able to design low‐order/fixed structure controllers, a partial pole‐assignment approach is used instead of the full pole‐assignment used in the Characteristic Ratio Assignment (CRA) method. The developed inequalities and additional stability conditions are combined into an optimization problem using time domain restrictions when necessary. Although the method given in the paper is general, particular inequalities are developed for PI and PI‐PD controller cases, due to their frequent use in industrial applications. Similarly, First‐Order‐Plus‐Delay‐Time (FOPDT) and Second‐Order‐Plus‐Delay‐Time (SOPDT) systems are considered specifically, since most of the practical systems can be approximated by one of these types. The study is extended to plants with uncertainties where a theorem is developed to decrease computation time dramatically. The benefits of the proposed methods are demonstrated by several examples. [ABSTRACT FROM AUTHOR]

Redundant power supplies are commonly used in systems that require long-term uninterrupted operation and high reliability. When redundant power supplies are used as N+1 backup power supplies to supply power to devices at the same time, parallel current sharing must be considered.In order to solve the problem of large loss of passive redundant power supply and inability to achieve current equalization, this study adopts the design scheme of active redundancy and designs a 1+1 redundant power supply system with two parallel DC voltage inputs.The system uses GD32E103 as the main control chip. By changing the on-resistance of MOSFET(Metal-Oxide Semiconductor Field Effect Transistor), PI(Proportional Integral) control is adopted to realize the automatic balance of the output current of two redundant power supplies.The simulation and experimental results show that the active redundancy design scheme can achieve the purpose of automatic current equalization.In normal operation, the maximum error of the two current channels is less than 0.1 A, and the accuracy of current sharing meets the design requirements. [ABSTRACT FROM AUTHOR]

This article presents the results of simulation research of a diesel engine for a light helicopter. The simulations were performed using the 1D software AVL Boost RT. The engine model includes elements such as cylinders, turbine, compressor, inlet and outlet valves, ambient environment definition, and fuel injection control strategy. The simulations aimed to evaluate the engine's response to step changes in the main rotor load, both increasing and decreasing power demands. Parameters analyzed included power deviation, torque, engine rotational speed, and stabilization time of the main rotor rotational speed. All tests were conducted using a single set of PI controller settings. The results demonstrate that these parameters are dependent on the magnitude of the step change in the main rotor load demand. The study compares the maximum engine rotational speed deviation from the nominal value for both increasing and decreasing main rotor load demands. The findings indicate that using PI regulator to control rotational speed in the diesel engine in a light helicopter significantly depends on the change in the load torque on the rotor.

This paper addresses the stabilization of a general class of linear single-input/single-output (SISO) second-order non-minimum phase systems with input channel delays using Proportional-Integral (PI) controllers. Such systems arise in various applications, including power electronic circuits and biochemical reactors. The primary goal is to enhance system performance by determining optimal control gains that shift the spectral abscissa of the closed-loop system as far to the left as possible, thereby improving its decay rate. To achieve this, we introduce a geometric framework that characterizes the stability region of the closed-loop system in three distinct cases. Our main contribution is a systematic tuning approach to achieve the desired decay rate when feasible. Additionally, we discuss the controller’s fragility and the delay margin of the closed-loop system to ensure practical applicability. The effectiveness of the proposed method is demonstrated through numerical simulations for each scenario. Finally, two practical case studies—a boiler steam drum and a DC-DC boost converter—are presented to illustrate the results’ relevance in practice.

For the efficiency optimization problem of wireless power transfer system, the most important thing is that the frequency tracking control is needed to make the system work in a resonant state. The parameters of the frequency tracking controller directly determine the control performance. In this paper, we consider using an improved whale optimization algorithm to complete the PI parameter tuning of the frequency tracking controller as a way to save personnel’s effort and time on the controller design. This improved whale optimization algorithm mainly has the following improvements: firstly, it uses Kent chaotic mapping to initialize the whale population, which improves the variegation of the initial solution; secondly, it introduces adaptive weight coefficients and nonlinearly improves the convergence factor, which achieves a balance between the algorithm’s global and local searching ability; finally, it introduces sine-cosine algorithmic strategy and Cauchy reverse learning strategy, which avoids the problem that the algorithm is easy to mature prematurely. The superiority of the improved algorithm is verified through the testing of eight benchmark functions and the Wilcoxon rank sum test method. Finally, the algorithm is applied to the PI parameter optimization of frequency tracking control, and the phase difference curves under the control of different PI parameters are compared by simulation. The results show that the improved algorithm proposed in this paper has a better performance for the PI parameter tuning of frequency tracking control in wireless power transfer system, which can effectively help reduce the investment of human resources.

This research paper presents a novel approach to current control in Grid-Connected Inverters (GCI) using Deep Reinforcement Learning (DRL) based Twin Delayed Deep Deterministic Policy Gradient (TD3) method. The study focuses on addressing the limitations of traditional control techniques and state of the art techniques, particularly Proportional-Integral (PI) control and Model Predictive Control (MPC), by leveraging the adaptive and autonomous learning capabilities of DRL. The proposed novel modified TD3-based DRL method learns an optimal control policy directly from raw data, enabling the controller to adapt and improve its performance in real-time. The research includes a comprehensive analysis of the implementation and validation of the modified TD3-based DRL control in a grid-connected three phase three level Neutral Point Clamped (NPC) inverter system with Inductor-Capacitor-Inductor (LCL) filter. Real-time validation experiments are conducted to evaluate the control performance, power transfer capability in grid compliance. Furthermore, a detailed comparison is presented with experimentation, highlighting the advantages of the TD3-based DRL control over PI and MPC control techniques. Robustness checking is performed under various operating conditions, including parameter variations and dynamic conditions in the grid. The results analysis demonstrates that the TD3-based DRL control outperforms traditional PI control techniques in terms of static, dynamic response, and robustness. Additionally, The DRL based grid connected inverter current control method is validated in Renewable Energy Source (RES) solar PV grid integration application.

This paper presents the design of a smooth starter for a DC motor that uses a full-bridge Buck inverter powered by renewable energy. For this aim, a renewable energy power supply is considered in the mathematical model of the “full-bridge Buck inverter–DC motor” system. Whereas, for the design of the smooth starter, a control based on sliding-mode and proportional-integral control is proposed. The performance of the developed control scheme is experimentally validated using the system prototype, the TDK-Lambda G100-17 renewable energy emulator source, the DS1104 board, and the Matlab-Simulink software. Experimental tests are conducted with two different power supply scenarios: 1) a time-varying input voltage and 2) a commercial photovoltaic panel emulator. The obtained experimental results show the robustness of the controller proposed here to abrupt disturbances in the system parameters and torque.

The utilization of closed-loop control in stepper motors has become prevalent in scenarios requiring high-precision control. In this paper, classical proportional-integral (PI) and sliding mode control (SMC) are combined, and a compound control strategy based on the vector closed-loop control of stepper motors is proposed. The primary advantage of this approach is its ability to harness the precision of PI control and the robustness of SMC, mitigating the limitations of each method when used independently. A key innovation is the introduction of an automatic weight adjustment mechanism, which allows adaptive modulation of the two control strategies based on varying operating conditions, ensuring that the two algorithms work together in a coordinated manner. Simple fuzzy logic is implemented for automatic weight adjustments, and a smoothing mechanism is incorporated to prevent instability arising from swift weight adjustments. Simulations were conducted using MATLAB/Simulink to distinctly assess the speed and position control of stepper motors and compare them with those of individual PIs, SMCs, and adaptive network-based fuzzy inference system intelligent controllers. The results indicate that the compound control demonstrates a swifter speed response, a diminished steady-state error, and robust anti-interference capabilities. These results confirm the effectiveness of the compound control strategy in applications where both precision and robustness are paramount.

Abstract This paper presents an auto‐tuning method for dc‐ac voltage source converters (VSCs) with an inductive load that is based on the modified relay feedback test (MRFT). Controllers tuned by the proposed method can produce near‐optimal dynamic performance for dc–ac VSCs without requiring knowledge of the plant's parameters. The controller consists of a PID cascaded with a digital notch filter. The tuning involves two steps. In the first step, the MRFT is used to tune the digital notch filter to compensate for the LCL resonance resulting from the LC filter's interaction with the inductive load. In the second step, one more MRFT is used to tune the PID controller using optimal tuning rules that are derived in advance (offline). The proposed optimal for the class of the dc–ac VSCs tuning rules can guarantee a specified phase margin and near optimal transient performance for any randomly picked VSC. The performance of the proposed tuning of the PID + notch filter is verified by simulations and experiments. The dynamic response of the auto‐tuned controller compares well to the response of a theoretically optimal but non‐auto‐tuned PID + notch filter designed using the full knowledge of the LC filter and the load.

Abstract In photovoltaic (PV) systems, inverters play a crucial role for supplying electricity to meet the demand while maintaining power quality. For a local load connected to a grid‐interfaced photovoltaic (GIPV) system, active and reactive power control is necessary at the distribution level. Thus, the foremost purpose of this article is to get the best optimally designed robust controller for control of active and reactive power. A GIPV system with Improved Arithmetic Optimisation Algorithm (IAOA)‐based Super Twisting Sliding Mode Controller (ST‐SMC) methodology has been proposed in this article for active and reactive power management. The conventional PI controller in the GIPV system that is most frequently used has considerable undershoot and a long settling period. PI controller tuning parameters were also changed to account for the wide change in the reference pattern. Therefore, STSMC and SMC are used for ensuring robustness against external disturbances. The conventional SMC comes out to have a chattering issue. Furthermore, the proposed IAOA technique is validated through some benchmark functions. The proposed IAOA technique outperforms Particle Swarm Optimisation (PSO), Forensic Based Investigation (FBI), and Traditional Arithmetic Optimisation Algorithm (TAOA) in terms of the number of iterations and accurately achieving optimal solutions for active and reactive power control. The results show that the proposed IAOA‐based STSMC technique has an improved performance of settling time and undershoot for active and reactive power control. This article also presents stability analysis and robustness test of the above mentioned controllers to illustrate the effectiveness of each optimally designed controller. A 40 kW GIPV system performance is evaluated using the MATLAB environment, and the results are validated in a real‐time simulator platform OPAL‐RT 4510.

Abstract This study focuses on analyzing the robust stability regions and robustness margin of a time‐delayed load frequency control (LFC) system with Electric Vehicles (EVs) using the Kharitonov Theorem. Communication time delays in LFC systems can jeopardize stability and reliability, leading to suboptimal controller performance. Integrating EVs into LFC systems enhances dynamical stability but introduces additional complexity. Therefore, it is crucial to employ robust analysis and controller design techniques to ensure system stability. In this study, we utilize the Kharitonov Theorem to determine the robust stability regions and stability boundaries in the parameter plane of the Proportional‐Integral (PI) controller. By considering communication time delays and parametric uncertainties in the LFC system with EVs (LFC‐EVs), the robust PI controller gains using these methods are efficiently computed. To evaluate the performance of the theoretically computed robust controller parameters, time‐domain simulations are conducted.

After wind power is connected to the grid, because the power of wind power will fluctuate greatly, the frequency deviation of the grid will increase with access to wind power generation, then the challenge of frequency control in power grid is also increasing. The Load frequency control(LFC) is one of the important components of frequency control, the fluctuation of wind power output of the system will put forward a higher demand for load frequency control (LFC) of the power grid so as to increase the proportion of wind power in the system. In this paper, a PI controller whose parameters are set by an intelligent cloud calculation result is designed for LFC of the interconnected power system with large-scale wind power. The parameters in PI controller are obtained through the cloud model whose inputs are the control error and the corresponding rate of change so as to realize the adaptive tuning. The subordinate cloud parameters are designed considering randomness of wind power, which effectively solves the problems of poor parameter robustness in traditional PI control. The simulation of the two-area interconnection system with wind power is carried out to verify the effectiveness of the proposed method in the case of random wind power.

In this paper, the increase in the quality of the rotor speed of wind turbines and the decrease in mechanical loads on the turbines are investigated. Adjusting the angle of the blade to the nominal wind speed, the rotor speed of the wind turbine is maintained at its nominal value. Using control methods (such as proportional integral (PI), genetic algorithms (GAs), and particle swarm optimisation (PSO)), different results can be recovered. In addition, individual control of the blade tilt angle allows us to reduce the mechanical loads on the turbine with the control methods. The wind turbine was modelled in Matlab/Simulink. The simulation results show that individual control of the blade tilt angle ensures the quality of the rotor speed of the wind turbine and reduces the balanced periodic loads on the wind turbine. In the first part, we study the wind turbine in a global way, as well as the method used to calculate them. Then, we discuss the FAST system, which was used to model the wind turbine, as well as the design of individual pitch angle control. As a result, it is possible to reduce the fatigue of the mechanical wind turbine parts. According to the study, the mechanical load for all three blades was reduced by an average of 44 % compared to the PI and PSO methods and by 1 % compared to the PI and GA methods. The control of the pitch angle in wind energy systems is performed with different control methods. The study analysis of the mechanical loads found that they are largely balanced. Winds that blow perpendicular to the turbine blades on the x-axis provide these loads.

This paper presents an auto‐tuning method for dc‐ac voltage source converters (VSCs) with an inductive load that is based on the modified relay feedback test (MRFT). Controllers tuned by the proposed method can produce near‐optimal dynamic performance for dc–ac VSCs without requiring knowledge of the plant's parameters. The controller consists of a PID cascaded with a digital notch filter. The tuning involves two steps. In the first step, the MRFT is used to tune the digital notch filter to compensate for the LCL resonance resulting from the LC filter's interaction with the inductive load. In the second step, one more MRFT is used to tune the PID controller using optimal tuning rules that are derived in advance (offline). The proposed optimal for the class of the dc–ac VSCs tuning rules can guarantee a specified phase margin and near optimal transient performance for any randomly picked VSC. The performance of the proposed tuning of the PID + notch filter is verified by simulations and experiments. The dynamic response of the auto‐tuned controller compares well to the response of a theoretically optimal but non‐auto‐tuned PID + notch filter designed using the full knowledge of the LC filter and the load. [ABSTRACT FROM AUTHOR]

In this paper, the implementation of the Fuzzy Sliding Mode Controller (FSMC) in the inner loop of the cascaded control structure of the DC–DC Boost Converter is presented. On account of nonlinearity and nonminimum phase nature, switched-mode DC–DC converters show a poor response in their dynamic characteristics. In most of the works, the inner loop is served by SMC/FLC, and the outer loop by PI. In this study, the proposed FSMC, which is the combination of SMC and FLC is recommended in the inner current loop which reduces the chattering phenomena and improves the robustness against uncertainties, disturbances and varying circuit parameters with the reaching law. The Lyapunov approach is considered to study the stability of the proposed controller. A comparative analysis is made with the results obtained from the proposed FSM controller, Fuzzy and SMC control. The effectiveness of the FSMC controller is validated by observing its system performance. [ABSTRACT FROM AUTHOR]

The inverter module serves as a critical component in the conversion of electrical energy within arc plasma power sources, exerting a profound influence on the overall performance and stability of the power supply. Consequently, the meticulous design and precise control of the inverter module are of paramount importance in ensuring the effective operation and application of arc plasma power sources. This paper introduces a dual-closed-loop control system, integrating a voltage outer loop with a current inner loop, as the cornerstone of its inverter module design. It also undertook a comprehensive comparative analysis of various voltage-control strategies, encompassing four control methods (PI, PID, PR, QPR) and two modulation techniques (bipolar modulation and unipolar, carrier-based modulation) under diverse operating conditions. Additionally, simulation experiments were conducted on a prototype 10 kW inverter module using the Matlab/Simulink simulation platform, with evaluation criteria including waveform tracking performance, voltage waveform distortion rate, and steady-state error. The results indicate that in low-frequency operating conditions, the voltage-control strategy employing QPR control plus unipolar, carrier-based modulation, and in high-frequency operating conditions, the voltage-control strategy utilizing PI control plus unipolar, carrier-based modulation exhibited superior waveform tracking performance. The waveform distortion rates were measured at below 0.47% and 4.2%, respectively, aligning perfectly with the stringent standards of IEEE 519. This research provides valuable theoretical support and practical guidance for future engineering endeavors in the field of inverters. [ABSTRACT FROM AUTHOR]

Dual three-phase Permanent Magnet Synchronous Motor (DTP-PMSM) is a nonlinear, strongly coupled, high-order multivariable system. In today's application scenarios, it is difficult for traditional PI controllers to meet the requirements of fast response, high accuracy and good robustness. In order to improve the performance of DTP-PMSM speed regulation system, a control strategy of PI controller based on genetic algorithm is proposed. Firstly, the basic mathematical model of DTP-PMSM is established, and the PI parameters of DTP-PMSM speed regulation system are optimized by genetic algorithm, and the modeling and simulation experiments of DTP-PMSM control system are carried out by MATLAB/SIMULINK. The simulation results show that, compared with the traditional PI control, the proposed algorithm significantly improves the performance of the control system, and the speed output overshoot of the GA-PI speed control system is smaller. The anti-interference ability is stronger, and the torque and double three-phase current output fluctuations are smaller.

The current study investigates the stability analysis based on gain and phase margin (GPM) using fractional-order proportional-integral (FOPI) controller in a time-delayed single-area load frequency control (LFC) system with demand response (DR). The DR control loop is introduced into the classical LFC system to improve the frequency deviation. Although the DR enhances the system’s reliability, the excessive use of open communication networks in the control of the LFC results in time delays that make the system unstable. A frequency-domain approach is proposed to compute the time delay that destabilizes the system using GPM values and different parameter values of the FOPI controller. This method converts the equation into an ordinary polynomial with no exponential terms by eliminating the exponential terms from the system’s characteristic equation. The maximum time-delay values at which the system is marginally stable are calculated analytically using the new polynomial. Finally, the verification of the time delays calculated is demonstrated by simulation studies in the Matlab/Simulink environment and the root finder (quasi-polynomial mapping-based root finder, QPmR) algorithm to define the roots of polynomials with exponential terms providing information about their locations.

This paper presents studies of the four maximum power point tracking (MPPT) algorithms of a single-phase grid-connected photovoltaic (PV) inverter based on single loop voltage control (VC) and cascaded voltage and current control (CVCC). The purpose of this research was to evaluate four techniques for maximum power tracking control: (1) the Perturbation and Observation (P&O) MPPT&VC, (2) the Incremental Conductance (InC) MPPT&VC, (3) the P&O MPPT&CVCC and (4) the InC MPPT&CVCC. The MPPT efficiency values of each technique were affected by sudden changes in various irradiances. The CVCC was found to reduce the oscillating PV power and have a faster response time of MPPT from the PV array than the VC configuration. The InC MPPT&CVCC technique can track maximum power when irradiance changes rapidly. The simulation results showed that the InC MPPT&CVCC technique can decrease oscillation at a steady state around the set point and has a fast response time of MPPT, reduced electrical power ripple, and less power loss. The average efficiency of MPPT was 99.98%.

AbstractLow energy inertia, a high penetration level of renewable energy sources, and a large ratio of power deviations in a small power transmission system have put microgrid frequency at risk of instability. Based on the close coupling between microgrid frequency and system security requirements, providing sufficient ancillary services from cost-effective and environmentally friendly resources is a major challenge in an efficient energy management system. In this article, a fuzzy approach and a new optimization technique on the PI controller are used to solve the problem of frequency stability in the AC micro-grid in the island mode by optimising the PI-fuzzy controller parameters. The suggested modified new self-organizing hierarchical PSO with jumping time-varying acceleration coefficients (MNHPSO-JTVAC) based controller’s results show that the control system has been investigated under three scenarios: load variations, RES uncertainty, white noise, and frequency correction. In terms of frequency responsiveness, the results are good when compared to traditional algorithms: The suggested design has been able to optimise the control system parameters by the proposed MNHPSO-JTVAC algorithm to solve microgrid frequency deviations caused by source uncertainty, load changes, and white noise, respectively, 0.008473, 0.01334, and 23.71, compared to classical PI control—PI, fuzzy And PI-fuzzy-GOA shows that in practical systems, this method can be considered very desirable and attractive.

As road traffic develops, energy-saving and efficient street lights have become a key research field for relevant professionals. To reduce street lights energy consumption, a fireworks algorithm is used to optimize the membership function parameters of fuzzy control and the initial parameters of PI control. A fireworks algorithm improved adaptive fuzzy PI solar LED street light control system is designed. The results showed that in the calculation of Root-mean-square deviation and Mean absolute error, the Root-mean-square deviation of the adaptive fuzzy PI control system improved by the fireworks algorithm was 0.213, 0.258, 0.243, 0.220, and the Mean absolute error was 0.143, 0.152, 0.154, 0.139, respectively, which proved that the prediction accuracy was high and the stability was good. In the calculation of the 1-day power consumption of the solar LED intelligent control system, the average power consumption of the designed solar LED intelligent control system was about 2000W, which was 25.9%, 47.4%, and 42.9% lower than the other three control methods, respectively. This proves that its energy consumption is low, and its heat generation is low, and the battery service life is long. The research and design of an adaptive fuzzy PI control solar LED street light intelligent control system has good performance, which can effectively achieve intelligent management and energy conservation and emission reduction in smart cities.

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This study focuses on analyzing the robust stability regions and robustness margin of a time‐delayed load frequency control (LFC) system with Electric Vehicles (EVs) using the Kharitonov Theorem. Communication time delays in LFC systems can jeopardize stability and reliability, leading to suboptimal controller performance. Integrating EVs into LFC systems enhances dynamical stability but introduces additional complexity. Therefore, it is crucial to employ robust analysis and controller design techniques to ensure system stability. In this study, we utilize the Kharitonov Theorem to determine the robust stability regions and stability boundaries in the parameter plane of the Proportional‐Integral (PI) controller. By considering communication time delays and parametric uncertainties in the LFC system with EVs (LFC‐EVs), the robust PI controller gains using these methods are efficiently computed. To evaluate the performance of the theoretically computed robust controller parameters, time‐domain simulations are conducted. [ABSTRACT FROM AUTHOR]

Reducing costs and time spent in experiments in the early development stages of vehicular technology such as off-road and agricultural semi-autonomous robots could help progress in this research area. In particular, evaluating path tracking strategies in the semi-autonomous operation of robots becomes challenging because of hardware costs, the time required for preparation and tests, and constraints associated with external aspects such as meteorological or weather conditions or limited space in research laboratories. This paper proposes a methodology for the real-time hardware-in-the-loop emulation of path tracking strategies in low-cost agricultural robots. This methodology enables the real-time validation of path tracking strategies before their implementation on the robot. To validate this, we propose implementing a path tracking strategy using only the information of motor's angular speed and robot yaw velocity obtained from encoders and a low-cost inertial measurement unit (IMU), respectively. This paper provides a simulation with MATLAB/Simulink, hardware-in-the-loop with Qube-servo (Quanser), and experimental results with an Agribot platform to confirm its validity. [ABSTRACT FROM AUTHOR]

The research on high-performance vector control of permanent magnet synchronous motor (PMSM) drive system plays an extremely important role in electrical drive system. To further improve the speed control performance of the system, a fast non-singular end sliding mode (FNTSM) surface function based on traditional NTSM control is developed. The theoretical analysis proves that the FNTSM surface function has a faster dynamic response and more finite-time convergence. In addition, for the self-vibration problem caused by high sliding mode switching gain, an FNTSM control method with anti-disturbance capability was designed based on the linear disturbance observer (DO), i.e. the FNTSMDO method was employed to devise the PMSM speed regulator. The comparative simulation and experiment results with traditional PI control and NTSM control methods indicate that the FNTSMDO method could improve the dynamic performance and anti-interference of the system.

Inductance – Capacitance – Inductance (LCL) filter is a very attractive candidate for renewable energy system applications due to its high efficiency. High attenuation of the switching frequency harmonics, small size, low fee, and improving the overall harmonic distortion (THD). This paper presents how voltage is affected by increased loads or voltage sag. Therefore it is necessary to control it with certain controllers. The Adaptive Neuro-Fuzzy Inference System (ANFIS) is used as an intelligent controller, the voltage constraint as training data for ANFIS obtained from PI. The filter works in a good connection between the inverter and the grid and rewords unwanted harmonics from using the inverter. The mathematical models for the LCL filter are investigated. The proposed approach shows more effective results than previous performance for voltage controlling and harmonic reduction. It gives overshoot (0.5%), steady state error (0.005), settling time (0.03 sec), rise time (0.005 sec), and improving THD 8.67% to 2.33% by comparing these results of ANFIS respectively with the results of PI which gave(3%),(0.01),(0.2sec)and( 0.02sec).

This article presents a three-phase four-wire inverter to generate voltage sources under wide filter inductance variation. The voltage sources with distortion and unbalance are to emulate grid voltages. The distortion includes voltage sags, voltage swells, and harmonic components, and the unbalance includes voltage and phase-angle differences. With a conventional PI control and direct digital control (DDC) only, the voltage distortion cannot fulfill precisely because of the improper controls. While with the proposed modified DDC (PDDC) and harmonic-angle adjustment algorithm, the soft core saturation can be taken into account and the harmonic voltage distortion can be accurately emulated, respectively. Moreover, the proposed control scheme can achieve a fast transient response. The control law is derived and the inverter with the control to generate grid voltage is described in detail. Simulated and experimental results from the 10-kW prototype have verified the analyses and discussions.