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Showing papers on "Voltage regulator published in 2022"


Journal ArticleDOI
TL;DR: In this article , the authors investigated the coordination and optimization of fuzzy controllers for designing PSS and STATCOM controllers for more attenuation of power system fluctuations, where fuzzy sets of membership functions were tuned based on a performance index.
Abstract: The low frequency oscillations have always been the main problem of power system and can lead to power angle instability, limiting the maximum power to be transmitted on tie-lines and system separation. For boosting power system stability limits, the most effectiveness way is to install supplementary excitation control, power system stabilizer (PSS) to add a supplementary feedback stabilizing signal into the automatic voltage regulator (AVR). This article investigates the coordination and optimization of fuzzy controllers for designing PSS and STATCOM controllers for more attenuation of power system fluctuations. The designed fuzzy controller replaces the STATCOM AC voltage regulator. Moreover, for more damping a fuzzy power system stabilizer (FPSS) is placed on all machines. Coordination between Fuzzy Based STATCOM (FSTATCOM) and FPSS is achieved by Self-Adaptive Learning Bat Algorithm (SALBA) in two stages. At first, scaling factors and then fuzzy sets of membership functions (MFs) will be tuned based on a performance index. To indicate the effectiveness of the proposed scheme, the coordinated optimized FPSS and FSTATCOM are compared with conventional design approaches like conventional PSS (CPSS) and proportional-integral controller based STATCOM (PISTATCOM). The simulations clearly demonstrate the effectiveness of the coordinated fuzzy controllers in terms of transient and dynamic stability.

21 citations


Journal ArticleDOI
TL;DR: In this paper , a merged two-stage 48-V-to-1-V point-of-load (PoL) architecture with a 24-V virtual intermediate bus (VIB) for CPU voltage regulator applications is presented.
Abstract: This article presents a merged two-stage 48-V-to-1-V point-of-load (PoL) architecture with a 24-V virtual intermediate bus (VIB) for CPU voltage regulator applications. The VIB-PoL architecture includes two power conversion stages linked by a 24-V VIB with a significant voltage ripple. The first stage is a 2:1 interleaved charge pump, which converts 48 to 24 V. The second stage comprises multiple interleaved four-level series-capacitor buck modules with coupled inductors, converting 24 V to regulated 1 V with an equivalent voltage conversion ratio of 6:1. The VIB-PoL architecture achieves high efficiency and high power density by reducing the power conversion stress of both stages and eliminating the intermediate bus capacitors. A 48-V-to-1-V 640-A CPU voltage regulator with a peak power stage efficiency of 95.2% (93.3%, including gate driver loss), a full-load efficiency of 84.4% (83.1%, including gate driver loss), and a power density of 463 W/in $^3$ (at 1-V output with liquid cooling) is built and tested to demonstrate the VIB-PoL architecture.

20 citations


Journal ArticleDOI
TL;DR: A Fuzzy proportional–integral–derivative (Fuzzy PID) controller design is presented to improve the automatic voltage regulator (AVR) transient characteristics and increase the robustness of the AVR.
Abstract: In this paper, a Fuzzy proportional–integral–derivative (Fuzzy PID) controller design is presented to improve the automatic voltage regulator (AVR) transient characteristics and increase the robustness of the AVR. Fuzzy PID controller parameters are determined by a genetic algorithm (GA)-based optimization method using a novel multi-objective function. The multi-objective function, which is important for tuning the controller parameters, obtains the optimal solution using the Integrated Time multiplied Absolute Error (ITAE) criterion and the peak value of the output response. The proposed method is tested on two AVR models with different parameters and compared with studies in the literature. It is observed that the proposed method improves the AVR transient response properties and is also robust to parameter changes.

20 citations


Journal ArticleDOI
TL;DR: In this article , the authors proposed a direct adaptive control for several power system applications such as the Egyptian power system (EPS), a three-zone interconnected microgrid (MG), and a single machine connected to the grid (SMIB).

19 citations


Journal ArticleDOI
TL;DR: In this paper , a modified smoothed function algorithm (MSFA) based method was proposed to tune the FOPID controller of AVR system since it requires fewer number of function evaluation per iteration.

13 citations


Journal ArticleDOI
10 Jul 2022-Energies
TL;DR: The results of the study prove the superiority of the proposed IWOA-based AVR system in terms of transient response and stability metrics and robustness analysis was conducted to assess the robustness of the optimized AVRSystem.
Abstract: The proportional integral derivative (PID) controller is one of the most robust and simplest configuration controllers used for industrial applications. However, its performance purely depends on the tuning of its proportional (KP), integral (KI) and derivative (KD) gains. Therefore, a proper combination of these gains is primarily required to achieve an optimal performance of the PID controllers. The conventional methods of PID tuning such as Cohen-Coon (CC) and Ziegler–Nichols (ZN) generate unwanted overshoots and long-lasting oscillations in the system. Owing to the mentioned problems, this paper attempts to achieve an optimized combination of PID controller gains by exploiting the intelligence of the whale optimization algorithm (WOA) and one of its recently introduced modified versions called improved whale optimization algorithm (IWOA) in an automatic voltage regulator (AVR) system. The stability of the IWOA-AVR system was studied by assessing its root-locus, bode maps, and pole/zero plots. The performance superiority of the presented IWOA-AVR design over eight of the recently explored AI-based approaches was validated through a comprehensive comparative analysis based on the most important transient response and stability metrics. Finally, to assess the robustness of the optimized AVR system, robustness analysis was conducted by analyzing the system response during the variation in the time constants of the generator, exciter, and amplifier from −50% to 50% range. The results of the study prove the superiority of the proposed IWOA-based AVR system in terms of transient response and stability metrics.

13 citations


Journal ArticleDOI
TL;DR: A bilaterally transmitted domino-type multiload inductive power transfer (IPT) system for constant-voltage (CV) outputs, low voltage attenuation, and high efficiency is proposed, and the system efficiency is improved by the proposed bilateral IPT structure.
Abstract: In this article, we propose a bilaterally transmitted domino-type multiload inductive power transfer (IPT) system for constant-voltage (CV) outputs, low voltage attenuation, and high efficiency. There are three major contributions. First, the series–series/parallel (S–SP) topology is developed to design the multiload IPT system, which can realize the load-independent CV outputs without using compensation inductors, enabling a compact IPT system. Second, a bilateral IPT structure is proposed with two parallel power transfer routes to mitigate the practical output voltage attenuation issue, resulting in a better CV property. Third, system efficiency is improved by the proposed bilateral IPT structure. With the bilateral S–SP compensated multiload IPT design, the output voltage attenuation analysis and system efficiency are investigated considering parasitic resistances. A 70 W six-load bilateral IPT prototype is implemented and compared with the unilateral counterpart. With k = 0.26 and Q = 300, the proposed bilateral IPT system validates an improved CV output with a small attenuation rate of 10.22%, which is much lower than the unilateral one. The maximum efficiency achieves 90.39%, showing 5.17% higher than the unilateral IPT system in the identical load condition.

11 citations



Journal ArticleDOI
TL;DR: In this article, a proportional integral derivative (PID) controller for a synchronous generator (SG) automatic voltage regulator (AVR) is proposed to optimize load disturbance response under constraints to robustness of model uncertainties and sensitivity to measurement noise.

10 citations


Journal ArticleDOI
TL;DR: In this paper , a sigmoid-based PID (SPID) controller was proposed for the automatic voltage regulator (AVR) system in order to allow for an accelerated settling to rated voltage, as well as increasing the control accuracy.
Abstract: Automatic Voltage Regulator (AVR) is fabricated to sustain the voltage level of a synchronous generator spontaneously. Several control strategies have been introduced into the AVR system with the aim of gaining a better dynamic response. One of the most universally utilized controllers is the Proportional-Integral-Derivative (PID) controller. Despite the PID controller having a relatively high dynamic response, there are still further possibilities to improve in order to obtain more appropriate responses. This paper designed a sigmoid-based PID (SPID) controller for the AVR system in order to allow for an accelerated settling to rated voltage, as well as increasing the control accuracy. In addition, the parameters of the proposed SPID controller are obtained using an enhanced self-tuning heuristic optimization method called Nonlinear Sine Cosine Algorithm (NSCA), for achieving a better dynamic response, particularly with regards to the steady-state errors and overshoot of the system. A time-response specifications index is used to validate the proposed SPID controller. The obtained simulation results revealed that the proposed method was not only highly effective but also greatly improved the AVR system transient response in comparison to those with the modern heuristic optimization based PID controllers.

9 citations


Journal ArticleDOI
TL;DR: In this paper , a proportional integral-proportional derivative (PI-PD) controller with combined load frequency control (LFC) and automatic voltage regulator (AVR) is proposed to stabilize the nominal frequency and terminal voltage in an interconnected power system.
Abstract: The stability control of nominal frequency and terminal voltage in an interconnected power system (IPS) is always a challenging task for researchers. The load variation or any disturbance affects the active and reactive power demands, which badly influence the normal working of IPS. In order to maintain frequency and terminal voltage at rated values, controllers are installed at generating stations to keep these parameters within the prescribed limits by varying the active and reactive power demands. This is accomplished by load frequency control (LFC) and automatic voltage regulator (AVR) loops, which are coupled to each other. Due to the complexity of the combined AVR-LFC model, the simultaneous control of frequency and terminal voltage in an IPS requires an intelligent control strategy. The performance of IPS solely depends upon the working of the controllers. This work presents the exploration of control methodology based on a proportional integral–proportional derivative (PI-PD) controller with combined LFC-AVR in a multi-area IPS. The PI-PD controller was tuned with recently developed nature-inspired computation algorithms including the Archimedes optimization algorithm (AOA), learner performance-based behavior optimization (LPBO), and modified particle swarm optimization (MPSO). In the earlier part of this work, the proposed methodology was applied to a two-area IPS, and the output responses of LPBO-PI-PD, AOA-PI-PD, and MPSO-PI-PD control schemes were compared with an existing nonlinear threshold-accepting algorithm-based PID (NLTA-PID) controller. After achieving satisfactory results in the two-area IPS, the proposed scheme was examined in a three-area IPS with combined AVR and LFC. Finally, the reliability and efficacy of the proposed methodology was investigated on a three-area IPS with LFC-AVR with variations in the system parameters over a range of  ± 50%. The simulation results and a comprehensive comparison between the controllers clearly demonstrates that the proposed control schemes including LPBO-PI-PD, AOA-PI-PD, and MPSO-PI-PD are very reliable, and they can effectively stabilize the frequency and terminal voltage in a multi-area IPS with combined LFC and AVR.

Journal ArticleDOI
TL;DR: In this article , a new modified successive NRIM has been proposed for radial distribution system embedded Power Distribution Voltage Regulators (PDVRs) in order to improve the performance of power distribution networks.

Journal ArticleDOI
TL;DR: In this paper , a proportional integral derivative (PID) controller for a synchronous generator (SG) automatic voltage regulator (AVR) is proposed to optimize load disturbance response under constraints to robustness of model uncertainties and sensitivity to measurement noise.

Journal ArticleDOI
TL;DR: In this paper , a novel PD with filter coefficient (PDN) controller cascade with fractional-order PID with filter coefficients (FOPIDN) is proposed as a secondary controller for combined ALFC-AVR loop.
Abstract: This paper discusses the significance of various energy storage devices like redox flow battery (RFB), capacitive energy storage (CES), superconducting magnetic energy storage (SMES), and flywheel energy storage system (FESS) impact on the combined control of automatic load frequency control (ALFC) and automatic voltage regulator (AVR) of three areas interconnected power systems having thermal, hydro, gas, and geothermal plants in presence of HVDC link. A novel PD with filter coefficient (PDN) controller cascade with fractional-order PID with filter coefficient (FOPIDN), CPDN-FOPIDN is proposed as a secondary controller for combined ALFC-AVR loop. An artificial flora algorithm is utilized to obtain the various controller parameters under numerous system conditions. The proposed CPDN-FOPIDN controller provides less settling time, overshoots, undershoots, and reduces oscillation compare to the FOPIDN controller. The study also reveals that the RFB provides better system performance than SMES, CES, and FESS. Integration of HVDC link improves the system dynamic response. Furthermore, the sturdiness of the proposed CPDN-FOPIDN controller is tested against the changes in system loading conditions via sensitivity analysis.

Journal ArticleDOI
TL;DR: In this article , a combination of load frequency control and automatic voltage regulation of two interconnected micro-grids is presented, where a novel accelerating PID controller (PIDA) is applied using a new doctor and patient optimization technique (DPO).
Abstract: Frequency and voltage deviations are two main problems in microgrids, especially with the increase in the penetration level of renewable energies. This paper presents novel techniques to apply combined the load frequency control and automatic voltage regulation of two interconnected microgrids. The two microgrids are operated by solar energy and bioenergy technologies and include energy-storage facilities. The control is applied using a novel accelerating PID controller (PIDA), which is compared to state-of-the-art control schemes. The controllers are designed using a new doctor and patient optimization technique (DPO), which is compared to state-of-the-art techniques. The combined design of load frequency controllers and automatic voltage regulators is also compared to a standalone design. The comparisons are carried out by testing the system performance at each operation condition in addition to indicators such as integral absolute error for frequency and voltage and integral time absolute error for frequency and voltage. The results show that a combined DPO–PIDA design of LFC–AVR schemes for fully sustainable microgrids has better performance than other standalone designs and other control and optimization alternatives.

Journal ArticleDOI
TL;DR: In this paper , a novel PIλDND2N2 controller is designed for an Automatic Voltage Regulator (AVR) in a power system and is studied in this paper.

Proceedings ArticleDOI
29 Apr 2022
TL;DR: In this paper , a two degrees of freedom fractional Integral minus Tilt-Derivative filter (2DOF FOI-TDF) controller is proposed for a multi-area multi-unit interconnected power system.
Abstract: This article discusses the repercussions of Superconducting Magnetic Energy Storage (SMES) system and High Voltage DC link in amalgamated Automatic Load Frequency Control (ALFC) and Automatic Voltage Regulator (AVR) pattern of a multi-area multi-unit interconnected power system. Reheat thermal and hydro plants are included in each area, as well as a heavy duty gas turbine plant in Area 1 and 2, and a geo thermal plant in Area 3. In thermal plants, the appropriate amount of GRC and GDB is mounted, whereas in hydro plants, the appropriate amount of only GRC is mounted. The two degrees of freedom fractional Integral minus Tilt-Derivative filter (2DOF FOI-TDF) controller is observed such as controllers of ALFC and AVR systems. With the Harris Hawks Optimization (HHO) method, the preeminent controller values’ are found. Apropos all time-domain indices, the proposed 2DOF FOI-TDF controller is proven to be superior to FOI, TIDF controllers. Similarly, the system dynamics are explored in order to analyze the repercussions of SMES and HVDC links separately. Finally, sensitivity assessments are carried out with various magnitudes of system loading, demonstrating the proposed controller's robustness.

Journal ArticleDOI
TL;DR: In this paper , two controllers with a novel sliding surface function are proposed based on a mathematical model of the AVR (SMC3) and its approximate reduced-order model.
Abstract: Academic studies on the Automatic Voltage Regulator (AVR) have focused on a linear mathematical model which lacks protective features. More accurate model of the AVR system includes protective features as described in IEEE standards. The AVR models without protective features, namely limiters, result in less accurate control performance since the outputs of real controllers are always bounded. In the present study, the controller outputs are limited between -0.9pu and 1.0pu, and the upper bound of exciter output is limited by 3.1pu with the direction of IEEE standards. The effect of limiters on the controller performance is investigated. Two controllers with a novel sliding surface function are proposed based on a mathematical model of the AVR (SMC3) and its approximate reduced-order model (SMC2). The proposed controllers having only two parameters are optimized with improved particle swarm optimization (PSO) algorithm. After optimization, the robustness of the controllers is compared with the results of various operating conditions identical to the previous studies. Nominal time constants of the AVR constituents are perturbed from -50% to 50%, and ±10% output disturbance is applied to the output. Although controller outputs and exciter output are limited, the overshoot is measured less than 0.1% at no-load conditions. The robustness of the controllers against parameter uncertainties is measured with an average overshoot at the output. Another superiority among the reported results in the literature is obtained from the proposed controllers, where the minimum average overshoots are measured. In addition, when ±10% load is applied to the output of the AVR, the proposed controllers generate accurate control inputs that reject the load disturbance successfully. Furthermore, the proposed controllers keep the output within the ±5% band if there is a monotonic change at the output. All the results show that the proposed controllers with the improved PSO have drawn the best performance from the perspective of time-domain specifications in comparison with the recently reported controllers.

Journal ArticleDOI
19 Jan 2022-Energies
TL;DR: In this article , the use of a Low Voltage Regulator (LVR-sys) in a selected rural distribution network with PV micro-sources is discussed, and measured voltage levels in this network, before application and after application of this regulator are presented.
Abstract: The constant increase in the number of photovoltaic (PV) energy sources in distribution networks is the cause of serious voltage problems. The networks built at least a dozen years ago are not provided for the installation of a large number of micro-sources. It happens that the previously properly functioning power networks are not able to provide to consumers power with the required parameters, after installing many PV sources. The problem relates especially to the level of voltage in the networks. This phenomenon sometimes occurs on sunny days, especially in summer. This paper discusses the use of a Low-Voltage Regulator (LVR-sys) in a selected rural distribution network with PV micro-sources. Measured voltage levels in this network, before application and after application of this regulator, are presented. The application of the regulator significantly improved voltage levels in the network and enabled these levels to be maintained within the normative range.

Proceedings ArticleDOI
11 Feb 2022
TL;DR: In this article , the performance comparison of various tilt controllers in coalesced frequency and voltage control of multi-area multi-unit interconnected power system with their Automatic Load Frequency Control (ALFC) and Automatic Voltage Regulator (AVR) structures is presented.
Abstract: This article presents the performance comparison of various tilt controllers in coalesced frequency and voltage control of multi-area multi-unit interconnected power system with their Automatic Load Frequency Control (ALFC) and Automatic Voltage Regulator (AVR) structures. Every area has a thermal plant, along with a Wind turbine plant in Area-1, solar thermal plant in Area-2, and Dish-Stirling solar thermal unit in Area-3. The two degrees of freedom Integral minus Tilt-Derivative with filter (2DOF I-TDF) controller is perceived as supplementary and core controller of ALFC and AVR structures. The optimal controller values are achieved with Harris Hawks Optimization (HHO) technique. The proposed 2DOF I-TDF controller is found superlative in comparison to TID, TIDF, I-TDF controllers concerning all time-domain indices. Likewise, the system dynamics are also investigated with various controllers in AVR system. The supremacy of the proposed controller is assessed with random load perturbation. In the end, the sensitivity analyses are achieved with different system loading conditions which convey the robustness of the proposed controller.

Journal ArticleDOI
TL;DR: In this paper , a bilateral domino-type multiload inductive power transfer (IPT) system for constantvoltage (CV) outputs, low voltage attenuation, and high efficiency was proposed.
Abstract: In this article, we propose a bilaterally transmitted domino-type multiload inductive power transfer (IPT) system for constant-voltage (CV) outputs, low voltage attenuation, and high efficiency. There are three major contributions. First, the series–series/parallel (S–SP) topology is developed to design the multiload IPT system, which can realize the load-independent CV outputs without using compensation inductors, enabling a compact IPT system. Second, a bilateral IPT structure is proposed with two parallel power transfer routes to mitigate the practical output voltage attenuation issue, resulting in a better CV property. Third, system efficiency is improved by the proposed bilateral IPT structure. With the bilateral S–SP compensated multiload IPT design, the output voltage attenuation analysis and system efficiency are investigated considering parasitic resistances. A 70 W six-load bilateral IPT prototype is implemented and compared with the unilateral counterpart. With k = 0.26 and Q = 300, the proposed bilateral IPT system validates an improved CV output with a small attenuation rate of 10.22%, which is much lower than the unilateral one. The maximum efficiency achieves 90.39%, showing 5.17% higher than the unilateral IPT system in the identical load condition.

Journal ArticleDOI
TL;DR: In this paper , an Archimedes optimization algorithm (AOA) was used to tune the parameters of the PID controllers for automatic voltage regulators (AVRs) in electrical grids to preserve the voltage at its nominal value.
Abstract: Automatic voltage regulators (AVRs) in electrical grids preserve the voltage at its nominal value. Regulating the parameters of proportional–integral–derivative (PID) controllers used for AVRs is a nonlinear optimization issue. The objective function is designed to minimize the settling time, rise time, and overshoot of step response of resultant voltage with subjugation to constraints of PID controller parameters. In this study, we suggest using an Archimedes optimization algorithm (AOA) to tune the parameters of the PID controllers for AVRs. In addition, using an AOA to optimize the parameters of a fractional-order PID (FOPID) controller and a PID plus second-order derivative (PIDD2) controller for AVRs is also investigated to validate their effectiveness. The disturbance repudiation and robustness of the AOA-PID controllers are also examined and confirmed. To validate the results of the AOA-PID controllers, they are compared with those of other optimized controllers for convergence speed, the quality of the step response. The results indicate that the AOA functions perfectly and it has good potential for optimizing the PID controller parameters with better step response compared with the PID controller based on other approaches while preferring the results of the AOA–PIDD2 controller over other kinds of the AOA-PID controllers.

Journal ArticleDOI
01 Jan 2022-e-Prime
TL;DR: In this article , an improved Runge Kutta Optimizer (RUN) is obtained by integrating the pattern search (PS) method into the original form of the Run optimizer, and the constructed iRUN optimizer is proposed as an efficient tool to tune a real PIDD2 controller employed in an AVR system.
Abstract: It is crucial to maintain the terminal voltage of a power network in order to reach a desired power quality. In this regard, a system called automatic voltage regulator (AVR) holds a significant role as it allows the adjustment of the terminal voltage. However, an AVR system requires an efficient control technique in order to provide stability. Considering this requirement, a new method is presented in this paper for transient response enhancement and robustness of the automatic voltage regulator (AVR) system. In that sense, the structure of a recently developed metaheuristic algorithm named Runge Kutta optimizer (RUN) is improved. The improved RUN (iRUN) optimizer is obtained by integrating the pattern search (PS) method into the original form of the RUN optimizer. The constructed iRUN optimizer is proposed as an efficient tool to tune a real proportional-integral-derivative (PID) plus second-order derivative (PIDD2) controller employed in an AVR system. In the proposed control mechanism, a performance index known as ZLG is used as an objective function. The proposed iRUN optimizer based real PIDD2 controller is comparatively demonstrated to be superior in terms of transient response and robustness against other available and recently reported methods based on PID, PID with filter (PID-F), PID acceleration (PIDA), fractional order PID (FOPID) and PID plus second-order derivative (PIDD2) controllers that are respectively tuned with metaheuristic optimizers of stochastic fractal search algorithm, Archimedes optimization algorithm, whale optimization algorithm, Henry gas solubility optimization and particle swarm optimization. The proposed method is shown to achieve no overshot and less rise and settling times compared to listed methods. It is also shown to be sufficiently robust in case of potential variations that may occur in the parameters of the system. The superiority is further demonstrated using thirty good performing and recently reported different methods that adopt different controllers and metaheuristic optimizers, as well. All comparative analyses confirm the excellent capability of the proposed iRUN optimizer based real PIDD2 controller for the AVR system control.


Journal ArticleDOI
TL;DR: In this paper , a multi-input multi-output digital control strategy for a bidirectional interleaved boost converter with coupled inductors is proposed to operate as an interface between an ultracapacitor and a high-voltage dc-bus in a hybrid nanogrid.
Abstract: This article proposes a multi-input multi-output digital control strategy for a bidirectional interleaved boost converter with coupled inductors, designed to operate as an interface between an ultracapacitor and a high-voltage dc-bus in a hybrid nanogrid. The control strategy keeps the high-voltage side dc-bus of the nanogrid stable when the voltage at the low-voltage side, connected to the ultracapacitor, changes in a wide range. Bidirectional energy flow control with current protection is allowed too. The high-voltage regulation loop is closed around an inner, low-voltage side current control loop. In parallel to these, a third, clamp voltage regulator is set to keep tight control over switch voltage stress. This article discusses the controller organization, the design criteria, and shows the subsequent implementation on a general purpose digital control platform. The achievable performance is experimentally verified on a 1.5-kW converter prototype.

Journal ArticleDOI
TL;DR: In this article , a digital low-dropout (DLDO) regulator is described which is controlled by voltage-controlled oscillator (VCO) based feedback loop, there are two VCOs in the control loop whose frequencies are controlled by the output voltage and reference level.
Abstract: A digital low-dropout (DLDO) regulator is described which is controlled by voltage-controlled oscillator (VCO) based feedback loop. There are two VCOs in the control loop whose frequencies are controlled by the output voltage and reference level, respectively. By comparing the phase between the output clocks of the two VCOs and modulating the number of enabled power transistors and their on -times, the output voltage is regulated. The proposed VCO-based control is a hybrid of digital and analog control schemes because the number of enabled power transistors is controlled in discrete step while the on -time is modulated continuously. In order to improve the transient speed, transient detector is employed in the DLDO regulator. The DLDO regulator with the proposed VCO-based control has been implemented in a 65-nm CMOS process. The DLDO regulator can provide the output from 0.5 to 1.1 V from the input ranging from 0.9 to 1.2 V. The load transient time is smaller than 90 ns for both step-up and step-down changes of load current. The peak current efficiency is 99.3%.

Journal ArticleDOI
TL;DR: In this article , an optimal multi-term fractional-order PID (MFOPID) controller for automatic voltage regulator (AVR) system has been proposed for improving the performance of the AVR system.
Abstract: This article presents a novel application of an optimal Multi‐term Fractional‐Order PID (MFOPID) controller for improving the performance of the automatic voltage regulator (AVR) system. A recently developed Rao algorithm has been used to optimize the proposed Multi‐term FOPID controller. The effectiveness of the Rao algorithm tuned Multi‐term FOPID controller for the AVR system has been proved by performing transient response, robustness, and performance analyses. Statistical analysis of the proposed Multi‐term FOPID controlled AVR system has been carried out to explore the most effective performance index among ITAE, ITSE, ISE, and IAE. The external disturbance rejection capability of the Rao algorithm‐tuned MFOPID controller has been examined by injecting external disturbances into the AVR system of different capacities at different times. The superiority of the proposed Multi‐term FOPID controller is validated by comparing the simulation results with recently employed various PID, PID‐Acceleration (PIDA), and FOPID controllers tuned by different metaheuristic algorithms. In addition, the behavior of the proposed Multi‐term FOPID controller has been examined in a real synchronous generator that is connected to a 10,000 MVA, 230 kV electric power network via a 210 MVA transformer using a MATLAB/Simulink environment. From the various simulation results, it has been concluded that the proposed Rao algorithm tuned optimal and robust Multi‐term FOPID controller has significantly improved the performance, robustness and stability of the AVR system.

Journal ArticleDOI
TL;DR: A comparative study is performed to design an optimal PID controller for an automatic voltage regulator system using different optimization techniques that improved the transient response of the AVR system in a different way.
Abstract: A comparative study is performed to design an optimal PID controller for an automatic voltage regulator system using different optimization techniques. The presented approaches are referred to as particle swarm optimization (PSO) algorithm, cuckoo search optimization (CSO) algorithm, moth flame optimization (MFO) algorithm, water cycle optimization (WCO) algorithm, teaching–learning-based optimization (TLBO) algorithm, and hill climbing optimization (HCO) algorithm. Transient response parameters, which are rise time Tr, settling time Ts, and percentage overshoot Mp, are used as comparison criteria. The integral time absolute error ITAE is the used performance index. All the proposed optimization techniques improved the transient response of the AVR system in a different way and gave good preliminary results.

Journal ArticleDOI
03 Nov 2022-Energies
TL;DR: In this paper , the performance of the fractional-order tilt-integral-derivative (TID) controller is compared with that of a widely used proportional integral derivative controller in all three test systems studies, and the PSO-tuned TID controller is insensitive to variation in load damping factor and time constants of the AVR system.
Abstract: An interconnected power system requires specific restrictions to be maintained for frequency, tie-line power, and the terminal voltage of synchronized generators to avoid instability. Therefore, frequency stability and voltage regulation issues are covered individually and jointly in the current research work. Initially in test system 1, automatic generation control (AGC) investigations are done on two interconnected systems with thermal plants and electric vehicles in one area and distributed generation and electric vehicles in other area. The automatic voltage regulator (AVR) problem alone is chosen for investigation in test system 2. The third test system addresses the combined AGC and AVR issues. The performance of the fractional-order tilt-integral-derivative (TID) controller is compared with that of a widely used proportional integral derivative (PID) controller in all three test systems studies. The findings demonstrate better performance of the TID controller than PID in terms of providing superior dynamic metrics, such as low peak overshoots, undershoots, and settling time, as well as decreased oscillations amplitudes. Additionally, TID performs better than PID despite randomized load disturbance, system non-linearities, and time delays in AGC and the combined AGC and AVR problem. The PSO-tuned TID controller is insensitive to variation in load damping factor and time constants of the AVR system. Finally, the results are validated by an OPAL-RT 4510 real-time digital simulator.

Journal ArticleDOI
TL;DR: In this article , a nonlinear generalization of the robust coordinated power system stabilizer and automatic voltage regulator (PSS-AVR) is designed with the aim of enlarging the stability region and improving the transients about the unpredictable operating conditions determined by the faults.
Abstract: The transient stabilization and voltage regulation problem for a synchronous generator connected to an infinite bus is addressed, in this article, in the presence of all uncertain physical parameters. First, new interpretations for the desensitized four loops regulator, here referred to as robust coordinated power system stabilizer and automatic voltage regulator (PSS-AVR) are derived in terms of minimum phase properties with respect to a suitably chosen output for the linearized error system. Second, on the basis of such an output, a nonlinear generalization of the robust coordinated PSS-AVR is designed with the aim of enlarging the stability region and improving the transients about the unpredictable operating conditions determined by the faults. Its linear action coincides with the one provided by the robust coordinated PSS-AVR: the compelling simplicity of control structure (just one integrator is involved) and robust tuning procedure of the linear design are definitely inherited, with, additionally, no use of the mechanical input power. A numerical analysis, along with realistic simulations, confirms improved stability when the proposed nonlinear controller is applied.