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Abstract This paper presents an innovative control scheme designed to significantly enhance the power factor of AC/DC boost rectifiers by integrating an adaptive neuro-fuzzy inference system (ANFIS) with predictive current control. The innovative control strategy addresses key challenges in power quality and energy efficiency, demonstrating exceptional performance under diverse operating conditions. Through rigorous simulation, the proposed system achieves precise input current shaping, resulting in a remarkably low total harmonic distortion (THD) of 3.5%, which is well below the IEEE-519 standard threshold of 5%. Moreover, the power factor reaches an outstanding 0.990, indicating highly efficient energy utilization and near-unity power factor operation. To validate the theoretical findings, a 500 W laboratory prototype was implemented using the dSPACE ds1104 digital controller. Steady-state analysis reveals sinusoidal input currents with minimal THD and a power factor approaching unity, thereby enhancing grid stability and energy efficiency. Transient response tests further demonstrate the system’s robustness against load and voltage fluctuations, maintaining output voltage stability within an 18 V overshoot and a 20 V undershoot during load changes, and achieving rapid response times as low as 0.2 s. Comparative evaluations against conventional methods underscore the superiority of the proposed control strategy in terms of both performance and implementation simplicity. By harnessing the strengths of ANFIS-based voltage regulation and predictive current control, this scheme offers a robust solution to power quality issues in AC/DC boost rectifiers, promising substantial energy savings and improved grid stability. The results affirm the potential of the proposed system to set new benchmarks in power factor correction technology.

This paper presents an innovative control scheme designed to significantly enhance the power factor of AC/DC boost rectifiers by integrating an adaptive neuro-fuzzy inference system (ANFIS) with predictive current control. The innovative control strategy addresses key challenges in power quality and energy efficiency, demonstrating exceptional performance under diverse operating conditions. Through rigorous simulation, the proposed system achieves precise input current shaping, resulting in a remarkably low total harmonic distortion (THD) of 3.5%, which is well below the IEEE-519 standard threshold of 5%. Moreover, the power factor reaches an outstanding 0.990, indicating highly efficient energy utilization and near-unity power factor operation. To validate the theoretical findings, a 500 W laboratory prototype was implemented using the dSPACE ds1104 digital controller. Steady-state analysis reveals sinusoidal input currents with minimal THD and a power factor approaching unity, thereby enhancing grid stability and energy efficiency. Transient response tests further demonstrate the system's robustness against load and voltage fluctuations, maintaining output voltage stability within an 18 V overshoot and a 20 V undershoot during load changes, and achieving rapid response times as low as 0.2 s. Comparative evaluations against conventional methods underscore the superiority of the proposed control strategy in terms of both performance and implementation simplicity. By harnessing the strengths of ANFIS-based voltage regulation and predictive current control, this scheme offers a robust solution to power quality issues in AC/DC boost rectifiers, promising substantial energy savings and improved grid stability. The results affirm the potential of the proposed system to set new benchmarks in power factor correction technology. [ABSTRACT FROM AUTHOR]

The penetration of solar energy into the distribution network is affected by the seasonal and day-to-day variability of the solar power generation. In underdeveloped and developing countries, the power quality (PQ) deterioration issues are primarily observed due to the presence of the weak utility grid. Therefore, smart grid operability is achieved through power exchange along with the improvement in PQ indices by the application of the biquad filter, thereby exhibiting multifunctional control capability. The biquad filter is less affected by quantization errors and involves no additional usage of sensors or control loops, which are the significant advantages observed in its implementation. The biquad filter utilization in this work, includes the estimation of fundamental load current along with mitigation of harmonics, improving PQ, reactive power compensation, and satisfactory performance during voltage unbalance, sag, distortion, swell, and unbalanced loading conditions, which are observed during weak grid conditions. The stochastic inputs of the solar PV array interfaced utility grid system are agitated due to the erratic availability of solar power, and are overcome through an adaptive perturb and observe technique, which uses a variable perturbation step size. Test cases considered here, validate the performance in accordance to the IEEE-519 standard. [ABSTRACT FROM AUTHOR]

This study presents a single stage grid‐interfaced solar photovoltaic (SPV) system using a multifunctional complex coefficient reduced ordered generalised integrator (CC‐ROGI) based frequency‐locked loop (FLL) control. The main contributions of this study, include (i) the extrication of fundamental active components from load currents using CC‐ROGI‐FLLbased control to generate the reference grid currents for voltage source converter (VSC) switching, (ii) VSC works as a distribution static compensator, which performs multi‐functions like harmonics mitigation, reactive power compensation, unity power factor operation and grid currents balancing, (iii) this CC‐ROGI‐FLL also extricates the fundamental grid voltages component even under grid voltage harmonic distortion and grid voltages unbalancing. Moreover, SPV power feed‐forward component is assimilated in this control to reduce the oscillations in grid currents under variable irradiance. Simulated and experimental results show satisfactory behaviour of the system at different conditions like load unbalancing, variable solar irradiance and abnormal grid conditions. The comparative performance of CC‐ROGI‐FLL control with other FLL and phaselocked loop controls are shown in this study. This CC‐ROGI‐FLL control has manifested a good steady state performance and dynamic response. The total harmonic distortions of grid currents are found well within the limits of the IEEE‐519 standard, even under abnormal grid conditions. [ABSTRACT FROM AUTHOR]

This work introduces a novel damped fifth‐order generalized integrator (DFOGI) based control algorithm for grid‐integrated solar photovoltaic (PV) system. Moreover, for GMPPT (Global Maximum Power Point Tracking), HPO (Human Psychology Optimisation) algorithm is used. Here, a three‐phase three wire, single‐stage topology of grid‐integrated partially shaded PV array is implemented. Global maximum power peak searching behavior of HPO algorithm is very rapid and accurate, which gives a satisfactory steady‐state and dynamic performances, even in rapid solar irradiance change condition. The prime objective of proposed DFOGI control is to accurately transfer the solar power to the grid at unity power factor, even when grid suffers from abnormal and adverse conditions. During these conditions, on the grid side, the power quality is maintained, where the proposed control technique provides power factor correction, and harmonics mitigation. The proposed techniques are modeled, and their performances are verified experimentally on a developed prototype, in solar insolation variation conditions, as well as in different grid disturbances such as over and under‐voltage, phase imbalance, harmonics distortion in the grid voltage etc. Test results have met the objectives of the proposed work and parameters are under the permissible limit, according to the IEEE‐519 standard. [ABSTRACT FROM AUTHOR]

In this work, a simple phase‐locked loop – less control is presented for a single‐stage solar photovoltaic (PV) – battery‐grid‐tied system. As compared to traditional solar PV systems, the system has reduced losses due to the absence of boost converter and a flexible power flow due to the inclusion of a storage source (battery). The synchronous reference frame theory is used to generate the pulses for switching the voltage‐source converter (VSC), while maximum power is extracted from the solar PV array by using perturb and observe‐based maximum power point tracking technique. The inherent feature of shunt active filtering by the VSC has also been incorporated in this system. Test results for the system operation under fixed power and variable power mode are studied on a prototype developed in the laboratory. During fixed power mode, a fixed amount of power is fed to the grid, whereas in variable power mode the power fed to the grid varies. Test results obtained are in accordance with the IEEE‐519 standard. This work is a basis for the upcoming power market, where solar PV consumers can manage the generated electricity and maximise their profit by selling the power to the grid judiciously. [ABSTRACT FROM AUTHOR]

This study presents a real‐time implementation of the optimal operation of a single‐stage three‐phase grid interfaced solar photovoltaic (PV) system with active shunt filter capabilities. The control approach is based on the least logarithmic absolute difference with an adaptive filtering technique. It serves manifold objectives of power quality improvements in the distribution network as well as grid side abnormalities such as voltage distortions, voltage sag and voltage swell. The proposed control algorithm has advantages of better steady state as well as dynamic performances as compared to conventional algorithms. The perturb and observe‐based maximum power point tracking algorithm is used to harness crest power from the PV array. The proposed system is simulated in MATLAB/Simulink platform using Simscape power systems toolbox and its performance is compared with conventional algorithms. A prototype of the proposed system is developed in the laboratory and its responses are found satisfactory under various operating conditions such as load unbalancing, reactive power compensation, variable solar insolation, voltages distortion, voltage sag and voltage swell. The total harmonic distortions of grid currents and grid voltages are found within limits of an IEEE‐519 standard. [ABSTRACT FROM AUTHOR]

This study presents a solar photovoltaic distribution static compensator (SPV‐DSTATCOM) system feeding a non‐linear load connected at point of common coupling. A hybrid variable step size–least mean square–least mean fourth (VSS–LMS–LMF) algorithm is proposed for the control of voltage source converter, which acts as DSTATCOM. A weighing factor is used so that LMS and LMF work simultaneously, and a varying step‐size helps in obtaining an adaptable system. The proposed control shows high convergence rate and low value of mean square error. The SPV array uses perturb and observe technique for maximum power extraction. The transition of SPV‐DSTATCOM to DSTATCOM and vice‐versa is also studied. In SPV‐DSTATCOM mode, the SPV feeds power to the load and the grid, resolving the power quality issues of the system, whereas in DSTATCOM mode, the grid feeds power to the load at unity power factor. The system is first simulated in MATLAB environment and then these results are experimentally verified on the developed prototype in the laboratory. The system is studied for both power factor correction and zero voltage regulation modes and under distorted grid conditions. The obtained results adhere to an IEEE‐519 standard. [ABSTRACT FROM AUTHOR]

This study presents a single‐stage solar energy conversion system tied to a three‐phase grid using a multiple second‐order generalised integrator frequency locked loop (MSOGI‐FLL)‐based control algorithm to improve power quality of the distribution system with DSTATCOM (Distribution Static Compensator) capabilities. The estimated perturb and observe algorithm is used for maximum power point tracking to obtain maximum power from a solar photovoltaic (PV) array. The MSOGI‐based control algorithm is used for load balancing, harmonics elimination, and power factor correction and delivering active power to the grid. The MSOGI‐FLL has advantages of adaptive nature with frequency variation and better harmonics filtering capabilities when compared with conventional algorithms, which is demonstrated with frequency domain analysis. The comparative performance of amplitude extraction capabilities with conventional algorithms is also demonstrated. This system configuration is simulated in MATLAB®/Simulink. The proposed control algorithm is verified on a developed prototype for various conditions like variable solar insolation level, load balancing, reactive power compensation, PV to DSTATCOM mode, and DSTATCOM to PV mode. The total harmonic distortions of grid voltages and currents are found well within the limits of an IEEE‐519 standard. [ABSTRACT FROM AUTHOR]

This study deals with a control scheme for single‐stage solar photovoltaic (SPV) grid‐interfaced system. The voltage‐source inverter (VSI) is a power electronic interface between SPV array and the grid. The VSI provides power quality features, i.e. harmonics mitigation, power factor correction and perturb and observe maximum power point tracking for single‐stage SPV grid‐interfaced system. The SPV array supplies active power to the non‐linear load and grid through VSI, during daytime only or when SPV generation is more than the load power. To increase the utilisation of VSI, it is used as an active power filter at night, to mitigate harmonics and to provide active power to the load from the utility grid. The proposed adaptive linear combiner filter has the capability to extract harmonics and enhances the power quality in SPV grid‐interfaced system. It has also satisfied an IEEE‐519 standard of harmonics by improving the quality of power of SPV grid‐integrated system. Simulation results of the SPV system are presented, which are simulated using MATLAB and response of system under non‐linear load and varying environmental condition are also studied experimentally on a developed prototype in the laboratory. [ABSTRACT FROM AUTHOR]

This study deals with a single‐phase single‐stage multifunctional grid interfaced solar photo‐voltaic (SPV) system. The proposed SPV system is multifunctional as it has MPPT (maximum power point tracking) and it provides harmonics elimination, reactive power compensation and feeding SPV energy into the grid at unity power factor. The PV array is connected at the DC link of voltage source converter. The MPPT controller estimates reference PV voltage and a proportional integral controller is used to maintain the PV string voltage to the reference value. Feed‐forward terms are used for SPV array and load components for fast dynamic response. The performance of the system is analysed under abnormal grid (sudden sag and swell) conditions. Simulation studies are performed on MATLAB‐based platform. Simulation results are verified experimentally on a developed SPV system. Under steady‐state operating conditions, the total harmonic distortion of grid voltage and currents are found well under IEEE‐519 standard. A wide range of simulation and experimental results are presented to demonstrate all the features of the proposed SPV system. [ABSTRACT FROM AUTHOR]