This article investigates the power quality enhancement of a grid-tied photovoltaic (PV) distribution system by employing a fuzzy logic proportional-integrator-derivative multiple complex coefficient filter multiple second-order generalized integrator frequency-locked loop (FLPID-MCCF-MSOGI-FLL) hybrid control scheme based shunt active power filter. The MSOGI-FLL reference current generation strategy is implemented to mitigate the current harmonics by extracting the fundamental constituents (FCs) from the nonlinear load currents, whereas an MCCF is employed to separate the FC from the distorted grid voltages and eliminates the voltage harmonics during extremely polluted grid voltage condition. The main objective of using FLPID is to maintain the stable power between dc and ac sides by regulating the dc-link voltage constant under transient conditions. To track the maximum power from the PV panel under varying environmental condition, the particle swarm optimization based perturb and observe technique is used in this article. The comparative analysis is analyzed to check the effectiveness of the proposed hybrid control scheme with existing and adaptive control techniques in respect of power quality, better dc offset rejection, better FC and frequency extraction, and grid synchronization. The system with the proposed control scheme is simulated on MATLAB/Simulink and validated in a real-time field-programmable gate array platform under different test scenarios. In conclusion, the harmonic content of grid currents and voltages is found well within the IEEE-519 standard limits.Index Terms-Active power filter (APF), fuzzy logic proportional-integrator-derivative (FLPID), maximum power point tracking (MPPT), multiple complex coefficient filter (MCCF), multiple second-order generalized integrator frequency-locked loop (MSOGI-FLL), particle swarm optimization (PSO), perturb and observe, photovoltaic (PV) system, power quality, total harmonic distortion (THD).

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Summary This paper presents hybrid photovoltaic (PV)‐wind‐battery energy storage network tied to three‐phase utility grid side inverter using fuzzy logic proportional integral derivative‐improved second‐order generalized integrator‐quadrature signal generator‐phase locked loop (FLPID‐ISOGI‐PLL) for power quality enhancement at the consumer side terminals. An advanced ISOGI‐PLL control strategy is implemented to separate the fundamental constituent of each phase load current without sensing other phase currents, which makes phase independent and reliable. It has several characteristics, such as improved hybrid system (HS) power penetration, load sharing, and power factor correction. Additionally, FLPID adaptive voltage controller is incorporated in the presented scheme to enhance dynamic operation of the system and also keeping the power balance between the dc and ac sides by maintaining the dc bus voltage. Moreover, the photovoltaic system's feed‐forward constituent is incorporated in the proposed technique, which improves the system dynamic performance and minimizes oscillations in grid currents. The outcomes of the advanced control strategy are found adequate for enhancing active power filter (APF) performance at the consumer side terminals under several operating conditions. The proposed control technique is computationally analyzed by simulating the system through MATLAB/SIMULINK under steady state, dynamic, load removed, and unbalanced grid voltage conditions. The competency of an advanced control approach is examined with hardware‐in‐loop (HIL) co‐simulation using FPGA Virtex‐7 VC‐707 via very high speed integrated circuit hardware description language (VHDL) code generation. Finally, the simulation outcomes are verified through a real‐time prototype laboratory platform using FPGA Virtex‐7 VC‐707 evaluation kit, and the total harmonic distortion (THD) analysis of injected grid currents is tabulated under different operating scenarios and found good within the IEEE‐519 standard limits.

In this article, a modified reduced order generalized integrator based frequency locked loop (MROGI-FLL) is proposed for controlling the interfacing inverter of the grid-tied photovoltaic (PV) system to mitigate the harmonics. Additionally, a fuzzy tuned PID (FPID) controller is integrated in the proposed scheme to minimize the steadystate error which results the voltage level is maintained constant at the common dc-link bus terminals. The MROGI-FLL is designed to evaluate the three-phase reference currents by extracting the fundamental constituents from the load currents and grid voltages. The proposed MROGI-FLL have several advantages such as better harmonic mitigation capability, control adaptivity, adaptive frequency and phase, grid synchronisation and low computation burden. The proposed reference current generator is simulated on matlab/simulink platform under steady-state and various transient conditions.The comparative study of proposed scheme is compared with the existing and adaptive control techniques which assures the potency of the proposed control algorithm in-terms of harmonic mitigation, dc-offset rejection, frequency variation and computation burden. Finally, the experimental results are verified through an experimental platform by using the dSPACE evaluation kit and both the simulation and hardware characteristics are well justified to the IEEE-519 standard limits.