### Literature Review  
The SHAPF configurations for 1-0 and 3-0 with three and four-wire systems configurations along with the compensation methods for both sinusoidal/non-sinusoidal supply voltage conditions were reviewed. Additionally, the latest advancements and practical applications of SHAPF for future study were also discussed [1]. The SRFT-based new controller was developed to mitigate the PQ issues through the 30-4 wire UPQC for unbalanced and distorted loads of the distribution network [2]. The performance of the SHAPF was analyzed under balanced/unbalanced conditions with the hybridization of both the superior properties of the FL controller and PI controller to diminish THD [3]. A novel self-tuning perturb and observe technique-based solar battery integrated SHAPF was designed to minimize the THD and manage the reactive power effectively. In addition, a maximum Kalman filter was employed for the effective reference current estimation [4]. Moreover, the advancement in artificial intelligence systems such as FL and ANN controller was able to control the SHAPF effectively to reduce PQ issues during dynamic non-linear load changes [5; 6; 7]. The PV-connected UPQC was designed and its performance was studied under various load distortions by extracting maximum power to reduce THD and improve performance [8]. The fuel cell-supported SHAPF with SRFT-based PI controller was designed to maintain DC-link voltage and minimize THD [9]. The optimal tuning of SHAPF was carried out with the aim of reactive power and THD minimization based on the particle swarm optimization and grey wolf optimization hybridization algorithm along with the fractional proportional integral derivative control technique [10]. The modern smart grid with ANN feed-forward control strategy for wind-solar integrated DSTATCOM was proposed to boost the voltage profile and maintain reactive power at the grid [11]. The novel adaptive-power technique was implemented on the H-bridge eight-switch UPQC with the motive of reducing THD and source voltage-related fluctuations [12]. The PV/wind and PEMFCS connected multi-levels UPQC was proposed with the view of diminishing THD, eliminating sag, swell, voltage distortions, and swell efficiently. In addition, hardware was implemented to analyze the real-time performance of the proposed method [13]. However, to overcome the drawbacks of the conventional PI controller, the Sliding Mode controller was suggested for DSTATCOM to improve the THD and maintain the DC voltage constant during load variations [14]. The modern AC-DC microgrid with the intelligent FL-PI and FL-PID controller was designed with the view of minimizing PQ issues and improving voltage stability. In addition, the performance analysis was carried out with two different case studies with dynamic load changes [15]. The STF-based control for SHAPF was investigated to reduce the use of LPF and PLL, and theoretical and practical analysis was carried out [16]. The FLC was suggested for the UPQC to minimize the distortions in voltage and current waveforms for RL non-linear loads. In addition, a comparative analysis was done with and without UPQC [17]. Furthermore, the novel predictive phase dispersion modulation method was designed for the H-Bridge cascaded Multi-Level UPQC with the prime intention of compensating the voltage distortions, imperfections in current waveforms, and regulating DC-Link capacitor voltage [18]. The UPQC was suggested for the induction-furnace load at a steel plant to reduce current and voltage harmonics. In addition to exhibiting its superior performance, the comparison was done with that of the synchronous compensator [19]. A novel Fourier transform analysis was suggested for the PV, wind, fuel cell, and battery-integrated UPQC intending to eliminate voltage /current THD, sag, swell, and distortions in the supply voltage [20]. The various SVPWM control strategies were discussed for power quality enhancement and comparisons were carried out with the experimental results discussed in the literature [21].