Shunt Active Power Filter Research Articles

The extensive use of power electronics devices in power systems, including rectifiers and inverters, presents considerable issues regarding power quality. One problem is the creation of current and voltage harmonics, which result in load waveform distortion, voltage fluctuation, voltage drop, and equipment overheating. Harmonic current sources are prevalent in commercial, institutional, and medical establishments, encompassing computer power supplies, fluorescent lights with electronic ballasts, elevator motors, and electrical devices using switch-mode power supplies. Active power filters (APF) represent the most effective method for harmonic reduction and may be used across many applications. This study employs a digital active power filter to eliminate harmonics from the source current in a grid system characterized by non-linear demand. Nonlinear loads are essential components of every power system. The advent of power electronics has resulted in switching components constituting a substantial portion of electrical demand. These features create discontinuities in lines, exacerbating line losses and diminishing power quality and sine wave integrity. Passive filters effectively eliminate harmonics at specified frequencies within the design. Active filters, conversely, operate in accordance with the prevailing harmonics. This work develops a shunt active power filter that mitigates current harmonics generated by non-linear loads. The active filter includes a voltage source converter (VSC) that functions in conjunction with a DC coupling capacitor. The VCS delivers power at the point of common coupling (PCC). The reference current is obtained by the instantaneous power theory. The instantaneous power theory, or PQ theory, has been enhanced with the FIS control system to optimize DC voltage generation over the DC link capacitor. The fuzzy system substituting the PI controller has a 49-rule base structure organized in a 7x7 configuration for the generation of error signals. A comparative study of DC voltage and total harmonic distortions (THDs) is conducted using MATLAB software and the FFT analysis tool..

Improved harmonics estimation schemes-based shunt active power filter for quality enhancement under high distortions

Enhanced power quality with 15-level reduced switch count multi-level inverter based shunt active power filter

Distribution systems have been significantly impacted in the present scenario by incorporating solar and wind power electronic devices. This work optimally designs the solar PV system (SPVS), battery storage (BS), and fuel cell (FC) sourced seven-level cascade H-bridge converter for shunt active power filter (7L-SHAPF) by selecting the filter resistance and inductance parameters in addition to inductance of boost and buck boost converters of SPVS, BS, and FC by enhanced lyrebird optimization (LOA) called as (ELOA). The multilevel cascaded topology provides superior performances in power quality enhancement. The hybrid control ELOA trained ANNC-PID controller is developed by optimal selection of weights and bias values of artificial neural network controller (ANNC) by reducing mean square error (MSE) to obtain gain values of PID controller. The primary goal is to efficiently handle the current waveforms distortions with DC link voltage balancing, and to reduce the source current total harmonic distortion (THD) of the system connected to the grid that integrates SPVS, FC along with BESS which is denoted as (7L-SHAPF-SFCB). The effectiveness of the developed method is compared with genetic algorithm and artificial bee colony algorithm. The proposed hybrid optimally designed method reduces the THD to 3.53%, 2.44%, 4.15%, and 3.79% which are much lower than those of compared techniques and existing methods available in literature.

This paper presents an intelligent, optimized control approach designed to enhance the quality of power in power grids. It achieves this by integrating a Shunt Active Filter (SAF) with a UPQC with a renewable energy source (photovoltaic). The Shunt Active Power Filter (SAPF) is controlled using Ant Colony Optimization (ACO), a warm-based algorithm that draws inspiration from how ants forage for food. This ACO algorithm dynamically tunes the control parameters of the current reference generation mechanism, resulting in improved harmonic compensation. The effectiveness of this ACO-based controller is measured against conventional Proportional Integral (PI) and Fuzzy Logic Controllers (FLC). The simulation results clearly demonstrate the outstanding performance of the proposed ACO-SAPF. This is evident through a considerable reduction in Harmonic Distortion (THD), a more rapid dynamic behavior, and improved quality of voltage and quality of current, even when load and generation conditions fluctuate.

This study enhances the buck-boost modular converter topology, also known as the Y-voltage source inverter, by implementing a control strategy that simultaneously manages active power injection into the grid while functioning as a shunt active power filter. Each phase-module operates as an independent buck-boost dc-dc converter, allowing the converter to accommodate wide variations in photovoltaic (PV) voltage. The control strategy is derived from instantaneous id-iq power theory and employs a dead-beat-type current control, which is developed and validated. Simulation tests confirm the converter's efficiency as an Active Power Filter (APF) under unbalanced and distorted grid voltage conditions.

This study proposes a model to integrate the Multi-Attribute Decision-Making (MADM) method into the Analysis phase of the Six Sigma (DMAIC) method to improve product quality and optimize processing conditions during high-frequency quenching heat treatment. One of the breakthroughs of the study is the combination of Industry 4.0 technology and the implementation of Shunt Active Power Filter (SAPF) to improve power quality, reduce harmonic distortion (THD), ensure product hardness of 58–62 HRC, and thermal permeability of 1.8–2.2 mm according to standards. Previously, many studies only focused on improving the heat treatment process but did not fully integrate MADM, Six Sigma, and Industry 4.0 technology, nor did any study consider the combination of SAPF to control power quality during high-frequency quenching. Another gap is the lack of quantitative assessment of operator satisfaction after improvement using PLS-SEM. The study applied the Six Sigma DMAIC model combined with MADM to analyze and rank factors affecting product quality. In the improvement phase, the Taguchi method was used to optimize processing conditions, minimizing errors in the production process. At the same time, Industry 4.0 technology and RFID systems were integrated to control production conditions in real time, ensuring the accuracy and reliability of the process. Power quality was improved thanks to the implementation of SAPF, helping to control harmonic distortion (THD) below 5% according to the IEEE 519:2022 standard, minimizing the negative impact of voltage on the heat treatment process. In addition, the study also applied PLS-SEM to measure operator satisfaction after implementing the improved system. The research results show that the rate of substandard products has decreased sharply from 90 to 1%, ensuring hardness of 58–62 HRC and thermal permeability of 1.8–2.2 mm. Power quality is better controlled, with the THD value reduced from more than 34% to less than 5%, meeting the IEEE 519:2022 standard. As a result, production costs are optimized, helping to minimize the waste of raw materials and energy. After implementing the improved system, operators’ satisfaction levels have also increased significantly, reflected in the PLS-SEM measurement indicators. More importantly, this research model is not only effectively applied in the precision engineering industry but also has the potential to be expanded to many other industries, especially small and medium-sized manufacturing enterprises, helping them to increase productivity and improve product quality in the context of Industry 4.0.

Simulation and real-time implementation of a combined control strategy-based shunt active power filter in microgrid

Design and simulation of reduced switch converter based solar PV and energy storage fed shunt active power filter with butterfly optimization

This paper introduces an innovative design for the super-twisting sliding mode control (ST-SMC) strategy, which is applied for the first time to a three-phase shunt active power filter (SAPF) utilizing a flying capacitor multicellular inverter (FCMI). The objective of the proposed ST-SMC is to enhance control over filter currents, flying capacitor voltages and the DC bus voltage. Simulation results, under balanced and unbalanced nonlinear load conditions, demonstrated exceptional capabilities in harmonic reduction while maintaining robust dynamic response characteristics. Additionally, it showed remarkable performance in tracking both filter currents, DC voltage, and flying capacitor voltages.

Integration of nonlinear loads in modern power systems has led to many issues arising mainly due to the generation of harmonic currents and the presence of reactive power, both having adverse effects on power quality and grid stability. Harmonic currents cause increased losses, overheating of equipment, and voltage distortions, while reactive power imbalances result in inefficiencies in power delivery and compromised system performance. To overcome these problems, a Shunt Active Power FIlter design and an optimal control strategy for harmonic mitigation and reactive power compensation are proposed in this paper. The design incorporates an optimized anti-windup PI controller for DC-link voltage regulation and an optimized output filter to enhance the quality of the injected current. This design is formulated as an optimization problem and solved using the Golden Jackal Optimizer. MATLAB/Simulink simulations validate the proposed method under different operating conditions, covering dynamic change of loads and unbalanced grid conditions. The result shows a remarkable reduction in Total Harmonic Distortion (THD) of grid current, and reactive power compensation meanwhile maintaining the stability of the grid.

Mitigating power quality issues in distribution systems is of utmost importance to both electricity consumers and suppliers as it improves the distribution system’s efficiency, reduces electricity costs, maintains continuous supply, and diminishes the requirement for frequent maintenance. Custom power devices were introduced to eliminate power quality issues like voltage sags, swells, transients, imbalances, and current harmonics arising in distribution systems. Unified power quality conditioner (UPQC) is one such frequently used custom power device that enhances the power quality of distribution systems. Now days the usage of three phase loads is increasing gradually, therefore it is much required to get access to the three-phase distribution system. UPQC 1-ph-to-3-ph uses dual compensation principle makes possible to draw sinusoidal current, in phase with the grid voltage, from the single-phase grid to improve the power quality. The system compensates the voltage disturbances such as voltage sag, voltage swell and other voltage unbalances. The proposed system allows the balanced and regulated voltage with lower harmonic content. The present paper analyzes the compensation and control strategies using PI controller. The control strategies are simulated using MATLAB/SIMULINK. Keywords— Power quality (PQ), unified power quality conditioner (UPQC), Series and Shunt active power filter

This paper presents a discrete-time repetitive control strategy for a three-phase, four-wire (3P4W) shunt active power filter (SAPF). In typical power electronic control systems, a dual-loop structure is often employed—comprising a fast-acting inner current loop and a slower outer voltage regulation loop. However, due to the periodic nature of the current reference, conventional PI controllers often struggle to accurately track it. Repetitive controllers (RCs) are widely recognized for their ability to effectively follow periodic signals, offering high gain across all frequency components. Despite this advantage, the elevated gain in the higher frequency range can potentially cause system instability. To address this, the proposed research includes a modification where the sensitivity function of the standard RC is squared. Additionally, a modified RC based controller is integrated into the system to improve the overall power quality. This approach results in a sensitivity function characterized by moderate amplitude responses, with pronounced attenuation (notches) at low to mid frequencies and reduced impact at higher frequencies. The proposed control method has been tested and implemented on a 3P4W SAPF setup. Index Terms— Modified Repetitive Control, Active Power filter, harmonic compensation, Power Quality, 3P4W, Load Compensation, Non-linear load, Unbalanced Load.

In this paper a three phase Shunt Active Power Filter (ShAPF) is proposed to address the current related issues in a three phase Electrical Distribution System (EDS). A sliding mode controller (SMC) and an Enhanced Exponential Reaching Law based SMC (EERL-SMC) is proposed for a ShAPF to compensate the load current. The controller’s performance is tested by injecting the current harmonics into the system. A non-linear load along with different loads on the distribution side is connected in parallel in a distribution network at Point of common coupling (PCC). Modelling of the system is done using state space analysis. Stability of the system is analyzed using the state feedback approach. The reference source currents are generated using instantaneous PQ theory. For variations in the load, the THD in the source current is realized. It is found that EERL-SMC is more effective for a ShAPF in reducing the high frequency oscillations and settling time for convergence. The source voltage and current waveforms are observed to be sinusoidal in nature. Both the controllers are effective in reducing the THD levels in the source current as per the IEEE standards. A comparison between the controllers is presented in terms of settling time, THD in source current. PSCAD v4.6 is used for simulation works.

In recent decade, an introduction of innovative technological development in power electronics sector is to perform significantly for compensation of power quality issues. The sugar industry's widespread implementation of variable-frequency induction-motor drives cause the electrical distribution systems to become worse. Greater harmonics produced by semiconductor current converters affects the sinusoidal voltage and increase reactive component of current by voltage. To overcome the aforementioned issues, the research paper examines issues of power quality in an induction motor (IM) drive system attached to utility grid system. The addition of filters, which reduces the power quality, issues in induction motor drives by providing lower THD. The IM drive system with an enhanced filter is employed to reduce harmonics produced by power semiconductor switches to keep the three-phase power supply in good condition. So, the instantaneous imaginary controller-based shunt active power filter (I-Q active filter) is employed to lessen the harmonic content that exists in the current at the point of source. To enhance the electrical network system's power quality, the proposed filter is injected parallel within the source and the IM drive system. The outcomes of simulations are analysed and it is executed by MATLAB/Simulink.

To enhance the power quality in medium-voltage distribution networks, particularly for sensitive loads, a Unified Power Quality Conditioner (UPQC) device is proposed. The device combines both series and shunt active power filters to mitigate a wide range of power quality disturbances. These disturbances include frequency and voltage fluctuations, voltage sags, short-time interruptions, voltage flicker, harmonics, inter-harmonics, three-phase unbalance, and temporary over voltages. The UPQC's design incorporates a fixed voltage slow closed-loop control strategy that ensures stable operation by effectively compensating for disturbances in real-time. The power unit and the topology of the charging circuit are optimized to meet the demands of medium-voltage networks. Simulation and experimental results confirm that the UPQC significantly improves the quality of the power supply, providing reliable and stable voltage and current profiles for sensitive industrial and commercial applications. This approach offers a robust solution for addressing the challenges associated with maintaining high-quality power in medium-voltage distribution systems.

A novel Runge-Kutta-based model predictive controller for PUC7-based single-phase shunt active power filter

In this work, a cascaded two-loops nonlinear integral-backstepping based control has been derived for single-phase shunt active power filter to improve harmonic mitigation, reactive power compensation and dc-link voltage regulation. Two loops non-linear controllers based on an Integral-backstepping strategy is developed which is robust and stable in a wide range of output current and DC-link voltage changes. First, the model of the single-phase shunt active power filter is exposed. Then, an integral backstepping control strategy applied to current loop is developed to provide global control robustness. Moreover, the compensation control system is then supported by an another integral backstepping controller for DC-link voltage control in order to enhance DC-link loss compensation capability and to generate the required active power which should be taken by the SAPF from the power supply. Designed active power filter control has been implemented using Dspace 1103. The practical response of the developed controller is studied in some test; it is shown that the proposed controller is able to eliminate harmonic components of the local load current with a fast dynamic response.

any power topologies, such as microgrids (MG) or distributed generation (DG), mix many energy sources with different demand patterns and energy conversion techniques in the Smart Grid(SG).SGs employ power electronic devices, which cause load-side harmonics. These devices interrupt the supply current, deviating it from the fundamental signal. Adding renewable energy sources to the electrical grid and using grid-connected power electronics interfaces have also challenged power quality.Harmonic disturbance reduction and power quality enhancement are important in contemporary power systems. A Shunt Active Power Filter (SAPF) is recommended to regulate voltage and reduce harmonics by managing reactive power, and it also boosts the power factor. This research aims to evaluate harmonic disturbances in the SG and suggest a technique to reduce harmonic distortions and achieve a harmonic distortion level below 5% of the total harmonic distortion (THD). The fundamental contribution of this study is the creation of a complicated control strategy, the Tilt-Derivative (TD) and Tilt-Integral (TI) controller, which effectively regulates and produces switching pulses for the SAPF's Voltage Source Inverter (VSI). A unique metaheuristic algorithm called Dynamic Opposite Learning-based Enhanced Mountain Gazelle Optimisation optimises the controller settings with MATLAB/Simulink.

Shunt active power filters (SAPFs) have been around for a long time. They improve the quality of a current drawn from the grid when feeding non-linear loads formed by old-fashioned power electronic converters such as uncontrolled and controlled rectifiers. Most SAPFs are implemented using the well-known six-switch three-phase inverter (SSTPI) topology. This paper investigates the capability of adopting the four-switch three-phase inverter (FSTPI) scheme to develop low-cost SAPFs, mainly for low-power ranges. The performance of the proposed SAPF using the FSTPI topology is compared with the conventional scheme of an SAPF formed by the six-switch three-phase inverter (SSTPI) topology. Qualitative and quantitative analyses are conducted. The performance of the proposed FSTPI-based SAPF is investigated under different loading conditions. The obtained results indicate the validity and effectiveness of the FSTPI scheme in improving the quality of currents drawn from the AC grid. The SAPF scheme investigated is also feasible and results in cost reduction when the SAPF power circuit is constructed with modern WBG devices, such as SiC-based MOSFETs, which are relatively expensive (approximately three times the price of the equivalent Si IGBTs).