Plug Filters Research Articles

An Efficient Shunt Modulated AC Green Plug–Switched Filter Compensation Scheme for Nonlinear Loads

Nonlinear loads, crucial components of power system grids, pose a challenge due to harmonics injection. This work tackles this issue with a novel modified green plug–switched filter compensation scheme using fuzzy logic controllers. This innovative scheme presented in this paper utilizes dual action pulse width modulation to ensure switching functions from harmonics reduction and capacitive compensation for inrush nonlinear-type AC loads. The scheme’s multi-loop regulations and online switching effectively handle dynamic-type slow-acting inrush, motorized- and other rectifier-type nonlinear loads, enhancing the power factor, power quality at source and load buses, and reducing the total harmonics distortion at the key source and sensitive nonlinear load buses. A simulation model in the MATLAB/SIMULINK-2023b software environment demonstrates the efficiency of the proposed FACTS technique. The modulated dual mode switched filter-capacitive compensation scheme controlled by a fuzzy logic controller ensures less harmonics distortion and improved voltage stabilization. The results show that voltage, current, active power, reactive power, power factor regulation, and effective energy utilization are achievable with the designed Flexible AC Transmission System-Modulated Filter Capacitor Compensation–Switched Filter Compensator (FACTS-MFCC-SFC). The switched modulated AC green plug filter significantly improves power quality and enhances power factor in cases of inrush and nonlinear loads.

Amine-functionalized graphene oxide in polyamine based drilling fluids for nanosized pore plug filter cake

Water-based muds (WBM) is widely used in oil and gas wells drilling industry due to its environmental friendliness and lower operational cost implication. However, WBM drilling process has severe shale swelling problems caused by the hydration due to the shale minerals affinity to water from the WBM which reduces WBM technical performance. Thus, additives that fitted to its function should be added in WBM formulations to enhance overall drilling performance to achieve the target depth. In this study, graphene oxide (GO) is selected as the additive due to its excellent physico-chemical properties could benefit as an option to mitigate the above challenges. GO was synthesized via Modified Hummers' method where the average thickness obtained was ±46 nm. The GO additive was then modified with Octadecylamine (ODA) to alter the surface hydrophobicity. The contact angle of GO changed from 25° ± 0.5 to 98.9° ± 1.8 after the ODA modification. The hydrophobic GO (HGO) was then added in the drilling fluid formulation and the drilling fluid performance was evaluated based on filtration characteristics. The filter cake showed a thickness of 0.832 mm and a filtrate volume of 5.09 ml at 150 psi/30 min after the filtration with drilling fluid treated with HGO. The filter cake formed was the thinnest and the least filtrate volume was produced which are 30% and 20% reductions compared to drilling fluid without GO, which signify the remarkable reduction of fluid loss. On top of that, the drilling fluid with HGO demonstrated a good rheology property over wide shear rate scheme and enhanced thermal stability. Hence, GO was highly recommended as a potential fluid loss control nano-additive in drilling fluid formulation.

Improvement of harmonic conditions in the AC/DC microgrids with the presence of filter compensation modules

The main purpose of this research is to design a new connection of AC/DC microgrids to the grid under power compensation methods to reduce harmonics amplitude by some of the filter compensation devices. The green plug filter compensator (GPFC) is used in the DC side to stabilize the dynamic voltage and reduce the transient voltage. Also, the active power filter module (APFM) is used to reduce the amplitude of current and voltage harmonics in the AC microgrid. Challenges and innovations in this research include optimization of gains coefficients of APFM by some of the heuristic algorithms and applying this setting to the three loops of voltage and current harmonics, as well as controller error to obtain an optimal response to eliminate the current and voltage harmonic range. The optimized coefficients are related to PI controller and the cost function including the controller error, current harmonics, and voltage harmonics. The optimizing coefficients using artificial bee colony (ABC), particle swarm optimization (PSO), harmony search (HS) and differential evolution (DE) algorithms is done to determine the best answer to this problem. Finally, the simulation results show that the use of APFM is essentially effective in reducing system harmonics (more than thirty-percent for current harmonics in the A1 area, and nearly sixty-percent for voltage harmonics) and this effect is more evident by optimizing the APFM control coefficients.

An Efficient Switched Filter Compensation Used LED Lighting PV-Battery Scheme

This study presents a completely stabilized and novel flexible self-adjusting light emitting diode (LED) lighting scheme powered by a PV-Battery and using a pulse width modulation (PWM) switching multi-regulation dual-loop error-driven weighted modified proportional–integral–derivative (WM-PID) accelerated control scheme. The presented scheme incorporates a green plug filter capacitive switched compensator scheme to ensure efficient energy utilization and reduced inrush currents and switching transients. The LED lighting load is regulated using two stabilizing switched filter compensation (SFC) devices located at the DC side common and load buses. It ensures damping of transient voltage and reduces inrush currents for enhanced energy efficient operation and minimal stresses on the solid-state switches. The proposed multi-regulator controller uses a dual-loop error-driven, error-time de-scaled controller for the PWM switching scheme. The dual-action regulator uses total error-driven signal fed to the fast-acting modified proportional–integral–derivative (PID) controller equipped with error-squared acceleration loop and fast response auxiliary derivative type loop, to ensure efficient fast-acting control with minimal inrush conditions, and recovery from load excursions and fault conditions. Moreover, it also changes battery state of the charge (SOC) and solar insolation and ambient temperatures.

PSO-based control optimisation of microgrid with D-FACTS

Distributed energy resources are widely used within microgrid to offer optimised electricity supply to meet demand patterns in local regions. A proposed microgrid design comprising novel distribution FACTS devices is presented in this paper. The proposed design is used to stabilise the bus voltages, reduce the feeder losses, improve the power factor and mitigate the harmonic distortion. Modulated power filter compensators and green plug filter compensator are presented as AC-side and DC-side D-FACTS devices, respectively. D-FACTS devices are controlled using multi-loop error driven self-tuned PID controllers. The particle swarm optimisation is developed to optimise the self-tuning of PID controllers to achieve an effective integration of distributed energy resources technologies and to give higher microgrid performance. The results shown are generated from MATLAB simulation of the presented microgrid, where comparisons of the results with and without D-FACTS devices are presented. Results show superiority and improved performance using the presented D-FACTS.

Reforming of lignin-derived tars over char-based catalyst using Py-GC/MS

Tar removal is one of the major challenges in implementation of biomass gasification technology. Syngas tars causes formation of aerosols and soots, which plug filters, reactors and fuel lines. In this study, a char-derived catalyst was tested in removal of tar produced from pyrolysis of kraft lignin in a pyroprobe reactor. The effects of reaction temperature (700, 800 and 900°C), water amount (5–10μl), pressure (0.1–2.2MPa) and atmosphere (inert and hydrogen) on catalytic conditioning of tar components were assessed. The tar components were analyzed by GC/MS. Catechols were the most abundant tar components followed with phenols and guaiacols during non-catalytic kraft lignin pyrolysis. Results indicated that the char-based catalyst effectively decreased the contents of lignin tar. Reaction temperature, water loading and reaction pressure significantly affected the tar removal. An increase in reaction temperature led to an increase in removal efficiency of most tar components except naphthalene. Excessive water loading (10μl) decreased the tar removal efficiency of char-based catalyst. High pressure promoted the catalytic conversion of lignin tar. Tar contents decreased significantly when hydrogen was used as a reaction medium and thus promoted the conversion of lignin into non-condensable gas.

Influence of Phenols on the Oxidation Stability of Home Heating Oils/FAME Blends

The formation of deposits in fossil and biogenic home heating oils as well as in their blends is well-known. As a result, sediments can plug filters and nozzles in heating systems and thus cause operability problems. Different kinds of compounds are presumed to be involved in these processes. It is well-known that phenols play an important part but, on the other hand, phenols are also known to act as antioxidants that delay the oxidation of fuel compounds, and thus the formation of reactive products. To study the antioxidant effect of different phenols, model fuels (biogenic, fossil and a 10% v/v blend) were doped with several representatives of this class of compounds. The samples were artificially aged using the PetroOXY (DIN EN 16091) method. The induction time was recorded and gave information on the impact of the tested substance on the model fuel. Infrared spectrometry was used to investigate the oxidation products. Furthermore, the phenols of a commercial heating oil were extracted and then the oil...

Chemical Changes in Fossil and Biogenic Heating Oils on Long-Term Storage

The formation of sediments in biogenic and fossil heating oils as well as in their blends is a well-known problem. These deposits can plug filters and nozzles in heating systems and, consequently, cause economic losses. Polymerization and the formation of corrosive acids are possible explanations for these incidents. To study the influence of long-term storage on different heating oils (biogenic, fossil, and a 10% blend) and to investigate the changes in their composition, the oils were stored for a period of 12–24 months at nearly ambient (40 °C) and analyzed with different techniques every 6 weeks. The formation of several kinds of oxidation products was demonstrated, including ketones, epoxides, aldehydes, carboxylic acids, and furans. Size-exclusion chromatography was used to demonstrate the formation of oligomeric products of the fatty acid methyl esters (FAMEs) (up to pentamers). Short-chain (C1–C6) carboxylic acids were quantified with ion chromatography, and larger carboxylic acids were indicated by mass spectrometry. The first recorded experimental evidence for a coupling reaction between a FAME and components of the fossil oil, namely, such containing the nitrogen heterocycle indols, is described. Cross-coupling products between biogenic and fossil compounds were detected using Orbitrap ultrahigh-resolution electrospray ionization mass spectrometry.

Biodegradable Microfabricated Plug-Filters for Glaucoma Drainage Devices

We report on the development of a batch fabricated biodegradable truncated-cone-shaped plug filter to overcome the postoperative hypotony in nonvalved glaucoma drainage devices. Plug filters are composed of biodegradable polymers that disappear once wound healing and bleb formation has progressed past the stage where hypotony from overfiltration may cause complications in the human eye. The biodegradable nature of device eliminates the risks associated with permanent valves that may become blocked or influence the aqueous fluid flow rate in the long term. The plug-filter geometry simplifies its integration with commercial shunts. Aqueous humor outflow regulation is achieved by controlling the diameter of a laser-drilled through-hole. The batch compatible fabrication involves a modified SU-8 molding to achieve truncated-cone-shaped pillars, polydimethylsiloxane micromolding, and hot embossing of biodegradable polymers. The developed plug filter is 500 μm long with base and apex plane diameters of 500 and 300 μm, respectively, and incorporates a laser-drilled through-hole with 44-μm effective diameter in the center.

Determining the Oxidation Stability of Biodiesel and Blends Using a New Rapid Small Scale Oxidation Test (RSSOT)—The PetroOXY

Abstract Oxidation stability is a physical property of liquid fuels used to describe the ageing behavior of fuels during transport and storage. In biodiesel and its blends with diesel, oxidation of fuel can result in acid formation and polymer solids which plug filters and leave problematic deposits throughout the fuel supply system. ASTM Fuel Specification Standards include both 100 % biodiesel and biofuel-blends. Of all these fuel standards only ASTM D6751, which is for 100 % biodiesel “as a blendstock,” mentions the test method EN 14112. Although the following fuel specification standards permit the blending of biodiesel into the fuel, to date these standards have not yet identified a suitable oxidation stability test method for blended fuels: ASTM D975 for diesel fuel oils (<5 % biodiesel); ASTM D396 for burner fuel oils (<5 % biodiesel); and ASTM D7467 for diesel fuel oil (6–20 % biodiesel). ASTM D2274 is the most frequently used method to characterize ageing behavior of diesel by determining the polymer (sludge) content of artificially aged fuel. ASTM D02.14 approved two new test methods for evaluation of oxidation stability. ASTM D7545 is a new method for testing oxidation stability of middle-distillates. ASTM D7525 is the sister method for gasoline. These methods utilize a new rapid small scale oxidation tester (RSSOT) named PetroOXY. Within the RSSOT’s test chamber, a 5 mL sample of fuel is combined with oxygen, at 700 kPa, and heated to 140°C. This initiates a fast oxidation whose results are determined by the time needed to achieve a pressure drop of 10 % in the system. Testing confirmed that the time needed to achieve the 10 % drop in pressure is directly related to the sample’s oxidation stability. The RSSOT-method is quicker than other actual methods evaluating the oxidation stability biodiesel, petroleum middle-distillates, and blends. Round-robins based upon this have been conducted in Europe and Japan.