Symmetric Disturbances Research Articles

Aerodynamic performance and wind-induced response of carbon fiber-reinforced polymer (CFRP) cables

To study the aerodynamic performance and wind-induced response of carbon fiber-reinforced polymer (CFRP) cables, CFRP cable was designed by replacing a steel cable in a tied arch bridge based on stiffness, strength and area equivalent criteria, respectively. The aerodynamic performance and wind-induced response of CFRP cable and steel cable were studied and compared by computational fluid dynamics (CFD) model. Based on the computational results, optimal cable replacement criterion was proposed for CFRP cable to replace steel cable. In addition, surface modification was conducted by engrooving vertical symmetric (VS), vertical asymmetric (VA) and helical symmetric (HS) V-shaped grooves to improve the aerodynamic performance and wind-induced response of CFRP cable. Results showed that CFRP cables exhibited inferior aerodynamic performance and wind-induced response in most cases. However, CFRP cable based on stiffness equivalent criterion exhibited better aerodynamic performance and wind-induced vibration properties compared to the other two cable replacement criteria, thus is regarded as the optimal substitute for steel cable. In addition, HS grooves generated symmetric disturbances and caused approximately equivalent boundary layer separation delays uniformly and continuously along the cable length, thus exhibiting better effect in decreasing the reverse flow region, the maximum negative flow velocity, the vortex shedding frequency and the wind-induced vibration amplitude of CFRP cable. Hence, the stiffness equivalent criterion combined with surface modification with HS V-shaped grooves was proposed to replace steel cable with CFRP cable. This study can provide insights into the aerodynamic performance and wind-induced response of CFRP cable and instructions for cable replacement practice.

Optimal Design of Fractional-Order PID Controllers for a Nonlinear AWS Wave Energy Converter Using Hybrid Jellyfish Search and Particle Swarm Optimization

In this study, a nonlinear Archimedes wave swing (AWS) energy conversion system was employed to enable the use of irregular sea waves to provide useful electricity. Instead of the conventional PI controllers used in prior research, this study employed fractional-order PID (FOPID) controllers to control the back-to-back configuration of AWS. The aim was to maximize the energy yield from waves and maintain the grid voltage and the capacitor DC link voltage at predetermined values. In this study, six FOPID controllers were used to accomplish the control goals, leading to an array of thirty parameters required to be fine-tuned. In this regard, a hybrid jellyfish search optimizer and particle swarm optimization (HJSPSO) algorithm was adopted to select the optimal control gains. Verification of the performance of the proposed FOPID control system was achieved by comparing the system results to two conventional PID controllers and one FOPID controller. The conventional PID controllers were tuned using a recently presented metaheuristic algorithm called the Coot optimization algorithm (COOT) and the classical particle swarm optimization algorithm (PSO). Moreover, the FOPID was also tuned using the well-known genetic algorithm (GA). The system investigated in this study was subjected to various unsymmetrical and symmetrical fault disturbances. When compared with the standard COOT-PID, PSO-PID, and GA-FOPID controllers, the HJSPSO-FOPID results show a significant improvement in terms of performance and preserving control goals during system instability

Guillain-Barré syndrome: a review of immunotherapy, rehabilitation, and long-term outcomes

Guillain-Barré syndrome (GBS) is a complex autoimmune disorder characterized by the rapid onset of motor weakness and sensory disturbances, often precipitated by preceding infections. GBS is considered a rare disorder, with an estimated annual incidence ranging from 0.6 to 4.0 cases per 100,000 individuals. It constitutes a medical emergency due to its potential for severe disability or mortality. The hallmark clinical features of GBS include progressive symmetric muscle weakness and sensory disturbances. Diagnosis relies on clinical evaluation, cerebrospinal fluid analysis, and electrodiagnostic studies, with the Brighton criteria providing standardized diagnostic criteria. The hallmark clinical features include progressive symmetric muscle weakness, sensory deficits, and areflexia or hyporeflexia. The management of GBS primarily involves supportive care and immunomodulatory therapies. Plasmapheresis, or plasma exchange, and intravenous immunoglobulin (IVIG) are the mainstay treatments aimed at modulating the immune response and shortening the illness duration. Rehabilitation, encompassing physical and occupational therapy, is pivotal for restoring functionality and improving long-term outcomes.

Symmetric Nonlinear Feedback Control and Machine Learning for Sustainable Spherical Motor Operation

This paper presents a comprehensive evaluation of a new control technique for the sphere motor system, aimed at achieving accurate tracking, robust and dispersion of vibrations. Control methods include the determination of a nonlinear model and the application of feedback linearization, followed by the optimization of the proportional derivative (PD) coefficients through the Adaptive Neuro-Fuzzy Inference System. In addition, the system’s reaction to harsh environments is managed using Long Short-Term Memory. In order to gain a deeper understanding, symmetrical environmental disturbances and trajectories are introduced during the testing phase. The results demonstrate the superior performance of the control strategy, with reduced vibrations, faster recovery and confirmed tracking accuracy. In addition, the control method shows its adaptability and reliability, as evidenced by the significant reduction in CO2 emissions compared to conventional PD control methods. The use of symmetric trajectories and visualizations further emphasizes the behavior of the system under symmetric conditions, strengthening the effectiveness and applicability of the control strategy in real-world scenarios. Overall, this study presents a promising solution for converting complex systems under different conditions and making them potentially applicable in various industrial contexts.

Dynamic Response Analysis of the Bi-Tandem Axial Piston Pump with Dual-Loop Positive Flow Control under Pressure Disturbance

The bi-tandem axial piston pump is an indispensable powerhouse in high-pressure and high-power engineering hydraulic systems, with its output flow response characteristics under pressure disturbance exerting a significant influence on the working process of double pumps. Unfortunately, the stability of the original single-loop mechanical–hydraulic servo control system is sensitive to unpredictable interference. To alleviate this quandary, this paper proposes a dual-loop positive flow control method for the flow control of the bi-tandem axial piston pump, establishes a mathematical model of the bi-tandem axial piston pump with dual-loop positive flow control, and establishes a simulation model based on Simulink. The validity of the model is verified by experiments. The performance advantages of the dual-loop positive flow control method relative to the single-loop positive flow control method are analyzed. The results show a faster response speed and smaller steady-state error with the dual-loop method, which performs better than the original single-loop positive flow control. Furthermore, the study examines the influence of different forms, degrees, and directions of pressure disturbance on the dynamic response characteristics of the bi-tandem axial piston pump. Symmetric pressure disturbance results in an increase in the maximum relative error of the output flow proportional to its degree. Notably, the influence of asymmetric pressure disturbance on the output flow of the double pumps possesses characteristics of a superimposable nature, and the steady-state value of the output flow is highly dependent on superimposed pressure disturbance and less affected by the action time point of asymmetric pressure disturbance. Further, the unloading pressure disturbance exerts less influence on the system compared to the loading pressure disturbance. This paper provides valuable insights into improving the response speed and control accuracy of bi-tandem axial piston pumps equipped with positive flow control.

Kajian Koordinasi Sistem Proteksi Pada Sistem Transmisi 70 kV GI Banaran Kediri Transmission Line Bay Pare

The substation is one of the components in the electric power distribution system which plays a very important role because itis the connection between electricity services to customers. In the electric power distribution system, there are disturbances that often occur,one of which is a short circuit. For that, the way to overcome this is using the Distance Relay protection system, OCR / GFR and DEF. Thepurpose of writing this research is to determine the value of setting relay distance, setting Over Current Rele and Directional Earth Fault relayin order to secure the 70 kV transmission network connected to GI Banaran, which is then simulated using DigSILENT 15.1 software on thePare line by calculating symmetrical and asymmetrical disturbances. including 3-phase disturbance on February 1, 2018. The simulationresults show that the 3-phase disturbance occurs at Zone 1 relay distance of the Banaran Bay Pare substation with a trip time of 0.02 secondswith a fault impedance of 0.083 ohms below the relay impedance value of 0.887 ohms. The coordination between the distance relay on theside of the Banaran Bay Pare substation has worked well because there is no error reading the relay when it will cut off the disturbance.

Electrohydrodynamic Liquid Sheet Instability of Moving Viscoelastic Couple-Stress Dielectric Fluid Surrounded by an Inviscid Gas through Porous Medium

Viscoelastic liquid sheet of couple-stress type streaming with relative motion into an inviscid gas through porous molium is studied theoretically and quantitatively in this project. To derive the differential equations that describe liquids, gases, and the electric field, we linearized the governing equations of motion and continuity, Maxwell’s equations in quasi-static approximation, and the appropriate boundary conditions at the two interfaces. Then we used the normal mode method. It was demonstrated analytically that the solutions to these differential equations can be found for both symmetric and antisymmetric disturbances, respectively. We could not obtain an explicit form of the growth rates since we could not solve the dispersion relations for both situations because they were obtained in highly complex forms. The Mathematica program is used to solve the dimensionless forms of the dispersion relations numerically using Gaster’s theorem. Various influences on the stability analysis of the considered system have been studied in detail, and it is determined that the system in the presence of a porous material is more unstable than it would be otherwise. In a two-dimensional system, the antisymmetric disturbance case is found to be more unstable than the corresponding symmetric disturbance situation. Some characteristics, such as Wabe number, Ohnesorge number, and electric field, have destabilizing effects, whereas others, such as porosity, medium permeability, viscoelasticity parameter, gas-to-liquid viscosity ratio, and dielachic constants, have stabilizing effects. Finally, it is discovered that the gas-to-liquid velocity ratio plays a dual role in the stability condition depending on whether the gas-to-liquid velocity ratio U ≶ 1. In the past, we have only found evidence of very few previous studies.

LVRT Fulfilment of the DFIG-based WECS During Symmetrical Grid Voltage Dips

The doubly fed induction generator (DFIG)-based wind energy conversion system (WECS) has seen rapid growth all over the world, resulting in a growing access of this source of energy into electrical grids. The low-voltage ride-through (LVRT) capability of the DFIG-based wind turbine must be improved to make it stay connected to the grid during the occurrence of grid faults. Because of its vulnerability to grid disruptions, careful arrangements must be made to the DFIG to keep it connected with the grid. Hence, this paper presents a modified control technique with crowbar protection for improving the LVRT of the WECS. This proposed scheme can be sufficient to meet the LVRT requirements as demanded by grid codes. The fault ride-through capability of the rotor side convertor (RSC) and grid side converter (GSC) is regulated in accordance with grid code requirements. During grid faults, the proposed scheme enhances device recovery by providing reactive power support through the GSC and the stator. The dynamic performance of the proposed scheme is investigated under symmetrical grid disturbances. The operation of the proposed system has been simulated in a MATLAB/Simulink environment for a 2.6 MW-grid-connected DFIG system.

Nonlinear time series analysis of ionospheric electric current disturbance associated with geomagnetic storm

The wavelet power spectrum and nonlinear dynamics time series techniques were used to examine the ionospheric electric current disturbance (Diono) during the geomagnetic storms of 9–11 November 2004 and 14–16 May 2005. These storms were characterized by high solar wind speed from coronal mass ejections (CMEs). The time series of the solar wind parameters (interplanetary magnetic field, IMF Bz and solar wind speed, Vx) and geomagnetic indices (Symmetric disturbance field, SYM-H, eastward electrojet, AU and westward electrojet AL), were used to monitor solar wind conditions and the geomagnetic perturbation, respectively. The horizontal component of the geomagnetic field obtained from six ground-based magnetometer stations was also analyzed. The high latitudes stations (ESK, NUR, LER and SOD) show higher energy wavelet coefficient of Diono with high frequencies, due to the existence of ionospheric currents at high latitudes during geomagnetic storm. The mid and low latitude stations (HER and AAE) display low energy wavelet coefficient with low frequency. The low latitude geomagnetic stations display high values of Lyapunov exponent (LE) during 9–11 November 2004 and 14–16 May 2005 of the geomagnetic storm. The low values of Lyapunov exponent might be as result of the internal dynamics restructuring during geomagnetic storm. The electrodynamics of the magnetosphere-ionosphere due to solar wind influenced the chaotic signature of Diono. The solar wind is a stochastic driver which contributes in the generation of geomagnetic disturbance in the Earth’s magnetosphere due to CMEs that generates the geomagnetic storms.

Proposal for a normal pressure hydrocephalus syndrome center of excellence

Normal pressure hydrocephalus syndrome, characterized by ventriculomegaly and the classic triad of symmetric gait disturbance, cognitive decline, and urinary incontinence, is the most common cause of hydrocephalus in the adult population and a significant cause of reversible dementia among older adults. The only effective treatment for this syndrome, to date, is a cerebrospinal fluid shunting procedure, commonly a ventriculoperitoneal, ventriculoatrial, or lumboperitoneal shunt. The shunting success rate ranges between 73 and 96%. Hence, early identification, proper diagnosis, and treatment are paramount.We designed a protocol-based program supported on the best available evidence for an integral approach of patients with normal pressure hydrocephalus syndrome. The protocol consists of a series of patient-centered tests and interventions performed on adults with clinical suspicion, leading to optimized and sustainable outcomes for patients living with this condition.The program obtained the recognition of the Joint Commission International as an accredited center of excellence. The objectives of our center are increasing awareness and knowledge of normal pressure hydrocephalus syndrome within the community, delivering optimized interdisciplinary care, mitigating risks, improving quality of life to patients and their families, and ultimately saving from oblivion a significant number of patients who would be otherwise condemned.

A Review of Current-Limiting Control of Grid-Forming Inverters Under Symmetrical Disturbances

Grid-forming (GFM) inverters are recognized as a viable solution to increase the penetration of renewable energy in bulk power systems. However, they are physically different from synchronous generators in terms of overcurrent capability. To protect the power semiconductor devices and support the power grid under severe symmetrical disturbances, the GFM control systems should be able to achieve the following requirements: current magnitude limitation, fault current contribution, and fault recovery capability. Various current-limiting control methods are reported in the literature to fulfill these goals, including current limiters, virtual impedance, and voltage limiters. This paper presents an overview of those methods. Emerging challenges that need to be addressed, including temporary overcurrent, unspecified output current vector angle, undesired current saturation, and transient overvoltage, are pointed out. Comparative simulations are conducted to demonstrate the performance of different methods under grid voltage drops and phase jumps. Finally, open issues of current-limiting control methods for GFM inverters, including transient stability assessment, voltage source behavior under overcurrent conditions, and windup of voltage controllers, are shared.

Electrochemical Investigations of BaCe0.7-xSmxZr0.2Y0.1O3-δ Sintered at a Low Sintering Temperature as a Perovskite Electrolyte for IT-SOFCs

Perovskite materials have gained a lot of interest in solid oxide fuel cell (SOFC) applications owing to their exceptional properties; however, ideal perovskites exhibit proton conduction due to availability of low oxygen vacancies, which limit their application as SOFC electrolytes. In the current project, Sm was doped at the B-site of a BaCe0.7-xSmxZr0.2Y0.1O3-δ perovskite electrolyte for intermediate-temperature solid oxide fuel cells (IT-SOFCs). BaCe0.7-xSmxZr0.2Y0.1O3-δ electrolytes were synthesized through a cost-effective coprecipitation method and were sintered at a low sintering temperature. The effects of samarium (Sm) doping on the electrochemical performance of BaCe0.7-xSmxZr0.2Y0.1O3-δ were investigated. X-ray diffraction (XRD) analysis confirmed that the BaCe0.7-xSmxZr0.2Y0.1O3-δ electrolyte material retained the perovskite structure. The secondary phase of Sm2O3 was observed for BaCe0.4Sm0.3Zr0.2Y0.1O3-δ. Scanning electron microscopic (SEM) imaging displayed the dense microstructure for all the compositions, while prominent crystal growth was observed for composition x = 0.3. The formation of the perovskite structure and the presence of the hydroxyl groups of metal oxides for all the compositions were confirmed by Fourier transform infrared spectroscopy (FTIR). An increased symmetrical disturbance was also observed for the increased doping ratio of the Sm. Thermogravimetric analysis (TGA) of all the compositions showed no major weight loss in the SOFC operating temperature range. It was also noted that the conductivity of BaCe0.7-xSmxZr0.2Y0.1O3-δ gradually decreased with the increased contents of the Sm metal. The maximum power density of 390 mW cm−2, and an open-circuit voltage (OCV) of 1.0 V at 600 °C, were obtained, showing that BaCe0.7-xSmxZr0.2Y0.1O3-δ, synthesized by a cost-effective method and sintered at a low temperature, can be used as a proton-conducting electrolyte for IT-SOFCs.

Ventriculo-atrial shunt. Comparison of an ultrasound-guided peel-away technique versus conventional technique in the management of normal pressure hydrocephalus: A retrospective cohort.

Background: Normal pressure hydrocephalus (NPH) is a common neurodegenerative syndrome among the elderly characterized by ventriculomegaly and the classic triad of symmetric gait disturbance, cognitive decline and urinary incontinence. To date, the only effective treatment is a cerebrospinal fluid shunting procedure that can either be ventriculo-atrial, ventriculo-peritoneal, or lumbo-peritoneal shunt. The conventional ventriculo-atrial shunt uses venodissection, whereas the peel-away is a percutaneous ultrasound (US)-guided technique that shows some advantages over conventional technique. We sought to compare perioperative complication rates, mean operating time and clinical outcomes for both techniques in NPH patients at our institution.Methods: A retrospective cohort-type analytical study was conducted, using clinical record data of patients diagnosed with NPH and treated at our center from January 2009 to September 2019. Parameters to be compared include: Perioperative complication rates, intraoperative bleeding, mortality, and mean operating time. Perioperative complication rates are those device-related such as shunt infection, dysfunction, and those associated with the procedure. Complications are further classified in immediate (occurring during the first inpatient stay), early (within the first 30 days of surgery), and late (after day 30 of surgery).Results: A total of 123 patients underwent ventriculo-atrial shunt. Eighty-two patients (67%) underwent conventional venodissection technique and 41 patients (33%) underwent a peel-away technique. Immediate complications were 3 (3.6%) and 0 for conventional and peel-away groups, respectively. Early complications were 0 and 1 (2.4%) for conventional and peel-away groups, respectively. Late complications were 5 (6.1%) and 2 (4.9%) for conventional and peel-away groups, respectively. Mean operating time was lower in the peel-away group (P = 0.0000) and mortality was 0 for both groups.Conclusion: Ventriculo-atrial shunt is an effective procedure for patients with NPH. When comparing the conventional venodissection technique with a percutaneous US-guided peel-away technique, the latter offers advantages such as shorter operating time and lower perioperative complication rates.

Entrainment and growth of vortical disturbances in the channel-entrance region

The entrainment of free-stream unsteady three-dimensional vortical disturbances in the entry region of a channel is studied via matched asymptotic expansions and by numerical means. The interest is in flows at Reynolds numbers where experimental studies have documented the occurrence of intense transient growth, despite the flow being stable according to classical stability analysis. The analytical description of the vortical perturbations at the channel mouth reveals how the oncoming disturbances penetrate into the wall-attached shear layers and amplify downstream. The effects of the channel confinement, the streamwise pressure gradient and the viscous/inviscid interplay between the oncoming disturbances and the boundary-layer perturbations are discussed. The composite perturbation velocity profiles are employed as initial conditions for the unsteady boundary-region perturbation equations. At a short distance from the channel mouth, the disturbance flow is mostly confined within the shear layers and assumes the form of streamwise-elongated streaks, while farther downstream the viscous disturbances permeate the whole channel although the base flow is still mostly inviscid in the core. Symmetrical disturbances exhibit a more significant growth than anti-symmetrical disturbances, the latter maintaining a nearly constant amplitude for several channel heights downstream before growing transiently, a unique feature not reported in open boundary layers. The disturbances are more intense as the frequency decreases or the bulk Reynolds number increases. We compute the spanwise wavelengths that cause the most intense downstream growth and the threshold wall-normal wavelengths below which the perturbations are damped through viscous dissipation.

Deep Neural Networks With Convolutional and LSTM Layers for SYM‐H and ASY‐H Forecasting

AbstractGeomagnetic indices quantify the disturbance caused by the solar activity on a planetary scale or in particular regions of the Earth. Among them, the SYM‐H and ASY‐H indices represent the (longitudinally) symmetric and asymmetric geomagnetic disturbance of the horizontal component of the magnetic field at midlatitude with a 1‐min resolution. Their resolution, along with their relation to the solar wind parameters, makes the forecasting of the geomagnetic indices a problem that can be addressed through the use of Deep Learning, particularly using Deep Neural Networks (DNNs). In this work, we present two DNNs developed to forecast respectively the SYM‐H and ASY‐H indices. Both networks have been trained using the Interplanetary Magnetic Field (IMF) and the related index for the solar storms occurred in the last two solar cycles. As a result, the networks are able to accurately forecast the indices 2 h in advance, considering the IMF and indices values for the previous 200 min. The evaluation of both networks reveals a great forecasting precision, including good predictions for large storms that occurred during the solar cycle 23 and comparing with the persistence model for the period 2013–2020.

Detection of islanding and non-islanding fault disturbances in microgrid using LMD and deep stacked RVFLN based auto-encoder

This paper presents a hybrid AC/DC microgrid consisting of multiple distributed energy sources, modeled in MATLAB/Simulink environment that undergoes islanding and non-islanding (symmetrical and unsymmetrical Faults) disturbances. These disturbances result in various changes in circuit parameters (voltage, current, and frequency) and this paper focuses only on disturbed current signals that are extracted from the solar and wind-connected buses. Further to extract rich and useful fault features from the extracted current signals, an adaptive detection technique, local mean decomposition (LMD) is proposed that results in series of product functions (PFs). Various feature extraction indices are used to extract the underlying features of the decomposed PFs that are processed through a deep-stacked random vector functional link network (RVFLN) based auto-encoder (AE) technique for classifying the faults. The effectiveness of the proposed RVFLN based AE technique is evidenced in terms of classification accuracy (CA) and confusion matrix (CM). The performance of the proposed technique has been evaluated through reliability analysis (MAPE, MAE, RMSE, and CM) by comparison with various artificial neural networks under both islanding and non-islanding mode of operation.

Forecasting SYM‐H Index: A Comparison Between Long Short‐Term Memory and Convolutional Neural Networks

AbstractForecasting geomagnetic indices represents a key point to develop warning systems for the mitigation of possible effects of severe geomagnetic storms on critical ground infrastructures. Here we focus on SYM‐H index, a proxy of the axially symmetric magnetic field disturbance at low and middle latitudes on the Earth's surface. To forecast SYM‐H, we built two artificial neural network (ANN) models and trained both of them on two different sets of input parameters including interplanetary magnetic field components and magnitude and differing for the presence or not of previous SYM‐H values. These ANN models differ in architecture being based on two conceptually different neural networks: the long short‐term memory (LSTM) and the convolutional neural network (CNN). Both networks are trained, validated, and tested on a total of 42 geomagnetic storms among the most intense that occurred between 1998 and 2018. Performance comparison of the two ANN models shows that (1) both are able to well forecast SYM‐H index 1 h in advance, with an accuracy of more than 95% in terms of the coefficient of determination R2; (2) the model based on LSTM is slightly more accurate than that based on CNN when including SYM‐H index at previous steps among the inputs; and (3) the model based on CNN has interesting potentialities being more accurate than that based on LSTM when not including SYM‐H index among the inputs. Predictions made including SYM‐H index among the inputs provide a root mean squared error on average 42% lower than that of predictions made without SYM‐H.

Influence of Microscopic Morphological Disturbance on the Streamer Interface Stability in Liquid Dielectrics

This paper deals with the influence of microscopic morphological disturbances on the surface stability of streamer developing in a dielectric liquid. A dynamic model based on the stresses acting at the streamer channel surface is established, and the influence of different modes of microscopic morphological disturbances on the surface stability of streamer are analyzed. The model shows that disturbances on the streamer body can cause pinch-off when the applied voltage is low. At higher voltage, the short-wavelength disturbance is easier to cause unstable of streamer, such as branching, shrinkage, expansion and pinch-off, than long-wavelength disturbance. The symmetric disturbance grows faster than asymmetric disturbance. The streamer head is also sensitive to disturbances and becomes unstable. Depending on the form of the disturbance, the perturbation on streamer head may cause streamer branching and direction change.

Acute Guillain Barre Syndrome in A Hemodialysis Patient with Diabetic Nephropathy: A Case Report

Acute Guillain Barre syndrome is a common type of autoimmune mediated acute peripheral neuropathy. Its initial symptoms are symmetrical limb weakness, sensory disturbance, pain or other symptoms. This paper reports a case of acute Guillain Barre syndrome in a uremic patient with diabetic nephropathy and long-term regular hemodialysis, in order to further explore the clinical manifestations and differential characteristics of uremic patients with acute Guillain Barre syndrome, improve the early diagnosis rate of uremic patients with acute Guillain Barre syndrome, make the patients get timely treatment, so as to reduce the disability of such patients To improve the prognosis of the disease.

Kajian Koordinasi Sistem Proteksi Pada Sistem Transmisi 70 kV GI Banaran Kediri Transmission Line Bay Pare

The substation is one of the components in the electric power distribution system which plays a very important role because it is the connection between electricity services to customers. In the electric power distribution system, there are disturbances that often occur, one of which is a short circuit. For that, the way to overcome this is using the Distance Relay protection system, OCR / GFR and DEF. The purpose of writing this research is to determine the value of setting relay distance, setting Over Current Rele and Directional Earth Fault relay in order to secure the 70 kV transmission network connected to GI Banaran, which is then simulated using DigSILENT 15.1 software on the Pare line by calculating symmetrical and asymmetrical disturbances. including 3-phase disturbance on February 1, 2018. The simulation results show that the 3-phase disturbance occurs at Zone 1 relay distance of the Banaran Bay Pare substation with a trip time of 0.02 seconds with a fault impedance of 0.083 ohms below the relay impedance value of 0.887 ohms. The coordination between the distance relay on the side of the Banaran Bay Pare substation has worked well because there is no error reading the relay when it will cut off the disturbance.