Journal articles: 'Newton-Raphson Load Flow (NRLF) Method'

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Li, Yahui, Yang Li, and Yuanyuan Sun. "Online Static Security Assessment of Power Systems Based on Lasso Algorithm." Applied Sciences 8, no. 9 (August 23, 2018): 1442. http://dx.doi.org/10.3390/app8091442.

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As one important means of ensuring secure operation in a power system, the contingency selection and ranking methods need to be more rapid and accurate. A novel method-based least absolute shrinkage and selection operator (Lasso) algorithm is proposed in this paper to apply to online static security assessment (OSSA). The assessment is based on a security index, which is applied to select and screen contingencies. Firstly, the multi-step adaptive Lasso (MSA-Lasso) regression algorithm is introduced based on the regression algorithm, whose predictive performance has an advantage. Then, an OSSA module is proposed to evaluate and select contingencies in different load conditions. In addition, the Lasso algorithm is employed to predict the security index of each power system operation state with the consideration of bus voltages and power flows, according to Newton–Raphson load flow (NRLF) analysis in post-contingency states. Finally, the numerical results of applying the proposed approach to the IEEE 14-bus, 118-bus, and 300-bus test systems demonstrate the accuracy and rapidity of OSSA.

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Adetona, S., M. Iyayi, and R. Salawu. "Optimal Location of IPFC That Handles Operating Constraints for Reducing Transmission Lines Utilization Levels in Electric Power Grid." Engineering and Technology Research Journal 6, no. 2 (September 2, 2021): 31–39. http://dx.doi.org/10.47545/etrj.2021.6.2.082.

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The day-to-day increase in electric energy demand with increasing population and urbanization is causing transmission facilities to transfer load at their upper limits; therefore, the probability of failures of these facilities increases. One of the ways of mitigating failures is by constructing more transmission lines; which would serve as alternatives to reduce the transmission line utilization levels (TLUL). However, there are constraints in adopting this method; therefore, the use of Interline Power Flow Controller (IPFC) has been suggested by many researchers; but very few of these studies proposed the IPFC that has capability of handling operating constraints (IPFCthC) in solving power transmission systems issues. Some of the studies that proposed the IPFCthC use trial and error approach in identifying the optimal location for its injection in multi-buses power grid. Also, some of the studies that proposed the IPFCthC do not employ it to investigate its capability in reducing TLUL. In order to reduce the TSUL in the multi-bus grid, this paper therefore proposes optimal location for the injection of IPFCthC using Transmission Line Performance Index (TLPI) and Transmission Line Reactive Power Loss (TLRPL) in Newton-Raphson Load Flow (NRLF) algorithm. The proposed algorithm was tested on IEEE-30 Test-bed in Matlab environment. The results obtained reveal that the TLUL of each of the transmission lines of the Test-bed that is not connected to PV bus is reduced averagely by 4.00 % each, with the injection of the IPFCthC in an optimally location established by the proposed algorithm.

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Uche, Engr Obi, Fortunatus, Aghara, Jachimma, and Prof Atuchukwu John. "Shunt Compensaton of the Integrated Nigeria’s 330KV Transimission Grid System." Volume 5 - 2020, Issue 9 - September 5, no. 9 (September 25, 2020): 537–40. http://dx.doi.org/10.38124/ijisrt20sep230.

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The Nigerian Power system is complex and dynamic, as a result of this it is characterized by frequent faults and outages resulting to none steady supply of power to the teaming consumers. This has great effect on the activities and mode of living of Nigerians. The research work was carried out on contingency analysis on the existing integrated 330KV Nigeria grid system and to carry out a shunt compensation on the violated buses, the shutdown of Eket-Ibom line being the case study so as to determine the following; uncertainties and effects of changes in the power system, to recognize limitations that can affect the power reliability and minimize the sudden increase or decrease in the voltage profile of the buses through shunt compensation of buses. Determine tolerable voltages and thermal violation of +5% and -5% of base voltage 330 KV (0.95-1.05) PU and to determine the critical nature and importance of some buses. This is aimed at bridging the gap of proposing further expansion of the grid system which is not only limited by huge sum of finance and difficulties in finding right – of- way for new lines but also which faces the challenges of fixed land and longtime of construction. The data of the network was gotten and modeled. The power flow and contingency analysis of the integrated Nigeria power system of 51 buses (consisting of 16 generators and 35 loads) and 73 transmission lines were carried out using Newton-Raphson Load Flow (NRLF) method in Matlab environment, simulated with PSAT software. Shunt compensation of the weak buses were done using Static Var Compensator (SVC) with Thyristor Controlled Reactor- Fixed capacitor (TCR-FC) technique. Results obtained showed that the average voltage for base simulation was 326.25KV, contingency 323.67KV and compensation was 322.37 KV. Voltage violations for lower limit were observed at Itu as 309KV and Eket as 306.81 KV while violations for upper limit were recorded at Damaturu as 352.85KV, Yola as 353.62 KV, Gombe as 355.98KV, and Jos as 342.97 KV. However after shunt compensation there were improvements for the violations at lower limits and that of higher limit were drastically brought down as recorded below: Damaturu 329.93 KV, Jos 330 KV, Eket 327.2 KV, Gombe 333.55KV, Itu 330KV, and Yola 330.52KV

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Pang, Weichao, Fujun Qi, Jun Wang, Fuqiang Zhao, Qijun Song, and Xingyu Pan. "A Power Flow Calculation Method Considering High-order Load Models." Journal of Physics: Conference Series 2527, no. 1 (June 1, 2023): 012020. http://dx.doi.org/10.1088/1742-6596/2527/1/012020.

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Abstract Given the popularity of new energy and the connection between large power electronic equipment and power system, the operation of power system becomes more complex and requires higher accuracy of power flow calculation. Therefore, a power flow calculation method considering high-order load model is proposed. On the basis of the Newton-Raphson method, when considering the load voltage characteristics, it is necessary to change the variables in the Newton-Raphson method power flow. Therefore, the established polynomial load model is introduced into the Newton-Raphson method, and the effect becomes more obvious with the increase of the order. Finally, constant power, constant current, constant impedance load and fifth order load models are tested in IEEE14-bus system respectively to verify the good accuracy and robustness of the proposed method.

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Tien Tay, Lea, William Ong Chew Fen, and Lilik Jamilatul Awalin. "Improved newton-raphson with schur complement methods for load flow analysis." Indonesian Journal of Electrical Engineering and Computer Science 16, no. 2 (November 1, 2019): 699. http://dx.doi.org/10.11591/ijeecs.v16.i2.pp699-605.

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<p>The determination of power and voltage in the power load flow for the purpose of design and operation of the power system is very crucial in the assessment of actual or predicted generation and load conditions. The load flow studies are of the utmost importance and the analysis has been carried out by computer programming to obtain accurate results within a very short period through a simple and convenient way. In this paper, Newton-Raphson method which is the most common, widely-used and reliable algorithm of load flow analysis is further revised and modified to improve the speed and the simplicity of the algorithm. There are 4 Newton-Raphson algorithms carried out, namely Newton-Raphson, Newton-Raphson constant Jacobian, Newton-Raphson Schur Complement and Newton-Raphson Schur Complement constant Jacobian. All the methods are implemented on IEEE 14-, 30-, 57- and 118-bus system for comparative analysis using MATLAB programming. The simulation results are then compared for assessment using measurement parameter of computation time and convergence rate. Newton-Raphson Schur Complement constant Jacobian requires the shortest computational time.</p>

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Hiwarkar, Dr Chandrashekhar S., Abhay M. Halmare, Anurag A. Belsare, Nitin B. Mohriya, and Roshan Milmile. "Load Flow Analysis on IEEE 14 Bus System." International Journal for Research in Applied Science and Engineering Technology 10, no. 4 (April 30, 2022): 1572–74. http://dx.doi.org/10.22214/ijraset.2022.41590.

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Abstract: This article presents a load flow analysis of an IEEE14 BUS system using the Newton-Raphson method, which simplifies the analysis of load balancing problems. The software used for the programming platform is MATLAB. This paper gives an overview of the electrical performance and power flows (real and reactive) under a steady state. There are various methods for load flow computations. The gauss-seidel method is more popular in smaller systems because of less computational time. In the case of larger systems computation time increases in this condition, the Newton-Raphson method is preferred. This project aims to develop a MATLAB program to calculate voltages and active and reactive power at each bus for IEEE 14 bus systems. The MATLAB program is executed with the input data and results are compared. Keywords: load flow studies, Newton-Raphson method, IEEE 14 bus system.

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Seng, Chieng Kai, Tay Lea Tien, Janardan Nanda, and Syafrudin Masri. "Load Flow Analysis Using Improved Newton-Raphson Method." Applied Mechanics and Materials 793 (September 2015): 494–99. http://dx.doi.org/10.4028/www.scientific.net/amm.793.494.

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This paper describes a simple, reliable and swift load-flow solution method with a wide range of practical application. It is attractive for accurate or approximate off-and on-line calculations for routine and contingency purposes. It is applicable for networks of any size and can be executed effectively on computers. The method is a development on conventional load flow principle and its precise algorithm form has been determined to bring improvement to the conventional techniques. This paper presents a comparative study of the new constant Jacobian matrix load flow method built based on several conventional NR load flow methods. Assumptions are made so as to make the matrix constant, thus eliminating the need of calculating the matrix in every iteration. The proposed method exhibits better computation speed.

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Hlaing, Ya Min Su, and Ze Ya Aung. "Performance Analysis on Transmission Line for Improvement of Load Flow." Advanced Materials Research 433-440 (January 2012): 7208–12. http://dx.doi.org/10.4028/www.scientific.net/amr.433-440.7208.

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This thesis implements power flow application, Newton-Raphson method. The Newton-Raphson method is mainly employed in the solution of power flow problems. The network of Myanma electric power system is used as the reference case. The system network contains 90 buses and 106 brunches. The weak points are found in the network by using Newton-Raphson method. Bus 16, 17, 85 and 86 have the most weak bus voltages. The medium transmission line between bus 87 and bus 17 is compensated by using MATLAB program software. The transmission line is compensated with shunt reactors, series and shunt capacitors to improve transient and steady-state stability, more economical loading, and minimum voltage dip on load buses and to supply the requisite reactive power to maintain the receiving end voltage at a satisfactory level. The system performance is tested under steady-state condition. This paper investigates and improves the steady–state operation of Myanma Power System Network.

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Venkatasivanagaraju, S., and M. Venkateswara Rao. "Polar Coordinates based N-R Method for Load Modelling in Electrical Power Distribution Systems." WSEAS TRANSACTIONS ON POWER SYSTEMS 16 (December 31, 2021): 354–60. http://dx.doi.org/10.37394/232016.2021.16.35.

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In this paper, load modelling has been done in electrical distribution system using local real time test data. This distribution system supplies base loads, residential, industrial, commercial and composite loads. Using power and current-mismatch functions in polar form, a comprehensive framework for applying the Newton–Raphson method to solve power flow problems is presented. The Newton–Raphson approach for solving power flow problems can be applied in six different ways using these two mismatch functions. For load (PQ)buses and generator (PV) buses, we propose a theoretical framework for analyzing these versions. In addition, we compare newly created versions of the Newton power flow method to current variants in this study. Numerical studies on distribution networks are used to study the convergence behavior of all approaches. The measurements are formed for short term load forecasting with different types of realistic loads such as base loads, residential, industrial, commercial and composite loads. The long-term load forecasting and their losses also has been performed along with short term load forecasting. The results are obtained and validated through MATLAB.

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Janković, Stanko, and Bojan Ivanović. "Application of combined Newton–Raphson method to large load flow models." Electric Power Systems Research 127 (October 2015): 134–40. http://dx.doi.org/10.1016/j.epsr.2015.05.024.

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Le Nguyen, H. "Newton-Raphson method in complex form [power system load flow analysis]." IEEE Transactions on Power Systems 12, no. 3 (1997): 1355–59. http://dx.doi.org/10.1109/59.630481.

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Liu, Jianwei, M. M. A. Salama, and R. R. Mansour. "An Efficient Power Flow Algorithm for Distribution Systems with Polynomial Load." International Journal of Electrical Engineering & Education 39, no. 4 (October 2002): 371–86. http://dx.doi.org/10.7227/ijeee.39.4.7.

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A new, efficient power flow algorithm for complex distribution systems is presented. Voltage ratio is used for convergence control. This method has fast convergence ability for the polynomial load model for which the traditional Newton-Raphson method is usually not adaptable. Test results show the robustness of the proposed method.

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Chiba, Fumihiko, Eiichi Tanaka, Ken-ichi Nishiya, and Jun Hasegawa. "Newton-Raphson Load-Flow Method based on an Extended Complex-Number Plane." IEEJ Transactions on Power and Energy 111, no. 3 (1991): 252–58. http://dx.doi.org/10.1541/ieejpes1990.111.3_252.

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Noureddine, Tebbakh, and Labed Djamel. "Load flow analysis using newton raphson method in presence of distributed generation." International Journal of Power Electronics and Drive Systems (IJPEDS) 12, no. 1 (March 1, 2021): 489. http://dx.doi.org/10.11591/ijpeds.v12.i1.pp489-498.

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<p>Distributed generations (DG), specially including renewable sources such as wind and sun are offering several opportunities for the currently in existence distribution networks and becoming one of the keys of treatment of its problems. Knowing the effects of each kind of DG on distribution networks is a primordial task because DG impacts differ from one kind to another. In this paper, we have analyzed and compared the effects of two kinds of DG, DG which provides real power only and DG which provides real power and reactive power at the same time connected at the critical bus in DN on the voltage profile, real and reactive power losses. We have proposed Newton Raphson method using Matlab to investigate the impacts of these two kinds of DG on 57-bus IEEE distribution test system. The obtained results have been exposed in detail at the end of this paper.</p>

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Rao, B. Venkateswara, G. V. Nagesh Kumar, R. V. S. Lakshmi Kumari, and M. Vinay Kumar. "Effect of Advanced Static VAR Compensator on Control of Power System Load Shedding." Advanced Materials Research 403-408 (November 2011): 4867–72. http://dx.doi.org/10.4028/www.scientific.net/amr.403-408.4867.

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This paper investigates the effect of Static VAR Compensator (SVC) on power system load shedding. SVC is mainly used in power system stability improvement. This paper proposes a new use of SVC to reduce load shedding. An algorithm of Newton Raphson method (NR) to reduce the load shedding for installing SVC in the system is proposed in this paper. 5 bus test system example is used to demonstrate the effect on load shedding. The test results show that the effect of SVC is significant, in this Static VAR compensator (SVC) is incorporated in Newton Raphson method in which Power Flow Solution is a solution of the network under steady state conditions subjected to certain constraints under which the system operates. The power flow solution gives the nodal voltages and phase angles given a set of power injections at buses and specified voltages at a few, the model of SVC i.e. SVC Susceptance model is discussed. It is also shown that the power system losses are decreased after incorporating the SVC in this N-R method. The results are generated for 5-Bus system. By incorporating the SVC the amount of load shedding is reduced to get the voltages in their limits.

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Kirthiga, M. Venkata, and S. Arul Daniel. "Computational Techniques for Autonomous Microgrid Load Flow Analysis." ISRN Power Engineering 2014 (May 11, 2014): 1–12. http://dx.doi.org/10.1155/2014/742171.

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This paper attempts at developing simple, efficient, and fast converging load flow analysis techniques tailored to autonomous microgrids. Two modified backward forward sweep techniques have been developed in this work where the largest generator is chosen as slack generator, in the first method and all generator buses are modeled as slack buses in the second method. The second method incorporates the concept of distributed slack bus to update the real and reactive power generations in the microgrid. This paper has details on the development of these two methodologies and the efficacy of these methods is compared with the conventional Newton Raphson load flow method. The standard 33-bus distribution system has been transformed into an autonomous microgrid and used for evaluation of the proposed load flow methodologies. Matlab coding has been developed for validating the results.

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Shabbiruddin, Karma Sonam Sherpa, Sandeep Chakravorty, and Amitava Ray. "Power Flow Investigation Using Cubic Spline Function a Case Study." International Journal of Energy Optimization and Engineering 7, no. 4 (October 2018): 1–16. http://dx.doi.org/10.4018/ijeoe.2018100101.

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This article presents an approach using cubic spline function to study Load Flow with a view to acquiring a reliable convergence in the Bus System. The solution of the power flow is one of the extreme problems in Electrical Power Systems. The prime objective of power flow analysis is to find the magnitude and phase angle of voltage at each bus. Conventional methods for solving the load flow problems are iterative in nature, and are computed using the Newton-Raphson, Gauss-Seidel and Fast Decoupled method. To build this method, this paper used cubic spline function. This approach can be considered as a ‘two stage' iterative method. To accredit the proposed method load flow study is carried out in IEEE-30 bus systems.

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Agbontaen, Festus Osazee, Joel Osarumwens Egwaile, and Ignatius Kema Okakwu. "Power Flow Analysis of the Enhanced Proposed 330kV Transmission Network of the Nigeria Grid." Mehran University Research Journal of Engineering and Technology 38, no. 4 (October 1, 2019): 875–84. http://dx.doi.org/10.22581/muet1982.1904.02.

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The Nigeria’s power sector transmission infrastructure continues to be challenged as it still remains the weak link in the electricity supply chain. The Nigerian Federal Government on its Roadmap for power sector reform highlighted that to accommodate the planned increase in generation capacity, there was need for a 30% increase in the “true deliverable” transmission capacity of the country’s 330kV network. But the technical feasibility of this plan is an issue to be considered. In this work, the existing 330kV Nigeria transmission network was expanded by the introduction of new lines and power stations, simulation was carried out and the effect was analyzed using Newton-Raphson algorithm in ETAP 12.6. The base case operating condition as obtained from the power flow on which the various transfer cases were implemented, gives a fair generation and loading pattern of the Nigerian grid. The total installed generating capacity of the base case considered was 11,948MW out of which 4,347.21MW was available for load level of 3,633.6MW. Result shows that the maximum load ability of the enhanced network was increased to 238.4% compared with the existing network when the Newton – Raphson iteration method was applied.

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Mawuena, Medewou, Patrice Chetangny, Jacques Aredjodoun, Didier Chamagne, Gerald Barbier, Sossou Houndedako, and Antoine Vianou. "Load Flow Study of Togo and Benin Transmission Power Network by the Newton-Raphson Method." Advanced Engineering Forum 44 (January 17, 2022): 49–71. http://dx.doi.org/10.4028/www.scientific.net/aef.44.49.

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Within the framework of the Economic Community of West African States (ECOWAS) countries power networks interconnection project carried by the West African Power Pool (WAPP), operating guidelines have been defined by WAPP and ECOWAS Regional Electricity Regulatory Authority (ERERA) to ensure efficient operation of the interconnected network. Each operator is obliged to comply with these directives to guarantee the stability and reliability of energy supply to ECOWAS countries. The purpose of this paper is to carry out the study of the power flow on the existing Togo and Benin power transmission network and to propose solutions for compliance with the requirements relating to the voltage level required on the interconnection lines or at connection points with neighboring power network operators. The dynamic stability of generators will also be studied to assess the behavior of the network during major disturbances. CEB (Communauté Electrique du Bénin in french) is the power transmission network operator of the Republic of Togo and the Republic of Benin. After the inventory of CEB transmission and production infrastructure and the consumption report, the model of CEB power network is produced as well as the single-line diagram. The power flow calculation is performed with the Newton-Raphson algorithm and the node voltages were calculated using the Cyme software. From the voltage values obtained at the various nodes and depending on the behavior of each generator, solutions are proposed to improve the voltage plan of the power network in accordance with the recommendations of the Regulatory Authority.

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Kusekwa, Mashauri Adam. "Load Flow Solution of the Tanzanian Power Network Using Newton-Raphson Method and MATLAB Software." International Journal of Energy and Power Engineering 3, no. 6 (2014): 277. http://dx.doi.org/10.11648/j.ijepe.20140306.11.

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Pikutić, Marko, Goran Grdenić, and Marko Delimar. "Comparison of results and calculation speeds of various power system power flow methods." Journal of Energy - Energija 66, no. 1-4 (June 23, 2022): 117–27. http://dx.doi.org/10.37798/2017661-4100.

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The theoretical part describes basic power flow methods Gauss-Seidel and Newton-Raphson in their practical forms for solving a load flow problem. In practical part, IEEE test 24, 48 and 72 node networks are used to compare basic methods in terms of calculation speed: on execution of one iteration, entire calculation and on given accuracy influence. Also is analyzed optimal acceleration factor for Gauss-Seidel method and convergences of methods. On the end, final conclusions are obtained after analyzing comparison results.

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Deng, Jiao-Jiao, and Hsiao-Dong Chiang. "Convergence Region of Newton Iterative Power Flow Method: Numerical Studies." Journal of Applied Mathematics 2013 (2013): 1–12. http://dx.doi.org/10.1155/2013/509496.

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Power flow study plays a fundamental role in the process of power system operation and planning. Of the several methods in commercial power flow package, the Newton-Raphson (NR) method is the most popular one. In this paper, we numerically study the convergence region of each power flow solution under the NR method. This study of convergence region provides insights of the complexity of the NR method in finding power flow solutions. Our numerical studies confirm that the convergence region of NR method has a fractal boundary and find that this fractal boundary of convergence regions persists under different loading conditions. In addition, the convergence regions of NR method for power flow equations with different nonlinear load models are also fractal. This fractal property highlights the importance of choosing initial guesses since a small variation of an initial guess near the convergence boundary leads to two different power flow solutions. One vital variation of Newton method popular in power industry is the fast decoupled power flow method whose convergence region is also numerically studied on an IEEE 14-bus test system which is of 22-dimensional in state space.

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Rao, Bharath, Friederich Kupzog, and Martin Kozek. "Three-Phase Unbalanced Optimal Power Flow Using Holomorphic Embedding Load Flow Method." Sustainability 11, no. 6 (March 24, 2019): 1774. http://dx.doi.org/10.3390/su11061774.

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Distribution networks are typically unbalanced due to loads being unevenly distributed over the three phases and untransposed lines. Additionally, unbalance is further increased with high penetration of single-phased distributed generators. Load and optimal power flows, when applied to distribution networks, use models developed for transmission grids with limited modification. The performance of optimal power flow depends on external factors such as ambient temperature and irradiation, since they have strong influence on loads and distributed energy resources such as photo voltaic systems. To help mitigate the issues mentioned above, the authors present a novel class of optimal power flow algorithm which is applied to low-voltage distribution networks. It involves the use of a novel three-phase unbalanced holomorphic embedding load flow method in conjunction with a non-convex optimization method to obtain the optimal set-points based on a suitable objective function. This novel three-phase load flow method is benchmarked against the well-known power factory Newton-Raphson algorithm for various test networks. Mann-Whitney U test is performed for the voltage magnitude data generated by both methods and null hypothesis is accepted. A use case involving a real network in Austria and a method to generate optimal schedules for various controllable buses is provided.

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Okampo, Ewaoche John, Nnamdi Nwulu, and Pitshou N. Bokoro. "Optimization of Voltage Security with Placement of FACTS Device Using Modified Newton–Raphson Approach: A Case Study of Nigerian Transmission Network." Energies 15, no. 12 (June 8, 2022): 4211. http://dx.doi.org/10.3390/en15124211.

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Power flow reliability, voltage security and transmission congestion management are paramount operational issues in a power system. Flexible AC transmission system (FACTS) controllers are suitable technologies that can provide compensation and dynamic control of power system transmission parameters to enhance effective performance and reliability. The interline power flow controller (IPFC), if optimally placed, can regulate the impedance of multiple lines to improve active power transfer capacity and voltage profile. This study examines the performance of IPFCs for voltage enhancement by suppressing fluctuation. A modified Newton–Raphson load flow problem with an incorporated IPFC variable has been formulated with the objective to improve voltage stability and maintain active power flow. The effectiveness of the proposed method was tested on the Nigerian 41 bus transmission network. The obtained result of the system with an IPFC placed at the weakest bus of the network was compared with Newton–Raphson load flow analysis of the same network without an IPFC. The results of load flow analysis for Case 1 (the system without an IPFC) showed that the transmission network without an IPFC had a real power loss of 4.699488 p.u., and reactive power loss of 4.467413 p.u., whereas the integration of an IPFC to the power flow formation in Case 2 resulted in the reduction in the transmission network’s overall losses to 0.55297 p.u. and −38.3329 p.u. The modified method proves effective as the power system network with an IPFC returns a more stable voltage profile and improves active power flow. In addition, this method, similar to all other mathematical optimization approaches, returns a strong accurate result but may be a drawback in terms of longer computational time compared with metaheuristic methods which are preferred for a larger network system.

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Nabhan, M. B. W., G. A. Ibrahim, T. L. Whomes, and M. Z. Anabtawi. "Layered flow in slider bearings." Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology 212, no. 1 (January 1, 1998): 47–54. http://dx.doi.org/10.1243/1350650981541886.

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A procedure for solving the Navier-Stokes equations for the steady, one-dimensional flow of a binary water-based lubricant within an infinite slider bearing is described. The method uses an iterative process (Newton-Raphson procedure) to obtain the interface layer elevation between the liquid layers. The implementation of the Simpson rule integration technique into the equation set allows pressures along the bearing, drag on the moving bearing face, total flow into the bearing and the load-bearing capacity for a binary lubricant to be traced. Results are obtained for a range of non-linearity factors and lead to the conclusion that all the important indicators of bearing performance can be determined using the technique described.

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Wen, Ming, Li li, and Hai Hu. "Research on Weak Node Power Flow Calculation and Voltage and Reactive Power Compensation of Off Grid Microgrid." Journal of Physics: Conference Series 2254, no. 1 (April 1, 2022): 012016. http://dx.doi.org/10.1088/1742-6596/2254/1/012016.

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Abstract The voltage stability control of off grid microgrid is the key and core issue of power grid stability. Aiming at the problem of voltage stability control of off grid microgrid with unbalanced nodes, the Newton Raphson homotopy algorithm is proposed to calculate the power flow, estimate the reactive power margin of each load node, and adopt reactive power supply droop compensation control for weak nodes to improve the voltage stability level. The simulation verifies the effectiveness of this method.

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Wen, Ming, Li li, and Hai Hu. "Research on Weak Node Power Flow Calculation and Voltage and Reactive Power Compensation of Off Grid Microgrid." Journal of Physics: Conference Series 2254, no. 1 (April 1, 2022): 012016. http://dx.doi.org/10.1088/1742-6596/2254/1/012016.

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Abstract The voltage stability control of off grid microgrid is the key and core issue of power grid stability. Aiming at the problem of voltage stability control of off grid microgrid with unbalanced nodes, the Newton Raphson homotopy algorithm is proposed to calculate the power flow, estimate the reactive power margin of each load node, and adopt reactive power supply droop compensation control for weak nodes to improve the voltage stability level. The simulation verifies the effectiveness of this method.

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Sreeshobha, Dr E., and Prof E. Vidyasagar. "Reliability Improvement of Composite Power System using UPFC." International Journal of Engineering and Advanced Technology 12, no. 5 (June 30, 2023): 94–98. http://dx.doi.org/10.35940/ijeat.e4198.0612523.

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Together with quality power supply criteria, Composite Power System (CPS) reliability is also one of the important aspects of deciding the security of the CPS for a given load demand. In the current paper, the reliability of CPS is evaluated. The Newton Raphson (NR) approach is implemented in Power System Simulation for Engineering (PSSE) software to take into account, the load flows, then the power available to the load points, to evaluate the reliability of CPS. Newton Raphson NR Method was implemented by considering different contingencies of the CPS. Power available to the load points obtained by the NR method is critical in identifying the successful operating state of the CPS. Expected Load Curtailment (ELC), Number of Load Curtailment (NLC), Expected Energy Not Supplied (EENS), and Severity Index (SI) are the crucial dependability indices that are assessed. The main objective of the Reliability evaluation of the CPS is to investigate the scope for the improvement of reliability and explore the possible schemes to improve CPS reliability. The Unified Power Flow Controller (UPFC) one of the Flexible AC Transmission Systems is incorporated into the CPS to analyze the improvement in the reliability of the system. Further, the effect of UPFC on the power-carrying capacity of the lines under contingency conditions, resulting in the failure mode of CPS operation is examined. Improvement in the reliability indices of the system is observed due to UPFC incorporation.

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Yudanto, Doan, and Dasrinal Tessal. "Analisis Aliran Daya Sistem Tenaga Listrik Pada PT. Sele Raya Merangin Dua Menggunakan Metode Newton-Raphson." Journal of Electrical Power Control and Automation (JEPCA) 4, no. 2 (December 29, 2021): 51. http://dx.doi.org/10.33087/jepca.v4i2.53.

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Power flow analysis is used to determine the power flow parameters that are useful for planning the system to operate optimally as well as changes to existing systems, such as what happened at PT. Sele Raya Merangin Dua, which is currently making system changes in the form of additional loads. With the addition of this load, it is necessary to conduct a power flow analysis to determine the effect of increasing the load with the aim of knowing the system performance so that it can be in optimal condition. The research method used is qualitative-descriptive which is carried out in a simulation using ETAP 12.6 software where the results of the simulation will be tabulated and graphed. The results showed that the increase in load caused an increase in power generation and power distribution, especially on swing-buses to load-buses and branch buses. From the previous generation power of 1069.1 kVA increased to 1155.2 kVA but did not affect the performance of each power system equipment PT. SRMD and the electric power system are still in optimal condition.

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Darwis, M., I. C. Gunadin, and S. M. Said. "Study of power flow in electricity system using extreme learning machine." IOP Conference Series: Earth and Environmental Science 926, no. 1 (November 1, 2021): 012028. http://dx.doi.org/10.1088/1755-1315/926/1/012028.

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Abstract Load Flow or Power Flow Analysis in the power system in used to determine the power system parameters such as voltage, current, active power, and reactive power contained in the power grid. The method that has long been used in the calculation of load flow or power flow is the Newton-Raphson iteration method. As for its development, to complete the power flow study, it is carried out by implementing the Artificial Intelligence method, one of which is the Extreme Learning Machine method. This method is used in the simulation of the simple 39 Bus system calculation from IEEE. In this Extreme Learning Machine, the testing analysis is carried out with 2 inputs, 1 hidden layer, 5 neurons, and 2 outputs and the number of datasets is 39 to produce MAE and MAPE respectively 2.02 and 0.76% and with a very fast processing time of 0.010s

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Nathasri, Winai, Witsaroot Witoontorn, and Surachai Chaitusaney. "Substation Expansion Considering Reliability of Various Bus Configurations and Load Growth." Applied Mechanics and Materials 781 (August 2015): 258–61. http://dx.doi.org/10.4028/www.scientific.net/amm.781.258.

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This paper proposes a method for electrical substation expansion by considering reliability indices of various types of bus configuration in electrical substation. The reliability indices LOLF, LOLP, and EENS are evaluated by using Newton-Raphson power flow calculation with minimal cut sets. The yearly load growth, together with power capacity of components (capacity limit of components), and the operation of protective components are also taken into account. Two types of failures, i.e. active failure and passive failure, are considered. Finally, the reliability of all bus configuration types in electrical substation is compared by the reliability indices.

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AL-Rawi, Mohammed A., and Mohamed O. Mostafa. "Power Flow Control using Phase Shift Transformers." Tikrit Journal of Engineering Sciences 17, no. 1 (March 31, 2010): 10–15. http://dx.doi.org/10.25130/tjes.17.1.02.

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The present paper examines and tests an alternative method to control and redirect electric power flow through certain paths (transmission lines). The control and redirecting of power flow is achieved through the use of phase shift transformers PSTs. An algorithm is presented which searches for a proper phase shift angle introduced by a PST at any given location. The proposed method is based on modelling the PST and the power system employing Newton-Raphson load flow approach. Finally, the installation of series of PSTs on the interconnected power systems aims at mitigating uncontrolled parallel flows and unbalanced sharing of power among transmission lines. The obtained results showed the effectiveness of the proposed method in sharing and controlling the electrical power flow among different interties of the 5-bus network on which the study applied.

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Mohammed Salih, Truska Khalid, Zozan Saadallah Hussain, and Firas Saaduldeen Ahmed. "Voltage Profile Enhancing Using HVDC for 132KV Power System: Kurdistan Case Study." Journal of Engineering 28, no. 1 (January 1, 2022): 52–64. http://dx.doi.org/10.31026/j.eng.2022.01.04.

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Nowadays power systems are huge networks that consist of electrical energy sources, static and lumped load components, connected over long distances by A.C. transmission lines. Voltage improvement is an important aspect of the power system. If the issue is not dealt with properly, may lead to voltage collapse. In this paper, HVDC links/bipolar connections were inserted in a power system in order to improve the voltage profile. The load flow was simulated by Electrical Transient Analyzer Program (ETAP.16) program in which Newton- Raphson method is used. The load flow simulation studies show a significant enhancement of the power system performance after applying HVDC links on Kurdistan power systems. The bus voltages are significantly increased after connecting High Voltage Direct Current.

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Chanhome, Anuwat, and Surachai Chaitusaney. "A Modification of Newton–Raphson Power Flow for Using in LV Distribution System." Energies 14, no. 22 (November 14, 2021): 7600. http://dx.doi.org/10.3390/en14227600.

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The Newton–Raphson (NR) method is still frequently applied for computing load flow (LF) due to its precision and quadratic convergence properties. To compute LF in a low voltage distribution system (LVDS) with unbalanced topologies, each branch model in the LVDS can be simplified by defining the neutral and ground voltages as zero and then using Kron’s reduction to transform into a 3 × 3 branch matrix, but this decreases accuracy. Therefore, this paper proposes a modified branch model that is also reduced into a 3 × 3 matrix but is derived from the impedances of the phase-A, -B, -C, neutral, and ground conductors together with the grounding resistances, thereby increasing the accuracy. Moreover, this paper proposes improved LF equations for unbalanced LVDS with both PQ and PV nodes. The improved LF equations are based on the polar-form power injection approach. The simulation results show the effectiveness of the modified branch model and the improved LF equations.

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., Yusmartato, Zulfadli Pelawi, Ramayulis ., Oris Krianto Sulaiman, Abdurrozzaq Hasibuan, Mhd Asaad, Muhammad Rahman Rambe, Usman ., and Suhardi Napid. "Analysis of Stability Improvements by Using Capacitors." International Journal of Engineering & Technology 7, no. 2.13 (April 15, 2018): 357. http://dx.doi.org/10.14419/ijet.v7i2.13.16920.

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The demand for electricity has increased substantially while the expansion of electricity generation, power transmission is very limited, due to environmental restrictions, consequently some transmission lines, limiting power factor. Power flow in the generation system, covering the area of North Sumatra and Aceh which is managed by PT. PLN (Persero), ETAP 4.0 (Electrical Transient Analizer Program) is a program that can display GUI (Graphical User Interface) with unlimited bus number, ETAP 4.0 is useful for Power flow study. The data required by ETAP 4.0 on a generation system is a one-line diagram, nominal kV, and generator, bus, transformer, transmission, and safety rating. The power flow approach method used is the Newton-Raphson method with maximum iteration of 99 and the accuracy of 0.000001. The problem of power flows under consideration is the normal state system, one transmission is disconnected, one of the plants is not operating. The results of the power flow study for each problem obtained the lowest bus voltage, the highest losses in the transmis. The largest power distributed in power plants, new in high voltage transmission, increases the power of power from power to load, changes in voltage problems and improves system stability. This paper aims to verify the capacitor's ability to improve voltage regulation (voltage stability) in electric power transmission systems, from this capacitor simulated using ETAP 4.0 included in Newton-Raphson model.

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Pavić, Ivica, Frano Tomašević, and Ivana Damjanović. "Application of artificial neural networks for external network equivalent modeling." Journal of Energy - Energija 64, no. 1-4 (June 29, 2022): 275–84. http://dx.doi.org/10.37798/2015641-4156.

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In this paper an artificial neural network (ANN) based methodology is proposed for determining an external network equivalent. The modified Newton-Raphson method with constant interchange of total active power between internal and external system is used for solving the load flow problem. A multilayer perceptron (MLP) with backpropagation training algorithm is applied for external network determination. The proposed methodology was tested with the IEEE 24-bus test network and simulation results show a very good performance of the ANN for external network modeling.

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Al-Sakkaf, A., and M. AlMuhaini. "Power Flow Analysis of Weakly Meshed Distribution Network Including DG." Engineering, Technology & Applied Science Research 8, no. 5 (October 13, 2018): 3398–404. http://dx.doi.org/10.48084/etasr.2277.

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Power flow is one of the essential studies in power system operation and planning. All steady-state parameters for power distribution systems, such as bus voltage magnitudes, angles, power flows, and power losses, can be calculated by conducting power flow analysis. Distribution system features differ from those of transmission system, rendering conventional load flow algorithms inapplicable. In this paper, three distribution power flow techniques are presented and tested to evaluate their performance when applied to a networked distribution system including distributed generation (DG). These are the distribution load flow (DLF) matrix, the enhanced Newton Raphson (ENR), and the robust decoupled (RD) method. IEEE 33-bus system is adopted for implementing the above methods. Radial and weakly meshed configurations are applied to the tested system with DG inclusion to investigate their influence on the power flow study findings.

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Vinkovic, Anton, Marko Suhadolc, and Rafael Mihalic. "Current-based models of FACTS devices for three-phase load-flow calculations using the Newton–Raphson method." International Journal of Electrical Power & Energy Systems 45, no. 1 (February 2013): 117–28. http://dx.doi.org/10.1016/j.ijepes.2012.08.070.

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Ethmane, I. A., M. Maaroufi, A. K. Mahmoud, and A. Yahfdhou. "Optimization for Electric Power Load Forecast." International Journal of Electrical and Computer Engineering (IJECE) 8, no. 5 (October 1, 2018): 3453. http://dx.doi.org/10.11591/ijece.v8i5.pp3453-3462.

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Load flow studies are one of the most important aspects of power system planning and operation. The main information obtained from this study comprises the magnitudes and phase angles of load bus voltages, reactive powers at generators buses, real and reactive power flow on transmission lines, other variables being known. To solve the problem of load flow, we use the iterative method, of Newton-Raphson. Analysis of the found results using numerical method programmed on the Matlab software and PSS/E Simulator lead us to seek means of controlling the reactive powers and the bus voltages of the Nouakchott power grid in 2030 year. In our case, we projected the demand forecast at 2015 to 2030 years. To solve the growing demand we injected the power plants in the system firstly and secondly when the production and energy demand are difficult to match due to lack of energy infrastructures in 2030.It is proposed to install a FACTS (Flexible Alternative Current Transmission Systems) system at these buses to compensate or provide reactive power in order to maintain a better voltage profile and transmit more power to customers.

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40

Pan, Zhongmei, Jianzhong Wu, Tao Ding, Jian Liu, Fei Wang, and Xiangqian Tong. "Load flow calculation for droop-controlled islanded microgrids based on direct Newton–Raphson method with step size optimisation." IET Generation, Transmission & Distribution 14, no. 21 (November 2, 2020): 4775–87. http://dx.doi.org/10.1049/iet-gtd.2019.1722.

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Bhavithira, V., and A. Amudha. "Enhancement of Available Transfer Capability Using FACTS Controller." Applied Mechanics and Materials 573 (June 2014): 340–45. http://dx.doi.org/10.4028/www.scientific.net/amm.573.340.

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Abstract. This paper discusses about the available transfer capability by using Unified Power Flow Controller-UPFC. Flexible AC Transmission System-FACTS devices helps to reduce power flow on overloaded lines, thereby increasing the loadability of the power system, transient stability, damp out oscillations and also provide security and efficient transmission system. UPFC is one of the most versatile FACTS controllers. It is used for both shunt and series compensation. Newton Raphson method is used to calculate load flow for IEEE 30 bus system. By optimally placing the FACTS device Available Transfer Capability-ATC is improved. The ATC is calculated by using AC Power Transfer Distribution Factor- ACPTDF and this method is based on the sensitivity approach. Imperialistic Competitive Algorithm (ICA) is used to find optimal location of placing UPFC to improve ATC.

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Godbole, Prachi, and Sincy George. "A Novel Algorithm for Optimal Harmonic Load Flow including Harmonic Compensation." Engineering, Technology & Applied Science Research 13, no. 1 (February 5, 2023): 10093–99. http://dx.doi.org/10.48084/etasr.5475.

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Load flow analysis is widely used for finding voltage at various parts of a large, interconnected power system. The exponential increase in the use of power electronic devices and the noticeable percentage of integration of renewable energy sources in modern power systems result in the occurrence of non-sinusoidal voltages at various parts of the power system. By reformation of the Newton-Raphson load flow method, a few harmonic load flow algorithms have been developed for modern transmission systems. However, for larger transmission systems, complexity and heavy computational burden are often encountered in the load flow solution process due to the increased size of the Jacobean matrix that further increases with multiple non-linear load buses and compensation requirements. This leads to convergence problems and increased execution time. In this paper, an optimal harmonic load flow algorithm is proposed, that employs a modified PSO technique to select control variables and the harmonic load flow method to find solutions for load flow analysis with a reduced size of the Jacobean matrix. The formulated method uses a simple technique to take into account nonlinear loads and results in faster convergence. The novelty of the algorithm is that an optimal load flow solution with the desired amount of reactive and harmonic compensation currents is obtained. The algorithm can help in getting load flow solutions in future power systems with distorted voltage and currents with compensation. The performance of the proposed algorithm is tested on a modified IEEE 30-bus system with multiple non-linear load buses and is validated with the Simulink model of the system.

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43

Abdullah Alvi, Anas, and Mohammad Abdul Mannan. "Load Flow Analysis of Dhaka Grid Using PSAT and ETAP and Performance Comparison to PGCB Data." AIUB Journal of Science and Engineering (AJSE) 18, no. 3 (December 31, 2019): 81–87. http://dx.doi.org/10.53799/ajse.v18i3.58.

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This paper deals with a load flow simulation of existing Dhaka Grid Circle of Bangladesh National Grid by using Power System Analysis Toolbox (PSAT) which is a free and open source software of MATLAB Simulink and Electrical Transient and Analysis Program (ETAP) software designed for simulation, operation, and automation of generation, distribution, and industrial power systems. All the data used to simulate were collected from Power Grid Company of Bangladesh (PGCB) and Load flow analysis was carried out using Newton Raphson method and simulated results were compared with PGCB Base Case Data. The network we are considering to simulate has 71 buses (400, 230 and 132 kV), 135 interconnecting lines, 32 generators, 47 loads and only 4 shunt capacitors as per the Dhaka grid circle system. Regarding the maximum demand of the load centers, total 5,525 MW load is connected in this system and the average grid generation in September, 2018 was 10,919.57 MW, though only 5988 MW of the total generation is enlisted in the Dhaka grid circle.

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44

Wirasanti, Paramet, and Egon Ortjohann. "Active Distribution Grid Power Flow Analysis using Asymmetrical Hybrid Technique." International Journal of Electrical and Computer Engineering (IJECE) 7, no. 4 (August 1, 2017): 1738. http://dx.doi.org/10.11591/ijece.v7i4.pp1738-1748.

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A conventional distribution power flow analysis has to be improved regards the changes in distribution network. One of the changes is a grid operation because a new grid concept, e.g. micro-grid and aggregation, is aimed to be operated based on area itself. Consequently, each area can be actively operated in either grid connected mode or islanding mode. Hence, this paper proposes an asymmetrical power flow analysis using hybrid technique to support this flexible mode change. The hybrid technique offers an opportunity to analyze power flow in a decoupling way. This means that the power flow analysis can be performed separately in each grid area. Regards the distributed generation, this paper also introduces a model based on inverter-based operation, i.e. grid forming, grid supporting and grid parallel. The proposed asymmetrical hybrid load flow method is examined in three case studies, i.e. a verification study with the DIgSILENT PowerFactory, a demonstration of decoupling analysis approach and a performance study with the Newton-Raphson method.

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Jethmalani, C. H. Ram, Poornima Dumpa, Sishaj P. Simon, and K. Sundareswaran. "Transmission Loss Calculation using A and B Loss Coefficients in Dynamic Economic Dispatch Problem." International Journal of Emerging Electric Power Systems 17, no. 2 (April 1, 2016): 205–16. http://dx.doi.org/10.1515/ijeeps-2015-0181.

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Abstract This paper analyzes the performance of A-loss coefficients while evaluating transmission losses in a Dynamic Economic Dispatch (DED) Problem. The performance analysis is carried out by comparing the losses computed using nominal A loss coefficients and nominal B loss coefficients in reference with load flow solution obtained by standard Newton-Raphson (NR) method. Density based clustering method based on connected regions with sufficiently high density (DBSCAN) is employed in identifying the best regions of A and B loss coefficients. Based on the results obtained through cluster analysis, a novel approach in improving the accuracy of network loss calculation is proposed. Here, based on the change in per unit load values between the load intervals, loss coefficients are updated for calculating the transmission losses. The proposed algorithm is tested and validated on IEEE 6 bus system, IEEE 14 bus, system IEEE 30 bus system and IEEE 118 bus system. All simulations are carried out using SCILAB 5.4 (www.scilab.org) which is an open source software.

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Salih, Truska K. Mohammed, Zozan Hussain, and Shatha Y. Ismail. "Impact of High Voltage Direct Current Link on Transmission Line in Kurdistan Power System." Journal of Engineering 28, no. 3 (March 1, 2022): 46–59. http://dx.doi.org/10.31026/j.eng.2022.03.04.

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Kurdistan power system is expanded along years ago. The electrical power is transmitted through long transmission lines. The main problem of transmission lines is active and reactive power losses. It is important to solve this issue, unless, the most of electrical energy will lost over transmission system. In this study, High Voltage Direct Current links/bipolar connection were connected in a power system to reduce the power losses. The 132kV, 50 Hz, 36 buses Kurdistan power system is used as a study case. The load flow analysis was implemented by using ETAP.16 program in which Newton-Raphson method for three cases. The results show that the losses are reduced after inserted HVDC links.

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Hashimoto, H. "The Effects of Fluid Inertia Forces on the Static Characteristics of Sector-Shaped, High-Speed Thrust Bearings in Turbulent Flow Regime." Journal of Tribology 111, no. 3 (July 1, 1989): 406–12. http://dx.doi.org/10.1115/1.3261939.

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This paper describes a study on the performance characteristics of sector-shaped, high-speed thrust bearings subjected to the effects of both turbulence and fluid inertia forces. The basic lubrication equations are derived by integrating the momentum and continuity equations in the polar coordinates including the full inertia terms throughout the film thickness; and a numerical calculation technique combining the control volume integration and the Newton-Raphson linearization method is applied to solve the equations. The static characteristics such as the load carrying capacity and the pressure center are calculated for various values of pad extent angle and inner-to-outer radius ratio of a pad. The theoretical results of the load carrying capacity are compared with the experimental results. It was found that the fluid inertia forces have significant effects on the static characteristics of the bearings. Good agreement was obtained between theoretical and experimental results.

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Chen, Ching-Jin, Chun-Lien Su, Jen-Hao Teng, and Mahmoud Elsisi. "Feeder Losses Analysis of Marine Vessel Power Systems: A Case Study of Container Ship Power Loss Analysis Using Newton–Raphson Method." Energies 15, no. 23 (December 3, 2022): 9175. http://dx.doi.org/10.3390/en15239175.

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Load survey has become a routine project for shipbuilding and shipping companies to investigate electrical load characteristics to enhance the power system planning and operation of marine vessels. In this brief perspective, we will outline a few steps to feeder losses analysis based on the result conducted by the load survey. The power flow and feeder loss analysis are extracted and used to determine the critical parameters that can significantly affect the system feeder losses used in the electrical load analysis in new ships. Exploring this new research direction will provide a more thorough understanding of feeder losses in marine vessel power systems. In this paper, a case study of container ship power loss analysis using the Newton–Raphson method is presented. The analysis results can provide shipbuilding corporations and ship owners with useful information for planning, designing, operating, and controlling shipboard power systems. As an energy-saving measure for ship microgrids, the frequency converters are widely used by shipyards for seawater and freshwater cooling systems and heating, ventilation, and air conditioning (HVAC) systems, so that these systems can adjust the speed of the motor according to the actual demand of the load, so as to avoid full-load operation during the motor operation. With the proposed method, other measures, such as battery energy storage systems and energy-saving lighting equipment based on LEDs, are also utilized for shipboard power demand management.

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Soodi, Hamed Atyia, and Ahmet Mete Vural. "STATCOM Estimation Using Back-Propagation, PSO, Shuffled Frog Leap Algorithm, and Genetic Algorithm Based Neural Networks." Computational Intelligence and Neuroscience 2018 (2018): 1–17. http://dx.doi.org/10.1155/2018/6381610.

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Different optimization techniques are used for the training and fine-tuning of feed forward neural networks, for the estimation of STATCOM voltages and reactive powers. In the first part, the paper presents the voltage regulation in IEEE buses using the Static Compensator (STATIC) and discusses efficient ways to solve the power systems featuring STATCOM by load flow equations. The load flow equations are solved using iterative algorithms such as Newton-Raphson method. In the second part, the paper focuses on the use of estimation techniques based on Artificial Neural Networks as an alternative to the iterative methods. Different training algorithms have been used for training the weights of Artificial Neural Networks; these methods include Back-Propagation, Particle Swarm Optimization, Shuffled Frog Leap Algorithm, and Genetic Algorithm. A performance analysis of each of these methods is done on the IEEE bus data to examine the efficiency of each algorithm. The results show that SFLA outperforms other techniques in training of ANN, seconded by PSO.

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Hashimoto, H. "Performance Characteristic Analysis of Sector-Shaped Pad Thrust Bearings in Turbulent Inertial Flow Regime Under Three Types of Lubrication Conditions." Journal of Tribology 112, no. 3 (July 1, 1990): 477–84. http://dx.doi.org/10.1115/1.2920284.

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An influence of lubrication conditions on the performance characteristics of sector-shaped pad thrust bearings, which are subjected to the effects of both turbulence and fluid film inertia, is investigated theoretically and experimentally. The momentum equations in terms of pressure and stream function are solved by applying a numerical calculation technique combining control volume integration and the Newton-Raphson linearization method, under three kinds of inlet boundary conditions in relation to three types of lubrication conditions, namely: the flooded condition, the over flooded condition, and the starved condition. Sample numerical results pertaining to the pressure distribution, load carrying capacity and inlet flow rate are obtained for θ = 60 deg, R1 = 0.5, Re = 2000, Re* = 0 to 1.6 and A = 1.0 to 2.0, and the results of the load-carrying capacity are compared with experimental results. From the theoretical and experimental results, the relationships between the lubrication conditions and the static performance characteristics of the bearings are clarified.

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Journal articles on the topic 'Newton-Raphson Load Flow (NRLF) Method'

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