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Showing papers on "Power-flow study published in 2022"


Journal ArticleDOI
TL;DR: In this article, the authors presented a technique for the probabilistic simulation of power transmission systems under hurricane events and provided fundamental insights on the modeling and quantification of power system performance and resilience.

13 citations


Journal ArticleDOI
TL;DR: In this article, a linear continuous optimization model was used for the energy system optimization and the non-linear problem for the power system analysis to compare different energy planning scenarios; further, this also offers the possibility for implementation assessment of the proposed scenarios.

10 citations


Journal ArticleDOI
TL;DR: A damping scheme to the EOMs is proposed based on the sensitivity analysis and the optimization model and it is found that the not only the active power but also the reactive power of the SGs are effective to damp the E OMs.

5 citations


Journal ArticleDOI
TL;DR: In this paper , the application and extension of the trust-region method to solve the three-phase load flow problem are proposed and investigated, and case studies using 19-node, 25-node and 123-node distribution systems are also given in this paper.
Abstract: At present, the electric power system is getting bigger and more complex, and its loading is also increasing. As a consequence, planning, operation, and control of the power system also become more complicated. It is known that system planning and operation are mostly based on the steady-state condition of the power system, and the system steady-state condition can only be determined from the load flow study. Thus, the development of a reliable and efficient method to solve the load flow problem is necessary so that the system steady-state condition can properly be evaluated. Since the characteristics of the electric distribution system are different from those of the transmission system, special treatments are usually required in the distribution system load flow (DSLF) analysis. In this context, several interesting techniques have been proposed in the analysis. In this paper, the application and extension of the trust-region method to solve the three-phase DSLF problem are proposed and investigated. Case studies using 19-node, 25-node, and 123-node distribution systems are also given in this paper. Results of the studies show that the output values obtained by the proposed method are in excellent agreement with those obtained by previously published methods. These results confirm the validity of the proposed method. Case study results also indicate that the proposed method has better computational performances than the forward/backward sweeping (FBS) method.

4 citations


Journal ArticleDOI
TL;DR: In this article , a fast Newton-Raphson power flow implementation on multicore CPUs was proposed by combining sparse matrix techniques, mathematical methods, and parallel processing, and the power flow solution of a synthetic U.S. grid test case with 82,000 buses was found in just 1.8 seconds.
Abstract: Power flow (PF) calculation provides the basis for the steady-state power system analysis and is the backbone of many power system applications ranging from operations to planning. The calculated voltage and power values by PF are essential to determining the system condition and ensuring the security and stability of the grid. The emergence of multicore processors provides an opportunity to accelerate the speed of PF computation and, consequently, improve the performance of applications that run PF within their processes. This paper introduces a fast Newton-Raphson power flow implementation on multicore CPUs by combining sparse matrix techniques, mathematical methods, and parallel processing. Experimental results validate the effectiveness of our approach by finding the power flow solution of a synthetic U.S. grid test case with 82,000 buses in just 1.8 seconds.

4 citations


Journal ArticleDOI
TL;DR: In this paper , the authors developed an equivalent circuit-based model to perform power and emission tracing in power grids, which can be readily converted into a series of equivalent acyclic circuits so that the contributions of generators to a specific load can be clearly and unequivocally traced from a circuit point of view without making any assumptions on how nodal power inflows contribute to the outflows.
Abstract: This article develops an equivalent circuit-based model to perform power and emission tracing in power grids. By relying on the proposed model, a power network can be readily converted into a series of equivalent acyclic circuits so that the contributions of generators to a specific load can be clearly and unequivocally traced from a circuit point of view without making any assumptions on how nodal power inflows contribute to the outflows. The effectiveness of the proposed method is discussed through both power flow and optimal power flow simulations on three case studies, including a simple two-generator network, and the IEEE standard 14-bus and 118-bus systems. Furthermore, the proposed power flow tracing method is used in estimating the electricity-associated emissions from the customer side.

3 citations


Journal ArticleDOI
TL;DR: In this paper , a linear MW-only power flow algorithm with losses for multi-terminal VSC AC/DC systems is proposed, which provides a consistent estimation of converters' losses and allows modelling of all branches within the converter stations.
Abstract: Power flow analysis is a key tool for planning, operation and control of power systems. With future hybrid Supergrids in mind, a wide variety of power flow algorithms for multi-terminal VSC AC/DC systems have been proposed. However, the nonlinear nature of these formulations represents a challenge for its use in real power systems. Whereas in the study of AC networks linear approximations are frequently utilized to speed up multi-scenario steady-state analysis, an equivalent tool has not been proposed for hybrid AC/DC grids. This paper fills that gap by formulating a linear MW-only power flow algorithm with losses for multi-terminal VSC AC/DC systems. The proposed algorithm provides a consistent estimation of converters' losses and allows modelling of all branches within the converter stations. Moreover, two novel schemes for the inclusion of DC network losses are proposed and a circuit-equivalent model of the linear power flow problem in multi-terminal VSC AC/DC systems is suggested.

2 citations


Journal ArticleDOI
TL;DR: In this paper, the average power from the source flows along the wires on the transmitting side and passes the external areas of the coupling plates mainly along the channel between the two coupling pairs.

2 citations


Book ChapterDOI
01 Jan 2022
TL;DR: The researcher used the fast decoupled load flow method for the load flow analysis of the system considering all possible existing line outages in the system and will help the system engineer evaluate the power system network’s operating condition when a line outage will occur and tell him what essential steps should be adopted to nullify the consequences of a particular line outage.
Abstract: Power system security is one of the major parts of the electrical system. A power system should be robust enough to detect any kind of disturbance that can occur in the network and analyze its impact on the system. Disturbance in the power system network includes any kind of faults related to the generator, load, and transmission line. Due to the complex nature of the power system network, to protect the power system against any kind of outages, contingency analysis is used. In steady-state conditions, to evaluate the security of system contingency analysis solution is required. It includes the analysis of a system during outages or failure of equipment. Outages in a power system network can take place either due to maloperation of any internal component or due to natural calamities like lightning, tree fall, storm, and bad weather or it can also occur due to overloading of transmission lines, generators, etc. To effectively analyze the impact of individual contingencies on the power system network, performance indices or severity indices are used to rank the contingencies based on their severity. The performance index is the sum of the two indexes named as active power performance index and voltage performance index. In this paper, the researcher made a MATLAB program is utilized that screened on two standard benchmark test systems IEEE-5 and IEEE 15 bus system. The researcher used the fast decoupled load flow method for the load flow analysis of the system considering all possible existing line outages in the system. This contingency analysis will help the system engineer to evaluate the power system network’s operating condition when a line outage will occur and tell him what essential steps should be adopted to nullify the consequences of a particular line outage.

2 citations


Journal ArticleDOI
TL;DR: In this article , the average power from the source flows along the wires on the transmitting side and passes the external areas of the coupling plates mainly along the channel between the two coupling pairs.

2 citations


Journal ArticleDOI
TL;DR: In this paper , simultaneous allocation of DG and UPFC is done by using an exhaustive search technique to study the impact on the system in overloading conditions, the main objective is to minimize losses.
Abstract: The traditional method of power generation is not capable of fulfilling the increasing electricity demand. The main objective of installing DG is to put less pressure on the centralized power system and to install them nearer to the load or the consumer. DG and FACTS devices allocation in distribution systems has proved to improve the system performance that is the reduction in power loss, improved voltage profile, controlled power transfer capability, active and reactive power flow, improved transient and dynamic stability, better voltage regulation, etc. In this paper, simultaneous allocation of DG and UPFC is done by using an exhaustive search technique to study the impact on the system in overloading conditions. The main objective is to minimize losses. The power flow analysis is done by using the Newton Raphson method and tested on the IEEE 3-bus system and IEEE 14-bus system in Mi Power 9.0 software.

Proceedings ArticleDOI
19 Feb 2022
TL;DR: In this article , a load flow analysis for IEEE 14 and IEEE 30 bus systems is presented, where active power loss and reactive power loss for both IEEE 14 bus system and IEEE30 bus system are calculated.
Abstract: In Newton Raphson load flow analysis, scheduled active power, scheduled reactive power for each generating unit, Active power injections (from bus), Reactive power injections (from bus), Active power injections (to bus), Reactive power injections (to bus), Active power loss and Reactive power loss in each branch for IEEE 14 Bus System and IEEE 30 bus system are calculated. Graphs are plotted for active power loss and reactive power loss for both IEEE 14 Bus System and IEEE 30 bus system.


Proceedings ArticleDOI
25 Nov 2022
TL;DR: In this article , the capacity of the Custom Power Active Transformer that delivers UPFC services is investigated, including power flow management, reactive power compensation, voltage regulation, and the removal of harmonics.
Abstract: Nearly every component of the system, including the generators, the transmission and distribution lines, and the loads themselves, contributes either to the production of reactive power or to its consumption. The capacity of an interconnected power system to return to regular or stable functioning after being disrupted in some way is referred to as its stability. It is getting more difficult to maintain synchronism amongst the different components of the power system as linked systems continue to expand in size and spread out across huge geographical areas. In this paper, the capacity of the Custom Power Active Transformer that deliver UPFC services is investigated. These services include power flow management, reactive power compensation, voltage regulation, and the removal of harmonics. A 69kV transmission line American Electric Power system namely IEEE 14 test bus system is considered for dealing the power quality issues like reactive power compensation and harmonic elimination. A modified ANFIS (BA-ANFIS) controller is used to control the UPFC. All the simulations carried out in MATLAB/Simulink.

Proceedings ArticleDOI
16 Mar 2022
TL;DR: In this paper , the results of power flow calculations in unbalanced three-phase radial distribution networks with nonlinear loads obtained using the decoupled harmonic power flow (DHPF) method are presented.
Abstract: This paper presents the results of power flow calculations in unbalanced three-phase radial distribution networks with nonlinear loads obtained using the decoupled harmonic power flow (DHPF) method. The method is based on three-phase models of distribution network components and the current injection technique. Performances of the method are evaluated on the standard IEEE 13-bus test network. The DHPF method is verified by comparing its results with those generated by the software tool for the analysis of transmission, distribution, and industrial electrical power systems (i.e., DIgSILENT PowerFactory). It is shown that the DHPF method for solving the harmonic power flow (HPF) problem in unbalanced three-phase distribution networks provides effective and high-quality solutions.

Journal ArticleDOI
TL;DR: In this paper , a method for sizing the reactive power compensation in a non-interconnected island power system is presented and applied to determine the necessary inductive power compensation for the autonomous power system of Rhodes Island, Greece.
Abstract: In this paper, a method for sizing the reactive power compensation in a non-interconnected island power system is presented and applied to determine the necessary inductive reactive power compensation for the autonomous power system of Rhodes Island, Greece. The Rhodes power system is often confronted with an excess of reactive power, as a result—inter alia—of underground high-voltage (HV) cable lines and distributed generation penetration. Reactive power compensation is typically a local issue in power systems, usually aiming at maintaining an acceptable voltage profile on specific transmission segments, e.g., long underground or submarine cables. In autonomous systems, however, where network lengths are relatively short, reactive power compensation is meant to address the overall reactive power equilibrium of the system. The proposed method follows a three-step approach. First, power flow analysis is conducted to determine the size of the maximum compensation that may be necessary, i.e., the compensation size that practically allows unit commitment to be conducted without being constrained by reactive power considerations. Then, a unit commitment and economic dispatch model is executed over the course of a year to determine the optimal compensation size, using the output of the power flow analysis to formulate reactive power balance constraints. Finally, the results of the economic optimization are assessed in terms of dynamic security to verify the feasibility of the optimal solution.

Journal ArticleDOI
TL;DR: In this paper , an improved power injection model is proposed for power flow calculation, and the optimal power flow is solved by the stability of power system and the economy of power market.
Abstract: With the continuous improvement of the accuracy of power grid equipment components, the flexible control of unified power flow controller can better improve the stability of power grid. The continuous deepening of UPFC research meets the development needs of new power systems. Simulation analysis in PSAT environment can better study the power flow calculation of UPFC. In this paper, an improved power injection model is proposed for power flow calculation, and the optimal power flow is solved by the stability of power system and the economy of power market. The ieee9 node system is modeled, and the simulation calculation method is compared with BP neural network. The results are close, which shows that the PSAT analysis has high accuracy.


Journal ArticleDOI
TL;DR: Based on the interdependent network theory, a CPPS cascading fault analysis procedure considering the power flow constraints is given in this paper , which shows that some electrical components failures in the power network may lead to large-scale transfer of power flow, resulting in overloading of other electrical components or transmission lines.
Abstract: Comprehensively considering the power flow constraints of the power network, the cyber-physical power system (CPPS) network integration model is established by combining with the topological structure information of the power network and information network. The Newton–Raphson method is used to solve the AC power flow distribution in the power network. Based on the interdependent network theory, a CPPS cascading fault analysis procedure considering the power flow constraints is given. Finally, the importance of CPPS network nodes is evaluated and analyzed. Simulation experiments are carried out with the IEEE39 node system as an example. The results show that some electrical components failures in the power network may lead to large-scale transfer of power flow, resulting in overloading of other electrical components or transmission lines. It promotes further cascade propagation of failures in the CPPS network, which eventually leads to a sharp decrease in the robustness of CPPS.

Journal ArticleDOI
TL;DR: In this paper , the authors proposed a sensitivity analysis-based power flow (SAPF) method, in which the state variables of the extended AC grid are calculated via sensitivity analysis.
Abstract: The power flow calculation of the multiterminal high voltage direct current (MTDC) system is essential for planning sustainable energy sources and power flow analysis for the MTDC system. However, the traditional unified methods require a large system of non-linear equations leading to low calculational efficiency. Also, for a large DC grid, there is a concern about the convergence of sequential methods. This paper proposes a general power flow calculation method for voltage source converter (VSC) based MTDC systems. Based on an extended topology of an AC grid, a generalized calculation model of the MTDC power flow is proposed. Then, a novel sensitivity analysis-based power flow (SAPF) method is proposed, in which the state variables of the extended AC grid are calculated via sensitivity analysis. With a smaller system of equations, the proposed SAPF method has less computational burden than the traditional unified methods and causes no convergence problem compared to sequential methods. To further improve the calculational efficiency, the sensitivity-based variable updating is adopted to accelerate the iterative process. By comparing with the existing methods in calculating power flow for different MTDC systems, including large systems with multiple AC/DC grids, the effectiveness and scalability of the proposed methods are verified.

Proceedings ArticleDOI
30 Mar 2022
TL;DR: In this paper , a neural network (NN) model is trained to predict power flow results using historical power system data, which can find solutions quickly and more accurately than DC power flow model.
Abstract: Power flow analysis is used to evaluate the flow of electricity in the power system network. Power flow calculation is used to determine the steady-state variables of the system, such as the voltage magnitude / phase angle of each bus and the active/reactive power flow on each branch. The DC power flow model is a popular linear power flow model that is widely used in the power industry. Although it is fast and robust, it may lead to inaccurate line flow results for some transmission lines. Since renewable energy sources such as solar farm or offshore wind farm are usually located far away from the main grid, accurate line flow results on these critical lines are essential for power flow analysis due to the unpredictable nature of renewable energy. Data-driven methods can be used to partially addressed these inaccuracies by taking advantage of historical grid profiles. In this paper, a neural network (NN) model is trained to predict power flow results using historical power system data. Although the training process may take time, once trained, it is very fast to estimate line flows. A comprehensive performance analysis between the proposed NN-based power flow model and the traditional DC power flow model is conducted. It can be concluded that the proposed NN-based power flow model can find solutions quickly and more accurately than DC power flow model.

Journal ArticleDOI
01 May 2022
TL;DR: In this article , a power flow adjustment strategy based on a weak bus identification and a new bus type conversion is proposed, and the generator action set is determined by calculating the left eigenvector of the Jacobian matrix.
Abstract: The power flow solvability is greatly challenged by the growing pressure on power grid induced by the rapid development of economy. The approaches of restoring power flow solvability should be profoundly studied. Most of adopted power flow adjustment methods are based on manual interference which require extensive human resources with inefficiency. Thus, a power flow adjustment strategy based on a weak bus identification and a new bus type conversion is proposed. A weak bus identification index is defined and expressed when power flow has no solution. We propose a novel bus type and a concept of the power shortage to restore power flow solvability. The generator action set is determined by calculating the left eigenvector of the Jacobian matrix. At last, we establish a linear programming model to determine the generator output adjustment. Numerical results are obtained in 3 test systems and an actual system in China. Compared with other methods, the proposed method is verified to have a higher success rate of restoring power flow solvability and has robustness in various scenarios.

Journal ArticleDOI
TL;DR: In this article , the authors present a load flow analysis of an IEEE 14 bus system using the Newton-Raphson method, which simplifies the analysis of load balancing problems and gives an overview of the electrical performance and power flows under a steady state.
Abstract: 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.

Proceedings ArticleDOI
29 Apr 2022
TL;DR: In this paper , the authors calculate total transfer capability and available transfer capability (ATC) in different contingency conditions such as line outage and generator outage conditions for Indian 62 bus power system considering three other outage conditions arbitrarily.
Abstract: This paper calculates total transfer capability (TTC) and available transfer capability (ATC) in different contingency conditions such as line outage and generator outage conditions. The most common continuous power flow method is utilised for TTC calculations. These calculations are useful for power wheeling in different power systems for power trading purposes in deregulated power systems. The methods are implemented for an Indian 62 bus power system considering three other outage conditions arbitrarily.

Proceedings ArticleDOI
08 Jul 2022
TL;DR: In this article , a hot-start linearized power flow model was used to improve the accuracy and applicability of DC power flow models in a 33-node system, and the results showed that the hot start linearized model has higher accuracy when load variations in adjacent time periods are not significant.
Abstract: The traditional AC power flow model is accurate, but it needs to deal with a large number of nonlinear constraints, with low efficiency and convergence problems. The use of linearized power flow model can reduce the solution difficulty, which is an effective means to improve the analysis and calculation efficiency of urban networks. The DC power flow model is the most popular linearized model at present, which is applicable to transmission networks. But it cannot satisfy urban networks, has low calculation accuracy and cannot solve the two electrical quantities of voltage magnitude and line reactive power, both of which are important for the stability and control of power system. Therefore, a linearized power flow model and an improved DC power flow model in a hot-start environment are used to improve the calculation accuracy. The IEEE 33-node system is used to test and compare different linearized power flow models, which proves that the hot-start linearized model has higher accuracy and applicability when load variations in adjacent time periods are not significant.

Proceedings ArticleDOI
01 Jan 2022
TL;DR: In this paper , a rapid reconstruction modeling method of civil aircraft power system based on power flow topology and verifies this modeling method with MATLAB/Simulink and LABVIEV simulation.
Abstract: Aircraft power system is one of the most important systems, that ensures the normal power consumption of electrical equipment. The design and evaluation of power supply architecture are important parts of aircraft power system design. This paper introduces a rapid reconstruction modeling method of civil aircraft power system based on power flow topology and verifies this modeling method with MATLAB/Simulink and LABVIEV simulation. Simulation results are of great significance to the evaluation of aircraft power system architecture.

Proceedings ArticleDOI
29 Jun 2022
TL;DR: In this article , a simplified linear load flow strategy that can achieve the solution quickly without sacrificing accuracy is devised in this context, which is appropriate for offline studies like planning and online studies like control, irrespective of the size of the power system network.
Abstract: In case of power system operation, the necessity of calculating the load flow is very often to monitor the operational state of various electrical system components. Hence, load flow methodology adopted should reduce the computational burden. In this context, a simplified linear load flow strategy that can achieve the solution quickly without sacrificing accuracy is devised in this paper. This method is appropriate for offline studies like planning and online studies like control, irrespective of the size of the power system network. The proposed simplified linear load flow method is implemented on IEEE 14, 30 and 57 bus systems and the results are compared with DC Load flow and state independent linear power flow method. According to the results of the performance analysis, the proposed approach for transmission system performs better in terms of computational burden and produces results that are very near to the existing iterative load flow methods in the literature.

Proceedings ArticleDOI
23 May 2022
TL;DR: In this paper , a linear optimization method that takes into account the power flow section constraints and the branch power flow sensitivity is used to solve the problem of power supply adequacy of the district power grid.
Abstract: The current power grid is a hierarchical and partitioned power grid, and the power supply adequacy of the partitioned 220kV power grid needs to be evaluated in real time. The article analyzes the sensitivity between the branch power flow and the node load, the sensitivity between the branch power flow and the generator active power, and deduces the optimization model of the power supply adequacy of the district power grid. This paper uses a linear optimization method that takes into account the power flow section constraints and the branch power flow sensitivity to solve the model. This paper uses the IEEE30-node system as a calculation example to verify the above method. The results show that the real-time assessment of the power supply adequacy of the power grid can calculate the maximum power supply capacity of the regional power grid and reflect the current operating conditions of the power grid.

Proceedings ArticleDOI
29 Apr 2022
TL;DR: In this article , a fast flexible load flow (FFLF) solution for the radial distribution is proposed, where the radial configuration matrix (RCM) with the direct forward sweep method (DFSM) is used.
Abstract: The power distribution network connects the high-power transmission network to the end-users and thus plays an important role in the power system. The distribution system must be properly planned and operated in order to efficiently transfer power from the generator to the load end. As a result, load flow is a critical requirement for distribution system planning. This article proposes a fast flexible load flow (FFLF) solution for the radial distribution. The introduction of the radial configuration matrix (RCM) with the direct forward sweep method (DFSM) makes the fast flexible load flow method for radial distribution unique. The direct forward sweep method helps to reduce the number of iterations and calculation steps. Furthermore, the radial configuration matrix and simple bus numbering allow for the flexibility to adapt to any changes in the structure of the radial distribution networks, which is difficult with other methods. The proposed FFLF method can also be applied to the different practical loading conditions without forming a complex voltage equation. The proposed FFLF algorithm is tested on both balanced and unbalanced radial distribution systems and validated using IEEE standard test feeders.

Proceedings ArticleDOI
07 Oct 2022
TL;DR: In this paper , a non-iterative power flow method for a radial network is proposed, which is based on the principle of decoupled power flow and the fact that active/reactive power losses are miniscule compared to the generation and load in a typical power system.
Abstract: The founding principles of the decoupled power flow method together with the fact that active/reactive power losses are miniscule compared to the generation and load in a typical power system, are utilized to develop a new non-iterative power flow method for a radial network in the present paper. In the paper, first a scheme to find the sensitivities of injected power flows to changes in voltage magnitude and angles at the sending end and also to find the values of the power injected at the sending end for a particular voltage there, is developed for the branches of the network. Based on this scheme, fully utilizing its radial nature, a non-iterative algorithm is developed to find the power flow solution of the network. The highlight of the method is that since it is non-iterative, the problem of convergence of the solution encountered while using other methods to find the power flow solution of radial networks is overcome immediately. The method is used to find the power flow solutions of various networks for varying loading conditions and it is shown that the results obtained are at par with the results obtained by the direct application of Newton-Raphson method with minimum errors.