scholarly journals A Parameterization Technique for the Continuation Power Flow Developed from the Analysis of Power Flow Curves

2012 ◽  
Vol 2012 ◽  
pp. 1-24 ◽  
Author(s):  
Elisabete de Mello Magalhães ◽  
Alfredo Bonini Neto ◽  
Dilson Amancio Alves
Keyword(s):  
Power Systems ◽  
Power Flow ◽  
Jacobian Matrix ◽  
Size Control ◽  
Load Flow ◽  
Step Size ◽  
Real Power ◽  
Continuation Power Flow ◽  
Large Systems ◽  
Ill Conditioning

This paper presents an efficient geometric parameterization technique for the continuation power flow. It was developed from the observation of the geometrical behavior of load flow solutions. The parameterization technique eliminates the singularity of load flow Jacobian matrix and therefore all the consequent problems of ill-conditioning. This is obtained by adding equations lines passing through the points in the plane determined by the loading factor and the total real power losses that is rewritten as a function of the real power generated by the slack bus. An automatic step size control is also provided, which is used when it is necessary. Thus, the resulting method enables the complete tracing ofP-Vcurves and the computation of maximum loading point of any electric power systems. Intending to reduce the CPU time, the effectiveness caused by updating the Jacobian matrix is investigated only when the system undergoes a significant change. Moreover, the tangent and trivial predictors are compared with each other. The robustness and simplicity as well as the simple interpretation of the proposed technique are the highlights of this method. The results obtained for the IEEE 300-bus system and for real large systems show the effectiveness of the proposed method.

Continuation Power Flow: a Parameterization Technique and Adaptive Step Size Control

2021 ◽  
Author(s):  
Alfredo Bonini Neto ◽  
Luis Roberto Almeida Gabriel Filho ◽  
Dilson Amancio Alves
Keyword(s):  
Power Flow ◽  
Size Control ◽  
Step Size ◽  
Adaptive Step Size ◽  
Continuation Power Flow ◽  
Step Size Control ◽  
Adaptive Step

scholarly journals An Asymptotic Numerical Continuation Power Flow to Cope with Non-Smooth Issue

Energies ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3493 ◽  
Author(s):  
Huang ◽  
Ju ◽  
Zhu
Keyword(s):  
Power Flow ◽  
Reactive Power ◽  
Jacobian Matrix ◽  
Power Series Expansion ◽  
Complementarity Constraints ◽  
Step Size ◽  
Continuation Power Flow ◽  
Bus Network ◽  
Smooth Constraints ◽  
Size Adjustment

Continuation power flow (CPF) calculation is very important for analyzing voltage stability of power system. CPF calculation needs to deal with non-smooth constraints such as the generator buses reactive power limits. It is still a technical challenge to determine the step size while dealing with above non-smooth constraints in CPF calculation. In this paper, an asymptotic numerical method (ANM) based on Fischer‐Burmeister (FB) function, is proposed to calculate CPF. We first used complementarity constraints to cope with non-smooth issues and introduced the FB function to formulate the complementarity constraints. Meanwhile, we introduced new variables for substitution to meet the quadratic function requirements of ANM. Compared with the conventional predictor-corrector method combining with heuristic PV-PQ (PV and PQ are used to describe bus types. PV means that the active power and voltage of the bus are known. PQ means that the active and reactive power of bus are known.) bus type switching, ANM can effectively solve the PV-PQ bus type switching problem in CPF calculation. Furthermore, to assure high efficiency, ANM can rapidly approach the voltage collapse point by self-adaptive step size adjustment and constant Jacobian matrix used for power series expansion. However, conventional CPF needs proper step set in advance and calculates Jacobian matrix for each iteration. Numerical tests on a nine-bus network and a 182-bus network validate that the proposed method is more robust than existing methods.

scholarly journals An Innovatory Method Based on Continuation Power Flow to Analyze Power System Voltage Stability with Distributed Generation Penetration

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-15 ◽  
Author(s):  
Le Van Dai ◽  
Ngo Minh Khoa ◽  
Le Cao Quyen
Keyword(s):  
Power Systems ◽  
Distributed Generation ◽  
Power Flow ◽  
Voltage Stability ◽  
Step Length ◽  
Standard Test ◽  
Load Flow ◽  
Convergence Criterion ◽  
Continuation Power Flow ◽  
Stability Issues

With the penetration of distributed generation (DG) units, the power systems will face insecurity problems and voltage stability issues. This paper proposes an innovatory method by modifying the conventional continuation power flow (CCPF) method. The proposed method is realized on two prediction and correction steps to find successive load flow solutions according to a specific load scenario. Firstly, the tangent predictor is proposed to estimate the next predicted solution from two previous corrected solutions. And then, the corrector step is proposed to determine the next corrected solution on the exact solution. This corrected solution is constrained to lie in the hyperplane running through the predicted solution orthogonal to the line from the two previous corrected solutions. Besides, once the convergence criterion is reached, the procedure for cutting the step length control down to a smaller one is proposed to be implemented. The effectiveness of the proposed method is verified via numerical simulations on three standard test systems, namely, IEEE 14-bus, 57-bus, and 118-bus, and compared to the CCPF method.

scholarly journals Overload Alleviation And Determination of Cost of Rescheduling In An Open Acess Power System

2012 ◽  
pp. 255-259
Author(s):  
P. K. Hota ◽  
Banaja Mohanty
Keyword(s):  
Power Generation ◽  
Power Systems ◽  
New England ◽  
Power Flow ◽  
Load Flow ◽  
Relative Location ◽  
Real Power ◽  
Operational Load ◽  
Key Factor

This paper presents an approach for alleviation of network over loads in the day-to-day operation of power systems. The method used for over load alleviation is real power generation rescheduling based on relative electrical distance (RED) concept. The method estimates the relative location of load nodes with respect to the generator nodes. First congestion is observed, and then each generator’s contribution to the congested line is found out. Based on RED method desired generation rescheduling is obtained to relieve overloaded line. Cost is also a key factor which has to be considered in real power rescheduling. A case studied is carried out for modified IEEE 39-bus New England system, where power flow is found by Newton Rapson’s method and compared with operational load flow method.

Techniques for the Identification of Critical Nodes Leading to Voltage Collapse in a Power System

2018 ◽  
Vol 19 (2) ◽  
Author(s):  
Isaiah Adebayo ◽  
Adisa Jimoh ◽  
Adedayo Yusuff
Keyword(s):  
Power Systems ◽  
Power System ◽  
Power Flow ◽  
Eigenvalue Decomposition ◽  
Step Size ◽  
Suggested Approach ◽  
Voltage Instability ◽  
Critical Nodes ◽  
Voltage Stability Enhancement ◽  
Stability Enhancement

AbstractThis paper proposes two techniques for the identification of critical buses in a power system. The technique of Network Structural Theory Participation Factor (NSTPF) depends on the network structural interconnection of buses as captured by the admittance matrix of the system and is formulated based on the fundamental circuit theory law using eigenvalue decomposition method. Another power flow based technique which depends on the system maximum loadability, the system step size among other factors is also proposed. Traditional power flow based techniques are used as benchmarks to determine the significance of the proposed methods. To ensure voltage stability enhancement, STATCOM FACTS device is installed at the selected weak load buses of the practical Nigerian 24 bus and IEEE 30 bus test systems. The results of the simulation obtained show that, the suggested approach of NSTPF is more suitable in the identification of weak buses that are liable to voltage instability in power systems as it requires less computational burden and also saves time compared to techniques based on power flow solutions.

Power Flow Investigation Using Cubic Spline Function a Case Study

2018 ◽  
Vol 7 (4) ◽  
pp. 1-16 ◽  
Author(s):  
Shabbiruddin ◽  
Karma Sonam Sherpa ◽  
Sandeep Chakravorty ◽  
Amitava Ray
Keyword(s):  
Power Systems ◽  
Power Flow ◽  
Spline Function ◽  
Electrical Power ◽  
Flow Analysis ◽  
Cubic Spline ◽  
Load Flow ◽  
Electrical Power Systems ◽  
Flow Investigation ◽  
Cubic Spline Function

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.

scholarly journals Online Static Voltage Stability Monitoring for Power Systems Using PMU Data

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Jianhong Pan ◽  
Aidi Dong ◽  
Jiashu Fan ◽  
Yang Li
Keyword(s):  
Power Systems ◽  
Power Flow ◽  
Voltage Stability ◽  
Jacobian Matrix ◽  
Singular Values ◽  
Test System ◽  
Measurement Unit ◽  
Monitoring Method ◽  
Static Voltage Stability ◽  
Stability Monitoring

A new online static voltage stability monitoring method for power systems is proposed by using phasor measurement unit (PMU) data in this paper. This approach uses the real-time power, voltage, and phase angle data collected by the PMU to estimate the power flow Jacobian matrix of the system, and then the static voltage stability is monitored via the minimum singular values (MSVs) of the power flow Jacobian matrix. The novelty of the approach lies in the fact that it only utilizes PMU data for implementing online monitoring of the power system static voltage stability, independent of the physical model and its parameters. The application results on the IEEE 57-bus test system verify the effectiveness of the proposed approach.

scholarly journals Load Flow Analysis in Hybrid AC-DC Transmission Network

2021 ◽  
pp. 617-624
Author(s):  
Ajith M ◽  
Dr. R. Rajeswari
Keyword(s):  
Power Systems ◽  
Power System ◽  
Transmission Lines ◽  
Power Flow ◽  
Reactive Power ◽  
Short Circuit ◽  
Flow Analysis ◽  
Load Flow ◽  
System Stability ◽  
And Control

Power-flow studies are of great significance in planning and designing the future expansion of power systems as well as in determining the best operation of existing systems. Technologies such as renewables and power electronics are aiding in power conversion and control, thus making the power system massive, complex, and dynamic. HVDC is being preferred due to limitations in HVAC such as reactive power loss, stability, current carrying capacity, operation and control. The HVDC system is being used for bulk power transmission over long distances with minimum losses using overhead transmission lines or submarine cable crossings. Recent years have witnessed an unprecedented growth in the number of the HVDC projects. Due to the vast size and inaccessibility of transmission systems, real time testing can prove to be difficult. Thus analyzing power system stability through computer modeling and simulation proves to be a viable solution in this case. The motivation of this project is to construct and analyze the load flow and short circuit behavior in an IEEE 14 bus power system with DC link using MATLAB software. This involves determining the parameters for converter transformer, rectifier, inverter and DC cable for modelling the DC link. The line chosen for incorporation of DC link is a weak bus. This project gives the results of load flow and along with comparison of reactive power flow, system losses, voltage in an AC and an AC-DC system.

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