Integrated Power Flow Analysis with Large-scale Solar Photovoltaic Power Systems Employing N-R Method

2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Girisha H Navada ◽  
K. N. Shubhanga
Keyword(s):  
Power Systems ◽  
Power System ◽  
Power Flow ◽  
Large Scale ◽  
Control Strategies ◽  
Linear Equations ◽  
Flow Analysis ◽  
Load Flow ◽  
Flow Equations ◽  
Single Machine Infinite Bus

Abstract A method is proposed to modify the conventional load flow programme to accommodate large-scale Solar PhotoVoltaics (SPV) power plant with series power specifications. The programme facilitates easy handling of any number of SPV systems with standard control strategies such as pf-control and voltage-control, considering solar inverter’s power constraints. In this method, the non-linear equations related to SPV systems, located at multiple locations, are solved with the main load flow equations in an integrated fashion, considerably reducing the implementation task. This task is achieved by augmenting the inverter buses to the existing power system network in such a way that the changes required in the conventional programme are minimal. To show the effectiveness of the proposed method, it is compared with the alternate-iteration method popularly followed in the literature. The workability of the proposed method has been demonstrated by using a Single Machine Infinite Bus (SMIB) system and the IEEE14-bus power system with SPV systems. Various test cases pertaining to meteorological variables and control strategies are also presented.

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.

scholarly journals A Quasi-Oppositional Heap-Based Optimization Technique for Power Flow Analysis by Considering Large Scale Photovoltaic Generator

Energies ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5382
Author(s):  
Vedik Basetti ◽  
Shriram S. Rangarajan ◽  
Chandan Kumar Shiva ◽  
Sumit Verma ◽  
Randolph E. Collins ◽  
...  
Keyword(s):  
Power Systems ◽  
Power Flow ◽  
Large Scale ◽  
Renewable Energy Sources ◽  
Optimization Technique ◽  
Flow Analysis ◽  
Computation Time ◽  
Load Flow ◽  
Critical Conditions ◽  
The Impact

Load flow analysis is an essential tool for the reliable planning and operation of interconnected power systems. The constant increase in power demand, apart from the increased intermittency in power generation due to renewable energy sources without proportionate augmentation in transmission system infrastructure, has driven the power systems to function nearer to their limits. Though the power flow (PF) solution may exist in such circumstances, the traditional Newton–Raphson based PF techniques may fail due to computational difficulties owing to the singularity of the Jacobian Matrix during critical conditions and faces difficulties in solving ill-conditioned systems. To address these problems and to assess the impact of large-scale photovoltaic generator (PVG) integration in power systems on power flow studies, a derivative-free quasi-oppositional heap-based optimization (HBO) (QOHBO) technique is proposed in the present paper. In the proposed approach, the concept of quasi-oppositional learning is applied to HBO to enhance the convergence speed. The efficacy and effectiveness of the proposed QOHBO-PF technique are verified by applying it to the standard IEEE and ill-conditioned systems. The robustness of the algorithm is validated under the maximum loadability limits and high R/X ratios, comparing the results with other well-known methods suggested in the literature. The results thus obtained show that the proposed QOHBO-PF technique has less computation time, further enhancement of reliability in the presence of PVG, and has the ability to provide multiple PF solutions that can be utilized for voltage stability analysis.

scholarly journals A Full-Newton AC-DC Power Flow Methodology for HVDC Multi-Terminal Systems and Generic DC Network Representation

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1658
Author(s):  
Leandro Almeida Vasconcelos ◽  
João Alberto Passos Filho ◽  
André Luis Marques Marcato ◽  
Giovani Santiago Junqueira
Keyword(s):  
Power Systems ◽  
Direct Current ◽  
Power Flow ◽  
Large Scale ◽  
Flow Problem ◽  
Control Strategies ◽  
Problem Formulation ◽  
Expansion Planning ◽  
Dc Power ◽  
Power Flow Problem

The use of Direct Current (DC) transmission links in power systems is increasing continuously. Thus, it is important to develop new techniques to model the inclusion of these devices in network analysis, in order to allow studies of the operation and expansion planning of large-scale electric power systems. In this context, the main objective of this paper is to present a new methodology for a simultaneous AC-DC power flow for a multi-terminal High Voltage Direct Current (HVDC) system with a generic representation of the DC network. The proposed methodology is based on a full Newton formulation for solving the AC-DC power flow problem. Equations representing the converters and steady-state control strategies are included in a power flow problem formulation, resulting in an expanded Jacobian matrix of the Newton method. Some results are presented based on HVDC test systems to confirm the effectiveness of the proposed approach.

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 Simulation of Incidental Distributed Generation Curtailment to Maximize the Integration of Renewable Energy Generation in Power Systems

Energies ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 4173 ◽  
Author(s):  
Ingo Liere-Netheler ◽  
Frank Schuldt ◽  
Karsten von Maydell ◽  
Carsten Agert
Keyword(s):  
Renewable Energy ◽  
Power Systems ◽  
Power System ◽  
Distributed Generation ◽  
System Integration ◽  
Best Practice ◽  
Flow Analysis ◽  
Real Data ◽  
Load Flow ◽  
Practical Implementation

Power system security is increasingly endangered due to novel power flow situations caused by the growing integration of distributed generation. Consequently, grid operators are forced to request the curtailment of distributed generators to ensure the compliance with operational limits more often. This research proposes a framework to simulate the incidental amount of renewable energy curtailment based on load flow analysis of the network. Real data from a 110 kV distribution network located in Germany are used to validate the proposed framework by implementing best practice curtailment approaches. Furthermore, novel operational concepts are investigated to improve the practical implementation of distributed generation curtailment. Specifically, smaller curtailment level increments, coordinated selection methods, and an extension of the n-1 security criterion are analyzed. Moreover, combinations of these concepts are considered to depict interdependencies between several operational aspects. The results quantify the potential of the proposed concepts to improve established grid operation practices by minimizing distributed generation curtailment and, thus, maximizing power system integration of renewable energies. In particular, the extension of the n-1 criterion offers significant potential to reduce curtailment by up to 94.8% through a more efficient utilization of grid capacities.

An Optimization Framework for Decision Making in Large, Collaborative Energy Supply Systems

2016 ◽  
Vol 138 (5) ◽  
Author(s):  
Bryony DuPont ◽  
Ridwan Azam ◽  
Scott Proper ◽  
Eduardo Cotilla-Sanchez ◽  
Christopher Hoyle ◽  
...  
Keyword(s):  
Decision Making ◽  
Power Systems ◽  
Power Supply ◽  
Power Flow ◽  
Large Scale ◽  
Flow Analysis ◽  
Energy System ◽  
Future Research ◽  
Systems Research ◽  
Supply Systems

As demand for electricity in the U.S. continues to increase, it is necessary to explore the means through which the modern power supply system can accommodate both increasing affluence (which is accompanied by increased per-capita consumption) and the continually growing global population. Though there has been a great deal of research into the theoretical optimization of large-scale power systems, research into the use of an existing power system as a foundation for this growth has yet to be fully explored. Current successful and robust power generation systems that have significant renewable energy penetration—despite not having been optimized a priori—can be used to inform the advancement of modern power systems to accommodate the increasing demand for electricity. This work explores how an accurate and state-of-the-art computational model of a large, regional energy system can be employed as part of an overarching power systems optimization scheme that looks to inform the decision making process for next generation power supply systems. Research scenarios that explore an introductory multi-objective power flow analysis for a case study involving a regional portion of a large grid will be explored, along with a discussion of future research directions.

scholarly journals REDUCING SHORT CIRCUIT LEVELS BY USING SYSTEM SPLITTING STRATEGIES

2019 ◽  
Vol 11 (3) ◽  
pp. 309-331
Author(s):  
Assist. Prof. Dr. Inaam I. ALI ◽  
Mohanad Sh. Tarad AL-AASAM
Keyword(s):  
Power Systems ◽  
Power System ◽  
Large Scale ◽  
Short Circuit ◽  
Load Flow ◽  
Controlled Islanding ◽  
Power Stations ◽  
Stable Splitting ◽  
Three Phase ◽  
Proper Splitting

Preliminary studies on Iraqi power system show a significant increase in the short circuit level at some of the grid substations and some power stations. This increasing results from the growth of the power generation and transmission systems in size and complexity. Islanding or splitting is dividing the power system into several islands inorder to reduce short circuit levels and avoiding blackouts. The main islanding problem is determining the location of proper splitting points and load balance and satisfaction of transmission capacity constraints for each islands.This paper mainly introduces new proposed splitting strategies of large-scale power systems by using (PSS™E version 30.3 PACKAGE PROGRAME), such that, make re-interconnection of 400KV super high voltage substation based on three-phase load flow to be minimum flow at splitting point and infeed fault current details method to control short circuit levels in Iraq power system without islanding the power system into isolated islands. Controlled islanding or splitting scheme is frequently considered as the final solution to avoid blackouts of power system.Simulation IEEE-25 bus and Iraqi power system used as the test systems for this method. Furthermore, simulation results show significant effectiveness on reducing short circuit levels with same time give stable splitting islands with same frequency for preventing the system blackouts.

scholarly journals Power Flow Regulation by UPFC in Networks with Voltage Dependent Loads

2020 ◽  
Vol 8 (6) ◽  
pp. 925-932
Keyword(s):  
Power Flow ◽  
Flow Analysis ◽  
Flow Regulation ◽  
Load Flow ◽  
Constant Current ◽  
Voltage Source ◽  
Unified Power Flow Controller ◽  
Flow Equations ◽  
Load Flow Analysis ◽  
Voltage Dependent

In this paper calculations are made to find out the power flow regulation capabilities of Unified Power Flow Controller (UPFC) in load flow analysis with loads which are voltage dependent. New equations for load flow analysis are developed that includes the models of voltage sensitive loads and voltage sources model of UPFC. Newton Raphson algorithm is used to solve the power flow equations of the network. UPFC voltage source model when included in the power equations has unique advantages over other modeling approaches. Analysis is done for two types of Loads. In the first analysis Constant current, Constant Power and Constant Impedance type of loads are examined. In the second analysis Composite loads are analyzed. The results of analysis on standard 5 bus system is presented here as a case study.

scholarly journals Corrective Control by Line Switching for Relieving Voltage Violations Based on A Three-Stage Methodology

Energies ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1206 ◽  
Author(s):  
Zhengwei Shen ◽  
Yong Tang ◽  
Jun Yi ◽  
Changsheng Chen ◽  
Bing Zhao ◽  
...  
Keyword(s):  
Power Systems ◽  
Power System ◽  
Detailed Analysis ◽  
High Speed ◽  
Power Flow ◽  
Large Scale ◽  
Online Application ◽  
Multiple Line ◽  
Ac Power ◽  
Line Switching

An online line switching methodology to relieve voltage violations is proposed. This novel online methodology is based on a three-stage strategy, including screening, ranking, and detailed analysis and assessment stages for high speed (online application) and accuracy. The proposed online methodology performs the tasks of rapidly identifying effective candidate lines, ranking the effective candidates, performing detailed analysis of the top ranked candidates, and supplying a set of solutions for the power system. The post-switching power systems, after executing the proposed line switching action, meet the operational and engineering constraints. The results provided by the exact Alternating Current (AC) power flow are used as a benchmark to compare the speed and accuracy of the proposed three-stage methodology. One feature of the methodology is that it can provide a set of high-quality switching solutions from which operators may choose a preferred solution. The effectiveness of the proposed online line switching methodology in providing single-line switching and multiple-line switching solutions to relieve voltage violations is evaluated on the IEEE 39-bus and 2746-bus power system. The CPU time of the proposed methodology compared with that under AC power flow constitutes a speed-up of 9905.32% on a 2746-bus power system, showing good potential for online application in a large-scale power system.

scholarly journals Fast Heuristic AC Power Flow Analysis with Data-Driven Enhanced Linearized Model

Energies ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 3308
Author(s):  
Xingpeng Li
Keyword(s):  
Power Systems ◽  
Power System ◽  
Power Flow ◽  
Flow Model ◽  
Reactive Power ◽  
Unit Commitment ◽  
Flow Analysis ◽  
Data Driven ◽  
Dc Power ◽  
Ac Power

Though the full AC power flow model can accurately represent the physical power system, the use of this model is limited in practice due to the computational complexity associated with its non-linear and non-convexity characteristics. For instance, the AC power flow model is not incorporated in the unit commitment model for practical power systems. Instead, an alternative linearized DC power flow model is widely used in today’s power system operational and planning tools. However, DC power flow model will be useless when reactive power and voltage magnitude are of concern. Therefore, a linearized AC (LAC) power flow model is needed to address this issue. This paper first introduces a traditional LAC model and then proposes an enhanced data-driven linearized AC (DLAC) model using the regression analysis technique. Numerical simulations conducted on the Tennessee Valley Authority (TVA) system demonstrate the performance and effectiveness of the proposed DLAC model.

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