Ye Tao, A. P. Sakis Meliopoulos · 2011
This paper proposes an optimal power flow (OPF) algorithm based on quadratic modeling and incremental loading of the network. The proposed OPF algorithm is robust and highly efficient for large-scale power systems. Robustness is achieved by the design of the algorithm to operate on infeasible but optimal points and move towards the feasible and optimal operating point. Efficiency is achieved by (a) the design of the algorithm to include mainly the active constraints and therefore reducing the problem size and (b) quadratic modeling that provides faster solution times of the network update solutions. The algorithm guarantees a solution. In case that an optimal solution does not exist, it provides the best solution, the constraints that cannot be satisfied and the remedial actions necessary to satisfy the operating constraints. Numerical examples indicate that the proposed algorithm converges fast and the convergence speed is not affected by system size.
Cited by 11
Alexandra von Meier · 2024
This chapter provides the reader with a general sense of what power flow analysis is, how it is useful, and what it can and cannot do. It introduces the problem of power flow, showing how the power system is abstracted for the purpose of this analysis and how the known and unknown variables are defined. The chapter discusses the interpretation of power flow results based on a sample case and points out some of the general features of power flow in large alternating current systems. It explicitly states the equations used in power flow analysis and outlines a basic mathematical algorithm used to solve the problem, including some simplifications or shortcuts. The chapter addresses key applications of power flow analysis, and considers the case of radial distribution systems. Some useful simplifications of power flow analysis can be made for the special case of radial networks, which includes most distribution systems.
Cited by 0
Jun Li · Advances in intelligent systems and computing · 2012
Cited by 2
Muhammad Yousaf Ali Khan, U. Khalil, Hammad Khan et al. · Engineering Technology & Applied Science Research · 2019
The demand for electricity is increasing day by day and we have to produce more electrical energy to meet the load demands. Most of the experts prefer to extend the existing electrical networks over building the new network with greater costs. In this paper, the implementation of the flexible AC transmission systems (FACTS) devices in a simple electrical network is described. FACTS devices enhance power transfer capacity of the line without laying out new transmission line. These devices also protect the system from overloading in case of any contingency in the electrical network. Moreover, this paper describes the impacts of FACTS devices on improving the voltage stability and power handling capability of a transmission line. The proposed methods for the controllable flow of active and reactive power in a transmission line are also elaborated. A simple electrical system is examined to explain the improvement in the constraints of power system using FACTS devices.
Cited by 20Open access
Abhinanda Sutradhar · Zenodo (CERN European Organization for Nuclear Research) · 2021
<em>This paper presents the introduction of Unified Power Flow Controller (UPFC) for solving power flow control problem in power system. The Unified Power Flow Controller is a distinctive FACTS (Flexible AC Transmission Systems) device that is the utmost sophisticated and complex power electronic equipment and has developed for the control and optimization of power flow and too to control the voltage in electrical power transmission system. The goal of this paper is to observe the skill of Unified Power Flow Controller for power flow control in a power system. Unified Power Flow Controller can handle both the real and reactive power flows at the sending-end and the receiving-end of the transmission line. When no UPFC is installed</em> <em>genuine and receptive power through the transmission line cannot be controlled.</em>
Cited by 0Open access
Kiran A. Dongre, Amol P. Bhagat · 2015
Throughout the entire world, the electric power industry has undergone a considerable change in the past decade and will continue to do so for the next several decades. In the past the electric power industry has been either a government-controlled or a government-regulated industry which existed as a monopoly in its service region. All people, businesses, and industries were required to purchase their power from the local monopolistic power company. This was not only a legal requirement, but a physical engineering requirement as well. It just didn't appear feasible to duplicate the resources required to connect everyone to the power grid. The work presented in this paper utilizes an optimal power flow program as the tool for solving identified problems. This paper provides overall analysis of optimal power flow methods.
Cited by 5
Ali Khan, M. Y., Khalil, U., Khan, H. et al. · Zenodo (CERN European Organization for Nuclear Research) · 2019
The demand for electricity is increasing day by day and we have to produce more electrical energy to meet the load demands. Most of the experts prefer to extend the existing electrical networks over building the new network with greater costs. In this paper, the implementation of the flexible AC transmission systems (FACTS) devices in a simple electrical network is described. FACTS devices enhance power transfer capacity of the line without laying out new transmission line. These devices also protect the system from overloading in case of any contingency in the electrical network. Moreover, this paper describes the impacts of FACTS devices on improving the voltage stability and power handling capability of a transmission line. The proposed methods for the controllable flow of active and reactive power in a transmission line are also elaborated. A simple electrical system is examined to explain the improvement in the constraints of power system using FACTS devices.
Cited by 0Open access
Muhammad Yousaf Ali Khan, U. Khalil, Hammad Khan et al. · Greater South Information System · 2019
The demand for electricity is increasing day by day and we have to produce more electrical energy to meet the load demands. Most of the experts prefer to extend the existing electrical networks over building the new network with greater costs. In this paper, the implementation of the flexible AC transmission systems (FACTS) devices in a simple electrical network is described. FACTS devices enhance power transfer capacity of the line without laying out new transmission line. These devices also protect the system from overloading in case of any contingency in the electrical network. Moreover, this paper describes the impacts of FACTS devices on improving the voltage stability and power handling capability of a transmission line. The proposed methods for the controllable flow of active and reactive power in a transmission line are also elaborated. A simple electrical system is examined to explain the improvement in the constraints of power system using FACTS devices.
Cited by 0Open access
Bo Zhou, Jiakun Fang, Xiaomeng Ai et al. · IET Generation Transmission & Distribution · 2020
Power flow equations (PFEs) are the fundamental of power flow (PF) calculations and optimal PF (OPF) for power system analysis, but existing PFEs suffer from the trade‐off among various requirements in practice. This study presents a novel pyramidal approximation (PA) for PF and OPF. A multi‐sided pyramid is used to approximate the feasible region of PFEs. The PA‐based PFEs not only guarantee the linearity, tightness, and no dependence on the initial guess but also have high solution accuracy. The rotation‐and‐fold strategy is developed to balance the computational efficiency and approximation accuracy, so that the problem for a relatively large power system can be solved in a reasonable time. Case studies in different test systems validate the tightness and accuracy of the proposed PA method. The balance of accuracy and efficiency is also discussed, and the PA has a good performance in the small or medium power systems.
Cited by 8Open access
Aboutaleb Haddadi, A. Kazemi · Advances in Electrical and Computer Engineering · 2011
This paper presents a new power flow model for rotary power flow controller (RPFC). RPFC injects a series voltage into the transmission line and provides series compensation and phase shifting simultaneously. Therefore, it is able to control the transmission line impedance and the active power flow through it. An RPFC is composed mainly of two rotary phase shifting transformers (RPST) and two conventional (series and shunt) transformers. Structurally, an RPST consists of two windings (stator and rotor windings). The rotor windings of the two RPSTs are connected in parallel and their stator windings are in series. The injected voltage is proportional to the vector sum of the stator voltages and so its amplitude and angle are affected by the rotor position of the two RPSTs. This paper, describes the steady state operation and single-phase equivalent circuit of the RPFC. Also in this paper, a new power flow model, based on power injection model of flexible ac transmission system (FACTS) controllers, suitable for the power flow analysis is introduced. Proposed model is used to solve optimal power flow (OPF) problem in IEEE standard test systems incorporating RPFC and the optimal settings and location of the RPFC is determined.
Cited by 16Open access
Satakshi Singh · 2012
Abstract- This paper discusses the Unified Power Flow Controller (UPFC) a member of the FACTS family. UPFC is able to control both transmitted real and reactive power independently, at the sending and receiving ends of the transmission line. Also, the paper discusses UPFC modelling within the context of optimal power flow (OPF) solutions. The UPFC model is very flexible; it allows the control of active and reactive powers and voltage magnitude simultaneously. It can also be set to control one or more of these parameters in any combination or to control none of them. Considerable progress has been achieved in UPFC modelling intended for conventional load flow studies but here more complex issue of UPFC modelling intended for OPF solution is addressed.
Cited by 1
Fahd A. Banakhr · Yanbu Journal of Engineering and Science · 2023
In order to address power flow control issues, this study introduces the use of Unified Power Flow Controller (UPFC) models. These models are based on regulating the variables influencing the transmission line's power flow, and they are capable of controlling the bus voltage, the line's actual and reactive power, all at once and independently. The idea behind the UPFC technique proposed in this paper is to provide the unique functional capability of independently controlling both the real and reactive power flow in the line. The in-phase component of the series injected voltage dominates the reactive power while the quadrature component affects the real power. A conventional controlling steady-state analysis and dynamic stability analysis of the power system is developed based on the UPFC model. UPFC provides real-time controlling of all or any combination of the power system parameters which determine the transmittable power. UPFC can force and maintain strategically chosen values of the active power and the reactive power at a given point of the line by PI control.
Cited by 0Open access
Institution of Engineering and Technology eBooks · 2024
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2021
Optimal power flow Learning outcomesBy the end of this chapter, the student will be able to: Formulate the optimal power flow problem. Solve linear, SOC, and SDP approximations for the OPF. Identify the advantages and disadvantages of each approximation. OPF in power distribution gridsModern power distribution grids include renewable energy sources and energy storage devices that inject active and reactive power to the grid -each configuration of generation and demand results in a different operation point.However, not all operation points are equal; in practice, we seek operation points with minimum losses.This task is the main objective of the OPF.A power distribution grid is represented as an oriented graph = {, } where = {0, 1, 2, , -1} is the set of nodes and is the set of edges.As convention, the slack node is 0 and its voltage is 0 = 10.The nodal admittance matrix is represented by bus = [ ] allowing to calculate nodal current from nodal voltages as given in (10.1).This is an affine equation, thereby easily included in any optimization model.However, loads and generators are usually represented in terms of active and reactive power.Therefore, nodal equations become non-linear as given in (10.2).
Cited by 1Open access
2018
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Abdelhay A. Sallam, O.P. Malik · Institution of Engineering and Technology eBooks · 2015
One of the important tools for power system planning and operation is the optimal power flow (OPF). It is a power flow problem in which some control variables are adjusted to minimise or maximise an objective function, while satisfying physical and operating limits as constraints on various controls, dependent variables and functions of variables.
Cited by 0
Institution of Engineering and Technology eBooks · 2024
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Ventura Nadal, Ignasi · QRU Quaderns de Recerca en Urbanisme · 2021
Aquesta tesi consisteix en el desenvolupament d’un model per optimitzar l’operació d’un sistema elèctric de potència que integra tecnologies d’energies renovables, generadors de combustible i sistemes d’emmagatzematge d’energia. Desenvolupa un problema de flux de potència òptim no lineal, de programació mixta-entera i de diversos períodes, que determina com operar els generadors fotovoltaics, els generadors de combustible i l’estat de càrrega de les bateries cada hora per tal de minimitzar els costos de distribució. Totes aquestes variables s’adhereixen a restriccions que imposen les limitacions físiques del sistema. El problema formula la xarxa de distribució mitjançant el Branch Flow Model per a xarxes radials amb dues relaxacions. Eliminar els angles de tensió i corrent i introduir una relaxació de con de segon ordre perquè el problema sigui convex. A més, com que no es garanteix que la solució del flux de potència sigui factible per al problema no relaxat, es desenvolupa un algoritme per trobar la solució òptima que mantingui la relaxació. La implementació d’aquest model es farà mitjançant el programari GAMS, MATLAB i EXCEL i serà el més genèric possible per adaptar-se fàcilment a qualsevol sistema de distribució de mitja tensió. En aquest projecte, es desenvolupen tres casos pràctics diferents: un escenari base amb generació fotovoltaica i sense sistemes d’emmagatzematge d’energia, un escenari amb un alt nivell de penetració fotovoltaica i un tercer escenari que afegeix bateries al segon cas. Tots els models presenten una part tècnica i econòmica i l’objectiu d’optimització és minimitzar els costos operatius diaris
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Christopher Armstrong, Matthew Evenden, H. V. Nelles · McGill-Queen's University Press eBooks · 2009
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Antonio J. Conejo, Luis Baringo · Power electronics and power systems · 2017
Cited by 1