Installation Of Unified Power Flow Controller Research Articles

OPTIMAL LOCATION OF AN IDEAL TRANSFORMER UPFC MODEL USING OPF FIRST-ORDER SENSITIVITIES

This paper presents a screening technique for greatly reducing the computation involved in determining the optimal location of a unified power flow controller (UPFC) in a power system. The first-order sensitivities of the generation cost with respect to UPFC control parameters are derived. This technique requires running only one optimal power flow (OPF) to obtain UPFC sensitivities for all possible transmission lines. To implement a sensitivity-based screening technique for guidance in optimally locating a single UPFC in a power system, we propose a new UPFC model, wrach consists of an ideal transformer with a complex turns ratio and a variable shunt admittance. In this model, the UPFC control variables do not depend explicitly on UPFC input and output currents and voltages. Accordingly, this model does not require adding extra buses for UPFC input and output terminals. IEEE five-, 14- and 30-bus systems were used to frustrate the technique. Index Terms-Flexible ac transmission systems (FACTS), FACTS location, first-order sensitivity, optimal power flow (OPF), screening technique, unified power flow controller (UPFC), UPFC ideal transformer model, UPFC placement, UPFC uncoupled model. This study focuses on the development of an Ideal Transformer Unified Power Flow Controller (UPFC) model and its integration with Optimal Power Flow (OPF) first-order sensitivities analysis for determining optimal UPFC locations in power systems. The abstract outlines the significance of UPFCs in enhancing power system stability and efficiency by controlling voltage and power flow. It highlights the objectives of the research, including the development of the UPFC model, analysis of OPF first-order sensitivities, and their combined application for screening optimal UPFC locations. The study aims to contribute to the improvement of power system operation and control through strategic UPFC placement. The abstract provides a concise overview of the study, summarizing the key aspects of the research. It outlines the development of an ideal transformer Unified Power Flow Controller (UPFC) model, the analysis of Optimal Power Flow (OPF) first-order sensitivities, and their application in determining optimal locations for UPFC installation in power systems

Effect of unified power flow controller installation in dual feed induction generator (DFIG) wind turbines

Abstract In recent years, the use of wind energy to generate electricity in the world has been accelerating and growing. Wind farms are unstable when dynamic voltage fluctuations occur, especially sudden and sudden changes in load, and show oscillating performance at their output. In this paper, the Unified Power Flow Controller (UPFC) has been simulated and studied by Matlab software to improve the dynamic stability and transient behavior of the wind power plant in the event of sudden load changes. The simulation results show that by controlling the UPFC series inverter, voltage fluctuations in the PCC bus are prevented and the UPFC parallel inverter injects power after changing the load for faster recovery and stability of the PCC bus voltage and thus the stability of the wind farm. The UPFC can control the active and reactive power at the transmission line, and in fact, controls the output of the wind turbine with the generator from both sides to the fluctuations caused by sudden load changes that play a role such as sudden disturbances and oscillating errors. Also, the presence of UPFC in the system reduces power fluctuations.

The influence of Unified Power Flow Controller to increase the value of Available Transfer Capability on transmission system Java – Bali, Indonesia

Industrial growth and population in Indonesia led to an increase in demand for electricity. It needs a device that can perform a voltage correction profile online so that power will flow through transmission line. TJBTB (Transmisi Jawa Bagian Timur dan Bali) conditions before the installation of UPFC (Unified Power Flow Controller), the power supply received by the load is not 100% obtained from plants in the region, for example the Paiton power plant. In this research, the method used is with the help of MATLAB R2014a simulation by designing a 500 kV transmission system configuration and the placement of the UPFC found in regional IV namely East Java - Bali. From the simulation results, showing that there was a change in power flow when placing the UPFC. The right location is the West Surabaya - Gresik channel. On the Ngimbang bus there is a change in active power which before using UPFC by 1612 MW to 2208 MW after using UPFC, an increase in active power was 36.97%. The UPFC can fulfill all these functions and thereby meet multiple control objectives by adding the injected voltage with appropriate amplitude and phase angle, to the terminal voltage v.

Power Congestion Control Considering UPFC to Enhance Voltage Stability of the System

This paper proposes a new FACTS device, i.e., Unified Power Flow Controller (UPFC) to relieve power congestion on power grid network. A simple model of a three phase AC–network of 500/230kV, 5-bus network with two transformers and two power generation plants (1000MW, 500MW) is designed. UPFC is designed with IGBT converters connected in shunt- series and both interconnected with DC bus and connected to AC side with transformer and coupling reactors. A contingency case is considered such that two transformers are considered instead of three transformers. The power flow of an UPFC installed at Bus-3 in 5-bus system is analyzed to show how the congestion of power on the grid is relieved through it. A bypass circuit breaker is installed at Bus -3 in the circuit to show the natural power flow without UPFC and power flow after installation of UPFC. The topology of series converter build in UPFC can introduce maximum of 10% of line-ground voltage in series. The simulation network of the 5-bus transmission network with UPFC connected at Bus-3 is designed with MATLAB/SIMULATION Software to estimate the power flow with UPFC connected.

Real Power Loss Minimization and Voltage Stability Limit Enhancement by Using Shuffled Frog Leap Algorithm

This paper deals with the Optimal location and control of a unified power flow controller (UPFC) along with transformer taps are tuned to simultaneously optimize the voltage stability limit (VSL) and real power losses of a mesh power system network. This problem is dealt as a nonlinear equality and inequality constrained optimization problem with an objective function incorporating both the real power loss and VSL. An evolutionary algorithm known as shuffled leap is applied for solving the UPFC location, its injected series voltage, and also the tap positions of transformers as the variables. The then obtained results of SFC algorithm are compared with the results of Bacteria Foraging-Based Algorithm using IEEE 14 bus. Index Terms: Shuffled leap, continuation power flow, linearprogramming, optimal power flow (OPF). I. Introduction: The OPF methods are conventional and intelligent and solved by varieties of methods such as successive linear programming, the Newton-based nonlinear programming method, and with varieties of recently proposed interior point methods. The Optimal Power Flow solution is used to optimize a selected objective function such as fuel cost with optimal adjustment of the power system control variables, at the same time satisfying various equity and inequality constraints. The drawback of the OPF is solved from different perspectives, like analyzing the effects of load on voltage stability/power flow solvability, generation rescheduling for cost minimization of power generation, controls such as taps, shunts, and other modern VAR sources adjustments to minimize real power losses in the system. The advent of Flexible ac transmission systems (FACTS) system made the possibility for optimizing the power flow without the restoration of generation rescheduling or changes to topology. Unified power flow controller (UPFC) is the advanced in the controllers family and can provide the OPF with significant flexibility by injecting compensation in series and shunt in controlled manner. The UPFC can provide simultaneous control of all basic power system parameters (transmission voltage, impedance and phase angle). The controller can fulfil functions of reactive shunt compensation, series compensation and phase shifting meeting multiple control objectives. From a functional perspective, the objectives are met by applying a boosting transformer injected voltage and a exciting transformer reactive current. The injected voltage is inserted by a series transformer. The continuation power flow (CPF) method is robust; however has some weakness in large electric power system considering generators reactive power limits and gives information regarding how much percentage overloading the system can withstand before a possible voltage collapse. The CPF problem is incorporated into an OPF problem so that both the issues can be addressed simultaneously. In this paper, the voltage stability limit is defined as the maximum percentage overloading (λmax) the system can withstand and incorporated along with the objective of real power loss minimization. The classical techniques of OPF solution has the disadvantage that they are sensitive to starting points and leading to non-monotonic solution. To eliminate this problem evolutionary techniques have been applied in solving the OPF problem (10), (11) like particle swarm optimization (PSO) to the problem of OPF. In this paper a new evolutionary algorithm known as Shuffled Frog Leap algorithm (SFLA) is used to solve the combined problem of CPF-OPF for real power loss minimization and VSL maximization of the system. The algorithm has been inspired from memetic evolution of a group of frogs when seeking for food. In this method, a solution to a given problem is presented in the form of a string, called frog which has been considered as a control vector in this paper. The main objective is transformer taps optimization, location of UPFC and its series injected voltage for the single objective of real power loss minimization and then for the multiple objectives of loss minimization and VSL maximization. Finally, a cost analysis for installation of UPFC is carried out to establish the investment in putting a UPFC for the cause. Test results indicate that SFLA method can obtain better results than the simple heuristic search method on the 14-bus radial distribution systems.

Bacteria Foraging-Based Solution to Optimize Both Real Power Loss and Voltage Stability Limit

Optimal location and control of a unified power flow controller (UPFC) along with transformer taps are tuned with a view to simultaneously optimize the real power losses and voltage stability limit (VSL) of a mesh power network. This issue is formulated as a nonlinear equality and inequality constrained optimization problem with an objective function incorporating both the real power loss and VSL. A new evolutionary algorithm known as bacteria foraging is applied for solving the multiobjective multivariable problem, with the UPFC location, its series injected voltage, and the transformer tap positions as the variables. For a single objective of only real power loss, the same problem is also solved with interior point successive linearization program (IPSLP) technique using the LINPROG command of MATLAB. A comparison between the two suggests the superiority of the proposed algorithm. A cost effectiveness analysis of UPFC installation vis-agrave-vis loss reduction is carried out to establish the benefit of investment in a UPFC

Impact on Real and Reactive Power Pricing in Open Power Market Using Unified Power Flow Controller

Transmission pricing is an important issue in view of increased deregulation. A nonlinear optimization problem has been formulated to maximize the social welfare in the open power market using a unified power flow controller (UPFC) in this paper. With a static point of view, congestion management installation of UPFC requires a two-step approach. First, the proper location of these devices in the network must be ascertained and then the settings of its control parameters optimized for the required objective. Nodal spot prices for both real and reactive powers have been computed using optimal power flow solutions, and the impact of UPFC on the spot pricing have been studied. The effectiveness of the proposed methods is demonstrated on a test system.

Location of unified power flow controller for congestion management

This paper presents the development of simple and efficient models for suitable location of unified power flow controller (UPFC), with static point of view, for congestion management. Two different objectives have been considered and the results are compared. Installation of UPFC requires a two-step approach. First, the proper location of these devices in the network must be ascertained and then, the settings of its control parameters optimized. The effectiveness of the proposed methods is demonstrated on two test systems.