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In this paper, authors focus on the use of the synchronous condenser device for voltage stability and power flow control on a three-phase 33 kV Medium Voltage (MV) electric-power system network. Matlab/Simulink is used for the simulation of the proposed system model. To test the validity of the system, measured and calculated power factor values were obtained. Two scenarios were studied; Firstly,...
In this paper we are discussing about a FACTS device named as UPFC (unified power flow controller). Its special features are to control active and reactive power course in a transmission line and to adjust the voltage at the bus at which it is situated. This device gives great quality flow on power system stability; these features even more considerable and perceptive that the unified power flow controller...
In this paper, the combination of fuzzy logic controller and genetic algorithm are proposed. A fuzzy control system is a control system based on fuzzy logic a mathematical system that analyzes analog input values in terms of logical variables. The purpose of fuzzy system is to determine the capacity of interline power flow controller (IPFC) in terms of voltage deviation. The optimal location of IPFC...
Voltage control and stability are important aspects in the day to day operation of modern stressed power system networks. Unified power flow controller (UPFC) is an important FACTS device, which can simultaneously control the voltage at a bus and the active and reactive power flow through the transmission line to which it is connected. The variables of the UPFC must be controlled in accordance with...
The integration of renewable energy sources in power systems has steadily increased in the recent years in the vision of significantly decreasing the carbon emissions produced by the conventional power plants. Although the incorporation of the renewable energy sources in the power system network is environmentally beneficial, at the same time it poses some challenges regarding their smooth operation...
This paper presents a survey of the impact of large-scale wind power plants on the identification of Voltage Control Areas (VCAs). A Monte-Carlo based framework is proposed for the probabilistic analysis of variations in the arrangement of the VCAs, the critical buses as well as of estimation of the statistical properties of the loading margin. Test results, performed on the IEEE 39-bus system, showed...
In fully developed transmission power system, with networks overlaid with higher voltage transmission lines, power flows are predetermined by the network impedances, and generally cannot be controlled. Usually networks are developed initially using certain transmission voltages, and when lesser and lesser improvements in the transfers are realized, higher voltages are introduced. If the network that...
Monitoring and maintaining voltage stability in real-time is extremely important for operating a power system reliably. Inadequate voltage support was a contributing factor in several major blackouts in North America, including the 1996 Western Interconnection and the 2003 North East US /Canada blackout. The RTDMS enables monitoring of voltage stability over a wide area using SynchroPhasor technology...
This paper presents an on-line equivalent algorithm for power system based on phasor measurement unit. The method considers the changes of the system parameters and load level, which overcome parameters rift problem and the shortage of traditional two points power flow method that supposing the parameters are fixed after a small disturbance. On this basis, voltage stability and Alert margin are proposed,...
The power source in micro-grid (MG) is either atmosphere dependent source (e.g. wind generator, solar etc.) or it will be small hydro or diesel turbine. This introduces power quality concerns in MG. It is because of small power number (MW per Hz.) due to limited size of the system and limited resources for system stability. In this paper, a new application of the UPFC is introduced. The slightly modified...
This paper suggests an exact approach to deal with static assessment of Available Transfer Capability (ATC). It caters an expanded Newton Raphson-seydel (NRS) to see the problem from different point of view. Conventional Newton Raphson (NR) method has the singularity problem over its Jacobian matrix and thus could fail to get the solution. Continuation Power Flow (CPF) method is a very powerful method...
Increasing wind power penetration into power grids is desirable because of its environmental and other benefits, unfortunately wind farms could cause serious voltage stability problems due to their output variability and intermittency. So this paper proposes a method that determines the optimum penetration level of wind plants into power systems. To achieve this purpose, a nonlinear optimization problem...
Several papers have recognized the effect of uncertainties in system parameters on voltage stability analysis through probabilistic methods. In these papers, the unstable states are identified by the unsolvability of the power flow equations or the violation in the Voltage Stability Margin (VSM) minimum limit. However, voltage stability problems may also be associated with the loss of voltage controllability,...
Smart grids offer a wide application domain for power electronics. In fact, every distributed energy resource (DER) includes an electronic power processor (Switching Power Interface, SPI) which controls the currents drawn from the grid and can be driven to optimize the power flow, improve voltage stability and increase distribution efficiency. For these aims, such distributed SPIs must perform cooperatively...
The connection of distributed generation, mainly at the lower voltage levels, is transforming the legacy network. The evolution of the network has to overcome the problems associated with the integration of distributed generation. These problems include the management of the network's voltage, reactive and active power flows, fault current, power quality, and frequency and voltage stability issues...
A very simple and fast method for computing power systems maximum loading points is proposed in this paper. These points are simply computed through repeated load flow solutions. The main contribution resides in the appropriate use of a special load flow with step size optimization and the extraction of useful information from it, which guides the search for the desired maximum loading point. The...
A very simple and fast method for computing power systems maximum loading points is proposed in this paper. These points are simply computed through repeated load flow solutions. The main contribution resides in the appropriate use of a special load flow with step size optimization and the extraction of useful information from it, which guides the search for the desired maximum loading point. The...
After some disastrous instabilities and blackouts, power system voltage stability has drawn even more attention. When a serious fault occurs, proper control should be quickly adopted to terminate the system deterioration. In this paper, a control method based on power flow tracing is presented to enhance power system voltage stability. Firstly, a branch-admittance-decreasing algorithm is introduced...
Considering the dynamic characteristic of wind farms, especially the wind turbines' output fluctuate with wind speed, the optimal reactive power compensation problem for wind farms is formulated and solved by genetic/tabu search hybrid algorithm (GATS). A mathematical model of reactive power compensation, focused on voltage stability and power losses of wind farms, is developed, and the reactive power...
A robust and efficient tool for computing the voltage stability margin of distribution systems is proposed in this paper. This margin corresponds to the distance from the current operating point to the maximum loading point in load parameter space along a predefined load increase direction. This tool is based on computing the voltage stability index of a two-bus equivalent circuit for predicting load...
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