Unified Power Flow Controller Parameters Research Articles

Performance Analysis of Marine-Predator-Algorithm-Based Optimum PI Controller with Unified Power Flow Controller for Loss Reduction in Wind–Solar Integrated System

Transmission line losses are a crucial and essential issue in stable power system operation. Numerous methodologies and techniques prevail for minimizing losses. Subsequently, Flexible Alternating Current Transmission Systems (FACTSs) efficiently reduce transmission losses, and the Unified Power Flow Controller (UPFC) is a reactive power compensation controller. The parameter strength of the proportional–integral (PI) controller was calibrated with the Marine Predator Algorithm (MPA), a recent metaheuristic algorithm. An MPA-based optimum PI controller with a UPFC evaluates the optimal location of the UPFC and PI controller parameters to accomplish the desired research objective. The power rating of the UPFC was determined depending on the voltage collapse rating and power loss and an evaluated performance analysis of the MPA–PI-controlled UPFC on a modified IEEE-30 bus transmission network in MATLAB Simulink code. The Newton–Raphson method was used to perform the load flow analysis. Hence, the proposed MPA–PI controller was examined in contrast to preferred heuristic algorithms, the Artificial Bee Colony (ABC) and Moth Flame Optimization algorithms (MFO); the results showed that the MPA–PI controller exhibited better performance with an improved voltage profile and surpasses active power losses with the optimal placement of the UPFC device under different loading conditions. The active power loss, considering a UPFC with the proposed algorithm, reduced from 0.0622 p.u to 0.0301 p.u; consequently, the voltage profile was improved in the respective buses, and the loss percentage reduction during a 100% base load was 68.39%, which was comparatively better than the ABC and MFO algorithms.

Loss reduction of transmission lines using PSO-based optimum performance of UPFC

Transmission line losses are one of the essential topics and issues in power systems research. Several methods and techniques have been used to reduce these losses, and one of these modern techniques is flexible alternating current transmission systems (FACTS). In this paper, one of the most important types of this technology, the unified power flow controller (UPFC), was used to reduce losses in the Iraqi national grid (ING) 400 kV. This paper presents an efficient method for minimizing losses of transmission lines in the ING system (400 kV) 46-bus approach. A particle swarm optimization (PSO)-based optimum proportional-integral (PI) controller with UPFC was proposed to obtain the optimal location of UPFC and optimum parameters of the PI controller to achieve the objective function of the research. MATLAB coded the algorithm. The Newton-Raphson method was employed to perform load flow analysis. The results showed that the best place for UPFC is buses (14-17) named BGE4 (Baghdad)-AMN4 (Baghdad), and the total active power and reactive power losses decreased from 727.4593 to 579.3874 MW and from 5155.9 to 3971.1 MVAR, respectively and also led to voltage regulation.

Optimal UPFC Placement for Voltage Stability Enhancement

The Unified Power Flow Controller is a versatile and important device for improving the operational efficiency of power systems in the flexible AC transmission systems family. It finds applications in improving voltage stability in addition to provide a better voltage profile and reducing transmission loss. This paper presents a Chemical Reaction Inspired Optimization based method for placement of unified power flow controllers with the objective of raising the voltage stability. Most of the existing methods place all the given unified power flow controllers without analysing whether each of the given unified power flow controllers is actually needed to improve voltage stability or other selected performances. The proposed method tries to place only the essential unified power flow controllers from the allocated number of devices, besides providing optimal line locations and unified power flow controller parameters. It also includes the results of the proposed method for three standard test systems and compares them with existing methods to depict the dominance of the proposed method.

Optimal Power Flow Calculation of Active Distribution Network Based on Improved Comprehensive Technology

Comprehensive unified power flow controller ( UPFC ) technology can calculate voltage control parameters of UPFC, but it increases the nonlinearity of Newton power flow calculation. When the comprehensive technology is combined with the intelligent algorithm, the control parameters can only be optimized through the active and reactive power of UPFC on the branch, which makes the optimization convergence worse. Therefore, an optimal power flow calculation method for active distribution network based on improved comprehensive technology is proposed. First, based on the analysis of the influence of UPFC on branch power flow, an improved UPFC model is proposed. The accuracy of UPFC control parameters is enhanced by adjusting the voltage phase angle and regulation radius of series side transformer. Second, the optimal control model considering UPFC is established. Finally, the corresponding self-admittance and mutual admittance elements are extracted from the constructed UPFC model and introduced into the Jacobian matrix, so that while the comprehensive technology maintains the dimension of the Jacobian matrix, the intelligent algorithm can directly optimize the control parameters to reduce the search space. The IEEE33 bus system is used for example simulation, the results before and after the improvement are compared, and the Monte Carlo method is used to calculate the two algorithms 50 times respectively based on the installation number of UPFC, which verifies that the proposed optimization method has better convergence and operation speed.

Optimal location of UPFC based on sensitivity of CDF with power system’s stochasticity

In this paper, a stochastic sensitivity algorithm is introduced to optimize the location of unified power flow controller (UPFC) in large scale power grid. The stochastic sensitivities are defined as the total operation cost of power system to control parameters of UPFC. Firstly, probability optimal power flow (POPF) model with power system’s randomness is established. Then point estimate method (PEM) is utilized to solve the above problem, so that the stochastic sensitivities of UPFC in all possible transmission lines could be obtained. Finally, by sorting the influence degree of UPFC at different locations to cumulative distribution function (CDF) of operation cost, the optimal location for UPFC could be selected correspondingly. To this end, IEEE-5 and IEEE-14 systems are employed to verify our proposed approach. The results show that installing UPFC by the method in this paper could significantly reduce the probability distribution of operation cost in higher region.

Voltage Stability Improvement with finest position of UPFC using GA &PSO

Power system is a largely inter connected network, due to this interconnection some of the lines may get over loaded and voltage collapse will occur , hence these lines are called weak lines, this causes serious voltage instability at the particular lines of the power system. The improvement of stability will achieve by controlling the reactive power flow. The Flexible Alternating Current Transmission Systems (FACTS) devices have been proposed to effectively controlling the power flow in the lines and to regulate the bus voltages in electrical power systems, resulting in an increased power transfer capability, low system losses and improved stability. In FACTS devices the Unified Power Flow Controller (UPFC) is one of the most promising device for power flow control. It can either simultaneously or selectively control both real and reactive flow and bus voltage. UPFC is a combination of shunt and series compensating devices. Optimal location of UPFC is determined based on Voltage Stability Index (VSI). GA and PSO techniques are used to set the parameters of UPFC [6]. The objective function formulated here is fitness function, which has to be maximized for net saving. The results obtained using PSO on IEEE 14 Bus is compared with that of results obtained using GA, to show the validity of the proposed techniques and for comparison purposes

Optimal Allocation of UPFC and IPFC in Network Considering Sensitivity of Line Flows under Single Line Contingency

This paper presents, optimal location for deployment of Unified Power Flow Controller (UPFC) and Interline Power Flow Controller (IPFC) in network considering sensitivity of line flows under single contingency. A sensitive approach is proposed which is considered based on Ranking Index (RI) and Performance Index (PI). A unitary change of power flow (PF) in each transmission line after outage of a branch element can be obtained from proposed index. The proposed Index is used to quantify loading level of network after a given outage. Contingencies are structured in descending order depending on value of proposed Index. Sensitivity factors are obtained by differentiating PF indices subject to parameters of UPFC and IPFC devices. Optimal deployment of UPFC and IPFC device is considered by the value of sensitivity factors attained by considering line outages in order of their severities which is given by proposed Index. The efficacy of proposed approach is computed and programmed on 5bus and IEEE 14bus networks under MATLAB environment.

A Moth–Flame Optimization for UPFC–RFB-Based Load Frequency Stabilization of a Realistic Power System with Various Nonlinearities

In this article, a realistic multi-area multi-source test power system model is investigated by imposing the effects of nonlinearities for the betterment of automatic generation control (AGC) realization. The confined area of presented work is to cogitate the effectiveness of combined unified power flow controller (UPFC) and redox flow battery (RFB) in view of damping of oscillations subjected to increased load perturbation. The investigated power system model is a six-area system having reheat thermal, hydro and gas-generating units lumped together in each control area. The present prospect analyzes a very realistic approach of AGC by adding physical constraints like time delay, governor dead band, boiler dynamics, reheat turbine and generation rate constraint to the aforesaid system. A nature-inspired novel moth–flame optimization (MFO) algorithm is employed as an optimization tool in the design of proportional–integral–derivative gains and the tunable parameters of UPFC and RFBs. The substantial point of discussion is the guaranteed convergence mobility as the moths in this algorithm update their positions with respect to the flames which represent the most promising solutions. The MFO-based results are compared with genetic algorithm-based method to show the superiority of MFO over other similar metaheuristic optimization techniques. Robustness of the designed controller is also studied over ± 25% uncertainties in parametric values and under loaded condition. The simulation works showed that the inclusion of UPFC and RFB is very much effective in load frequency stabilization and is quite robust for a realistic power system.

A Three-Zone Distance Protection Scheme Capable to Cope With the Impact of UPFC

To improve the power transfer capability and reliability of the power grid, the unified power flow controller (UPFC) project has been put into operation in the western Nanjing power grid. Based on the practical project, the influence of UPFC on the distance protection is analyzed. To cope with that, the novel three-zone distance protection scheme is put forward. The zone 2 and zone 3 of the novel three-zone distance protection scheme are the same with those of conventional distance protection; however, the novel distance protection zone 1 is based on the parameter model of transmission line. According to the average value and fluctuation degree of the fault distance calculation results, the proposed distance protection zone 1 can effectively distinguish between the internal faults and external faults. More importantly, the proposed distance protection zone 1 can realize effective cooperation with the conventional distance protection zone 2 and zone 3, to construct a complete three-zone distance protection scheme and guarantee the correct operation of the novel three-zone distance protection scheme. The simulation cases in the PSCAD/EMTDC software environment verifies that the proposed three-zone distance protection has excellent performance, and would not be affected by the operational mode and control parameters of UPFC.

Congestion mitigation using UPFC

Transmission congestion is one of the most challenging issues in operation of deregulated electricity markets of today. This study investigates into benefit of unified power flow controller (UPFC) as a viable solution to the problem of congestion management. A comprehensive load flow model for the UPFC is presented which has the capability to control active and reactive powers and voltage magnitude simultaneously. This study discusses about two different approaches for determination of suitable location of UPFC. One of them is sensitivity-based approach and the other is pricing-based method. Reduction in total system losses has been taken as objective in sensitivity-based approach. Furthermore, sensitivity of total system losses with respect to control parameters of UPFC have been evaluated using two different methods. A pricing-based approach which makes use of locational marginal price difference and congestion rent for determination of suitable location of UPFC. Minimisation of cost of rescheduling subjected to system operating constraints is the objective to be met for congestion management. Interior point method, a mathematical tool for non-linear optimisation, is used to obtain the solution of above-mentioned problem.

Optimal Selection of UPFC Parameters and Input Controlling Signal for Damping Power System Oscillations

<p><em> </em>Unified power flow controller (UPFC), as one of the most important FACTS devices, can be used to increase the damping of power system oscillation. The effect rate of this controller on increasing oscillation damping depends on the appropriate selection of input controlling signal, optimal selection of UPFC controlling parameters, and its proper position in power system. In this paper, the capability of different UPFC inputs is studied by utilizing singular value decomposition (SVD) method and the best UPFC input controlling signal is selected. Supplementary control parameters are also optimally selected by PSO algorithm. This method's accuracy is simulated on a single-machine system connected to infinite bus.</p>

Optimal unified power flow controller application to enhance total transfer capability

For a power transfer path, total transfer capability (TTC) represents maximum power that can be transferred over the transmission system. Unified power flow controller (UPFC) is a device that can be used to increase in TTC. This study presents a new method for optimal UPFC application to minimise power loss while enhancing TTC. Based on UPFC injection model, the solution region of UPFC parameters is first found using the proposed method to maximise TTC. It then searches the solution region to find optimal UPFC control mode and setting to minimise system power loss. The proposed method is applied to the IEEE-Reliability Test System and the UPFC application impact are evaluated. Comparative studies are conducted between the TTC results obtained by the proposed method with those obtained using the existing approaches.

Robust placement and tuning of UPFC via a new multiobjective scheme‐based fuzzy theory

This article addresses a new modified honey bee mating optimization namely multiobjective honey bee mating optimization (MOIHBMO) based fuzzy multiobjective methodology for optimal locating and parameter setting of unified power flow controller (UPFC) in a power system for a long‐term period. One of the profits obtained by UPFC placement in a transmission network is the reduction in total generation cost due to its ability to change the power flow pattern in the network. Considering this potential, UPFC can be also used to remove or at least mitigate the congestion in transmission networks. The other issue in a power system is voltage violation which could even render the optimal power flow problem infeasible to be solved. Voltage violation could be also mitigated by proper application of UPFC in a transmission system. These objectives are considered simultaneously in a unified objective function for the proposed optimization algorithm. At first, these objectives are fuzzified and designed to be comparable against each other and then they are integrated and introduced to a MOIHBMO method to find the solution which maximizes the value of integrated objective function in a 3‐year planning horizon, considering the load growth. A power injection model is adopted for UPFC. Unlike, the most previous works in this field the parameters of UPFC are set for each load level to avoid inconvenient rejection of more optimal solutions. IEEE reliability test system is used as an illustrative example to show the effectiveness of the proposed method. © 2014 Wiley Periodicals, Inc. Complexity 21: 126–137, 2015

Multilayer feed-forward neural network approach for optimal dispatch of UPFC embedded pool-bilateral electricity market

The significance and influence of bilateral component on optimal dispatch of mixed pool-bilateral electricity market is the major issue to be examined for trade-off between pool and pre-specified bilateral transactions. This paper proposes single part optimal dispatch model that dispatches pool in coordination with privately negotiated bilateral transactions while minimizing cost of generation, accounting power balance equality constraints and inequality constraints. The critically loaded transmission line is identified, and when Unified Power Flow Controller (UPFC) is placed in it, optimal dispatch solution gets modified because of incorporation of UPFC parameters in the developed formulation. The methodology of multilayer perceptron network is adopted in this work with inputs to the neural network as percentage of bilateral component and status of UPFC for online evaluation of generation cost and incremental cost. The network is trained with back propagation training algorithm, and for IEEE 30 and IEEE 118 bus systems, it is established that Levenberg–Marquardt algorithm outperforms other algorithms in terms of accuracy. Copyright © 2014 John Wiley & Sons, Ltd.

TRANSIENT STABILITY IMPROVEMENT OF MULTI-MACHINE POWER SYSTEM USING UPFC TUNED-BASED PHASE ANGLE PARTICLE SWARM OPTIMIZATION

Optimal computation of parameters and placement of UPFC based minimization of New VoltageStability Index (NVSI) are presented in this paper. The application of Unified Power FlowController (UPFC) to enhance transient stability of a multi-machine power system is listed. Asupplementary stabilizer based on UPFC (like power system stabilizer) is designed to reach thedefined purpose. Phase Angle Particle Swarm Algorithm (θ-PSO) is used as an optimizationmethod. Several nonlinear time-domain simulation tests visibly show UPFC capability in dampingof power system oscillations and consequently transient stability betterment. Comparisons basedsystem transient stability enhancement among different UPFC locations and parameters areintroduced. The effectiveness of the proposed method is analyzed with IEEE 14-bus and IEEE 30-bus test systems.

A Review on Controllable Parameters of UPFC for Power Quality Methods ? Real Time Application

As a fact, steady state model of flexible alternating current transmission system (FACTS) devices have been used in many studies to improve power flow capability (PFC) in the transmission lines. Among FACTS devices, UPFC is the most versatile and efficient device. Two important considerations within UPFC are proper placement of FACTS devices is very important for the rapid and successful operation because of high cost and circuit complexities & To obtain damping of sustained oscillation in the power system with the help of Unified Power Flow Controller (UPFC). This research proposal propose an efficient way to optimize the placement of UPFC within distribution system, best location of UPFC (Unified Power Flow Controller) should calculate both for static and transient voltage stability enhancement. Also within the proposed work, the linear model of the UPFC is taken and the tuning of the controllable parameters is done with the help of multi-objective genetic algorithm. Also, splendid improvement in robust damping should observed with proposed implementation by comparing the proposed work with traditional UPFC which we are going to implement in Kanpur grid and Kanpur SVC.

A PSO-Based Fuzzy Long-Term Multi-Objective Optimization Approach for Placement and Parameter Setting of UPFC

This paper presents a Particle Swarm Optimization (PSO)-based fuzzy multi-objective methodology for optimal locating and parameter setting of Unified Power Flow Controller (UPFC) in a power system for a long-term period. One of the profits obtained by UPFC placement in a transmission network is the reduction in total generation cost due to its ability to change the power flow pattern in the network. Considering this ability, UPFC can be also used to remove or at least mitigate the congestion in transmission networks. The other issue in a power system is voltage violation which could even render the optimal power flow problem infeasible to be solved. Voltage violation could be also mitigated by proper application of UPFC in a transmission system. These objectives are considered simultaneously in a unified objective function for the proposed optimization algorithm. At first, these objectives are fuzzified and designed to be comparable against each other and then they are integrated and introduced to a PSO Algorithm to find the solution which maximizes the value of integrated objective function in a 3-year planning horizon, considering the load growth. A power injection model is adopted for UPFC. Unlike the most previous works in this field the parameters of UPFC are set for each load level to avoid inconvenient rejection of more optimal solutions. IEEE Reliability Test System is used as an illustrative example to show the effectiveness of the proposed method.

Controlling of UPFC Parameters Using Fuzzy Logic Based Supplementary Damping Controller

In this paper, use of the additional supplementary damping controller for unified power flow controller (UPFC) to damp out low frequency oscillations in a heavily loaded power system is investigated. Normal damping controllers are inferior when the power system is subjected to large and fast changing loads. In order to handle the situation, an additional supplementary damping controller for UPFC is designed using Fuzzy logic technique. The effectiveness of the proposed controller on damping low frequency oscillations is tested and demonstrated through simulation studies for single machine connected to infinite bus power system (SMIB). In addition power system response with UPFC damping controller & Fuzzy logic based supplementary damping controller (FLSDC) are compared at various loading conditions. It can be concluded that Fuzzy logic based supplementary damping controller improves greatly the system stability under heavily loaded conditions.

Application of genetic algorithm in optimization of unified power flow controller parameters and its location in the power system network

This work demonstrates the application of Genetic Algorithm (GA) technique for the simultaneous stabilization of power systems using a Unified Power Flow Controller (UPFC). The GA is applied to find the optimal location of the UPFC and to tune its control parameters under different operating conditions. The problem is formulated as a multiobjective optimization problem which aims at maximizing the damping ratio of the electromechanical modes using different lines fitted with the UPFC. The approach is successfully tested on the 16-machine 68-bus New England–New York interconnected system and on the Iraqi National Super Grid System (INSGS) to validate its effectiveness in the damping of local and inter-area modes of oscillations. In addition, the proposed approach demonstrated better performance when compared to a fuzzy-based UPFC damping controller.

Optimal Location of FACTS Device on Enhancing System Security

In this paper a Unified Power Flow Controller (UPFC) is a FACTS device that can be control the power flow in transmission line by injecting active and reactive in voltage components in series with the lines.The proposed methodologies are based on the use of line loading security Performance Index (sensitivity factors have been suggested in this paper for optimal placement of UPFC.This methods are computationally efficient PI sensitivity factors have been obtained with respect to change in two of the UPFC parameters viz., magnitude and phase angle of the injected voltage in the lines. The proposed methodologies are tested validated for locating UPFC in IEEE 30-bus system.ACO based Optimal Power Flow (OPF) formulation has been suggested to determine the optimal PI values, after placement of UPFC based on the proposed sensitivity factors. Both AC and DC power flow approximations have been used to define the sensitivity factors and their results have been compared on IEEE 30-bus system. DOI: http://dx.doi.org/10.11591/ijece.v2i3.250