Incorporation of Current Injection Modelling of Upfc And Analyzing Power Flow Solution Using Criss Cross Optimization Algorithm

This paper presents a multiobjective optimization methodology to find the optimal location for an optimal unified power flow controller (OUPFC) device. Moreover, the installation cost function of the OUPFC device is developed. The objective functions are the total fuel cost, power losses, and system loadability with and without the minimum cost of the OUPFC installation. The \varepsilon-constraint approach is implemented for the multiobjective mathematical programming formulation. The proposed algorithm is implemented in the IEEE 30- and 118-bus test systems. The solution procedure uses nonlinear programming to optimally locate the OUPFC incorporated in an optimal power flow problem considering these objective functions and improves the operation of the power system. The optimization problem is modeled in the general algebraic modeling system software using a MINOS solver. Furthermore, the results obtained by the OUPFC are compared to those of the phase shifting transformer (PST) and unified power flow controller (UPFC) devices. The performance and applicability of the OUPFC is highlighted compared to the PST and UPFC from an analytical and technical point of view.

The introduction of the flexible AC transmission system (FACTS) in the power system reduces the losses, reduces the cost of the generation, improves the stability and also improves the load capability of the system. Some application of the Flexible AC transmission system (FACTS) technologies to existing high voltage power system has proves the use of FACTS technology may be a cost effective option for power delivery system enhancement. Amongst various power electronic devices unified power flow controller (UPFC) may be considered to be a capable of regulating the power flow and minimizing the power loss simultaneously. Since for the cost effective application of the FACTS technology a proper selection of the number and the placement of these devices is required. The main aim of this paper is to propose the methodology based on the genetic algorithm, able to identify the optimal number and the location of the UPFC devices in an assigned power system network for maximizing system capabilities. In order to validate the usefulness of the approach suggested here is , a case study using a IEEE 30-bus power system is presented and discussed.

The increases in power flows and environmental constraints are forcing electricity utilities to install new equipment to enhance network operation. Some application of Flexible AC Transmission System (FACTS) technologies to existing high-voltage power systems has proved the use of FACTS technology may be a cost-effective option for power delivery system enhancements. Amongst various power electronic devices, the unified power flow controller (UPFC) device has captured the interest of researchers for its capability of regulating the power flow and minimizing the power losses simultaneously. Since for a cost-effective application of FACTS technology a proper selection of the number and placement of these devices is required, the scope of this paper is to propose a methodology, based on a genetic algorithm, able to identify the optimal number and location of UPFC devices in an assigned power system network for maximizing system capabilities, social welfare and to satisfy contractual requirements in an open market power.In order to validate the usefulness of the approach suggested herein, a case study using a IEEE 30-bus power system is presented and discussed.

This paper presents a formulation of the Optimal Power Flow problem with an explicit modeling of Static Var Compensator (SVC) and Unified Power Flow Controller (UPFC) devices. The optimization problem is solved by using Sequential Quadratic Programming, where two convergence criteria and four different methods are studied to solve the quadratic subproblems. The proposed model is integrated in an object-oriented based decision support platform for competitive power markets. Validation of the method and practical applications to real longitudinal systems are discussed, where FACTS location and a UPFC-based interconnection are described. Results show the impact of SVC and UPFC FACTS technologies in the physical and economic behavior of a real system.

The Unified Power Flow Controller (UPFC) is the most complex and powerful FACTS device, which can provide full or independent control of line transmission parameters, such as voltage, line impedance and phase angle. In this paper, steady-state model of unified power flow controller (UPFC) and power flow algorithm of power system with UPFC were studied. The parallel and series sides of UPFC were equivalent to separate power injections, and an alternating iteration algorithm of power flow for power system with UPFC was presented. In order to improve the convergence of the algorithm, this paper analyzes the impact of UPFC’s various control strategies on the convergence of power flow calculations, and proroses a control strategy for converting constant power control to constant variable control during the iterative process. Based on the actual project of Nanjing Western UPFC, the correctness and effectiveness of the model and algorithm are verified.

Application of the injection modeling approach to power flow analysis for systems with unified power flow controller

This paper evaluates critically the operational aspects of multi-infeed HVDC network during various conditions such as ESCR variation and faults at any one of the remote converter terminals. The study reveals that FACTS controllers may significantly improve operational reliability under dynamical changes. It has been demonstrated through extensive simulation studies that voltage and power in the multi-infeed network is regulated effectively with Unified Power Flow Controller (UPFC). During course of investigation, this has been found that an appropriate integration of a tuned UPFC in multi-infeed network greatly helps not only to optimize the power flow in the AC transmission lines maintaining voltage and power stability during sudden loss of generator or fault in the network but also assists in smooth multi-infeed converter operation with least excursions on converter controls. A sample multi-infeed HVDC network with UPFC is modelled in PSCAD/EMTDC environment and the simulation results demonstrate significant contribution of UPFC controller for effective oscillation damping even in weak AC system conditions and also recovery after fault is cleared.

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, which 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 illustrate the technique

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

This paper proposes a novel model of unified power flow controller (UPFC) for enhancing voltage stability margin of the power systems. This model is based upon an innovative approach where, real power exchange of series and shunt elements of UPFC are decoupled with each other. The UPFC model is incorporated into an existing Newton-Raphson load flow algorithm and Jacobian matrix is modified to include the decoupled modes of power exchange of series and shunt elements of UPFC. The modeling approach presented in this paper is tested on standard IEEE 30-bus and IEEE 118-bus systems to validate its feasibility.

New approach for optimal UPFC placement using hybrid immune algorithm in electric power systems

SUMMARY The task of modelling and locating steady-state unified power-flow controllers (UPFCs) for static voltage stability enhancements in power system planning is addressed. A hybrid UPFC model for power flow studied is proposed. The series side of the UPFC is represented by an ideal voltage source, while the shunt side is represented by an idea current source model. Equivalent relationships among our new models and existing models will also be investigated. Integrations of this hybrid UPFC model into existing Newton-type power-flow solvers are presented. Extensions of continuation methods for locating the voltage collapse point of power systems embedded with UPFCs are studied. Strategies of determining the UPFC rating and locations for voltage stability enhancements will also be discussed. Numerical demonstrations of IEEE 300-bus test system and Taiwan power system are performed to verify the correctness of the proposed UPFC model and the computational tool. Copyright © 2012 John Wiley & Sons, Ltd.

Objective: The goal of this project is to provide an advanced optimization approach for Dynamic Power Dispatch (DPD) by combining a Unified Power Flow Controller (UPFC) with a Genetic Algorithm (GA). The main objective is to improve power flow management and grid performance in complicated power networks. Methodology: The suggested method takes advantage of the capabilities of the UPFC, a versatile component of the Flexible AC Transmission System (FACTS), and combines them with the optimization power of GA. The UPFC provides close oversight over power flow, voltage ranges, and phase angles, while GA, known for its ability to solve multi-objective and nonlinear problems, improves the UPFC’s installation and operational settings. The effectiveness of this hybrid technique is proven by simulations using the IEEE 14-bus test system. Findings: Simulation results demonstrate that the integration of GA with UPFC yields significant improvements in power flow stability, reduces operational costs and transmission losses, and enhances voltage profiles compared to conventional DPD techniques. Furthermore, the approach increases grid flexibility and stability, addressing the evolving demands of modern power networks. Novelty: This study introduces a unique combination of UPFC and GA to address the challenges in DPD. The approach merges the real-time control capabilities of UPFC with the evolutionary optimization strengths of GA, presenting a scalable and adaptive solution for power dispatch optimization. Applications: The proposed technique is especially useful for improving the efficiency and reliability of current power grids, including those that use renewable energy sources. Its use in smart grid scenarios can help accelerate the transition to more sustainable and resilient energy systems. Keywords: Dynamic power dispatch; Unified Power Flow Controller; Genetic Algorithm; power system optimization; FACTS devices; and an IEEE 14bus testing system

This paper presents a study based on versatile bio-inspired metaheuristic stud krill herd (SKH) algorithm to tackle the optimal power flow (OPF) problems in a power system network. SKH consists of stud selection and crossover operator that is incorporated into the original krill herd algorithm to improve the quality of the solution and especially to avoid being trapped in local optima. In order to investigate the performance, the proposed algorithm is demonstrated on the optimal power flow problems of IEEE 14-bus, IEEE 30-bus and IEEE 57-bus systems. The different objective functions considered are minimization of total production cost with and without valve point loading effect, minimization of active power loss, minimization of L-index and minimization of emission pollution. The OPF results obtained with the proposed approach are compared with the other evolutionary algorithms recently reported in the literature.

This chapter proposes a newly improved particle swarm optimization (IPSO) method for solving optimal power flow (OPF) problem. The proposed IPSO is the particle swarm optimization with constriction factor and the particle’s velocity guided by a pseudo-gradient. The pseudo-gradient is to determine the direction for the particles so that they can quickly move to optimal solution. The proposed method has been tested on benchmark functions, the IEEE 14-bus, IEEE 30-bus, IEEE 57-bus, and IEEE-118 bus systems, in which the IEEE 30-bus system is tested with different objective functions including quadratic function, valve point effects, and multiple fuels. The test results have shown that the proposed method can efficiently obtain better total costs than the conventional PSO method. Therefore, the proposed IPSO could be a useful method for implementation in the OPF problem.