Abstract: Load flow studies are the backbone of power system analysis and design. They are necessary for planning, operation, optimal powerflow and economic scheduling and power exchange between utilities. This paper describes modelling procedure and present models of system components used in performing load flow analysis. The developed models are joined together to form a system network representing an approximate Tanzanian power network model. A load flow problem is formulated using the model and a MATLAB program developed using Newton-Raphson algorithm is applied in solving the problem. Simulation results are presented and analysed. The results indicate that the voltage magnitude and voltage phase angle profiles are within the operating limits of the system; it means that the selection of system components and modelling process is appropriate and accurate. The results will form the basis of other critical power system studies of the network in the future such as power system state estimation, optimal powerflow and security constrained optimal powerflow studies.
Optimal powerflow is one of the important methods used to increase the powerflow between the buses. OPF is not only to increase the powerflow in the system, but also to generate power based on the requirement with low cost. The powerflow between the buses can also be increased by connecting FACTS controller in suitable places. By considering the above problems, here a new method for OPF with FACTS controller using Mat Lab Simulation was proposed. Initially, the load flow between the buses is calculated using Newton raphson method and then the amount of power to be generated by each generator is computed using PSO. Finally, the FACTS controller is placed in a suitable location using PSO and Fuzzy Controller to increase the powerflow between the buses. The process that takes place in the proposed method is explained briefly in the below sections.
It is clear from eq (5) that the terms representing the J(X (i-1) ) are the Jacobian elements which are the Partial derivatives of real and reactive powers with respect to the known state variables X (V and θ). Proper selection of initial values for X is important factor to reduce iterative process, which will be continued until ∆X given in eq. (6) attains the value that should be within the prescribed tolerance. And at this popint X(i) (V’s, ∆’s) given in eq. (7) gives the feasible solution of load flow problem.
The state of power system and the methods of calculating this state are very important in evaluating the operation and control of power system and determination of future expansion for this system. The state of any power system can be determined using load flow analysis that calculates the power flowing through the lines of the system. Developments have been made in finding digital computer solutions for power-system load flows. This involves increasing the reliability and the speed of convergence of the numerical-solution techniques. There are different methods to determine the load flow for a particular system such as Gauss-Seidel, Newton-Raphson and Fast decoupled methods .
residual is reduced by more than one order of magnitude in the first few iterations) and then stagnates for a while before exhibiting the quadratic convergence behavior. Clearly, the finer the grid, the longer the stagnation period becomes. To understand how INB updates the intermediate solution during the stagnation period, we focus on the case with grid size equals to 1/128. INB takes 223 steps to converge, and the 11 selected Mach curves corresponding to the computed velocities are shown in Fig. 4.1 (right). It is interesting to observe that at most grid points the solution convergence happens after the second INB iteration, and the rest of the INB iterations are devoted exclusively for grid points near the shock. Note that, practically speaking, after the second INB, the Newton corrections are needed only in the neighborhood of the shock, but the Newton calculations (including the nonlinear residual evaluation and the Jacobian solve) are actually carried out for the whole computational domain. This is clearly a waste of computation!
In this paper, the existing ERP system of electric power production enterprises restricts the production scheduling and coordination of the company, and puts forward a construction plan of the business process monitoring APP of electric power production enterprise. Through the software's real-time network to ensure that the progress of the production process can be the first time in the APP display to ensure that the departments can be the shortest possible time to make the appropriate response and work arrangements. Enterprise departments and managers through the APP can be real-time view of the progress of each project, and to achieve each department can be through the APP software to complete some of the daily work of the coordination of various departments function, improve efficiency and enhance business efficiency.
ABSTRACT:The main objective of this thesis is to simulate and analyze the 220 KV Substation. The simulation and analysis includes powerflow analysis and short circuit analysis. Powerflow study also known as load flow constitutes an important part of power system analysis and design of any power system network. The powerflow analysis and short circuit analysis is done in the Power World Simulator Software. For the powerflow analysis using the single line diagram of 220 KV substation, the model of the substation is developed in the Power World Simulator. The different kinds of faults are also simulated at various buses of the substation. Power World Simulator is very useful software for analyzing power system operation. By doing the powerflow analysis in the Power World Simulator we estimate the real and reactive power flows, power losses in the entire network and phase angle using Power World Simulator. Short circuit analysis is also useful to select, set, and coordinate protective equipment such as circuit breakers, fuses, relays, and instrument transformers. Simulation technique is very useful in the power system planning and design.
the frequency. Also, the conventional assumption to classify the droop bus (the bus at which the DG is connected) either as slack, PV or PQ bus in a powerflow is invalid as the active and reactive powers as well as the voltage magnitude and angle of the droop bus are not pre-specified and depend upon the system parameters so conventional methods are not applicable in case of an islanded microgrid –. Thus, new methods have been proposed to solve the powerflow analysis for islanded microgrids –. These methods take into account the droop characteristics of DGs. A new powerflow formulation that incorporates the droop bus has been presented as a set of nonlinear equations and solved using a globally convergent Newton-trust region method in . In , the algorithm was modified by introducing a virtual impedance in the droop model. In , a novel load flow technique that utilizes particle-swarm is proposed for islanded microgrids. The proposed methods are accurate but are complex and not easy to implement and extend for power system studies. Fur- thermore, these papers suggest that the conventional methods cannot be applied to islanded microgrids. In  and , powerflow for an islanded microgrid is solved using the conventional approach in which the DG with highest rating is selected as the slack bus while other DGs are represented as PV or PQ buses. The method considers the frequency in an islanded microgrid to be constant. Other powerflow methods, such as backward/forward sweep (BFS) method, proposed in – are specifically designed for distribution systems. However, the applications of BFS method and its variants are only limited to radial and weakly meshed distribution systems –.
In this paper, an iterative technique is proposed to solve linear integrated active/passive design problems. The optimality of active and passive parts leads to the nonlinear algebraic Riccati equation due to the active parameters and some associated additional Lyapunov equations due to the passive parameters. Rather than the solution of the nonlinear algebraic Riccati equation, it is proposed to consider an iterative solution method based on the Lyapunov equations in the Newton optimization scheme for both active and passive parameters. The main contribution of the paper is considered as the concept that it doesn't require to optimize controller when the plant is not optimal. The proposed method is verified by designing a one-quarter active suspension system. The results indicate that the algorithm is more efficient as compared to solving the problem through the direct Riccati solution based method while its derivation and application is simple. Significant improvements can be seen in comparison to the previous method.
The FACTS devices represent a relatively new technology for power transmission systems. They provide the same benefits as conventional compensators with mechanical switches (circuit breaker) in steady state power system operation; in addition, they improve the dynamic and transient performance of the power system. This is achieved by fast switching time and repeatable operation of solid state switches as compared to mechanical switches. The switching time of solid state switch is a portion of a periodic cycle; and this is much faster than that of a circuit breaker with a switching time of a number of cycles. Generally, the main objectives of FACTS are to increase the useable transmission capacity of lines and control powerflow over designated transmission routes. The powerflow over a transmission line depends mainly on three important parameters, namely voltage magnitude of the buses (V), impedance of the transmission line (Z) and phase angle between buses (θ). The FACTS devices control one or more of the parameters to improve system performance by using placement and coordination of multiple FACTS controllers in large-scale emerging power system networks to also show that the achieve significant improvements in operating parameters of the power systems such as, small signal stability, transient stability, damping of power system oscillations, security of the power system, less active power loss, voltage profile, congestion management, quality of the power system, efficiency of power system
________________________________________________________________________________________________________ Abstract - With the perspective of the developing Smart grid notions, the upcoming distribution network will require repetitive and fast load flowsolution that must be resolved as proficiently as possible in some applications frequently in distribution planning, automation, optimization of power system etc. This induces the continued exploration for precise and fast powerflow procedures for distribution networks. In this paper a novel and effective method for power-flowsolution of radial distribution networks is presented. This method is based on formulation of two matrices bus injection to branch current matrix and branch current to bus voltage matrix and load flowsolution is obtained by simple multiplication of matrices in matlab platform. The proposed method is robust and proficient and effectiveness of proposed method is demonstrated by solving a 33-bus radial distribution system.
Abstract: - This paper describes Crow Search Algorithm (CSA), inspired by the intelligent behaviour of crows to solve Optimal PowerFlow (OPF) problem. CSA is a population-based method; works on behaviour of crows how to retrieve their reserve food in secrete places when the food is needed. OPF is the most familiar problem in power system optimization. The OPF problem formulation includes various constraints like generator, active power; reactive power limits and also valve point loading. The proposed method developed on the IEEE 14-bus, 30-bus and 26-bus power systems for optimize the cost of generation, emission and active power loss in single objective optimization space. The optimal results are compared to those informed in the literature. The results prove that the CSA has faster convergence and lesser cost as compared with other OPF solution methods. Keywords: - Crow Search Algorithm, Optimal PowerFlow, Emission, Active power loss, Valve-point loading. ----------------------------------------------------------------------------------------------------------------------------- ---------- Date of Submission: 18-12-2018 Date of acceptance: 03-01-2019 ----------------------------------------------------------------------------------------------------------------------------- ----------
Many numerical approaches have been suggested to solve nonlinear problems. Some of the methods utilize successive approximation procedure to ensure every step of computing will converge to the desired root and one of the most common problems is the improper initial values for the iterative methods. This study evaluates Palancz et.al’s. (2010) paper on solving nonlinear equations using linear homotopy method in Mathematica. In this paper, the Newton-homotopy method using start-system is implemented in Maple14, to solve several nonlinear problems. Comparisons of results obtained in terms of number of iterations and convergence rates show promising application of the Newton-homotopy method for nonlinear problems.
This method utilizes again the simple projection but has the drawback that it does not always produce a descent in the objective function. Bertsekas  and  introduced for the nite dimensional case with simple constraints such as upper and lower bounds on the variables a projected Newton method which alleviated this problem. For H = R n let
¾ Business process‐driven applications—as opposed to business function packaged applications—follow the latest IT paradigm: service orientation architecture. Together, BPM and SOA define a new IT world, which drives innovation and efficiencies using existing IT assets and producing results within months. The new paradigm promotes loosely coupled IT systems that replace the previous tightly integrated, hardwired packaged applications. Packaged applications are broken down into services of different granularities. These services are orchestrated on the process level and are simply consumed in a way that supports optimized business processes. For example ORACLE implemented The industry‐leading modeling and simulation engine—Oracle Business Process Analysis Suite—which shares the same metadata format with the process execution engine and helps business and IT to seamlessly collaborate. Similarly, Oracle BPEL Process Manager—for human workflow‐ and application‐ driven integration tasks with BPEL; part of the Oracle SOA Suite.
In order to investigate the feasibility of the proposed technique, a large number of power systems of different sizes and under different system conditions have been tested. It should be pointed out that the results are under so- called normal powerflow, i.e. the control parameters of UPFC are given and UPFC is operated in an closed -loop form. All the results indicate good convergence and high accuracy achieved by the proposed method. In this section, the IEEE 5-bus system and a 14-bus practical system have been presented to numerically demonstrate its performance. It have been used to show quantitatively, how the UPFC performs. The original network is modified to include the UPFC. This compensates the line between any of the buses. The UPFC is used to regulate the active and reactive power flowing in the line at a pre specified value. The load flowsolution for the modified network is obtained by the proposed powerflow algorithm and the Matlab program is used to find the control setting of UPFC for the pre specified real and reactive powerflow between any buses and the powerflow between the lines are observed the effects of UPFC. The same procedure is repeated to observe the powerflow between the buses. (Depending on the pre specified value of the active and reactive power the UPFC control setting is determined after the load flow is converged.).
In this paper, we introduce a new method, E- Ψtc. By two examples, one of them is a tough nonlinear equation; another one is super lager scale ill-conditioned linear equations. These results fully demonstrate the capability of the new method. For Load Flow Problems, the preconditioning technique is needed. If the system is ill-condi- tioned, using 2-dimension block diagonal preconditioning. For well-conditioned problems, use point diagonal preconditioning. As for the reliability, we compare our results with the results of existing methods and find that they are basically coincident (we did not list the results of the 43-bus).
The FACTS controllers clearly enhance power system performance, improve quality of supply and also provide an optimal utilization of the existing resources. This paper discusses the development of a Thyristor Controlled Series Capacitor (TCSC) with open loop control system. The TCSC circuit and characteristics are discussed in brief. Next the determination of TCSC parameters is discussed. With these parameters the capacitive mode of operation of TCSC is simulated and implemented on a power system model with 300 km long transmission line. MATLAB R2006b software had been used as the simulation tool. Results of simulation made are discussed. Significant enhancement in the power transfer capability of transmission line is
A wide variety of ZnO nanostructures have been syn- thesized by the various techniques and are reported in the literature till date [12-14]. Recently, self-catalysis of Zn or ZnO was discovered in the catalyst-free methods for preparing ZnO nanostructures. So far, nanocrystalline ZnO with different particle morphologies and sizes has been obtained by several preparation approaches includ- ing thermal decomposition, chemical vapor deposition (CVD), pulsed laser deposition (PLD), gas phase reaction, hydrothermal synthesis and so on. However, these meth- ods are expensive and require high vacuum and forma- tion controlling conditions. Recently, solution phase rou- tes including microemulsion, solvothermal, hydrothermal, self-assembly and template assisted sol-gel process have been employed to synthesize ZnO nanostructure . Among the fabrication methods, solution deposition me- thod is the simplest, cheapest and the most attractive one. Our work is focused on the growth of ZnO nanostructure using aged sol-gel solution of zinc acetate di-hydrate. This work reports on improvement in optical and crys- tallographic properties of ZnO nanostructure using aged solution with different annealing temperature. The ZnO nanostructures have been grown in large areas without a
The main objective of this paper is to develop an LFB formulation of power balance equations for analyzing a radial distribution system that will efficiently incorporate embedded series and shunt FACTS devices. The LFB equations use bus voltage magnitudes and line power flows as independent variables and directly relate the FACTS device variables with system operating conditions. The line loss terms are the only nonlinear terms in the formulation. By adding them to bus power injections, the coefficient matrix of LFB equations is rendered linear. A preliminary Breadth-First-Search (BFS) ordering of the branches transforms the coefficient matrix structure to strictly upper/lower diagonal and leads to simple backward/forward substitution for calculating real and reactive line power in each branch and voltage at each bus. The FACTS device models are described first, and the development of LFB equations follows. Numerical examples, including multiple FACTS devices in the standard IEEE systems, illustrate the power of the new approach. The procedure exhibits good convergence characteristics, high reliability, and computational efficiency. A balanced distribution feeder modeled by the positive sequence impedance is used in the paper, since the aim of this paper is to demonstrate the advantages of the LFB formulation in handling the embedded FACTS devices. FACTS devices can be assumed to be cost-effective when deployed on the main distribution feeder.