The Study Of Topological Analysis And Flow Calculation In Power System Dispatching

Network topology analysis of power system, its main function is to transfer the physical model to the mathematical model.Network topology analysis is the foundation of the various analysis and calculation in electric power system.First,it provides the run-ning situation of the grid,such as security protection, lose electric etc; secondly,it gives the numerical model for flow calculation and state estimation.So it is an extremely vital role.The core is that when the grid changes, we need finish topology quickly for topology analysis timely.Flow calculation, its essence is solving nonlinear equations and its difficulty is that when solving tide problem with many nodes,we need calculate its function values, derivative value.If we choose initial value far from true solution or not appropriate, the iterative times will increase greatly and don't converge.For parameters with zero impedance and small impedance,it may produce the sickly node admittance matrix eas-ily which affects convergence speed and precision.If rapid decoupling method doesn't satisfy assumptions, the iterative times may increase or it doesn't converge.The sickly system, such as heavy load, will cause the calculation process shock or not convergence.Newton method is the most commonly used methods for solving nonlinear equa-tions,and is the traditional method of the flow calculation in the power system, but it also has the defects.When coefficient matrix is singular, Levenberg-Marquarat algo-rithm can avoid its defect, but the speed is slow.Genetic algorithm is a new effective intelligent algorithm,it has good effect now.Ant colony algorithm only solve discrete problem firstly,after improving we also have good effect for continuous problem.Its ini-tial velocity is faster than genetic algorithm.The two kinds of intelligent algorithm can solve shortcoming that initial point of Newton algorithm is difficult to choose.For the problem of not convergence, instability, slow convergence speed in tra-ditional flow algorithm,we give new method combining intelligent algorithm and im-proved LM algorithm,and give theory analysis and convergence proof.The main content includes:chapter 1.Introduce the developing situation of Chinese power grid and question source.Topological method research status.Newton method, ant colony, genetic algo-rithm progress.chapter 2.Through the introduction of three common topological method, give the design scheme.Combining with the initial topology and local topology, realize fast real-time analysis.chapter 3.For the defects of classic tide calculation method,we give an improved rapidly LM algorithm,and proof its convergence.Through several examples compari-son.we know the new methods increase speed and are better than traditional methods.For nonsingular coefficient matrix,We design a new method with not second derivative but three order convergence.Then proof its three order convergence. Multivariable equations form:chapter 4.We insert improved LM algorithm into ant colony algorithm.And give the convergence analysis and parameter analysis.The result is better than traditional meth-ods.And genetic algorithm is similar to ant colony algorithm.chapter 5.Ant colony algorithm is beginning from N ants-path,and genetic algorithm need N population.We use orthogonal generation and randomly generation to ensure density appropriate.Through an example,we have data analysis.