On Real-time Simulation System Of Interconnected Power System

Nowadays, interconnected power systems are the international development trend. In order to satisfy the demand that the national economy is increasing day by day, to enhance the power supply reliability,security and economy, to be accommodated to the balance of energy supply and demand , to ensure environmental protection and continuable development, interconnected power systems are extensively applied in the world. It's a major concern to research the large-scale interconnected real-time simulation system.In this paper, the whole structure of the distributed real-time simulation system about interconnected power system is put forwarded. the mathematics calculation model and simulation model of the system main part are built up. The electric power system supervisary algorithm are analysized and designed.Making use of this simulation system , the IEEE power system example tests are carried on.The concrete research contents mainly includes a few aspects as follows:(1) According to the typical power system structure, the whole structure of the distributed real-time simulation system about interconnected power system is put forwarded,which is composed of power generation plants,power network/load and man-machine interface .The three parts cooperate separately in order to complete the function of simulation system.(2) Power plants mathematics model and electric power network model are introduced respectively. PSAT software model library and their main functions are described in detail.3-area interconnected power network model is set up as a research object.The power plant model example introduces skegton system in the paper[10], and make use of the MATLAB/Simulink model library to build up the real-time simulation model.Particularly the theory and usage of the MATLAB toolbox PSAT is presented in detail.By means of object-oriented method, PSAT visualize the main parts of power system:nodes, transformer, transmission line, customer load and the various control units.Electric power network model can be build up conveniently according to the network topology and the system parameters.This paper still build up 2-area interconnected power network The interconnected 3-area power network is a modification to the IEEE9 system.(3) The main supervision mission of simulation system is also accomplished in this paper.Aiming to fulfill the distributed simulation task, power system supervisory algorithms are elaborated: power flow algorithm and time-domain simulation algorithm.At first, two kinds of widespread power flow algorithms:Newton-Raphson algorithm and PQ algorithm are advanced. and then these two kinds of algorithms are carried on the 2-area and 3-area interconnected power systems respectively to analysis.The simulation results indicats these two kinds of algorithm have their own advantages as aspects of iteration times and convergence speed, and they both can carry on an accurate calculation results of power flow.Secondly, this paper presents two kinds of electric power systems time-domain differential algebra equation integration methods. The main point is trapezoid integration method due to its accurancy. The algorithm is tested on IEEE standard power network and interconnected systems to carry on example analysis. The simulation results indicated algorithm can achieve expected simulation results.Besides, in order to realize the stability analysis of the power system, this paper still analyzed the influence of the usage of FACTS controller to inter-area low frequency oscillation.The mechanism of the inter-area low frequency oscillation is studied and the classification of FACTS controller and work principle are discussed. Prabha Kundur 4 machines 11 node 2-area interconnected power system is made use of in order to carry on simulation tests. The simulation results indicated: FACTS controller can obviously damp the inter-area low frequency oscillation to guarantee the stability and security of the interconnected power system.(4) Man-machine interface is developed in the VisualC++ environment. MATLAB calculation engine technique is also used to carry out the interface of supervisory part and other two parts. The power plants part and power network part can be respectively started up in the interface, and costomer can also modify the power plants setpoint values to adapt to the supply and demand variety of the whole system.Another function of man-machine interface is to manifestate the results visually.Finally, the IEEE standard power network is used to validate the credibility of the whole system, and to test some general regulation of the electric power system.Summarily, this paper accomplishes the foundational distributed interconnected power simulation and the application of this system. The main respect of this dissertation is interconnected technologies and supervisory algorithms of the whole distribute system. The simulation results indicats the credibility of the simulation system.