Small Signal Stability Analysis Of Power System Used Of Flow Equations To Simply Network

Power system is a complex dynamic system described by differential equations.Ideally,the power system is a system capable of running at a constant voltage and frequency continuous power to the load at any time.However,the operation of the power system in this ideal is unrealistic,and it is ever a hit some small interference.With large-scale interconnected power systems,accompanied on electric power,the implementation of a national network engineering,systems network architecture,continue to expand the scale,restricting economic and environmental factors,case of power system operation is closer to extreme conditions.In this case,the low frequency oscillation after a large grid interconnection will become increasingly prominent.So selecting the appropriate dynamic component model,Network Interface Variables and the network Interface equations are important research to quickly resolve small signal stability calculations.For the study of small signal stability,improvements in the literature are mostly carried out on the model and methods.Interface variable is injected amount of current.Flow equations are also a system of network equations.Jacobi matrix elements of power flow equations include very completely the power system dynamic parameter information in static operating point,and they are partial derivatives between injected into the power system to voltage node.This paper makes full use of the advantages of this trend Jacobi matrix to propose the model,which based on flow equations to simplify network system small signal stability analysis.Load using voltage static characteristics(ZIP)model.This paper is used of the relationship between the node inject power and the node voltage deviation to derive correction of the generalized flow Jacobi matrix about load.In this method,generator model,load static characteristics(ZIP)model will be used the form of injected power.According to Lyapunov theory and local stability linear of nonlinear systems,electricity networks through flow equations are combined to form a broad trend Jacobi.In this method,the interface variables between dynamic element and the network are the amount of power electricity.Interface equations are flow equations.This simplifies the model in dealing with dynamic elements.This allows the network to contract,and reduces the computational space.Jacques generalized flow ratio correction is not very complex matrix.And the continuous change in the way the system is running small-disturbance stability analysis,the matrix elements can be corrected in real time,to better reflect the authenticity of the system small signal stability and flexibility.In this paper,simulation examples are on the EPRI-3 machine 7-node system and EPRI-36 node system.The results show that small signal stability analysis method used of flow equations can simplify the network,truly reflect the operational status of the system.Simulation results show the practicality and validity of the method,provides a very effective method of analysis for power system stability analysis.