A Grid Voltage Stability Monitoring Method Based on Node Voltage Stability Index Considering Static Load Characteristics

Abstract

The invention discloses a network voltage stability monitoring method based on node voltage stability indexes taking account of the static load characteristic. A method for building the voltage stability local index according to existence conditions of real root solutions of a quadratic equation and determinant of an expansive Jacobian matrix is abandoned, the voltage stability local index taking account of the ZIP static load influence is built according to the voltage and the critical load level factor of a solving system at a saddle-node bifurcation point, and the voltage stability local index accurately reflects the influence on the system voltage stability from load voltage characteristics; in consideration of the problems such as the selection sensitivity of the convergence of the local Newton method on the initial value and the rate of convergence, a system of nonlinear equations in the process of solving the critical load level factor is solved according to the global convergence and a self-adaption optimal iterative step length NLEQ-RES method, and the convergence and the rate of convergence of numerical calculation are improved when the system of nonlinear equations is solved.

Description

technical field [0001] The invention relates to a grid voltage stability monitoring method based on a node voltage stability index considering static load characteristics. Background technique [0002] The voltage instability of the power system may lead to large-scale blackouts, resulting in huge economic losses and seriously affecting social life. The use of node voltage indicators to realize rapid monitoring of the grid voltage stability is of great significance to ensure the safe and stable operation of the power system. The existing nodal voltage index method is generally based on a simple transmission system, assuming that the load is a constant power load model, the equation is established with the bus voltage on the load side as a variable, and the index is established directly or indirectly by using the existence conditions of the real root solution of the equation, and its stable critical point is the maximum power transfer point of the system. However, many studi...

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Problems solved by technology

[0004] The purpose of the present invention is to overcome the deficiencies in the prior art, abandon the method for setting up the index only according to the existence condition of the real root solution of the equation and the Jacobian matrix determinant, by introducing the characteristic equation when the simple transmission system reaches the saddle node bifurcation point, give A power deviation index considering the static load characteristics is proposed, which accurately reflects the influence of the static load characteristics on the system voltage stability; for solving the nonlinear equations encountered in the node voltage stability index taking into account the static load characteristics, The invention applies the NLEQ-RES algorithm to solve the proposed voltage stability index, which overcomes the problems of difficulty in selecting the initial value and slow convergence speed of solving the above-mentioned nonlinear equations with the conventional Newton method

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