Voltage stability estimation based on approximate model and voltage measurement

The paper presents method of voltage stability margin estimation based on approximate model and measurements of the node voltage. The first part contains basic information about Thevenin model and methods of parameters of this model calculation. In second part, method of voltage stability margin estimation using approximate model and measurements of voltage is described. For the simulations, the 14-bus IEEE test model was implemented in ATP-EMTP software. Basing on this model the impact of configuration changes on the variations of Thevenin parameters can be determined. This information and voltage measurements allow to calculating range of voltage stability changes. Additionally, determined Thevenin model was used to calculate variations of stability margin for different types of load.