Study On The Impact Of Load Characteristics On Voltage Stability

This thesis carries out studies around the impact of load characteristics on voltage stability-the key problem of power system voltage stability analysis. The impact of load characteristics on static voltage stability is analyzed with the methods based on V-P-and-V-Q curves, and the dynamic voltage stability of different loads in the context of both small disturbances and large disturbances is studied with the method of time domain simulation. In sum, the main contents of the thesis include:1. Analyses of the impact of different load characteristics on static voltage stability with the V-P-and-V-Q curves of power system loads.2. Simulation of dynamic voltage stability of induction motor in the context of small disturbances and analyses of the simulation results with its load characteristics.3. Simulation of dynamic voltage stability of the (composite) induction motor load in the context of large disturbances and analyses of the simulation results with their load characteristics.4. Simulation and comparisons of the dynamic voltage stability of constant impedance load, constant current load and constant power load in the context of large disturbances, and analyses of the simulation results with their load characteristics.5. Analyses of the internal relations and the essential differences among voltage instability, voltage collapse and load instability on the basis of the simulation results and their analyses.6. Presentation of the essential explanations of both voltage stability and the mechanism of voltage collapse, which hold: the essence of voltage stability is the balance between the power that loads absorb from the network to meet the requirements of energy conversion and the power that the network can actually supply.