Voltage Stability Static Analysis Of Power Systems Based On Load Model

At present, power system become larger and larger, it is developed to big units , huge grids, high voltage and long distance . This needs higher requirement of security and stability. How to prevent the occurrence of voltage collapse accidents, increase stability of the grids, and improve system voltage stability margin? They are the very difficulties which operators are focus on.In this paper considers using ZIP load model to replace of constant power load model in the past in continuation method to trace the PV curve of power system. It is suitable to the actual condition if thinking about the effect of load model on system stability. Constant power model use in the past does not consider the effect, so it has different to the actual condition. Adopts ZIP load model which include the effect will be more close to the actual condition. Static load model and Jacobin comparable matrix's structures features were analyzed ,the results showed that the Jacobin comparable matrix characteristic would be changed after considered the load character, which have an impact on the static voltage stability.According to simulation and analysis between constant power load model and ZIP load model in IEEE5 and IEEE30 grids. The result is improved the method. The voltage result in ZIP model is higher than the result in constant power model. It will be conservative and incorrect if not consider the effect of load stability.Simulation different load rate base on ZIP load model in IEEE5 and IEEE30. and get the difference P-V curves. The more the constant power load rate is, the lower the voltage is. The more the resistance load rate, the more the voltage is. It is importance to chance load model in analysis.