The Prediction of Voltage Stability Status Considering the Impact of the Protection System

In this paper, a novel algorithm is proposed to evaluate the dynamic voltage stability of power systems considering the effect of the protection system. In short circuit occurrence and the correct or incorrect operation of the protection system, which leads to the operation of the power system in N-1 and N-k conditions, respectively, this algorithm can accurately predict the voltage stability status. For this purpose, in this method a suitable feature set is presented, according to which a database will be prepared to record the conditions in which the disturbances and correct / incorrect operations of the protection system leading to voltage instability, occur. By grouping and encoding this data, while the size of the database decreases and the execution speed of the algorithm increases significantly, the effect of errors caused by the measuring equipment is also reduced as much as possible. Finally, with the help of this data set and a new index called FSI, the stability of the system in online conditions is accurately predicted. The results of dynamic simulations performed on the Nordic32 network show that the proposed method can predict the instability occurrence several seconds to a few minutes in advance and thus provide ample opportunity for the system operators to implement appropriate control measures.