A study on voltage collapse mechanism in electric power systems

A mechanism of the dynamic phenomenon of voltage collapse is presented from the physical point of view. It is shown that an iterative reaction of voltage drop between a dynamic load and the system network can cause voltage collapse. The dynamic phenomenon of voltage collapse is analyzed on a simple power system model which includes a synchronous motor. Dynamic equations describing the mechanism of voltage collapse caused by a very small disturbance are derived, and the physical explanation of the voltage collapse mechanism is presented in detail for the case when the system is operating near the bifurcation point and its linearized system matrix has a very small negative eigenvalue. It is shown that an iterative reaction of voltage drop between a dynamic load and the system network can cause voltage collapse