Abstract
Recently, according as electric power systems become very large and complicate, several phenomena of voltage collapse at the load end of power systems have been observed. So, the voltage stability problems of power systems have been closed up. There are many reports about the voltage instability phenomena that progress relativery fast. However, most of them are reported about the phenomena for normal cases of the balanced transmission line condition.
In this paper, we describe the voltage stability of the power system from some experimental results. The influences of the load condition and the faults condition of the transmission line to the dynamic voltage stability and the progressive speed of unstable phenomena are discussed. We also inventigate the improvement of the voltage stability and the transient phenomena of the power system when the falut transmission line is closed with multiple reclosing system.