Physical test study on power system voltage collapse

In order to test and verify the phenomena of power system voltage collapse, this article chooses a single-load infinite-bus system and a single-machine single-load system as the sample systems based on the PS-5G test system to carry out the voltage stability physical tests, and an induction motor and an adjustable resistor are used to constitute the comprehensive load. The test results show that in the single-load infinite-bus system, with the decrease of the adjustable resistance gradually, the comprehensive load active power is gradually increasing and the load bus voltage is gradually decreasing; and the slight adjustment for the adjustable resistance can cause the load bus voltage collapse when the induction motor has the locked-rotor. In the single-machine single-load system, the locked-rotor of the induction motor can lead to the occurrence of the reactive power limit-induced bifurcation, it causes the terminal voltage of the synchronous generator and the load bus voltage to have an instantaneous collapse. The test results are conducive to comprehend the mechanisms of voltage instability and collapse in power systems.