Abstract: A voltage stabilization control method for controlling a voltage of a power system that is connected to an adjustable speed machine includes detecting an active power change of the power system; outputting a control signal indicative of the amount of adjustment when the adjustment of the active power of the adjustable speed machine is required on the basis of the active power change; and receiving a steady operation command value with respect to the adjustable speed machine, generating a stabilization control signal resulting from adding the control signal to the steady operation command value and outputting the stabilization control signal to the adjustable speed machine. The present invention also resides in a voltage stabilization control apparatus.