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.

Abstract: A voltage stabilization control method for controlling a voltage of a power system that is connected with an adjustable speed machine includes the steps of: 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 resides in a voltage stabilization control apparatus.

Abstract: A transmission voltage of a power transmission system in a transmission voltage control depends on a product of a voltage drooping factor and a difference between a reactive current of a synchronous generator and a reference value. The voltage drooping factor depends on a gain and a voltage-up ratio of a transformer arranged between the power transmission system and the synchronous generator. The voltage-up ratio changes with a tap position of the transformer. The tap position of the transformer is always detected to update the voltage-up ratio, the gain is determined according to the updated voltage-up ratio to maintain the voltage drooping factor at a constant value, and the transmission voltage is regulated by using the gain. Therefore, even though the tap position of the transformer is changed, the voltage drooping factor is maintained at a constant value, and the stability of the transmission voltage of the power transmission system is maintained.

Abstract: A control signal processor effects control to permit or inhibit the passage of an input signal, by a logic operation, based on a ratio of input and output signals of a filter circuit having a double differentiation function characteristic.

Abstract: A power system stabilizer (PSS) and a power system stabilization method estimate system construction parameters (k2 to k6) based on gains and phases of basic frequency components, and estimate an optimum frequency characteristic G.sub.PSS (j.omega.) of the power system stabilizer (PSS) based on the estimated system construction parameters (k2 to k6).