A method of controlling a shaft of a turbine generator to stabilize torsional oscillations induced in the shaft by fluctuating loads coupled with the generator causing rapid transients in electrical power on generators, wherein a static excitation system provides a field voltage to the turbine generator , wherein the shaft is being driven in a first rotational direction at a predetermined speed, the method comprising: measuring a rotational speed of the shaft; detecting , based on the measured rotational speed of the shaft, a torsional oscillation of the shaft; calculating a control signal based on the torsional oscillation; using the control signal , controlling an amount of electrical power drawn by the static excitation system from the turbine generator ; wherein the torsional oscillation comprises a first amplitude corresponding to a difference between the measured rotational speed and the predetermined speed; determining a second amplitude of the control signal based on the first amplitude ; wherein the torsional oscillation comprises a first portion , lasting a first time period, corresponding to the first rotational direction and a second portion , lasting a second time period, corresponding to a second rotational direction opposite to the first rotational direction; wherein the torsional oscillation comprises a frequency corresponding to the reciprocal of a sum of the first time period and the second time period; determining a second amplitude of the control signal based on the first amplitude ; applying the control signal , to the static excitation system , with the second amplitude and a first polarity during the first time period; and applying the control signal , to the static excitation system , with the second amplitude and a second polarity during the second time period, the second polarity opposite that of the first polarity ; wherein the control signal causes the static excitation system to increase an amount of power being drawn from the turbine generator during the first time period; wherein the control signal causes the static excitation system to decrease an amount of power being drawn from the turbine generator during the second time period. measuring a rotational speed of the shaft; detecting , based on the measured rotational speed of the shaft, a torsional oscillation of the shaft; calculating a control signal based on the torsional oscillation; using the control signal , controlling an amount of electrical power drawn by the static excitation system from the turbine generator ; wherein the torsional oscillation comprises a first amplitude corresponding to a difference between the measured rotational speed and the predetermined speed; determining a second amplitude of the control signal based on the first amplitude ; wherein the torsional oscillation comprises a first portion , lasting a first time period, corresponding to the first rotational direction and a second portion , lasting a second time period, corresponding to a second rotational direction opposite to the first rotational direction; wherein the torsional oscillation comprises a frequency corresponding to the reciprocal of a sum of the first time period and the second time period; determining a second amplitude of the control signal based on the first amplitude ; applying the control signal , to the static excitation system , with the second amplitude and a first polarity during the first time period; and applying the control signal , to the static excitation system , with the second amplitude and a second polarity during the second time period, the second polarity opposite that of the first polarity ; wherein the control signal causes the static excitation system to increase an amount of power being drawn from the turbine generator during the first time period; wherein the control signal causes the static excitation system to decrease an amount of power being drawn from the turbine generator during the second time period. <EOS>