Water turbine governor parameter optimization method and system in weak-damping low-frequency oscillation mode

The invention discloses a water turbine governor parameter optimization method and system in a weak-damping low-frequency oscillation mode. The method comprises the steps of determining the weak damping mode related to a unit to be optimized and the oscillation frequency of the weak damping mode; establishing an open-loop transfer function of the water turbine and the regulating system thereof, and calculating a damping torque coefficient of the open-loop transfer function of the water turbine and the regulating system thereof under the oscillation frequency of the weak damping oscillation mode; calculating a square error integral of the output mechanical power of the water turbine and the regulating system thereof under the step signal according to the open-loop transfer function of the water turbine and the regulating system thereof; calculating a damping ratio corresponding to the maximum characteristic value of the primary frequency modulation closed-loop system; establishing an objective function accordi