A variable speed pumping system includes a generator motor including a frequency converter, in which the variable speed pumping system, in the pumping mode, supply a power command to the generator motor to perform power control, and the power control correction signal generator adds a value obtained by multiplying a signal based on a difference between the power input command and an actual power input measured by a power detector in the pumping mode by a constant gain to a signal based on the deviation and inputs the added value to an integration control element to generate the power control correction signal based on an output signal of the integration control element.

Disclosed are a method and a system for correlating hydro-turbine governing system control parameters and oscillation characteristics, and the method includes the steps: calculating a eigenvalue, a zero point and a pole of a state matrix in a hydro-turbine governing system state space model, taking a pole which is the closest to the imaginary axis and has no zero point in a preset distance as a dominant eigenvalue; determining an oscillation characteristic region of the hydro-turbine governing system on the complex plane according to the dominant eigenvalue; obtaining a system control parameter stability domain according to a Hurwitz stability criterion; and calculating dominant eigenvalues corresponding to different control parameters, classifying the control parameters according to an oscillation characteristic region of a complex plane where the dominant eigenvalue is located, and dividing the oscillation characteristic region in a system control parameter stability domain.