Standard centrifugal pumps designed for grid applications are usually specified by one Head vs Flowrate curve, for nominal grid conditions (fixed voltage, 50 or 60 Hz). To be fully determined, the model will also need the specification of the efficiency for each given Flowrate(Head) operating point.

For an operating point, the electrical power is easily deduced from the Efficiency, using the Hydraulic Power calculated as the product of the Head and Flowrate.

Therefore this case is equivalent to the model from Head and Power as f(FlowRate).