Methods for controlling pump flow rate based on pump flow rate estimation using pump head and performance curves and pump control systems having the same

Systems and methods for determining a pump flow (Q) of a pump are disclosed. A method for determining a pump flow (Q) of a pump includes calculating an inverse of a polynomial equation defining a DP-Q performance curve of a pump, where the inverse is a Q-DP polynomial equation defining the performance of the pump, receiving a pump head (DP) value from a pump head sensor associated with the pump, computing a pump flow based on the Q-DP polynomial equation, comparing the computed pump flow to a preset target flow rate, and automatically controlling a pump parameter of the pump such that the calculated flow rate becomes the preset target flow rate.