Patent ID: 7534096

Claim:
A method for controlling the operation of a pump for optimizing pump efficiency and productivity under electrical power disturbance conditions, wherein the pump is driven by an AC electrical motor having a rated operating speed and a motor drive energized by a voltage derived from a bus voltage resulting in a motor flux and field current and a present operating speed of the motor; said method comprising the steps of: detecting the occurrence of an electrical power disturbance; determining when the electrical power disturbance is a power dip condition; and using a power dip controller to provide controlled operation of the motor when the electrical power disturbance condition is determined to be a power dip condition, by adjusting motor field current and motor flux as the bus voltage fluctuates during the power dip condition; wherein the step of using the power dip controller includes the steps of monitoring the bus voltage and present operating speed of the motor, continually calculating a value for a field weakening ratio, and managing the motor field current and motor flux in correspondence with the value of the field weakening ratio.