Patent ID: 7707125
Filing Date: 2010-04-27
Classification: E03B,G06Q

Abstract:
1. A method of controlling a water supply system having at least one pump and at least one storage facility, wherein power utilized by said water supply system is subject to an energy charge and a demand charge, the method comprising: a) establishing a scheduling period having a length and dividing the scheduling period into a plurality of time periods, each time period having an associated utility cost rate; b) establishing an initial pumping schedule constrained by pumping capacity for the scheduling period, the initial pumping schedule having an inflow amount for each time period of the plurality of time periods of the scheduling period that assigns inflow to at least one lowest available cost rate time period before assigning inflow to higher cost rate time periods; c) repetitively revising the initial pumping schedule with consideration to a minimum water level constraint, wherein revising includes identifying a chronologically first of the time periods where projected water level will violate the minimum water level constraint (FMLV time period) and reassigning scheduled water inflow from after the identified FMLV time period to at least one time period before or including the identified FMLV time period, and wherein the reassigned scheduled water inflow is selected to avoid violation of the minimum water level constraint in the identified FMLV time period, said reassigned scheduled water inflow being reassigned to at least one time period having an associated cost rate that is lower than a cost rate of another time period of the at least one time period before or including the identified FMLV time period, and wherein the reassigned scheduled water inflow assigns as much inflow as the system has the capacity to pump in at least one time period before or including the FMLV time period that is chronologically most distant from a current time period and has the lowest available cost rate before assigning inflow to time periods chronologically closer to the current time period and having the lowest available cost rate, said reassigned scheduled water inflow being reassigned from at least one time period chronologically after the identified FMLV time period that has scheduled inflow and an associated cost rate that is higher than a cost rate of another time period chronologically after the identified FMLV time period, and said reassigned water inflow reassigned from at least one time period chronologically closer to and after the FMLV time period having the same associated cost rate before reassigning inflow from another time period that is chronologically further from and after the FMLV time period and having the same associated cost rate; d) smoothing the revised pumping schedule for the chronologically first of the time periods and subsequent time periods having the same cost rate over the first time period and the subsequent time periods having the same cost rate to reduce peak power consumption, wherein the sum of the smoothed scheduled water inflow amount up to any time period in the chronologically first of the time periods and the subsequent time periods having the same cost rate will be at least as much as that of the schedule prior to smoothing while any measure of variance of the smoothed scheduled inflow for the chronologically first of the time periods and the subsequent time periods having the same cost rate is at least lower than that of the schedule prior to smoothing; e) for the first time period of the pumping schedule, controlling, with computer assistance, the at least one pump in accordance with the pumping schedule; and f) after a time interval elapses, repeating b), c), d) and e) to reestablish the pumping schedule for each time period of the next entire upcoming scheduling period and control the at least one pump in accordance with the inflow amount scheduled for the first time period of the reestablished pumping schedule.