Power demand predicting control system

Claim 2

Apparatus for controlling total power consumption during a demand billing period of a plurality of controllable variablerate power-consuming devices which operate in a known pattern, said devices including control means operable to separately control the power consumption rate of each said device and thereby stretch or shorten said pattern therefor, and wherein metering means supplies signals indicative of the power consumption of said devices comprising: available power computer means responsive to said signals from said metering means and to a preset limit, which limit indicates the desired limit of power consumption during said demand billing period, for periodically computing the amount of remaining power available for consumption by said devices during the remainder of said demand billing period; priority means for periodically allocating priorities between said devices in accordance with a predetermined classification; first power usage computer means responsive to said priority means for determining the point in said pattern of said devices having the highest priority allocated thereto and responsive to said determination to estimate the power consumption thereof as defined by said pattern for the remainder of the demand billing period, and for signalling said control means therefor to operate said associated device at the maximum available power consumption rate in accordance with said pattern, subtraction means responsive to said first power usage computer means and said available power computer means for subtracting the value of said estimated power consumption from the value of said remaining available power to thereby determine the amount of power available for the remaining ones of said devices; and Second power usage computer means responsive to said priority means for determining the point in said pattern of each of said devices not having the highest priority allocated thereto and responsive to said determination to estimate the maximum amount of power consumption thereof as defined by said pattern for the remainder of the demand billing period, additionally responsive to said amount of power available for said remaining devices and to said estimated maximum amount of power consumption thereby to establish a ratio therebetween, and for signalling said control means therefor to operate said associated device at a power consumption rate in accordance with said ratio as related to the maximum rate of said pattern.

Claim 3

The apparatus in accordance with claim 1 wherein: said first power usage computer means includes means responsive to the occurrence of said signalling of said control means thereby for updating said point determination therein for each said remaining device in accordance with said pattern at the power consumption rate in accordance with said ratio.

Claim 4

The apparatus in accordance with claim 2 wherein: said first and second power usage computer means each include means to estimate said power consumption of each said associated device by employing the updated point in said pattern for estimating the power consumption rates and time to be spent at each such rate for each said device during the remainder of said demand billing period and employing said estimated rates and times to estimate the maximum total power consumption of said associated devices during the remainder of the demand billing period.

Claim 5

The apparatus in accordance with claim 3 wherein: said power consumption estimation means in said power usage computer means includes multiplication means for multiplying the value of each said power consumption rate for each associated device by the value of said time to be spent thereby at such rate during the remainder of said demand billing period and adding means to add the products of said multiplication.

Claim 6

The apparatus in accordance with claim 4 additionally including: timing means responsive to a synchronizing signal supplied from a synchronizing source to thereupon and at predetermined periodic intervals supply signals to said available power computer means and said priority means to cause said periodic operation thereof.

Claim 7

The apparatus in accordance with claim 5 additionally including: monitoring means for monitoring the power consumption of each of said devices to determine the point in said pattern of each said device and responsive to said timing means for periodically supplying signals to said first and second power usage computer means for correcting said point-determining means. 7 The method of controlling total power consumption during a demand billing period of a plurality of controllable variable-rate power-consuming devices which operate in a known pattern, said devices including control means operable to separately control the power consumption rate of each said device and thereby stretch or shorten said pattern therefor, and wherein metering means supplies signals indicative of the power consumption of said devices, comprising the following series of steps, which series is initiated at predetermined intervals; responding to said signals from said metering means and to a preset limit of the amount of power consumption for said demand billing period to compute by an instrumentality the amount of remaining power available for consumption by said devices during the remainder of said demand billing period; allocating priorities between said devices in accordance with a predetermined classification; based upon an estimate of the present point in said pattern of the operation of said devices having the highest priority allocated thereto, computing by an instrumentality an estimate of the power consumption thereof as defined by said pattern for the remainder of the the demand billing period; signalling by an instrumentality said control means for said highest priority devices to operate said associated device at the maximum available power consumption rate in accordance with said pattern: subtracting by an instrumentality the value of said estimated power consumption from the value of said remaining available power to thereby determine the amount of power available for the remaining ones of said devices; based upon an estimate of the present point in said pattern of operation of said devices not having the highest priority allocated thereto, computing by an instrumentality an estimate of the maximum amount of power consumption thereof as defined by said pattern for the remainder of the demand billing period; computing by an instrumentality the ratio between the value of said amount of power available for said remaining devices and the value of said estimated maximum amount of power consumption thereby and signalling by an instrumentality said control means for said remaining devices to operate said associated device at a power consumption rate in accordance with said ratio as related to the maximum rate of said pattern.

Claim 8

The method in accordance with claim 7 additionally including the steps of: updating by an instrumentality said estimate of said point in said pattern of the operation of each said highest priority device in accordance with said pattern at said maximum power consumption rate thereof; and updating by an instrumentality said estimate of said point in said pattern of the operation of each said remaining device in accordance with said pattern at the power consumption ratio thereof in accordance with said ratio.

Claim 9

The method in accordance with claim 8 wherein said steps of computing estimates of the power consumption of said devices each comprise the steps of: based upon said updated estimate of the present point in said pattern of the operation of each of said associated devices, computing by an instrumentality an estimate of the power consumption rates and time to be spent at each such rate for each said device during the remainder of said demand billing period; and computing by an instrumentality from the values of said estimated rates and times an estimate of the maximum total power consumption of said associated devices during the remainder of the demand billing period.

Claim 10

The method in accordance with claim 9 wherein said step of computing an estimate of the maximum total power consumption of said associated devices comprises the steps of: multiplying by an instrumentality the value of each said estimated power consumption rate for each associated device by the value of said estimated time to be spent thereby at such rate; and adding by an instrumentality the products of said multiplication.

Claim 11

The method in accordance with claim 9 including the additional step of: monitoring by an instrumentality the power consumption of each of said devices to determine the point in said pattern of each said Device; and correcting by an instrumentality said estimates of said point in pattern of each said device in accordance with said determination thereof.