Non-intrusive appliance monitor apparatus

Claim 2

Apparatus for non-intrusive measurement of energy usage and operating characteristics of each of a plurality of individual electric units, said units each contributing to a portion of a total electric load of a circuit of a facility, comprising: (a) sensor means for measuring electrical characteristics of the total load of said circuit and producing an analog signal proportional thereto, said sensor means being coupled to said circuit at a location external to said facility; (b) analog-to-digital conversion means for converting said analog signal into a digital signal; and (c) signal processor means responsive to said digital signal for separating out said portion of the total load contributed by each of the plurality of units.

Claim 3

The apparatus of claim 1 wherein the electrical characteristic is admittance, said admittance being comprised of a conductance and a susceptance, and the sensor means comprises voltage and current sensing transformers and the analog-to-digital means includes calculator means for calculating the values of the conductance YG and susceptance YB of the load from the sensed voltages and currents; wherein YG is calculated as PR/V 2 and YB is calculated as RP/V 2 ; in which RP=real power, PR=reactive power and V=RMS voltage.

Claim 4

The apparatus of claim 2 wherein the circuit is powered by voltage from a line and the calculator means includes scaler means for normalizing the calculated susceptance and conductance values with respect to a fixed value to avoid inconsistencies caused by voltage fluctuations on the line.

Claim 5

The apparatus of claim 1 wherein the units are taken from a class of electric units comprising appliances or machines.

Claim 6

The apparatus of claim 1 wherein the sensor means senses an electrical property taken from a class of voltage or current.

Claim 7

The apparatus of claim 1 including an output device for recording said portion of the total load due to each of the plurality of units.

Claim 8

The apparatus of claim 1 including an output device for displaying said portion of the total load due to each of the plurality of units.

Claim 9

Apparatus for non-intrusive measurement of load characteristics of each of a plurality of individual electric units in a facility, based on voltage and/or current sensing of the aggregate loads on a power circuit to which said units are connected, comprising: (a) monitor means coupled to said power circuit at a location external to said facility for sampling the aggregate load and converting the sampled load into digital signals representing at least one of the load characteristics from a group comprising: real power, reactive power, current, admittance, harmonics, sub-harmonics, dc current, starting-transient peak; starting-transient duration, starting-transient time-constant, or starting-transient shape; (b) net change detector means for determining from said signals changes in the load characteristics between periods of steady operation, by computing and generating a net change signal proportional to the net change in load characteristics from one steady period to a next steady period and; (c) cluster logic means responsive to said net change signal for: (i) determining which changes can be associated with a given unit having individual specific load characteristics; (ii) determining energy consumed by said unit between successive ON and OFF changes in load characteristics; and (iii) from the determinations in (i-ii) determining energy consumption and usage characteristics for each unit.

Claim 10

Apparatus for non-intrusive measurement of load characteristics of each of a plurality of individual electric units in a facility, based on voltage and/or current sensing of the aggregate loads on a power circuit to which said units are connected, comprising: (a) monitor means coupled to said power circuit at a location external to said facility for sampling the aggregate load and converting the sampled load into digital signals representing at least one of the load characteristics from a group comprising: real power, reactive power, current, admittance, harmonics, sub-harmonics, dc current, starting-transient peak; starting-transient duration, starting-transient time-constant, or starting-transient shape; (b) net change detector means for determining from said signals changes in the load characteristics between periods of steady operation, by computing and generating a net change signal proportional to the net change in load characteristics from one steady period to a next steady period and; (c) cluster logic means responsive to said net change signal for: (i) determining which changes can be associated with a given unit having individual specific load characteristics; (ii) determining energy consumed by said unit between successive ON and OFF changes in load characteristics; and (iii) from the determinations in (i-ii) determining energy consumption and usage characteristics for each unit.

Claim 11

The apparatus of claim 8 further including, in said logic means, a means for normalizing the load characteristic for variations caused by changing circuit line-voltage, using the formula: ##EQU2## wherein N is a constant.

Claim 12

The apparatus of claim 8 including, in said logic means, a means for analyzing simultaneous changes by detecting unusual changes which can consistently be decomposed into two or more individual appliance changes which add up to an observed change and which fit into a pattern of observed ON/OFF changes for individual units.

Claim 13

The apparatus of claim 10 wherein a unit class is identified based on changes and timing behavior of a cluster of changes.

Claim 14

The apparatus of claim 8 including means for displaying the energy consumption and usage characteristics for each unit.

Claim 15

The apparatus of claim 8 including means for recording the energy consumption and usage characteristics for each unit.

Claim 18

The method of claim 14 wherein prior to step b, the load characteristics are normalized to correct for variations caused by changing circuit line-voltage, using the formula: ##EQU3## wherein N is a constant.

Claim 19

The apparatus of claim 14 wherein if simultaneous changes occur in step c, they are analyzed be detecting any unusual changes which can consistently be decomposed into two or more individual unit changes which add up to one of the detected unusual change and which fit into a pattern of observed ON/OFF changes for individual units.

Claim 20

The method of claim 14 wherein a unit class is identified based on observed changes and timing behavior of a cluster of changes.

Claim 21

The method of claim 14 wherein the units are taken from a class of electric units comprising appliances or machines and the facility is taken from the class comprising residential commercial, or industrial facilities.

Claim 22

The method of claim 14 including the step of displaying the energy consumption and usage characteristics for each appliance.

Claim 23

The method of claim 14 including the step of recording the energy consumption and usage characteristics for each appliance.