APPLIANCE OPERATION STATE DETECTION
A system and method of identifying an operational state change in an appliance is provided. Power consumption can be measured using a power consumption measuring device such as a utility meter. The power consumption signal can be filtered by applying a filter to the power consumption signal. An initiation of a change in an operational state of the appliance can be detected. When an initiation of a change in the operational state is detected, at least one derivative of the filtered power consumption signal can be determined and compared to a predetermined threshold. When the derivative of the filtered power consumption signal exceeds the predetermined threshold, an achievement of the operational state change can be identified. An achievement of an operational state change can alternatively be identified when a counter increment exceeds a threshold.
1 . A computer-implemented method of identifying an operational state of an appliance, comprising:
receiving a power consumption signal indicative of power consumption;
applying a filter to the power consumption signal to generate a filtered power signal;
detecting an initiation of change in operational state of the appliance;
determining a derivative of the filtered power consumption signal;
comparing the derivative of the filtered power consumption signal to a predetermined threshold; and
identifying an achieved operational state change of the appliance when the derivative of the filtered power consumption signal falls outside the predetermined threshold.
2 . The computer-implemented method as in claim 1 , further comprising:
incrementing a counter when the derivative of the filtered power consumption signal is within the predetermined threshold; and
identifying an achieved operational state change of the appliance when the counter exceeds a predetermined counter threshold.
3 . The computer-implemented method as in claim 1 , wherein the power consumption signal is indicative of power consumption of the appliance, a subset of appliances including the appliance, or power consumption at a premises.
4 . The computer-implemented method as in claim 1 , wherein determining a derivative of the filtered power consumption signal comprises:
determining a first derivative of the filter power consumption signal; and
determining a second derivative of the filter power consumption signal.
5 . The computer-implemented method as in claim 4 , wherein the method comprises comparing first derivative of the filtered power consumption signal and the second derivative of the filtered power consumption signal to the predetermined threshold.
6 . The computer-implemented method as in claim 5 , wherein an achieved operational state change is identified when at least one of the first derivative of the filtered power consumption signal and the second derivative of the filtered power consumption signal falls outside the predetermined threshold.
7 . A controller coupled to an appliance, the controller configured to execute computer readable instruction to cause a processor to perform operations, the operations comprising:
receiving a power consumption signal indicative of power consumption;
applying a filter to the power consumption signal to generate a filtered power consumption signal;
detecting a signal indicative of an initiation of change in operational state of the appliance;
determining a derivative of the filtered power consumption signal;
comparing the derivative of the filtered power consumption signal to a predetermined threshold; and
identifying an achieved operational state change of the appliance when the derivative of the filtered power consumption signal falls outside the predetermined threshold.
8 . The controller as in claim 7 , wherein the operations comprise:
increment a counter when the derivative of the filtered power consumption signal is within the predetermined threshold; and
identify an achieved operational state change when the counter exceeds a predetermined counter threshold.
9 . The controller as in claim 7 , wherein the filter is a Gaussian filter.
10 . The controller as in claim 7 , wherein the operation of determining a derivative of the filtered power consumption signal comprises:
determining a first derivative of the filter powered consumption signal; and
determining a second derivative of the filter powered consumption signal.
11 . The controller as in claim 10 , wherein the first derivative of the filtered power consumption signal and the second derivative of the filtered power consumption signal are compared to the predetermined threshold.
12 . The controller as in claim 10 , wherein an achieved operational state change is identified when at least one of the first derivative of the filtered power consumption signal and the second derivative of the filtered power consumption signal falls outside the predetermined threshold.
13 . A system of identifying an operational state of an appliance installed on a premises, comprising:
an appliance configured to consume power; and
a controller coupled to the appliance, the controller configured to:
receive a power consumption signal indicative of power consumption,
apply a filter to the power consumption signal to generate a filtered power consumption signal,
detect an initiation of change in operational state of the appliance,
determine a derivative of the filtered power consumption signal,
compare the derivative of the filtered power consumption signal to a predetermined threshold, and
identify an achieved operational state change of the appliance when the derivative of the filtered power consumption signal falls outside the predetermined threshold.
14 . The system as in claim 13 , wherein the controller is further configured to increment a counter when the derivative of the filtered power consumption signal is within the predetermined threshold, and identify an achieved operational state change of the appliance when the counter exceeds a predetermined counter threshold.
15 . The system as in claim 13 , wherein the filter is a Gaussian filter
16 . The system as in claim 13 , wherein the controller is configured to determine a derivative of the filtered power signal by determining a first derivative of the filter powered consumption signal and determining a second derivative of the filter powered consumption signal.
17 . The system as in claim 16 , wherein the controller is configured to compare the first derivative of the filtered power consumption signal and the second derivative of the filtered power consumption signal to a predetermined threshold.
18 . The system as in claim 17 , wherein an achieved operational state change of the appliance is identified when at least one of the first derivative of the filtered power consumption signal and the second derivative of the filtered power consumption signal falls outside the predetermined threshold.
19 . The system as in claim 13 , wherein the controller is located in at least one of the appliance and a home energy management system.
20 . The system as in claim 13 , wherein the appliance is at least one of a HVAC system, a refrigerator, a washer, a dryer, an oven, a cooktop, and a range.