Randomly jittered under-sampling and phase sampling for time-frequency and frequency analyses in AFCI, GFCI, metering, and load recognition and disaggregation applications

A method of analyzing a current or voltage signal, comprising:

• providing, at a sense circuit, a current or voltage signal from an AC mains to an analog-to-digital converter (ADC);
• providing, at a randomly jittered sampling module coupled to the ADC, a trigger input to the ADC, the trigger input causing the ADC to acquire a sample of the current or voltage signal provided by the sense circuit;
• and
• changing, at the randomly jittered sampling module, a timing of the trigger input to cause the ADC to acquire an aperiodic sequence of samples of the current or voltage signal, the aperiodic sequence of samples having an amount of aperiodicity that is randomly generated and fewer than an ideal number of samples for the current or voltage signal;
• and
• performing, at a controller coupled to the ADC, signal processing on the aperiodic sequence of samples to extract information from the signal and providing the information to an external system.

A non-transitory computer-readable medium having computer-readable instructions stored thereon for analyzing a current or voltage signal, the computer-readable instructions, when executed by a controller, cause the controller to perform a process that:

• receives a current or voltage signal from an AC mains at an analog-to-digital converter (ADC);
• provides a trigger input to the ADC, the trigger input causing the ADC to acquire a sample of the current or voltage signal provided by the sense circuit;
• and
• changes a timing of the trigger input to cause the ADC to acquire an aperiodic sequence of samples of the current or voltage signal, the aperiodic sequence of samples having an amount of aperiodicity that is randomly generated;
• and
• performs signal processing on the aperiodic sequence of samples to extract information from the signal and provides the information to an external system.