SYSTEM AND METHOD OF IDENTIFYING PATH OF RESIDUAL CURRENT FLOW THROUGH AN INTELLIGENT POWER STRIP
A system and method is disclosed for detecting a specific voltage phase, from a multiphase voltage source, and a specific outlet of an intelligent power strip, that is associated with a residual current flow. The method accomplishes this by using a system that employs a statistical time series analysis using a Pearson's correlation coefficient calculation to measure the linear dependence between the discretely sampled residual current waveform and each phase and outlet's discretely sampled current waveforms, in turn. A residual current as low as 1 mA can be accurately measured and its associated voltage phase source, as well as which outlet of an intelligent power strip it flows out of, can be reliably determined.
1 . A method for detecting a residual current flowing through an intelligent power strip having at least one alternating current (AC) power outlet, the method comprising:
obtaining current sensing information;
performing an analog-to-digital (ADC) conversion of the current sensing information to obtain ADC samples;
managing a time series collection of the ADC samples as residual and outlet current waveform samples;
calculating residual current (RC) RMS values for the obtained residual current samples;
calculating phase current from the aggregation of the outlet current waveform samples having the same phase;
calculating Pearson's correlation coefficients for variables relating to residual current and the phase outlet current waveforms;
calculating Pearson's correlation coefficients for the variables relating to residual current and individual outlet currents waveforms from each AC power outlet;
calculating the phase having a maximum positive Pearson's correlation when the residual current RMS is greater than a predetermined residual current RMS threshold; and
determining an individual one of the AC power outlets having the maximum Pearson's correlation when the residual is greater than the predetermined RC threshold.