Patent ID: 9658261
Date: 2017-05-23
CPC Classifications: G01R,H02J

Claim:
1. A harmonic-characteristics based current pattern matching method performed with a monitor device for the non-intrusive power load monitoring, comprising steps: (a) establishing a load signature database of household appliances, said database comprising information about (i) power states and operating states which each appliance of said various appliances has, and (ii) steady-state current harmonic parameters of each of said operating states of each said appliance; (b) registering all electrical appliances inside a total household load and initializing a linear load state word space table in an on-board memory module of said monitor device by (i) acquiring load characteristic information for each of said electrical appliances from said load signature database and (ii) performing statistical analysis on all possible operating states of said total household load and storing results of said statistical analysis in said memory module in the form of a linear state word table; (c) performing data acquisition and data preprocessing by measuring terminal voltage and steady-state total current of said household load, which are then processed in a processing module in said monitor device to obtain a measured total fundamental active power value, a total fundamental reactive power value and a unit total current pattern; (d) performing a looking-up search on said linear state word table to obtain a feasible state word space based on said measured total fundamental active power value and said total fundamental reactive power value; (e) performing an optimal matching of current pattern based on the following equation: to obtain conresponding SW (f) displaying said information of the power state and operating state on a screen of said monitor device; wherein in step (a) said steady-state current harmonic parameters in step (a) is determined based on the following equation: where ai is appliances, Si is operating states of each appliance, H is the maximum harmonic order, h is harmonic order, α wherein in step (b) said statistical analysis is performed on total load power state, which is expressed as power vectors P where superscript “1” is fundamental wave, N is the number of appliances inside said total load, i is individual appliance ai; said statistical analysis is performed further on N-dimensional state word vector SW(t) Z N as expressed in equation: SW(t)=(s( 1 ), . . . , (s)(i), . . . s(N)) T , which represent all possible operating states of said total household load and stored in a linear table in an order according to a reference value of total fundamental active power corresponding to each state word vector; and wherein in step(c) said measured total fundamental active power P