Phase noise as power characteristic of individual appliance for non-intrusive load monitoring

摘要

Phase noise, a unique characteristic of electrical appliances, for non-intrusive load monitoring (NILM) is proposed. NILM is a technique, which can distinguish the power consumption of an individual electrical appliance, without requiring the installation of sensors on the appliance, reducing the number of sensors required in an energy management system. It utilises the previously-recorded power supply characteristics of individual appliances and measures the changes in the bus voltage or current, which provide power supply to several appliances, thereby distinguishing the operational appliances without direct measurement. Considering electrical appliances that can be commonly found in a laboratory, such as an electric drill, soldering iron, and light bulb, the authors found that, when each was turned on, the current at an offset of 5 Hz from the centre frequency of 60 Hz was 61.4, 18.8, and 6.2 mA for each appliance, respectively. As each appliance was turned on in the sequence, the bus current providing electrical energy to all three appliances was measured to be 60.4, 11.1, and 5.7 mA, respectively. Thus, it was experimentally confirmed that the current at frequencies near the centre frequency, i.e. the phase noise, can be used for NILM.