This paper presents a novel method for non-intrusive home current measurement using an array of magnetic field sensors. It is specifically designed for measuring the real-time currents on three wires, including two hot wires and one neutral wire, enclosed in the electric conduits of North American homes. The key idea is to extract information from appliance state changing events captured by sensor measurement changes. Since each detected event only corresponds to two wires between which the state-changing appliance is connected, the events can be clustered according to the wire connections. Wire position identification is formulated as a nonlinear least square problem and is efficiently solved. Then, real-time current measurement is achieved by using the trans-impedance matrix built based on the solved wire positions and the sensor parameters obtained from the manufacturing process. The proposed method is evaluated by extensive laboratory and field tests.
- Event detection and clustering
- Magnetic field sensor
- Current measurement
- Nonlinear least square
- Sensor array