| 摘要 |
A device or appliance 5 connected to a power circuit 2 is monitored by a sensor 10 connected to the circuit e.g. in a circuit breaker unit or box 3. The sensor samples electric conditions in two time windows of different length. The longer window is used to determine a harmonic vector and the shorter window is used to determine a transient vector. A signature vector of the device is determined from the harmonic and transient vectors. The sensor (figure 2) may be configured to fit in a standard mounting unit in a distribution box in place of a DIN standard circuit breaker. It includes a toroid (12) for sensing current and two voltage contact probes (14, 16) attached by magnets (17). The sensor may communicate via a communications link 46 to a central data processor 40 including a database 44 of appliance signatures to identify the device. Automatic switching off of the appliance may be controlled based on the sensor measurements or a display made on a user interface 48. |
