Investigation of magnetic interference to enhance the system sensitivity of the self-powered piezoelectric current sensors network

Recently, the substantial need of current sensors network for smart grid application has been noticed by energy research society. Because numerous current sensors are used in the sensors network, self-powered function for the sensors becomes extremely important. To address this issue, some researchers recently demonstrated piezoelectric-based self-powered current sensors [1]-[5]. In general, the major structure of the sensor is a permanent magnet mounted on the free-end of a piezoelectric cantilever beam. When the sensor is placed close to an AC current-carrying wire, the beam vibrates due to a magnetic force interaction between the wire and the magnet. Vibrated beam produces voltage outputs due to the piezoelectric effect. This enables the self-powered function for the sensors. However, while the energy/power issue of the sensors network is addressed, the system sensitivity is significantly decreased because of the strong magnetic interference produced by each neighborhood sensors in the network (especially when the sensors must be set on each breaker in a ultrahigh dense breakers panel used in a densely inhabited city). Thus, the magnetic interaction among the sensors in the network must be investigated in order to optimize the system sensitivity. Hence, in this paper, we present a systematic investigation of the magnetic-interaction among piezoelectric current sensors in the network and consequently provide an optimization approach for the system sensitivity of the sensors network.