Applications of ZigBee wireless technology for industrial instrumentation

Measuring current is fundamental to electrical engineering. Wireless current sensing systems, which do not involve the insertion of a sensor into a circuit, are attractive. This paper describes the implementation and performance of such a system using the recently introduced ZigBee wireless protocol. The system uses a Rogowski coil as the sensor, and a transmitter unit incorporating an integrator, microcontroller and ZigBee transmitter module. The receiver has a further ZigBee module, and a further microcontroller driving a liquid crystal display giving a current readout. Testing shows that the system works, with a linearity error of less than 0.04A and a potential battery lifetime of eight months.