Design and implementation of a wireless node for advanced sensor processing and network integration

This paper presents the design and implementation of a portable base station for a wireless sensor network (WSN) for monitoring power substations. Apart from serving as the sink for all sensor data in the WSN, this node is also capable of high-speed data acquisition, image capture, and connection to the Internet via a cellular modem. In particular, we demonstrate its capabilities for performing high data rate voltage sampling for monitoring the health of transformer bushings from a power substation. Laboratory experiments demonstrate that the samples can be used to estimate phase differences with errors below 0.03° for 60 Hz voltage signals, which is lower than the requirement of a commercial transformer bushing monitoring system. Additional features of the advanced wireless node that are appropriate for substation monitoring applications are also described.