Design Considerations for a Large-Scale Wireless Sensor Network for Substation Monitoring

This paper describes the design and deployment of a large scale wireless sensor network (WSN) for monitoring the health of power equipment in a substation. The sensor network consists of 122 low power nodes that that are spread over an area approximately 1000 x 400 feet in size and perform monitoring of equipment such as transformers, circuit breakers, and compressors. All nodes communicate over a multihop wireless mesh network that uses a dynamic link-quality based routing protocol. A primary objective of this project is to develop effective monitoring applications for the substation using low-cost wireless sensor nodes that can sustain long periods of battery life. We study the battery consumption in the network and present a transmission scheme that conserves communication cost by enabling the sensor nodes to transmit observation samples only when their values are significantly different from those transmitted previously. Experimental results that demonstrate the performance of the sensor network for several monitoring applications are presented.