A robust smart sensor for smart substations

A low-cost, self-powered, current and temperature smart wireless sensor that can be used in conjunction with several types of utility assets including bus-bars, transformers, disconnect switches, cables, and conductors promises high value for utilities as they move towards a smarter grid. Such sensors will increase asset utilization and reliability, and help utilities in making proactive decisions via an increased amount of information. This paper extends the concept of universal, low-cost, smart, wireless sensors that can be flexibly used with many assets. Challenges related to optimal design for the energy harvester of the sensor, operation of the sensor under fault conditions, and protection of the sensor from lighting strikes, faults, and EMI/corona noise have been addressed. Based on extensive simulation and experimental study, novel designs for an optimal harvester, a versatile protection circuit, and a robust enclosure for the sensor have been proposed. Furthermore, a conceptual network architecture that uses such sensors in a distributed manner to create a smarter substation has been economically justified.