On the application of wireless sensor networks in condition monitoring and energy usage evaluation for electric machines

Condition monitoring of electric motors avoids unexpected motor failures and greatly improves system reliability and maintainability. Energy usage evaluation, which shares many common requirements with condition monitoring, could be implemented into an integrated motor monitoring system. Advances in micro-electro-mechanical systems, wireless communications, and highly integrated electronics have enabled the implementation of wireless sensor networks (WSN). The unique characteristics of WSNs such as flexibility, high fidelity, self-organization, inherent intelligence, low cost, and rapid deployment make them the ideal structure for incorporating energy usage evaluation and condition monitoring functions. This paper proposes a scheme for applying WSN in energy usage evaluation and condition monitoring for electric machines. The importance of this scheme lies in its non-intrusive, intelligent, and low-cost nature. As the focus of this paper, the system requirements and non-intrusive methods for energy usage evaluation and motor condition monitoring are discussed. Finally, the overall system applicability is investigated by verifying the air-gap torque method for motor efficiency estimation and the air-gap eccentricity detection algorithm for motor condition monitoring in the proposed scheme using experimental results.