Conception of a wireless cell for the energy consumption diagnosis of AC rotating machines

The paper presents a application of wireless sensor network used to diagnose the efficiency of AC electrical machines. It explains the functions of the cell and the constraints which makes it a real tool for industry. The key point of the energy diagnosis consists in determining the electromagnetic torque in steady state, taking into account only the indications of the rating plate and without measuring the voltage or the speed. A simple but little-intensive computing technique based on the current estimation is presented. A specific probe for the current estimation is also described, as well as the device to transmit and collect data. Application concerns a 3kW induction machine. The complete wireless sensor network is composed of small spatially distributed cells that can communicate with each other over the air.