International Conference on Optimization of Electrical and Electronic Equipment (OPTIM) / Intl Aegean Conference on Electrical Machines and Power Electronics (ACEMP), Brasov, Romania, 25 - 27 May 2017, pp.330-335
Energy in the world is one of the priority issues and energy demand is rapidly increasing depending on the growing population and industry. The usable energy sources in the world are to be insufficient to meet the energy need. Therefore, the efficient and economical usage of energy sources is getting great importance. In a survey conducted among electric consuming machines, the electrical machines are consuming 40% of the total electrical energy consumed by electrical devices. About 96% of this consumption belongs to induction motors. Induction motors are the workhorses of industry and have very large application areas in industry and urban systems like water pumping and distribution systems, steel and paper industries and etc. Monitoring and controlling the motor operation, have important effect on the operating performance of the motor, driver selection and replacement strategy management of electrical machines. In this paper the design of a sensor less monitoring system for monitoring and calculating efficiency of induction motors is studied. The IEEE equal circuit model of induction motor is used in designing the monitoring system. The terminal current and voltage of induction motor are used to measure efficiency of induction motor. The system uses motor nameplate information and the current and voltage values measured using suitable devices to calculate accurate losses of induction motor to calculate input and output power. The proposed monitoring system monitors the induction motor efficiency online, without disconnecting the motor from the driven equipment and without using any additional connection at the motor terminal box. The proposed monitoring system measures accurately the efficiency by including all losses without using torque meter and speed sensor. An embedded architecture is used in monitoring system and there is no need to connect to personal computers to measure and logging the measured data. The conclusion regarding the efficiency, accuracy, technical and economic benefits of the proposed method are presented. The experimental verification has been obtained on a three phase 1.1 kW 2-pole induction motor. The proposed method can be used for optimal control of induction motors, efficiency monitoring and motor replacement strategy.