Single-phase grid-fed variable frequency high-efficiency induction motor drive for fan applications

This work deals with a single-phase grid-fed fan type variable speed load profile system operated by a mechanical sensorless induction motor (IM) drive. A power factor corrected (PFC) boost converter is utilised for the development of the system. A full speed range of a fan with enhanced power quality during normal and abnormal grid voltage conditions is achieved by using this system. The system is simulated and analysed under variable speed and load conditions, during both the normal and weak grid, for a fan type load profile. To comply the IEEE-519 standard at the utility grid, the power quality limits are achieved by developed control. Simulated results are validated with test results obtained on a developed prototype. The simulated and test results validate the suitability of the developed system at diverse operating conditions. The operational cost of the system is reduced by the use of a high-efficiency IM and its efficiency is optimised. A combined approach of design of experiment (DOE) for reduction of variables and a particle swarm optimisation (PSO) technique with an objective function as the maximisation of efficiency is used to design and develop an IM with improved performance. Initially, parametric analysis of different variables of the IM is performed analytically to design the IM, design of experiment is used to reduce the number of variables, and different components of the motor are designed and optimised using PSO. Design simulations are performed using RMxprt analysis and finite element analysis is performed using Maxwell-2D design software. The developed high-efficiency motor is tested on a test setup in the laboratory and its tests are conducted as per the IEEE-standard 112-2017, with comparative analysis of a conventional motor of a 1.5 kW four-pole, three-phase squirrel cage IM, and simulated and experimental performances justify its suitability for grid-fed fan applications.