Design Optimization of Capacitor Start Single Phase Induction Motor /

Abstract

Single-phase induction motors (SPIMs) have been commonly used in domestic and industrial applications because of their low power rating and simplicity of power supply. Due to the widespread application of SPIMs, efficient electric motors are more demanded to save the overall consumption of electricity. These motors are typically operating many hours a day and most of them are highly inefficient that cause huge power loss. There are other highly efficient motors are available like brushless DC but the cost of magnet and electronic circuits are very high. Therefore, to overcome the inefficiency, there is a greater demand for highly efficient induction motor. An induction motor has proven superior performance, rugged construction, and low cost. From the manufacturer perspective, it is less expensive to build a single-phase induction motor where no need for a permanent magnet that makes it economically viable. The optimization of SPIM can achieve the objective of energy-efficient design. The purpose of this thesis is to maximize the efficiency and another performance parameter like power factor, output power and input power etc. and aimed to increase the dynamic performance of the capacitor start SPIM for domestic and industrial applications like water pumps. The analytical model is developed for a motor that is available in the market and is validated using finite element analysis. This thesis focuses on the efficiency improvement of SPIM by employing genetic algorithm-based multi-objective optimization. To design the optimal SPIM, the multi-objective analysis is carried out through the ANSYS Maxwell software and optimal design characteristics are compared to the basic motor. Basic and optimized motors are also analysed using a Maxwell-2D transient solver to validate the analytical model. Stator/rotor core and rotor cage materials are also explored to further improve the performance. As a result of the optimization process, a high-performance SPIM is obtained with a 17% increase in efficiency, reduction of rated current and input power compared to the basic motor which proves more efficient than the existing design. This design also complies with the IE3(Premium Efficiency) standard.