Insulation Structure Calculation And Analysis For Middle Size Induction Motor With High Efficiency And High Voltage

Motors are the electrical equipments of the largest power consumption in industry and everyday life. In our country, the electricity consumption of three-phase induction motors occupies national amounts 60% above. Therefore, improving the efficiency of the motor has great significance for saving resources and protecting the environment. Generally, we can improve the efficiency of the motor by using the methods of the electromagnetic design and optimum technique. For the motor with high voltage, reducing the stator insulation thickness is not only saving the insulation costs, but also increasing the utilization ratio of the slot and decreasing the value of the stator winding resistance, and improving the efficiency of the motor.The main content of this dissertation are two sides, one side analyse the electric field in department of the slot, the corner and the end by using the finite element software. Observe the factors, which as the most influence in electric-field strength distribution. Analyse the electric-field distribution before and after reducing insulation. On the other side, based on finite element analysis and made the test coils, through the dielectric loss factor test and dielectric strength test before and after reducing insulation to determine the feasibility of reducing the main insulation.The conclusions of this dissertation are as follows: (1) The maximum and minimum values of electric-field strength all appear at 45 degrees direction rays. Giving consideration to improve slot utilization ratio and minimize electric-field concentration factor two metrics, is suitable for choosing 0.8mm as the coil cross section fillet radius. (2) The test coil with 1.1mm insulation thickness adopts less glue mica tape with high dielectric properties and optimized structure, which could meet the insulation structure requirements compared with original 1.5mm insulation thickness. (3) Obtain that the end after reducing insulation could meet job requirements through the comparison results of simulation and experiment, and the whole motor test data shows that the efficiency is improved.