Research and analysis on overheating protection design of aviation oil-cooled generator

Abstract

The thermal field distribution of generator is of a significant effect on the failure phenomenon of the overheat protection component,which is a key parameter to be considered in the optimization design. The thermal field distribution of the motor under fault mode is simulated by using the steady-state pressure solver and turbulence model in ANSYS software. The thermal field distribution of the stator,rotor and shell circulating oil circuit is obtained. On this basis,the material melting point and softening temperature of key components are adjusted,and design scheme of thermal trip protection device is optimized,which will be helpful to realize the protection of motor overheating,which is successfully applied to a certain aircraft and verified through experiments and flight tests. The results show that the simulation is consistent with the actual temperature field distribution. The simulation results of the thermal field distribution of the generator and low melting point alloy show that the insulation liner softens as the oil temperature at the outlet of the motor reaches 260 ℃ leading to oil leakage in the motor cavity. Meanwhile,with the softening temperature of generator insulation liner increases to 350 ℃,generator burnout is significantly prevented.

Keywords

• oil-cooled generator
• thermal tripping
• thermal field distribution
• overheating protection temperature
• temperature matching