Carbon brush wear calculation in marine environment based on temperature field analysis

Abstract In the marine environment, the working environment of the doubly fed wind generator carbon brush and slip‐ring system is complicated, salt spray deposits and seawater erosion affect the temperature field and contact surface friction factor leading to carbon brush wear increase and shortened replacement cycle. The three‐dimensional temperature field simulation model of the carbon brush and slip‐ring system is established. The main factors affecting the carbon brush and slip‐ring system temperature field are sliding velocity, load current, ambient temperature, contact surface condition and contact pressure applied to the brush. Wear capacity of carbon brushes is affected by contact surface temperature. An experimental platform combined with the salt spray test machine was built to carry out the contact current, contact pressure, salt spray concentration and experimental temperature experiment. The improved Coulomb‐viscous friction force model was used for the wear prediction model. The sliding velocity, contact pressure, contact current, experimental temperature and salt spray concentration were introduced into the model. The experimental verification has shown that the prediction model can effectively predict the carbon brush wearing capacity under different conditions. This model can be applied to formulating the carbon brush wear amount and replacement cycle in the marine environment reducing operation and maintenance costs.