Research on contact resistance modeling of carbon brush and slip-ring system in Doubly-fed wind turbines under marine environment

Abstract The working environment of carbon brush and slip-ring is poor in the marine environment, and salt spray deposition causes a change in contact surface and contact resistance. It is necessary to investigate the mathematical model of contact resistance in the marine environment in order to measure the electrical contact performance of carbon brush and slip-ring. The main factors influencing brush slip ring contact resistance are salt spray concentration, sliding speed, contact current, and contact pressure. The changing trends of dynamic contact resistance with these four factors were studied and the action mechanism were analyzed by testing the contact resistance under different salt spray concentrations, sliding speed, contact current, and contact pressure. The results indicate that as the concentration of salt spray increases, so does the contact resistance, and the upward trend continues. The contact resistance gradually increases with increasing sliding speed, and the change trend is gradual. The contact resistance gradually decreases with increasing contact pressure, and the trend is gradual. The contact resistance decreases as the contact current increases, and the decrease is gradual. The sliding electrical contact resistance model related to salt spray concentration, sliding speed, contact current, and contact pressure was established based on the experimental results. The experimental results show that the model can be used to calculate the sliding electrical contact resistance in an ocean environment under various working conditions.