The effect of high current density and uneven current distribution on a current collection system

The complex relationship between current density, flash temperature, contact voltage drop, brush wear, and brush hardness is discussed. The flash temperature is estimated for a wide range of current densities and the effect of brush softening at high temperature is included in the analysis. Experimental results obtained from two screening rigs provided strong evidence that a nonlinear current distribution occurred on a current collection system. How the flash temperature and the current collector performance are affected by the effect of such a nonhomogeneous current distribution are discussed. >