  We present our recent results on the temperature dependence of
current-voltage characteristics for polycrystalline Y_{1-x}Pr_{x}Ba_2Cu_3O_7
superconductors with x = 0.0, 0.1 and 0.3. The experimental results are found
to be reasonably well fitted for all samples by a power like law. According to
the theoretical interpretation of the obtained results, nonlinear deviation of
our current-voltage characteristics curves from Ohmic behavior below Tc is
attributed to the manifestation of dissipation processes related to the current
induced depinning of Abrikosov vortices.
