The equation for hypervortex in a slightly granular superconductor is obtained, and the vortex lattice is numerically simulated. The dissipation associated with the formation, collapse, and movement of hypervortices is considered. The equations describing the dynamics of magnetic field distribution, nonlinear susceptibility, and current–voltage characteristics in the resistive state are obtained. The numerically simulated equations give results that are in good agreement with those obtained experimentally. ©1997 American Institute of Physics.