On the basis of the time-dependent Ginzburg–Landau equation we studied the dynamics of the superconducting condensate in a wide two-dimensional sample in the presence of a perpendicular magnetic field and applied current. We could identify two critical currents: the current at which the pure superconducting state becomes unstable ( J c2 1 Everywhere in the paper we define the current by J=I/d=∫ 0 Wj(x) dx . 1 ) and the current at which the system transits from the resistive state to the superconducting state ( J c1< J c2). The current J c2 decreases monotonically with external magnetic field, while J c1 exhibits a maximum at H ∗ . For sufficient large magnetic fields the hysteresis disappears and J c1= J c2= J c. In this high magnetic field region and for currents close to J c the voltage appears as a result of the motion of separate vortices. With increasing current the moving vortices form `channels' with suppressed order parameter along which the vortices can move very fast. This leads to a sharp increase of the voltage. These `channels' resemble in some respect the phase slip lines which occur at zero magnetic field.