Hello Marimuthu,
simulink wires can carry multiple signals (aka, they can be vectors instead of scalars). This can be controlled with the mux and demux blocks, or the selector block. Your simulation is reporting a mismatch, so you might be using a power systems block that requires more signals than you are passing to it, or you might be passing too many signals. You will to make sure your input lines have the appropriate dimensions for the input ports they are connecting to. The error tells you the specific signal that is causing the problem.
Regards,
Joel
