The surge current is the peak current flowing into the power supply  equipment when the power is turned on. Since the output filter capacitor is quickly charged, the peak current is much larger than the steady-state output current. The power supply should limit the surge levels of AC switches, rectifier bridges, fuses, and EMI filters. Repeated switching of the loop, the AC input voltage should not damage the power supply or cause the fuse to blow.

The electrical term for the peak current means the current value at the maximum load. Generally refers to the alternating current, in the stable working time, the current and time function

In the figure, the peak of the sine wave is the peak current. It is also within the range of rated current.

Surge current peak is as same as the peak current, peak inrush current and RMS current.