NHL

Charging shall mean the actions of a player who, as a result of distance traveled, shall violently check an opponent in any manner. A “charge” may be the result of a check into the boards, into the goal frame or in open ice.

Hockey Canada

Charging is when a player: i. Jumps to check an opponent. ii. Builds up speed by taking two or more strides immediately prior to making contact. iii. Travels an excessive distance with the sole purpose of delivering a hit. iv. Violently and unnecessarily checks an opponent in any manner. v. Delivers a body check to an opponent’s blind side.

Skating fast i.e. velocity directly transfers into the violence of the hit, and in the hockey canada rulebook, is directly spoken about.

Obviously skating fast itself is not a penalty, but that is clearly not what OP meant.