動力制軔

Dynamic brake is a braking system type designed to aid mechanical brakes when slowing down trains .

為防止軔塊磨損和過熱，大多數的機車和機動車輛都配備著替代的減速方式，例如「電阻電軔機」、「液力軔機」和「引擎軔機」。這些制軔方式使用車輛的動力總成作為減速手段，而不是依靠軔塊的摩擦力。

Depending on the powertrain type, there are different types of dynamic brakes, such as rheostatic , hydrodynamic and engine brakes.