Abstract: A bus bar assembly having a high-speed switching device, a bus bar, and a heat sink. The switching device is integrated into a cavity on the top surface of the bus bar, and the heat sink is mechanically coupled to the bottom surface of the bus bar. The bus bar may include capacitors that are positioned upside down on the top surface of the bus bar to more effectively communicate heat from the capacitor to the bus bar and then the heat sink. The heat sink may be formed from a pair of parallel plates that oppose each another to form a cooling channel, wherein a coolant, such as gas or water, may be passed through. An interior surface of one of the plates may incorporate a cooling structure such as grooves or fins.