Figure 7 illustrates the main functional blocks within the WACU.
An AC output EMI filter limits conducted and radiated emissions from the WACU.
The WACU power stage consists of an active 3-phase bridge, 2- level inverter.
The WACU contains inverter output filtering for EMI compatibility.
The WACU contains a differential mode EMI filter for the 28Vdc control input power.
The WACU cable interfaces consist of both signal level and high-power connections.
The 3-phase AC power cable that delivers the power from the WACU to the TM has stringent requirements.
A picture of the prototype WACU used in the PAS is shown in Figure 8.
The AC-to-DC converter needs to have voltage boosting capability to reduce the currents in the WACU, the TM, and the interface cables, which will lead to substantial weight savings.
The WACU architecture uses a three-phase active bridge arranged as a two-level inverter.
Self cooling with dedicated fans for the large components like the ATRU, the WACU, and the TM is probably the most efficient method since the distance between the components is large and an active liquid cooling system is not justifiable