400 Hz Power Distribution Units

Marway has developed and shipped many power distribution units operating at 400 Hz for military and commercial aircraft applications in both on-board and support-role installations. Typically powered from generators on the aircraft, Marway’s PDUs provide distribution and device control for downstream equipment.

For the most part, 400 Hz PDUs aren’t a lot different from other rugged-environment PDUs. However, certain components such as filters and circuit breakers must be selected for 400 Hz compatibility. One less obvious concern is the design of the control scheme in a 400 Hz PDU. Although many 400 Hz compatible control components are available (relays, contactors, etc.), they tend to have a significantly higher cost and lead time than their 50/60 Hz and dc counterparts. One solution is to implement a small universal-input dc power supply in the control scheme, and then utilize control components with dc coils.

In keeping with a “weight is everything” theme for aircraft applications, enclosure chassis for on-board applications can be made from aluminum rather than steel. Understanding the application environment is also important so that cooling efficiency and reliability in conditions with low atmospheric pressure can be considered.

Photo of a 400 hertz power distribution unit front panel. Photo of a 400 hertz power distribution unit rear panel.