Naval Military Power Supply and THD
One of the key differences between the naval specified military power supplies and ground defense power supplies and aerospace power supplies is the tight specification of total harmonic distortion (THD).
The MIL-STD-1399 specifies maximum THD for Type I power as 5%, with a single harmonic maximum of 3%. The THD is a measure of the quality of input source and is determined by summing all the harmonic components of a signal and comparing it to the fundamental frequency. THD standards for current are important because those higher-frequency current components have various undesirable effects on electrical systems, including increased total currents, increased core losses in motors, and electromagnetic interference with other electronic equipment.
In order to meet the low THD and high power-factor requirements, Viable Power uses active Power Factor Correction (PFC), either with discrete designs or with industry standard AC front end power factor correction modules or harmonic attenuation modules. The result is a custom power supply suitable for military naval applications.