MIL-STD-1399 Power Supply
Viable Power shipboard/naval powers systems are designed to meet MIL-STD-1399 requirements. A key characteristic of a MIL-STD-1399 power supply is its high power-factor and low total harmonic distortion of the connected AC source. A power supply with a power factor of 1 behaves like a resistive load across the source and is able to utilize the maximum power from that source. As the power factor falls, the power supply appears as a more reactive load (inductive or capacitive) and is able to use less of the power available from the source.
The military standard MIL-STD-1399 Section 300, Part 1 establishes electrical interface characteristics for shipboard equipment utilizing AC low voltage electric power to ensure compatibility between user equipment (the power supply) and the electric power system.
Types of Low Voltage Power Sources
The standard defines three types of low voltage power sources that are used on naval vessels. The preferred source is Type I power which is 440Vrms or 115Vrms at 60Hz. This is the standard AC shipboard electric power source. The sources are either grounded or ungrounded, single or three phase power systems. Types II and III are similar to Type I but 400Hz, Type III has tighter tolerances as compared to Type II.
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.
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.
Our Experts Are Here for You
Viable Power is offering reliable MIL-STD-1399 power supply solutions for the shipboard/naval industry. If you would like to get more information about our services and products for shipboard and naval applications, please feel free to contact us directly. One of our experts will be happy to answer any of the questions you might have.
