Military Applications: PDUs and UPS

A reliable source of power ensures critical systems, such as communications, weapons systems, surveillance and command centers, operate during outages. Efficient distribution of that power protects your equipment and maintains the optimal levels of power for each connected device. This guide discusses the key features and requirements of power supplies for military applications.

Military-Grade Uninterrupted Power Supplies (UPS)

A ruggedized UPS for military applications ensures a stable stream of power to sustain mission-critical operations. Military-grade power supplies like a UPS are essential for:

• Preventing data loss: Damage from power surges can cause systems to lose sensitive or classified data. A rugged UPS minimizes this risk by preventing fluctuations in the power supply.
• Reducing maintenance costs: While sudden power fluctuations can damage sensitive equipment, a rugged UPS can prevent downtime and costly repairs caused by power surges. 
• Maintaining high security: A constant power supply ensures security systems, such as perimeter defense and surveillance, stay on even when severe conditions would ordinarily shut them down.

The Role of Power Distribution Units (PDUs)

PDUs for military systems distribute power from a single source — such as UPS — to multiple other devices. These devices manage power for mission-critical equipment and optimize distribution for maximum efficiency.

Essential features of a military-grade PDU include:

• Resistance to extreme low and high temperatures.
• Protective casings to protect against drop damage.
• Noise reduction to ensure compatibility with other devices.
• Reliable operation at high altitudes and extreme cockpit conditions.
• Rugged and portable design to withstand abnormal conditions.

These features enable the device to operate in various conditions and locations, making them suitable for mobile applications such as field training and combat deployments.

Applications of Power Supplies in Military Settings

Common applications for military-grade power supplies include the following.

Field Deployments

Strategically placing rugged UPS and PDUs throughout remote and challenging environments ensures a reliable stream of power even in extreme conditions. Portable models are suitable for on-the-go operations where efficiency is vital, such as:

• Humanitarian aid missions in disaster zones.
• Domestic and foreign training exercises in remote areas.
• Combat deployments in hot regions.

Command Centers

The military's digital infrastructure requires a reliable source of uninterrupted power and a system for efficient power distribution to optimize the supply. A UPS connected to a PDU provides a centralized power management system for sustaining mission-critical communications and data center equipment.

By preventing power interruptions, a military-grade UPS:

• Averts loss of mission-critical data.
• Sustains consistent, clear communication.
• Securely transmits sensitive and classified information.

Military Vehicles and Aircraft

Compact UPS devices in ships, aircraft and ground vehicles protect electronic systems from sudden power fluctuations. This equipment is critical for:

• Communication with command centers.
• Navigation in unfamiliar environments.
• Sustaining equipment in combat operations.

By maintaining sufficient power for onboard equipment, units can significantly improve their chances of a successful mission.

Key Military Standards for Power Supplies

The U.S. Department of Defense (DOD) uses a set of standards to ensure military equipment can withstand the demands of the operations in which it will be used. The following military standards establish key requirements for power supplies and distribution devices.

MIL-STD-810

MIL-STD-810 requires engineers to test products against the environmental stresses they will encounter in the field. These stresses include:

• Vibration and shock
• Extreme high and low temperatures
• High humidity
• Altitudes
• Sand, dust and other debris

UPS and PDUs that meet the standards outlined in MIL-STD-810 are rugged enough to qualify for military use. In some cases, companies may also use this standard to qualify commercial products. 

MIL-STD-461

MIL-STD-461 establishes requirements for the following:

• Ensuring electromagnetic compatibility
• Controlling electromagnetic interference (EMI)

Rigorous testing ensures ruggedized power systems can block both incoming and outgoing EMI signals, which enables various devices in a system to work together without damage.

RTCA/DO-160

Document 160 (DO-160) from the Radio Technical Commission for Aeronautics is an aircraft-specific standard that establishes guidelines for environmental testing of avionics equipment. Some of the conditions this standard tests include:

• Voltage spikes
• Electrostatic discharge
• Temperature
• Magnetic effect
• Vibration and shock
• Crash safety

While it typically applies to commercial aircraft, DO-160 is often used to stress-test power supplies for military power equipment.

MIL-STD-704

MIL-STD-704 standardizes how a military aircraft interfaces with onboard power equipment. This standard applies to both alternating current (AC) and direct current (DC). 

Systems that comply with this standard are certified to be compatible with the aircraft, aircraft utilization equipment and any other power sources within the system. The standard requires manufacturers to test for many different conditions, including:

• Electrical noise
• Ripple
• Phase unbalance
• Voltage
• Frequency
• Maximum current
• Power factor
• Other abnormal conditions, such as under- and overvoltage

MIL-STD-1399

MIL-STD-1399 standardizes requirements for shipboard interface designs using AC power. 

Section 300 of this standard specifies requirements for connecting electrical systems, such as UPSs and PDUs. Power supplies must comply with Section 300 to be suitable for use in electrical interfaces. Section 300 divides shipboard power supplies into three types:

• Type I: A Type I power supply offers either 440 or 115V at an ungrounded frequency of 60 Hz. Type I is the most common shipboard power source and has the fewest restrictions on its use.
• Type II: Type II devices are restricted to specific applications and require users to make a special deviation request. They offer 440 or 115V at an ungrounded frequency of 400 Hz.
• Type III: Type III devices also require a deviation request for approved use, though they have tighter tolerances than Type I and Type II. They offer 440 or 115V at an ungrounded frequency of 400 Hz.

Note that the above types specifically apply to low-voltage power sources, which supply less than 1kV.

MIL-STD-1275

MIL-STD-1275 is a DOD standard that defines test conditions for the input of 28V DC power systems within grounded military vehicles. The four test conditions within this standard include:

1. Ripple
2. Spikes
3. Operating voltages
4. Surges

Essentially, the power supply must be fully operable when exposed to the test conditions. Any device that passes these tests qualifies as a suitable product for military applications.

Contact Astrodyne TDI Corporation for Customized Military Power Solutions

If you require a dependable, rugged power system, it's critical to find an established supplier that understands the importance of power supplies for military use and can meet your specific requirements. The right partner can make all the difference in mission-critical applications.

Astrodyne TDI has more than 60 years of experience developing highly intricate UPS and PDU solutions for applications in military and aerospace. We offer customization capabilities, and all of our solutions align with MIL-STD specifications. You can trust our power supplies to deliver reliability and durability, even in the harshest environments.

Let us worry about the power so you don't have to. Contact us today for more information on our products and capabilities, or request a free quote.