Power

Champion Aerospace is preparing for the age of the More Electric Aircraft (MEA) or All Electric Aircraft (AEA) by transforming its highly pedigreed 28VDC Transformer Rectifier Unit (TRU) to a 270VDC or 540VDC Power Supply system to support operation of new electromechanical equipment that will replace traditional pneumatic or hydraulic power. This operating voltage provides improved electrical efficiency, drives lower aircraft weight, improves aircraft safety/reliability and provides positive environmental impacts. 270VDC is accomplished by rectifying the traditional 3 phase 115VAC 400Hz line-to-line voltages via typical AC-DC conversion methods that meet requirements of MIL-STD-704.

270VDC Power Supply Key Design Parameters:

The 270VDC Power Supply may also be used in conjunction with a 270VDC Uninterruptible Power Supply (UPS) attached to the bus for critical mission equipment affected by AC bus transfers, low voltage sags, and other AC/DC interruptions. This allows utilization equipment to maintain full operational capability and “ride through” these interrupts. The device can also provide transient voltage surge suppression during harmful high voltage transients to prevent catastrophic system failures. This UPS device is compatible with all power converters and plays a vital role in preserving the life of utilization equipment.

270VDC UPS Key Design Parameters:

Champion Aerospace Model 28VUPS29FSPD is an uninterruptible power supply with an integrated transient voltage surge suppression (Surge Protection Device (SPD)) circuit specifically designed for airborne applications.
The UPS provides bridge power to mission equipment during AC bus transfers, low voltage sags, and other AC/DC interruptions. This allows utilization equipment to maintain full operational capability and “ride through” these interrupts. The device also provides transient voltage surge suppression during harmful high voltage transients to prevent catastrophic system failures. This UPS device is compatible with all power converters and plays a vital role in preserving the life of utilization equipment. Designed to meet MIL-STD-704 (A-F) for Aircraft Electrical Power, the 28VUPS29FSPD is the latest development of a complete line of uninterruptible power supplies produced by Champion Aerospace, LLC.

Conventional wisdom says that unregulated TRUs are unable to provide “clean”, low ripple and stabilized voltage whereas regulated TRUs (RTRUs) resolve these concerns with a “tight regulation”, but this is not the case as revealed here. The latest Champion Passively Controlled Transformer Rectifier Units (PCTRU) provide superior voltage stabilization for transients and ripple voltage simultaneously. Data shown here reveals the differences in these converters allowing technical decisions to be made with respect to the different topologies available. The PCTRU is available in existing designs from 50 to 300 amperes.

High Voltage Transients
High voltage transients are generally understood as “life altering events” for utilization equipment containing semiconductor devices. Nearly all advanced electronic utilization equipment contains semiconductors that are susceptible to these high voltage transients. High voltage transients greater than 40 Volts are known to cause equipment to fail catastrophically, and/or prematurely, resulting in the loss of avionics and increasing maintenance costs.

Champion’s PCTRU incorporates transient voltage surge suppression to keep high voltage transients under 40 volts. Champion’s PCTRU suppresses high voltage transients without using active feedback inherent to Regulated TRUs. This transient voltage surge suppression method protects utilization equipment without adding a high steady state failure mode associated with Regulated TRUs.

Ripple Voltage
Ripple voltage is defined as the variation of voltage about the steady state DC voltage during steady state electric system operation. Many TRUs being installed on aircraft today produce ripple voltage greater than 1.5Vpk-pk. This generates significant concerns with the overall system integration with regards to electronic system faults, compatibility, and performance degradations in advanced electronic systems. High ripple voltage (greater than 1.5Vpk-pk) can have a “poisoning” effect on equipment causing it to degrade over time.
Champion Aerospace’s simple passive techniques in the PCTRU provide a typical ripple voltage of 0.20 Vpk-pk (shown below) which is a 90-95 percent improvement beyond competitive aircraft power supplies.

Competitive Comparisons

Transformer Rectifier Unit (TRU) Competitive Evaluation