Overview:
In 2005 Vektrex developed and field tested a 6000A, 5V
current source to power a brush testing system for a homopolar motor program.
The current source features adjustable current with low ripple, reverse
Electro-Motive Force (EMF) protection, and water-cooled cables to the
brushes under test. Cooling was considered a critical issue due to the
unattended nature of operation and the requirement for multi-week
experiments. Although water-cooling was an option, the cooling problem was
solved with air through careful analysis and thermal design. The system
included a blank panel area for customer-furnished equipment and, as with
most Vektrex custom solutions, the customer was provided with a
commissioning and operation manual.
High Power Input:
30,000 watts of input power is supplied by a 480V 3
Phase AC 100A mains. To ensure safety and reliability the NEC (National
Electrical Code) was used as a reference throughout the design phase and a
licensed electrician approved the final configuration. The AC input included
remote trip capability to allow the user to remotely shut off the system.
Ergonomics and serviceability were part of the design driving the layout and
labeling of controls and wiring.
Custom 3D Bus Bar:
Output power is adjustable from 0-5VDC at 0-6000A. To
handle the high currents, custom bus bars were modeled using 3D rendering by
Vektrex mechanical engineers. This modeling helped assure the finished
copper bars would mate correctly with the power supply connectors,
protection diodes, and water-cooled cables. The bus bars are 4” wide x ¾”
thick and meets the temperature criteria of no more than a 30° C rise above
ambient. The bus bar assembly provides output balancing to divide the load
among the power supplies and reverse EMF protection to prevent power supply
damage during motor braking.
