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Power Management in Regenerative Life Support SystemsEffective management of power can reduce the cost of launch and operation of regenerative life support systems. Variations in power may be quite severe and may manifest as surges or spikes, While the power plant may have some ability to deal with these variations, with batteries for example, over-capacity is expensive and does nothing to address the fundamental issue of excessive demand. Because the power unit must be sized to accommodate the largest demand, avoiding power spikes has the potential to reduce the required size of the power plant while at the same time increasing the dependability of the system. Scheduling of processors can help to reduce potential power spikes. However, not all power-consuming equipment is easily scheduled. Therefore, active power management is needed to further decrease the risk of surges or spikes. We investigate the use of a hierarchical scheme to actively manage power for a model of a regenerative life support system. Local level controllers individually determine subsystem power usage. A higher level controller monitors overall system power and detects surges or spikes. When a surge condition is detected, the higher level controller conducts an 'auction' and describes subsystem power usage to re-allocate power. The result is an overall reduction in total power during a power surge. The auction involves each subsystem making a 'bid' to buy or sell power based on local needs. However, this re-allocation cannot come at the expense of life support function. To this end, participation in the auction is restricted to those processes meeting certain tolerance constraints. These tolerances represent acceptable limits within which system processes can be operated. We present a simulation model and discuss some of our results.
Document ID
Acquisition Source
Ames Research Center
Document Type
Crawford, Sekou
(Orbital Sciences Corp. Moffett Field, CA United States)
Pawlowski, Christopher
(Orbital Sciences Corp. Moffett Field, CA United States)
Finn, Cory
(NASA Ames Research Center Moffett Field, CA United States)
Mead, Susan C.
Date Acquired
August 20, 2013
Publication Date
January 5, 1999
Subject Category
Man/System Technology And Life Support
Meeting Information
Meeting: International Conference on Environmental Systems
Location: Toulouse
Country: France
Start Date: July 10, 2000
End Date: July 13, 2000
Funding Number(s)
PROJECT: RTOP 131-20-10
Distribution Limits
Work of the US Gov. Public Use Permitted.

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