A linear control design structure to maintain loop properties during limit operation in a multi-nozzle turbofan engineThe implementation of multi-variable control systems on turbofan engines requires the use of limit protection to maintain safe engine operation. Since a turbofan engine typically encounters limits during transient operation, the use of a limit protection scheme that modifies the feedback loop may void the desired 'guarantees' associated with linear multi-variable control design methods, necessitating considerable simulation to validate the control with limit protection. An alternative control design structure is proposed that maintains the desired linear feedback properties when certain safety limits are encountered by moving the limit protection scheme outside of the feedback loop. This proposed structure is compared to a structure with a limit protection scheme that modifies the feedback loop properties. The two design structures are compared using both linear and nonlinear simulations. The evaluation emphasizes responses where the fan surge margin limit is encountered.
Document ID
19910061157
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Mattern, Duane (NASA Lewis Research Center Cleveland; Sverdrup Technology, Inc., Brook Park, OH, United States)
Ouzts, Peter (NASA Lewis Research Center Cleveland, OH, United States)