Adaptive control of speed and equivalence ratio dynamics of a diesel driven power-plant

A method of modeling, involving approximation of dead-times, is presented for diesel driven power prime-movers. The resulting predictive adaptive control scheme is compared to a conventional PI scheme on the basis of common disturbances encountered by a practical prime-mover. It is found that the adaptive scheme achieves significant improvement despite the nonlinearities introduced by turbocharger operation. It is observed in general that adaptive schemes, such as the one described, affect the prime-mover dynamics in essentially two ways. First, the engine fuel-flow response is improved by better control of the actuator. Secondly, by indirectly controlling the exhaust energy of the plant, the turbocharger air-dynamics is made faster, leading to better dynamic fuel/air ratio. The overall effect is good response of the prime-mover speed notwithstanding the fact that the diesel prime-mover is a low inertia structure and that the system parameters suffer from various nonlinear variations.<
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