Robust model-based switching MIMO air handling control of turbocharged lean-burn SI natural gas variable speed engines

Abstract

This paper demonstrates a multiple-input multiple-output (MIMO) controller design framework and a controller switching algorithm for MIMO controllers in their state-space form, which together achieve robust, efficient control of turbocharged lean-burn engines over a wide operating space. The controller design framework requires a linearized plant model, and uses the [Formula: see text]-synthesis and DK-iteration algorithms while considering state and output uncertainties and actuator bandwidths to synthesize a robust [Formula: see text] controller. A controller switching methodology using slow-fast controller decomposition and also incorporating hysteresis at switching points is utilized to smoothly transfer control authority between several MIMO controllers. The approach is applied to a high-fidelity truth-reference GT-Power engine model for a lean-burn natural gas-fueled engine to evaluate the closed-loop controller performance. The multi-tracking control problem targets engine speed, differential pressure across throttle as well as air-to-fuel ratio to achieve satisfactory engine performance and emissions without compressor surge. The engine response obtained using the robust MIMO controller is compared with that obtained using a state-of-the-art benchmark controller to evaluate the additional benefits of the MIMO controller.

Control design-oriented modeling and µ-synthesis-based robust multivariate control of a turbocharged natural gas genset engine

“…With proper denotation, the comprehensive control design-oriented mathematical model for the studied engine can be represented by the equations on the left side of the following expression. Linearizing the nonlinear model around an equilibrium condition of the engine could yield a linear model, as shown on the right side of equation (11). The symbolic A, B, and V Jacobian matrices are obtained by taking partial derivatives of the seven state equations (denoted as f 1 through f 7 ) with respect to x, u, and d. Similarly, the symbolic C and D Jacobian matrices are obtained by taking partial derivatives of the three output equations (denoted as g 1 through g 3 ) with respect to x and u.…”

“…Therefore, developing a comprehensive framework for synthesizing robust multivariate controllers to solve multifaceted engine control problems arising from engine performance requirements, safe operation, and emission regulation is meaningful. One such effort by the authors of the present work is published in Rayasam et al, 11 in which a robust switching multivariate air handling controller is proposed for a natural gas variable speed engine with marine application. The controller proposed in this previous work contains multiple local controllers, and needs to perform switching between different local controllers to realize appropriate control of the engine over its entire operating region.…”

Transient Performance of Gas-Engine-Based Power System on Ships: An Overview of Modeling, Optimization, and Applications

“…At present, this method enjoys the widest acceptance in transient situation studies. This method has been implemented in GT-Power and, then, was integrated into various loading scenarios to investigate the engine performance and test the control strategies [65,95,166,[207][208][209][210][211][212]. One-dimensional simulation has also been developed on another platform; Marco et al [115] established the dual-fuel gas engine model for comparing the influence of the turbocharger on engine power management based on the Matlab/Simulink environment.…”