Quasi-LPV system modeling and identification of a variable speed electro-mechanical and hydraulic MISO system

Abstract

An accurate digital model is of great significance to system operation inversion and behavior prediction. The multi-energy domain coupling mechanism of the Electro-mechanical and Hydraulic (EMH) system is complex and has strong nonlinear characteristics. At present, the research mainly focuses on the mechanical-hydraulic coupling characteristics, while the research on the large operating range and the influence of electric motor and load characteristics on the nonlinear dynamics of the EMH system are less. Based on the first principle description, the nonlinear characteristics of the system components are described in this paper. Furthermore, the nonlinear dynamic model of the EMH system described in multi-state space is established based on the Quasi-LPV system. Combined with the experimental data, the structural and non-structural uncertain parameters of system are identified. Finally, the influence of the mechanical characteristics of electric motor, load on the nonlinear dynamics of the EMH system are discussed. Experiments show that the Quasi-LPV models proposed in this paper can accurately reproduce and predict system behavior. It provides technical support for rapid design, selection, and scheme optimization of hydraulic systems in general scenarios.

Stability Analysis of the Output Speed in a Hydraulic System Powered by an Inverter-Fed Motor

“…Jeong [14] provided a mathematic description of the first-principle-based characteristics of different nonlinear losses in piston hydraulic motors. Geng [15] described the nonlinear characteristics of the hydraulic components based on the first principle description and discussed the influence of the mechanical characteristics of load on the nonlinear dynamics of the system. Kumar et al [16] explored how the system performs regarding energy efficiency and dynamic features during the unloading and intermittent operation of hydraulic pumps.…”