Mathematical simulation and parameter determination of regulation of a linear electrical reciprocating machine

Abstract

A linear switched-reluctance electrical machine (LEM) intended to be used as an electric-power generator together with a free-piston internal-combustion engine (ICE) has been analyzed. Taking into account the hard service conditions of an electrical machine (EM) in close proximity to a cylinder ICE, hottemperature zones and heavy mechanical loads of the EM of the vent-inductor type have been recommended to be used. Development of a control system for this type of machine is one of the most complicated problems when developing it. It has been suggested to determine the reasonable principles and regulating algorithms of the machine that is being considered, as well as its regulation system and energy-data evaluation, on the basis of a model of the electromagnetic process. Taking into account the characteristic properties of the linear switched-reluctance machine as a modeling object, a mathematical model has been developed to solve the problems mentioned above. As stator phases have separate coil-flux guides and are not connected magnetically, the electromagnetic processes in each phase are analyzed independently. For experimental corroboration of ideas for design calculation, an experimental model of the machine has been constructed. Parameters required for modeling the characteristics’ correspondences of flux linkage and phase current’s generating force at various positions of a moving element have been determined for this machine experimentally. Performance of the linear switched reluctance electrical reciprocating machine has been analyzed with the mathematical model with moving-element movement frequencies unfeasible for study on a proving stand. Reasonable parameters of the current pulses’ phases of the machine have been determined, and its energy data have been evaluated. The obtained results have confirmed the correctness of the design approaches, choice of regulation principles, and adjustment of a linear vent-inductor electrical machine of forward and backward action and the feasibility of using it as an electric-power generator together with a free-piston ICE.