Integrated Software for Numerical Calculation of Active Magnetic Bearings Force Characteristics with Data Accumulation for Various Parameters

Abstract

The paper proposes a technique and a software tool for calculating the force characteristics of a radial active magnetic bearing with an eight-pole stator with a known control law. It is based on the application of the finite element method implemented in a software package for a general technical analysis of physical processes. The procedure for constructing a computational model, electromagnetic analysis, and displaying graphical and numerical results is implemented in the form of a program code in a parametric programming language of the software package itself. The main program created in C++ is a software integrated with it. It performs an interaction between the user and the software package by setting the bearing parameters, the control law and the initial data of a variant parametric analysis of magnetic forces depending on the position of the rotor in active magnetic bearings and control signals. The active magnetic bearing control law is control signals (control voltages) that are applied to electromagnet windings. Their values depend on the current position of the supporting sections of the rotor and, as an option, the instantaneous values of currents in circuits. All specified data are entered into the code for the software package prepared in advance and stored in the main program. After that, an analysis in the complex is launched in a hidden batch mode. The magnetic forces are calculated from the Maxwell tension tensor in a given cloud of points of the rotor position. The force characteristics are dependences of the restoring magnetic forces in the bearing depending on the displacement of the supporting sections of the rotor in two radial directions. They are also rendered in the main program. For the analyzed design variants of active magnetic bearings and control laws, storage in a database is provided with the possibility of subsequent download and display. The results of computational studies to determine the dependences of magnetic forces on rotor displacements for the design of an active magnetic bearing used in an experimental scale model of a turbocompressor of a gas compressor unit with active magnetic bearings are presented. Verification of the integrated software tool was performed by comparing the calculated and experimental data.