An Enhanced Dynamic Simulation Model of a Hybrid Magnetic Bearing Taking Account of the Sensor Noise

Abstract

The paper presents simulation and experimental verification of the hybrid magnetic bearing (HMB) performance characteristics. It has been demonstrated that the additional errors from the eddy current sensors have a significant impact on the control signals. An improved mathematical model combines a nonlinear magnetic equivalent circuit of the HMB with the ordinary differential equations of its transients. These equations describe the rotor motion and the electric circuit of the system, as well as the control system required for stable levitation of the rotor. Certain harmonics have been observed in the displacement signals of frequencies equal to the multiples of the cylinder rotations. The calculation model has, therefore, been improved, taking into account the interference of the harmonics. Simulation results were validated by comparing the time responses of the transients obtained from the numerical calculations with those measured on a real object; a satisfactory agreement between the results has been achieved.

Using a Current Shunt for the Purpose of High-Current Pulse Measurement

“…For numerical calculations of the power supply system dynamics, the circuit method was used [ 29 , 30 , 31 , 32 ]. The circuit model of the shunt was implemented in Matlab/Simulink software.…”

Modeling of Magnetic Field and Transients in a Novel Permanent Magnet Valve Actuator

“…The dynamic inductance Ld of the excitation coil was calculated from the current derivative of the magnetic flux which is linked with the coil turns, and the electromotive force (EMF) can be calculated from the position derivative [17] = , = We want to underline advantages of our construction. The excitation field generated by a current in a winding is needed only for switching the extreme positions.…”

“…The dynamic inductance L d of the excitation coil was calculated from the current derivative of the magnetic flux which is linked with the coil turns, and the electromotive force (EMF) can be calculated from the position derivative [17]…”

“…•100 % (17) where: N-number of measurement points, y meas i -measured value in i-th point, y calc i -calculated value in i-th point.…”

Two Models for Time-Domain Simulation of Hybrid Magnetic Bearing’s Characteristics

“…The third type of simulation model is a flux-circuit directly coupled magnetic equivalent circuit (FC-MEC). For this model, the magnetic field parameters of the electric machine are calculated directly from the magnetic equivalent circuit (MEC) at every solution of the external electric circuit equations and torque/force balance equations [16]. MEC of an electric machine can incorporate nonlinear characteristics of the magnetic material, as well as leakage and fringing fluxes [17,18].…”