Control of Magnetic Bearings for Rotor Unbalance With Plug-In Time-Varying Resonators

Abstract

Rotor unbalance, common phenomenon of rotational systems, manifests itself as a periodic disturbance synchronized with the rotor's angular velocity. In active magnetic bearing (AMB) systems, feedback control is required to stabilize the open-loop unstable electromagnetic levitation. Further, feedback action can be added to suppress the repeatable runout but maintain closed-loop stability. In this paper, a plug-in time-varying resonator is designed by inverting cascaded notch filters. This formulation allows flexibility in designing the internal model for appropriate disturbance rejection. The plug-in structure ensures that stability can be maintained for varying rotor speeds. Experimental results of an AMB-rotor system are presented.

A novel iterative learning control method and control system design for active magnetic bearing rotor imbalance of primary helium circulator in high-temperature gas-cooled reactor

“…Most research results on the AMB rotor unbalance control need to extract the periodic components of the signal, but unfortunately most of them only described the algorithm theory and did not analyze the existing problems from the perspective of digital control system. [11][12][13][14][15][16][17][18][19][20][21] However, we found PCEA based on Fourier transform theory would occupy numerous computing resources, which ultimately cannot meet the real-time requirement of the control system.…”

“…The former is suitable for high-precision applications 8,11 and the latter is suitable for high-speed applications. 12,14 However, RPV is not only caused by the problems stated above, but also a large number of non-periodic disturbances existing in the operational process of AMB system. Therefore, most of unbalance control methods need to extract periodic components from the rotor displacement signal directly or indirectly.…”

“…Until now, there are lots of research results on the AMB rotor unbalance control. From the literature research works, [8][9][10][11][12][13][14] AMB rotor unbalance control methods were divided into unbalance compensation and automatic balance. The unbalance compensation is a method that can control the rotor spins around its geometric axis via compensating periodic signal, and the automatic balance is a method that can control the rotor spins around its inertia axis via ignoring periodic signal.…”

A Model-Free Control Method for Synchronous Vibration of Active Magnetic Bearing Rotor System

“…In [18], the unbalance control technologies of AMB system are comprehensively summarized, and divided into two categories, including force freedom and force control respectively. From the literature investigation, most of current AMB rotor unbalance control algorithms rely heavily on the rotor system model [19]- [21], and some control algorithms can only be effective at the fixed speed. Furthermore, most of the control methods just verified on the simulation platform, but not fully verified on the actual AMB system [19]- [23].…”

Unbalance Compensation and Automatic Balance of Active Magnetic Bearing Rotor System by Using Iterative Learning Control

“…Among them, unbalance compensation is to offset the existing unbalanced force by the opposite force generated in controller, to ensure the rotor spins the geometric axis, which is also known as force-control mode and suitable for high-precision fields, such as [11]- [13]. Similarly, automatic balance is to achieve rotor spins freely around its inertial axis by ignoring the periodic component of rotor vibration signal in the control process, which is also known as force-freedom mode and suitable for high-speed fields, such as [7], [14], [15]. Among these unbalance control methods, some algorithms rely heavily on the rotor system model, and most algorithms are only studied in theory and simulation, but not fully verified in the actual AMB system.…”