The analysis of similarities and differences between ADRC and PID controller for AMB system

Active magnetic bearing (AMB) system is a typical electromechanical system which requires a controller for stable levitation. Active disturbance rejection controller (ADRC) is considered as an effective way to stabilize a system under external disturbance. And a classical proportion-integration-differentiation (PID) controller is still a simple yet effective method for most engineering applications for its robustness. In this paper, ADRC and PID controller are implemented for the stable levitation of AMB system. By the mathematical analysis, the connecting relationships of control parameters between those two methods are researched. And in view of the unbalance effect while AMB-rotor is rotating, the output responses and control performance comparison are analyzed for the closed-loop system models of AMBs using ADRC and PID. The derivations reveal the advantages of ADRC than PID clearly, which means that ADRC is a great substitute for PID to suppress unbalance force. Finally, the simulations are conducted to verify the analytical conclusions of this paper.