Rotor Unbalance Estimation with Reduced Number of Sensors

Active Power Filter with a Reduced Number of Current Sensors

In this paper, a modification of a parallel active power filter (APF) control is presented. Its purpose is to decrease the cost of the hardware by minimizing the number of current sensors, normally present in conventional topologies. The approach employs the direct current control (DCC), a method for predictive control of currents in polyphase systems, developed by the authors. Since in traditi...

Estimation and Active Damping of Unbalance Forces in Jeffcott-Like Rotor-Bearing Systems

Linear and Nonlinear Regression with Application to Unbalance Estimation

This paper considers estimation of parameters that enters nonlinearly in a regression model. The problem formulation is closely connected to unbalance estimation of rotating machinery. The parameter estimation problem can after approximation be formulated as a linear estimation procedure, while neglecting the effects of the disturbing term. Two such estimators are derived. In addition, a third ...

Estimation of the Number of Rotor Slots and Rotor Speed in Induction Motors Using Current, Flux, or Vibration Signature Analysis

Effective condition monitoring of induction motors requires knowledge of the number of rotor slots and the rotor speed. These were primarily obtained in the literature by multiple measurements and using design knowledge of the motor under test. Furthermore, the earlier studies have mainly concentrated on stator current analysis. This paper investigates the use of the stator current, axial flux,...

On line identification of unbalance parameters and active control in a rotor bearing system

In this paper an algebraic technique for unbalance parameters identification along with an active control scheme for a rotor bearing system are presented. The system has two disks asymmetrically located along the shaft which is supported by a conventional ball bearing at one end and by an active suspension at the other one. The active suspension is based on linear springs and linear force actua...