Abstract
This paper presents a minimal order rotor current and rotor flux observer for an indirect field oriented induction motor drive with consideration of core loss due to eddy current from the viewpoint of nonlinear observer using bilinear model. The state equations for an induction motor were derived which behaved as a bilinear system in terms of the product of input and state variables. The design of the proposed observer is based on Lyapunov's stability method whose estimation error converges to zero exponentially irrespective of the inputs. We have also proposed a control system by using multi-input and multi-output optimal regulator theory. The estimated rotor current and rotor flux are fed back to the multi-input and multi-output optimal regulator. Simulation results are presented to show the validity of the proposed controller as well as rotor current and rotor flux estimation of induction motor drive.
