A comparison between the algebraic and the reduced order observer approaches for on‐line load torque estimation in a unit power factor rectifier‐DC motor system

In this article, a comparison between the performances of an online algebraic estimator and a reduced order observer is established in the context of adaptive load torque estimation in a controlled unit power factor rectifier‐DC motor system combination. A passivity‐based output feedback controller was constructed to regulate the angular speed while correcting the power factor of the mono phase boost rectifier. The proposed controller allowed us to compare the results of both on‐line estimation techniques. The experimental results show a superiority of the algebraic approach in which the angular velocity was maintained at the desired reference value by the adapted controller, even under severe load changes on the motor shaft, while the power factor was also kept at high values in the power supply system. Copyright © 2010 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society