Abstract

In this paper, the efficiency analysis of an induction motor with field-oriented control (FOC) at a hot rolling mill in South Africa is presented. It is shown that the energy consumption of an induction motor at a hot rolling mill can be improved with the introduction of FOC with a variable input reference compared to direct torque and flux control (DTC) with a fixed input reference. An overview on the control process of the induction motor with FOC and the schematics of the field-oriented controller are presented. Results for the following two scenarios are presented: 1) the induction motor is controlled at a constant speed with a variable thickness slab by means of DTC and 2) the induction motor is controlled according to the thickness of the slab by means of FOC. Overall results obtained showed an average improvement of 3.67% in the energy consumption of the experimental test setup system from scenario 1 to scenario 2. The simulation and experimental results that illustrate the performances of the proposed scenarios are also presented.

Key words: Induction motor, field-oriented control, hot rolling mill, energy efficiency.