Plenary lecture 5: variable step adaptive algorithms in controlling industrial distorted loads

The numbers of the industrial nonlinear distorting loads that pollute the electric power supply network from electromagnetic viewpoint has increased and increase permanently. Their connection to the electric network produces significant current distortions and, taking into account that their total power is not negligible against the supply network's power, are producing also voltage distortions, which decrease the electric power's quality. In this paper we propose an adaptive control method of the electrical installation of an Electric arc furnace. Based on the experimental results will be proposed an adaptive control system of the process. The algorithm used is known as the LMS algorithm (Least Mean Square) or the stochastic gradient's algorithm, being, due to its simplicity, the most used algorithm implemented in the current systems. It was used standard and variable step size LMS algorithm. The efficiency of the proposed algorithms is verified using simulations based on modeling the electric arc. For modelling the electric arc the authors are using a model which parameters like of a real electric arc. For simulation it was use the PSCAD-EMTDC program (Power Systems CAD - a program dedicated to power systems).