symbolic dynamic models for highly varying power system loads

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CHAPTER 1
1.1 Motivation
INTRODUCTION
Representation and modeling of loads in a power system is very important, as a
system may have different types of complex loads. Some loads are highly varying in
nature like electric arc furnaces, steel rolling mills and other electric loads involved in
different processes in the steel industry. These loads still do not have fully accepted
physical models because of the unpredictable nature of the load current, but they have a
rich set of data over a wide range of operation.
The motivation of the proposed approach is to develop a load model for highly
varying loads by using time series measurements of voltage and current only. The
proposed model can also be used to study distortion in non-periodic and poorly behaved
signals. This work introduces the concept of Symbolic Dynamics to accomplish the
objectives mentioned above. Symbolic Dynamics is a mathematical approach in which
signals are discretized and represented as sequence of symbols. Another motivation of the
work reported here is to use a very innovative approach for load modeling, and again,
Symbolic Dynamics fits this description.
1.2 Scope
The scope of this project is twofold. One element is the utilization of time series
historical data of voltages and currents of a load or industrial process in order to
formulate a model M. The model M might be used in routine power engineering
applications