symbolic dynamic models for highly varying power system loads

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Recorded current data from the electric arc furnace have been measured through a
CT with ratio 400/5. To represent these data by symbols and thus to form a Symbolic
Dynamic dictionary, the data needs to be discretized in a suitable manner. To discretize,
the data set can be divided into different cells. Let N is the number of cells and ?x is the
width of each cell, the first cell denotes the minimum value of current and the N th cell
denotes the maximum value of current. The process of discretization is shown in the
Figure 4.1.
i
N
Imax
? x
N-1
:
:
3
2
1
Imin
Figure 4.1 Transforming the real data
Division of cells can be done in the following two ways:
1. Constant cell width: Keeping cell width ?x constant, the data set can be divided into N
number of cells where N depends on minimum and maximum value in the data set, thus
N=(I max -I min )/ ?x