Page 268 - Power Electronic Control in Electrical Systems

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256 Power electronic equipment

Fig. 6.88 CSC based single-phase shunt connected active filter.

Fig. 6.89 CSC based single-phase combined series/shunt connected active filter.

VSC-based active filter as shown in Figure 6.85. The power circuit shown in Figure
6.83 is used mainly as a shunt compensator and it is known as a STATCOM. Its basic
function in utility applications is to provide reactive power compensation, eliminate
the line current harmonics and balance the three-phase loads in a three-phase con-
figuration. It can be used to restore the voltage in a series connection as a DVR
shown in Figure 6.84. In all figures where a converter is used as an active filter, the
AC mains is shown as a voltage source with series inductance, and at the point of
connection, an inductor is also used on the side of the converter. The only difference
is that if the converter is of a current-source type, a capacitor is connected prior to the
inductor as square-wave currents are generated at the output of the converter which