Tuesday, September 21, 2010
To minimize the low frequency ripple without using a large LC filters, active filters such as the installation can be seen in Figure 3 (a) has been proposed in the literature [80-10]. Figure three (b) shows an equivalent circuit of the dc side of Figure 3 (a). Vd states the average value (dc component) and declare the filter capacitor voltage ripple. If the active filter is controlled so as to produce the voltage ripple voltage ripple burden no longer contain. In these systems, a passive LC filter is used to reduce ripple and high frequency active filter to reduce low frequency ripple. Therefore, the required size of passive filter is not too large. This active filter can be implemented with a series of linear mode power converters and switching. As mentioned previously, the relationship between the series active filter with a load capacity of the current causes the active filter must be at least equal to the maximum current load, although the low-voltage itself, which is equal to the voltage ripple is compensated. Since a large current capacity required, the application of this method for very large currents will complex and inefficient.
