Abstract: Nowadays in applications of renewable energy sources
it is important to develop powerful and energy-saving photovoltaic
converters and to keep the prescriptions of the standards. In grid
connected PV converters the obvious solution to increase the
efficiency is to reduce the switching losses. Our new developed
control method reduces the switching losses and keeps the limitations
of the harmonic distortion standards. The base idea of the method is
the utilization of 3-state control causing discontinuous current mode
at low input power. In the following sections the control theory, the
realizations and the simulation results are presented.
Abstract: Nowadays there are several grid connected converter
in the grid system. These grid connected converters are generally the
converters of renewable energy sources, industrial four quadrant
drives and other converters with DC link. These converters are
connected to the grid through a three phase bridge. The standards
prescribe the maximal harmonic emission which could be easily
limited with high switching frequency. The increased switching
losses can be reduced to the half with the utilization of the wellknown
Flat-top modulation. The suggested control method is the
expansion of the Flat-top modulation with which the losses could be
also reduced to the half compared to the Flat-top modulation.
Comparing to traditional control these requirements can be
simultaneously satisfied much better with the DLF (DC Link
Floating) method.