Sunway NT 4000 Power Supply User Manual


 
135
EN
4.2 Function and information index
Functional principle and explanations
The electrical energy of the PV generator
is buffered by a capacitive storage, from
where it is fed into the public grid via a
solar inverter synchronised with the grid,
with an ideal phase angle of [cos phi = 1].
A sinusoidal current with a very low harmo-
nic distortion is injected into the public
grid by the current injection inductor. This
improves the grid quality.
Thanks to the HERIC
®
technology (patent
applied for) in the self-commutated
Sunways Solar Inverter, the hysteresis losses
in the current injection inductors that
occur in conventional solar inverters and
the switching losses in the semiconductors
are considerably reduced. Consequently,
Sunways Solar Inverters achieve a peak
efficiency during conversion. The concept
of the Sunways Solar Inverter is completed
by a rapid MPP control, which maintains
the MPP point with a very high adaptation
efficiency.
· DC and AC filters
The DC and AC filters are specially designed
EMC filters, which are integrated as direct
components on the board. They guarantee
compliance with the EMC limit values on
the AC side and on the PV generator side.
High-frequency emissions are avoided by
the filters on the PV generator side.
· Differential measurement
The generator current and the voltage are
recorded via a current transformer and a
differential measurement. The values are
important input values for the regulation
and setting of the correct working point.
· Solar inverter with HERIC
®
technology
The heart of the solar inverter with the
power semiconductors serves for conver-
sion of the current from direct into
alternating current. Peak efficiencies are
achieved, thanks to the HERIC
®
techno-
logy. The switching frequency (PWM) is
16 kHz.