Sunway NT 4000, NT 6000, NT 2600 Functional principle and explanations, · DC and AC filters

4.2Function 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	EN
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.

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