Siemens 600 Link between solar power and public AC grid, How solar power is fed into the AC grid

© Siemens AG 2012

SINVERT PVS in power plants

Link between solar power and public AC grid

How solar power is fed into the AC grid

Sunlight is transformed into solar energy in the photovoltaic modules. The direct current obtained is bundled in the field with the aid of SINVERT PVS CombinerBoxes and then fed into a SINVERT PVS inverter (see diagrams on this page).

The alternating current supplied by the inverters is transformed by medium-voltage transformers into the higher voltages of 20 kV, for example, that are needed for feed-in to the grid.

The inverters and the transformers are in a protected location in inverter stations, as is the optional medium-voltage switchgear, which allows energy to be distributed and fed into the medium-voltage grid (see diagram on page 14).

SINVERT PVS CombinerBoxes for bundling partial currents

With the SINVERT PVS CombinerBox, the individual strings of the photovoltaic generator are collected in the field, connected in parallel and the energy conveyed via large cross-section cables to the SINVERT PVS inverter or the inverter station.

Module strings can be "collected" and their energy transported to the SINVERT PVS inverter or inverter station using a single- stage or two-stage connection concept:

With the two-stage concept, the module strings are initially brought together in the SINVERT PVS CombinerBoxes (first stage). The outputs of these SINVERT PVS CombinerBoxes are then connected to other SINVERT PVS CombinerBoxes (second stage). The outputs of the SINVERT PVS CombinerBoxes of the second stage are then connected to the inputs of the SINVERT PVS inverters or inverter stations. The advantage of this two-stage concept is that power losses are reduced thanks to the increased cable cross-sections.

Photovoltaic modules

	SINVERT PVS
	CombinerBoxes 108
Photovoltaic array	SINVERT PVS
	00026bRE10
	CombinerBoxes 204

Service room

SINVERT PVS inverters

With the single-stage concept, the energy supplied by the module strings to the inputs of the SINVERT PVS Combiner- Boxes is transported directly to the SINVERT PVS inverter or the inverter station via one output in each case.

Photovoltaic modules

Bundling of the solar direct current using SINVERT PVS CombinerBoxes (two-stage concept)

The SINVERT PVS CombinerBoxes 108, 120, 124 with eight, twenty, and twenty-four inputs are used in the first stage. The CombinerBox 204 with four inputs is used in the second stage.

SINVERT PVS

CombinerBoxes 120

Photovoltaic array

Service room

SINVERT PVS inverters

RE10_00027a

Bundling of the solar direct current using SINVERT PVS CombinerBoxes (single-stage concept)

SINVERT PVS CombinerBoxes 124, 204, 120, 108 (from left to right)

12SINVERT PVS in power plants