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INTEGRATED INVERTER ALGORITHMS FOR OPTIMAL PERFORMANCE

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Integrated inverter algorithms for optimal performance

Steca inverters are equipped with various sophisticated functions that can be used to optimize the performance of solar installations. Two of these are ModuleScan and ShadingScan.

- The ShadingScan automatically optimizes solar power in case of shading.
- ModuleScan can be used for troubleshooting, diagnostics, or feed-in improvements

ShadingScan: Optimal solar power even in shaded areas

If solar power systems are to deliver optimal yields, they need direct sunlight. But even with carefully planned and constructed systems, temporary shading is often unavoidable - for example, due to dormers or other structures on the roof. In such cases, the ShadingScan function of Steca inverters avoids unnecessary yield losses by quickly tracking to the current, actual maximum power point (MPP).

In order for a photovoltaic system to deliver maximum yields, the inverter must continuously detect the maximum power of the connected modules. In technical jargon, this value is called the maximum power point (MPP). This depends on the current solar irradiation and therefore changes depending on the time of day and cell temperature.

The MPP is usually not determined for individual solar modules, but for a certain number of modules connected together, also called string. As long as the sun shines evenly on all modules in a string, there is only one unique power maximum for it. Every modern inverter can recognize this.

However, the situation is different if parts of a string are in the shade, which often happens in practice: Then there is not only one, but several MPPs. In this case, conventional inverters are no longer able to select the optimal MPP. The result: noticeably less solar power is generated than possible.



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In such situations, the Steca ShadingScan algorithm ensures that the inverter finds the actual maximum power of the solar system and thus maximizes solar power production. To make this possible, the inverter checks at regular intervals whether the current MPP is correct or whether a higher power value cannot be achieved. In this way, the optimal power is always retrieved - completely without additional technology and additional investments.



ModuleScan: Integrated diagnostics, troubleshooting and optimization

Just like the ShadingScan, the ModuleScan serves to reduce unnecessary yield losses of the photovoltaic system. Compared to the ShadingScan, however, it enables a more comprehensive analysis and also serves to detect contamination and defects. However, it is comparatively time-consuming. Therefore, unlike the faster ShadingScan, which is permanently active in the background, it must be initiated individually by the operator.

Like ShadingScan, ModuleScan analyzes the characteristic curve of interconnected solar modules. The goal here is also to identify the "global" MPP with the highest power (see explanation above).

However, while the ShadingScan only checks a certain part of the solar system characteristic curve in order to continuously and gradually optimize everyday operation, the ModuleScan always runs through and analyzes the entire characteristic curve. This is why it can be used in a particularly versatile way: Not only can the point of maximum power be determined with the help of the characteristic curve, but the course of the line also provides system operators and installers with valuable insights into the condition of the solar system.

For example, operators can use the characteristic curve to see if the system is so dirty that it should be cleaned. If, on the other hand, the system is clean and not shaded, the characteristic curve can show that individual modules are damaged.



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