Nexans meets the requirements of solar power plants, Sungrow testifies

A photovoltaic system includes a range of components: panels, junction boxes, inverters, transformers and, of course, the cable. The cable represents only a small part of the total cost of a solar project and may be wrongly considered to be a non-critical factor. However, they are essential to the smooth running of the installation.

Appropriate cabling, selected in accordance with the rules of practice and the recommendations of component manufacturers (including inverters, see below), maximises the yield and reliability of solar power plants. Conversely, an inappropriate choice can lead to safety risks, a drop in performance or even a shutdown.

Evolving architectures: ever more stringent electrical requirements
As the efficiency of panels and inverters increases, solar power plants are growing in size and power, resulting in ever-greater electrical demands.

Centralised architecture: a starting point
The first solar power plants used a centralised architecture, in which a single inverter converted the direct current (DC) from all the panels into alternating current (AC). Although this approach was economical and easy to manage, it had to evolve as the energy output of large-scale power plants increased.

To reduce energy losses, voltages were raised to 1,500V direct current (DC), enabling electricity to be transmitted over long distances. However, this increase in voltage has also introduced new technical challenges, particularly with regard to PID (Potential Induced Degradation).

The PID phenomenon and its management
PID, or Potential Induced Degradation, occurs when high voltages between the solar cells and the metal frame of the panel cause current leakage, leading to a drop in efficiency.

The initial solution to this phenomenon was to connect one polarity to earth, at voltages of up to 1,500V. This approach, while necessary for safety, was not sufficient to prevent PID.

The advent of Anti-PID modules
To improve protection against PID, anti-PID modules have been integrated into the inverters, creating a virtual earth polarity and reducing the risk of panel degradation. Although these modules offer better voltage management, the cables are still subject to high stresses, with voltages of up to 1500V DC.

To meet this challenge, Nexans has developed special cables such as Nexans PV AC/DC 1-1.5kV, designed to withstand high voltages and harsh environmental conditions.

The transition to decentralised architectures
The move towards decentralised architectures was seen as a response to the limitations of centralisation in terms of flexibility and resilience.

Several inverters distributed throughout the installation now each manage a group of panels, increasing the flexibility and resilience of the power plants.

Managing high voltages, particularly in alternating current (AC), remains a major challenge. Anti-PID solutions, although effective, can result in high AC voltages between phases and earth, sometimes up to 906V. This requires specially designed cables, such as Nexans PV AC/DC 1-1.5kV, that meet these technical constraints and ensure system safety.

Conclusion
The choice of cables in a photovoltaic installation is crucial to ensure the safety, efficiency and longevity of the system. Rapidly evolving architectures and technologies, including inverters, require appropriate cables, such as the Nexans PV AC/DC 1-1.5kV range, to meet the technical challenges. As demand for power continues to rise, the photovoltaic industry must constantly innovate to keep pace with this growth.

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