DEHN protects solar parks
DEHN protects Solar Parks

Lightning and surge protection for free field systems and solar parks

Protect your solar plant against direct lightning strikes and transient overvoltage

A lightning protection system for free field systems and solar parks has two main goals:

  • Protection of the power plant area from lightning-related damage
  • Protection of the modules, inverters and monitoring systems from the effects of electromagnetic impulses

Since the investment volume is high, operators require permanent system availability. For this reason, the lightning-related risk should be calculated according to IEC 62305-2. This risk analysis provides the basis for planning a lightning protection system.

Minimize the risk for existing systems

Existing systems are often insufficiently protected against direct lightning strikes and surges. We offer adequate products for retrofits and will be pleased to help you find a solution – just contact us: itss@dehn.de.

Have a look at some sample applications for possible configurations:

#1 - Centralised configuration with central inverter: show details

#2 - Distributed configuration with string inverter: show details

Centralised configuration with central inverter

Example 1

Extended DC cables are routed in the field in case of system concepts with central inverter technology.

What has to be observed for the selection of surge protective devices (SPDs)?

In the event of a direct lightning strike to the PV array, the extended DC cables serve as an equipotential bonding conductor between the "local" earth potential of the PV array and the "remote" equipotential bonding surface of the in feed transformer/central inverter. Due to the partial lightning currents on the DC lines to be expected, type 1 arresters are used for protecting the electrical systems in PV power plants.

Normative regulations and notes: Supplement 5 to DIN EN 62305-3 provides information on the minimum discharge capacity of voltage-limiting or combined type 1 SPDs for a free field PV system in case of class of LPS III and a mesh size of the earth-termination system of 20 x 20 m. The values stated in this standard must be observed when selecting an adequate type 1 SPD for use on the DC side.

Comprehensive protection of electronic components

Type 1 + type 2 combined arresters are installed at the DC input of the inverters and in the generator junction boxes. Moreover, a type 1 combined arrester is used to protect the central inverter on the AC side. The data interfaces are also protected by adequate surge arresters.

Protection against direct lightning strikes

Air-termination systems are used to protect the PV array of the operations building from direct lightning strikes. The air-termination rods are often mechanically fixed on the metal mounting structures where the modules are mounted.

Distributed configuration with string inverter

Example 2

If PV power plants with distributed string inverters are used, most of the power cables are installed on the AC side.

Distributed configuration with string inverter

In the event of a direct lightning strike, the AC cables serve as equipotential bonding conductor between the "local" earth potential of the PV array and the “remote” equipotential bonding surface of the in feed transformer.

Therefore, type 1 arresters are used on the AC side. On the DC side of the string inverter type 2 SPDs are sufficient since they basically limit induced interference impulses.

Comprehensive protection for electronic components

Type 2 arresters are installed at the DC input of the inverter. These arresters also protect the modules in close proximity. Type 1 combined arresters are installed on the AC side of the string inverter and the low-voltage side of the infeed transformer. The communication interfaces are also provided with adequate surge protective devices.

Protection against direct lightning strikes

Air-termination systems are used to protect the PV array and operations building from direct lightning strikes. These systems are often installed on the metal mounting structures.

Contact

Have you got questions? Contact us.

Technical support ⎟ Photovoltaic

Phone: +49 9181 906 1740

back to top

This website uses cookies to ensure you get the best experience on our website. Learn more