The PV systems are gaining popularity in the Renewable Energy sector.
Despite the upsurge of the systems and its numerous benefits, they are exposed to the risk of Lightning strikes.
PV systems are vulnerable to Electrical Surges or Transient overvoltages, that may enter the system following a direct Lightning strike to a structural LPS or via the wider Electrical network.
Surge Protection is usually achieved through installation of appropriate SPDs on the DC and AC sides of the DC-AC inverter of the system.
Installation follows the guidance provided in Technical Specification DD CLC/TS 50539-12.
Pictures below show how to deploy Surge Protection Devices (SPDs) for facilities with or without Structural Lightning Protection System (LPS) and Protection of solar park/PV array respectively.
Installation on the DC side of the DC-AC inverter
An SPD specifically designed for use on the DC side of a PV system should be installed.
Where the distance between the PV array and the inverter is <10 m, a single SPD suffices, mounted as close as possible to the inverter.
Where the distance >10 m, two SPDs should be installed, one close to the inverter and the other close to the to PV array. The minimum type of SPD is dependent on presence of structural LPS/separation distance as shown in the Table below.
Installation on the AC side of the DC-AV inverter
The presence (or lack) of a structural LPS, plus whether sufficient separation distance has been kept between the LPS and the PV array, defines the SPD requirement on the AC side of the inverter.
Where the distance between service entrance (Main Distribution Board (MDB)) and inverter is < 10 m, a single SPD should be installed at the service entrance (MDB).
Where >10 m, two SPDs should be installed, one at the MDB and the other close to the inverter.
Furse combined Type SPDs for AC mains power circuits are applicable here. The SPD to be installed will be dependent on the class LPS around the structure, and the location of the metallic services connected to it ( i.e underground/exposed overhead supply).
The table below shows in a nutshell, the SPD requirements according to structural LPS configuration.
At FullSpectrum Energy, we offer and deploy Furse ESP PV Series SPDs that offer combined Type 1 + 2 protection, and therefore apply across all scenarios.
We Advice, Specify; Procure and Commission Furse SPDs for Specific Systems Protection no matter your needs, saving you MONEY by reducing Downtime and aintenance costs .
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Victor Oyedu, FNSE, FNIEEE, CPQ.
Power Quality and Energy Management Specialist.
Publisher at Afrienergyonline.com
CEO, FullSpectrum Energy Solutions Limited, Nigeria.
