Solutions for protection of photovoltaic energy systems

Photovoltaic energy is today one of the highest growing sources of renewable energy, and the forecast of the future also shows the same trend. With our care for the environment, ETI prepares solutions to the protection of photovoltaic energy systems. Green protect solutions includes NH fuse-links, CH fuse-links, fuse-holders, switch disconnectors, SPDs and all accessories which are needed for safe protection and also for a user-friendly operation and maintenance.

Anže Jerman
Product manager

With the growing nominal power of photovoltaic power plants, there are also growing nominal voltage on the DC side of photovoltaic inverters. With a higher nominal, DC voltage level up to 1 500V d.c. photovoltaic panels have become more effective. But for our company, there were new challenges. We prepared solutions for the protection of the DC side of photovoltaic power plants with NH fuse‑links and protection of photovoltaic panels with CH fuse-links. The main challenge for ETI was how to develop the new generation of products and equipment which will be effective and safe, also at nominal voltage up to 1 500V d.c.. Our solutions are in fuse-link technology because silica sand which can absorb a lot of energy in a rapid time, is still the best way to interruption - in case of a fault on the 1 500V d.c. system.

 

The second challenge was how to develop gPV characteristics that must not be influenced by electric and temperature cycles which are due to the nature of figuring out one of the main issues in photovoltaic applications. But with our knowledge and experience, we developed an innovative shape of fuse-elements which are not influenced by photovoltaic cycles. The benefits of using fuse-links for photovoltaic protection are higher for breaking capacity, lower cut-off current in case of fault and reliable protection compared to other protection technologies. The gPV characteristic has been developed specially for photovoltaic applications and combines fast operation characteristics without influence on electric cycles. ETI Green protect products are appropriate for mounting in the first installation and also maintenance of existing installations.

 

NH fuse-links are dedicated to the protection of conductors near photovoltaic inverters. They have been developed in sizes 01XL, 1XL, 2XL, and 3L up to 500A and 1 500V d.c. gPV characteristic with breaking capacity up to 70kA at a time constant less than 3ms. Higher breaking capacity is because of the highest nominal power of invertors and consequently the highest nominal currents more and more important so we dedicate special care to this technical specification. NH fuse-links are available in different connecting types, blades for mounting in fuse holder and S170, U170 for direct connection in the combiner box. All fuse-links have a standard top indicator that is available to connect with the NVS5 microswitch for fuse-link operating monitoring at a distance. NH 1 500V fuse-links are approved according to related IEC and UL standards.

For the protection of the photovoltaic panels against reverse currents in case of photovoltaic modules faults, have been developed a new generation of cylindrical CH gPV fuse-links up to 32A and 1 500V d.c. with the breaking capacity up to 50kA. Cylindrical fuse-links from 2 to 20A are available in standard cylindrical size 10x85mm, fuse-links from 25 to 32A are available in size 10/14x85mm. For cylindrical fuse-links, we have different types of connecting, ferrule type for mounting in fuse holder and SU type for direct connecting in the electric circuit. Fuse-links in size 10/14x85mm have a patented design for interrupting in case of short circuit conditions. Cylindrical fuse-links have been developed according to the IEC standard and are also pending to be approved by UL certification. In all of the photovoltaic fuse-links, we are using pure silver fuse-elements which we reach high conductivity and lower power dissipations of fuse-links. Connecting parts are silver-plated because of batter connection and protection against environmental conditions. Also, all of our fuse-links are assembled with a ceramic fuse-link body which is environmentally friendly instead of a competitor's melamine solutions. The trend in photovoltaic will probably grow in solutions that will capable accept the highest capacity of fault energy. Our company started to develop products and solutions in this direction. For all of our products and solutions, they are the most important the safe of the end-users and also protective of the equipment for the purpose of our solutions.