A photovoltaic inverter converts the direct current output from solar cells into alternating current before it is fed into the mains grid. To modulate current with as close to sinusoidal a waveform as possible, so-called filters, consisting of capacitors and filter chokes, are required. New chokes, from SMP, feature low losses, very low stray fields and a compact design that increases the chokes’ – and therefore the inverters’ – energy efficiency. The manufacturer uses core materials made of powder composites with low magnetostriction that have been purpose-designed specifically for this application.
The materials also have low eddy current and hysteresis losses, increasing the efficiency of the inverters. Their encapsulated design ensures that the power converters emit only low-intensity stray fields – another requirement for chokes for solar power inverters because it allows other components to be placed in close proximity to the choke without running a risk of magnetic interaction.
Compact choke design is another important aspect. These chokes occupy 25% less space than conventional designs. In addition, the chokes operate quietly, which allows their use in residential areas.
The inductive components are available for frequencies up to 200 kHz and current ratings up to 1000 A. Depending on their application, they are constructed either as single-conductor chokes for high-current applications, single-phase individual chokes, three-phase choke modules or LC filters. These components offer high-energy storage capacity in a compact design as well as reduced losses and good EMC characteristics.
SMP Sintermetalle Prometheus (SMP)
www.westendorfassoc.com (USA contact)