Low-loss inductive components for solar power inverters

Paul Boughton
Sintermetalle Prometheus (SMP) is presenting chokes for inverters in photovoltaic systems at this year’s Intersolar trade show in Munich this June.

These inductive components feature low losses, very low stray fields and a highly compact design, which significantly increases the chokes’ – and therefore the inverters’ – energy efficiency. SMP uses core materials made of powder composites with low magnetostriction that have been purpose-designed specifically for this application.

A photovoltaic inverter converts the direct current output from the solar cells into alternating current before it is fed into the mains grid. To be able to modulate current with as close to sinusoidal a waveform as possible, so-called filters, consisting of capacitors and filter chokes, are required. For this purpose, SMP has developed high-performance, low-loss chokes that meet the requirement for solar power inverters with an ever increasing efficiency.

The SMP-developed materials used have low magnetostriction and exceptionally low eddy current and hysteresis losses, making the inverters in which they are used highly efficient. 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. SMP’s chokes occupy 25 percent less space than conventional designs. In addition, the chokes operate extremely quietly, which allows their use in residential areas.

For use in wind turbines, railway engineering, drives, power electronics, power generation, and instrumentation and control, SMP supplies inductive components for frequencies up to 200 kHz and current ratings up to 1000 amperes. 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 a high energy storage capacity in a compact and cost-conscious design as well as reduced losses and good EMC characteristics.

For more information, visit www.smp.de