Depending on application, the chokes are constructed either as single-conductor designs 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.
A recent electrical choke design for power inverters in wind turbines is an inductive component that features low losses, low stray fields, a compact design, and energy efficiency. Developer Sintermetalle Prometheus (SMP), based in Germany, uses materials made of powder composites engineered for each application. “Direct current from the modules must be converted into a sinusoidal waveform with values required by the grid. The converter’s filters, which consist of capacitors and filter chokes, ensure that current fed into the grid has a near sinusoidal waveform”, says Stefan Schauer, technical sales manager at SMP. The company developed these low-loss chokes to meet the demanding requirements of modern wind turbines.
The company says the materials used have low magnetostriction and exceptionally low eddy current and hysteresis losses. This makes the inverters highly efficient, so that a larger proportion of wind generated power is fed into the grid. The result is a faster return on investment.
“The profitability of a wind turbine is directly related to the efficiency of the inverters, which, in turn, is determined by the energy efficiency of the components used”, adds Schauer.
In addition to low losses, components in power converters must have low-intensity stray fields. SMP chokes achieve this through an encapsulated design, which allows placing other components in close vicinity to the chokes without risk of magnetic interaction. In comparison to conventional designs, SMP chokes occupy 25% less space.
The maintenance-free chokes are said to have a long lifespan, make a significant contribution to reducing the expensive maintenance of wind turbines. SMP chokes are tested and approved for use in offshore installations.
SMP supplies inductive components for frequencies up to 200 kHz and current ratings to 1,000 A and for use as well in photovoltaics, railway engineering, drives, power electronics, power generation, and instrumentation and control,. SMP says it manufactures all components to customer specifications using in-house developed powder composites. All products are RoHS and REACH-compliant, and their materials are UL-listed. Components can be made to all common international standards.
Filed Under: Generators, Sensors
