Electrical chokes for inverters in wind turbines are now approved for use in offshore installations. These inductive components from manufacturer SMP feature low losses, low stray fields, and a compact design. The chokes’ cores consist of powder composites engineered for this application.
Direct current from wind turbine generators must be converted into a sinusoidal waveform with the characteristics required by the grid. The converter’s filters, which consist of capacitors and filter chokes, ensure that current being fed into the grid exhibits a near sinusoidal waveform. To maximize the inverter’s efficiency, its components must exhibit low losses. The materials that SMP developed for use in its energy efficient, high-performance chokes have low magnetostriction, and exceptionally low eddy current and hysteresis losses. Their encapsulated design ensures that the power converters emit only low-intensity stray fields, so they do not affect other components. The chokes have a space-saving compact design, are maintenance-free, and have a long lifespan – a significant contribution to cutting the maintenance costs for offshore wind turbines.
To protect components in offshore turbines from the corrosive action of the sea water, it is necessary to use special salt-resistant materials, additional corrosion protection, and a complete encapsulation of certain subassemblies. The company’s inductive components for wind turbine inverters are now certified IP66 and approved for use in offshore installations. Because of their high protection class of IP66, these chokes can be fitted outside the inverters, which means the heat generated by the choke is not discharged inside the inverter. This results in a lower internal inverter temperature, which removes the need for cooling fans and saving energy and installation space. Another advantage to placing the choke outside the inverter, reduces its overall dimensions, which further cuts space and energy demand. To simplify mounting outside inverters, SMP provides the chokes with special mounting fixtures. The choke and the mounting plate are fitted on the device’s outside and the connecting cables pass through a sealed opening.
SMP supplies inductive components for frequencies up to 200 kHz and current ratings up to 1,000 A for use in onshore wind turbines and other applications. 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. SMP manufactures all components to customer specifications using in-house developed powder composites. All products are RoHS- and REACH-compliant and the materials used are UL-listed. To allow for a wide range of requirements, components can be made to all common international standards.
Westendorf Associates Inc
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