SMP is introducing a range of chokes designed specifically for use with inverters. A feature of these units is their ingress protection class of IP66, which makes them suitable for use in harsh environments, for example in rail vehicles or on oil platforms. Chokes have the function of restricting incoming current on the line side.
Because of their IP66 rating, these chokes can be fitted outside the inverters, which means that the heat generated by the choke is not discharged inside the inverter. This results in a lower internal inverter temperature, thereby eliminating the need for cooling fans and saving both energy and installation space. Placing the choke outside the inverter has the further advantage of reducing the inverter's overall dimensions, which saves more space and energy demand.
For the choke itself, external mounting has the benefit of allowing it to be designed for lower ambient temperatures. While inverters, for example in railway applications, can have an internal temperature of 70-80degC, the outside temperature to which underfloor-mounted electronics are exposed is unlikely to exceed about 40degC. SMP has developed chokes for external mounting even for use on offshore oil platforms. Their special protective paint coating protects these components from direct sunlight, sea water, rain and corrosive gasses.
To simplify mounting, SMP provides the chokes with special brackets. The choke and the mounting plate are fitted on the outside of the device and the connecting cables pass through a sealed opening.
For use in power electronics, power generation, and instrumentation and control, SMP supplies chokes and filters for frequencies up to 200kHz and current ratings up to 1000A. Depending on their application, they are constructed either as single-conductor chokes for high-current applications, individual chokes, choke modules or LC filters. SMP's inductive components offer a high energy storage capacity in compact dimensions, reduced losses, good EMC characteristics and a cost-conscious design. All SMP components are manufactured to customer specifications using powder composites developed in-house. To allow for a wide range of requirements, components can be manufactured to all common standards. All products are RoHS- and WEEE-compliant, and the materials used are UL-listed.