Development of Internal EMC Filters for Variable Speed Drives
A company that designs and manufactures variable frequency drive products, recently approached Roxburgh EMC for assistance with the development of their internal EMC filters.
Variable frequency drive products often contain an integrated EMC filter that specifies the requirement to meet a defined conducted emissions limit when used with a defined motor lead length. The customer was displeased with the performance of their existing integrated filters and chose to embark on a testing and development programme to improve their specifications.
The greatest challenge throughout the project was the limited space within the case that is allocated to house the filter. Roxburgh EMC engineers needed to improve the filtering performance without taking up any additional space or repositioning other internal components within the drive. Furthermore, earth leakage requirements were strict and the solution had to be achieved in a short space of time.
In the field of EMC filter design, component position can be as important as component type or value. To resolve the issue, Roxburgh EMC engineers used their extensive filter design experience to “tweak” the component values and, more critically, the physical location of the filter components. This achieved the desired performance within the space permitted, without increasing heat dissipation.
If you would like our support with the development of your filters, please contact us on +44 (0)1724 273228.