New approaches for DC Link Smoothing Solution for Variable Speed Drives

Request Number N682826
Need details
Size of DC Link Choke relative to low-power Variable Speed Drive


Variable Speed Drives require combinations of common mode and differential mode filters in order to meet EMC and harmonic standards. In

particular, DC Link chokes (also called reactors) are large and very heavy, adding to the size of the product and increasing shipping and handling costs. A new approach is required to optimize or replace the DC Link choke, whilst reducing cost, weight and size of the solution. We are looking for smaller DC Link chokes or radical new alternatives to DC Link Chokes.


Relevant standards for orientation are e.g.: EN 61000-3-12 (harmonics) plus design/testing to all applicable IEC product standards and the UL/CSA standards.



Today, we include DC Link chokes in drives to achieve longer cable lengths, harmonic reduction and drive robustness against trips etc. These components are large, heavy and expensive. This is particularly important for smaller drives, from 500W up to approximately 20kW.


Example operating conditions for 7.5kW drive at a peak current of 30A.


Graphs showing line currents with and without DC Link Choke, and harmonic reduction using 4% choke


Block diagram of Variable Speed Drive showing DC Link Choke (Reactor)
Block diagram of Variable Speed Drive showing DC Link Choke (Reactor)


Key Success Criteria
  • Size optimized, small solution
  • Lightweight
  • Cheap

Physical environment for solution:

  • Minimum inductance: 4%
  • Max. DC voltage: 900V
  • Temperature range: -10°C to +65°C 


Size of DC Link Choke relative to standard computer mouse


Possible Approaches

Siemens is open to all solutions that meet the success criteria.


Approaches not of interest



Preferred Collaboration types
  • Joint Development
  • Contract Research
  • Technology Acquisition
  • Supply Agreement
  • To Be Negotiated
Items to be submitted

We are looking for concise, non-confidential proposals. The proposal should:

•           Describe the technical approach

•           Include a description of the responding organisation or team and their experience


Please use the Respond button in order to submit your proposal.


We recommend:

•           including a concise abstract summarising your submission

•           attaching your proposal

•           attaching any additional documents


Please note that only non-confidential information can be accepted. By submitting a response you confirm that the response does not contain any confidential information.


Point of Contact
Stephen Clulow
Area of Interest
  • Aerospace & Defense
  • Computer Hardware
  • Electronics & Electronic Components
  • Energy & Power Production
  • Manufacturing & Fabrication
  • Professional Services
  • Utilities
Due Date
March 15, 2018