Traction Power Converters Shipped

SPS has just completed supplying the first batch of traction power converters used by Clayton Equipment in their innovative full-electric and hybrid locomotives. They are rated at up to 180 kW and suitable for use at up to 750 V DC (max) with IP68 rating. Specific steps have been taken with the design to ensure high reliability with the inevitable power cycling such units experience in operation.

Unusually, these are air-cooled to provide packaging flexibility and improve reliability vs a liquid cooled approach. The fans maintain the IP68 rating and give several years of life before servicing is required. The converters can be supplied liquid cooled if required.

SPS is very well placed to both design and manufacture specialist power conversion equipment for lower-volume demanding applications. Please contact us if this is something you are interested in.

Innovate UK Project a Success!!

SPS has now completed the IUK funded project with it’s long term customer Ceres Power that began in July 2017. SPS’s part of the project was associated with a low-cost 1kW isolated DC to AC grid tied inverter system for use on Fuel Cell based micro combined heat and power residential applications. SPS’s two main objectives for the project were:

  1. To increase efficiency (without adding undue additional cost) targeting 92% at full power from low voltage DC in to 230V AC mains out. This is quite a tough target as two series power conversion stages are required for the application.
  2. To build in the necessary hardware to support new grid connection standards for the UK and other geographic markets.

We are delighted to report that using one of our calibrated digital power meters, the efficiency was measured at 92.1% once the unit had reached its final temperature. This efficiency was achieved using low-cost silicon power semiconductor technology rather than using the latest “Wide-bandgap” devices. The latter is too expensive for the target application at this point in time. However, the new design is flexible enough to be upgraded with minimal effort when this situation changes in the future. Efficiencies of more like 95% will then be achievable.

SPS is now looking to exploit what it has learned through this project both from the core power electronics and the grid connectivity requirements. Please do get in contact if this is of interest. A photo of one of the prototypes that were produced in house is shown below.