From Ac to Dc: Benefits in Household Appliances

Low voltage dc grids are a rising topic of research. However, research for low voltage dc grids for household appliances is still an academic topic. Most of today's household appliances use switched-mode power supplies and, thus, have an internal dc voltage link. By directly connecting this dc-link to a low-voltage dc grid, the rectifier and power factor correction stages can be removed and which increases efficiency. This paper shows that commercially available ac devices can easily be adapted to work with dc grids. Various devices commonly found in households are modified to run with dc. The power consumptions of the same devices running on ac and on dc are measured and compared. The efficiency benefits arising from the modifications are outlined as well as possible drawbacks.