Battery Chargers
The battery chargers of today go beyond the simple
transformer/rectifier sets. Battery chargers used for electric
vehicles are a good example of this. Due to the high power demands
and designs for low cost, power electronics designers are looking to
provide high performance while meeting these demands. Forward
converter topologies offer isolation and the flexibility to satisfy
most voltage requirements. The use of power factor correction (PFC)
controllers are helping designers meet power quality specifications
set by the IEEE. New regulations include total harmonic distortion
specifications which are set at 5% and power factor ratings of
0.97.
New designs of battery chargers include the system designed below.
The charger is rated at 4 kW and includes PFC as well as low harmonic
distortion. Design is focused on low cost, small size with capability
of accepting universal input voltages. Soft-switching is also
employed to help increase efficiency.
This
schematic comes from the report: Design of a 4 kW On-board
Battery Charger for Electric Vehicles which appeared in the
1995 VPEC seminar procedings. The authors are: Ju Zhang, C.Y. Lin, X.
Zhuang, K. Rinne, and F. C. Lee.