Development of High Efficiency Rectifier with MOSFET in “eSC Alternator”

Paper #:
  • 2017-01-1228

Published:
  • 2017-03-28
DOI:
  • 10.4271/2017-01-1228
Citation:
Nakanishi, M., "Development of High Efficiency Rectifier with MOSFET in “eSC Alternator”," SAE Technical Paper 2017-01-1228, 2017, doi:10.4271/2017-01-1228.
Author(s):
Affiliated:
Pages:
5
Abstract:
Alternator, which supplies electric energy to a battery and electrical loads when it is rotated by engine via belt, is one of key components to improve vehicle fuel efficiency. We have reduced rectification loss from AC to DC with a MOSFET instead of a rectifier diode. It is important to turn on the MOSFET and off during a rectification period, called synchronous control, to avoid a current flow in the reverse direction from the battery. We turn it off so as to remain a certain conduction period through a body diode of the MOSFET before the rectification end. It is controlled by making a feedback process to coincide with an internal target conduction period based on the rotational speed of the alternator. We reduced a voltage surge risk at turn-off by changing the feedback gain depending on the sign of the time difference between the measured period and the target. In addition to reducing the rectification loss, reducing copper loss with low resistance coil winding and iron loss with magnetic steel contributed to improve the alternator efficiency by 10%. As a result, we achieved 2.6g/km CO2 reduction in a petrol-fuelled vehicle calculated by a guideline with a reference to [1].
Access
Now
SAE MOBILUS Subscriber? You may already have access.
Buy
Select
Price
List
Download
$27.00
Mail
$27.00
Members save up to 40% off list price.
Share
HTML for Linking to Page
Page URL

Related Items

Article
2016-08-15
Technical Paper / Journal Article
2011-04-12
Article
2016-08-15
Training / Education
2017-10-26
Technical Paper / Journal Article
2010-10-25
Standard
2001-04-26
Book
2005-12-08