Abstract:
Abstract
Current charging techniques for lithium-ion batteries use a predominantly
open-loop strategy, where the charging profile is defined on the basis of a
prior knowledge of cell parameters. With the given CC-CV method where
temperature has no effect, a new method which uses Voltage and
Temperature values to modulate the current value is needed. This paper
tackles this gap by proposing a constant temperature constant voltage
(CTCV) charging technique, which considers cell temperature as a key
degradation metric. The proposed CT-CV charging method uses a simple
(PID) controller with feed-forward support. The charging current is
dynamically modified in response to the temperature of the battery, which
implicitly represents its aging and thermal environment. As per recent tests,
the proposed method would result in a 20 percent faster charging at the same
total temperature rise as the constant-current constant-voltage (CCCV)
technique. Conversely, the change in cell temperature is 20 percent smaller,
despite the total charge time. It can easily satisfy applications that need even
faster charging by simply increasing the set temperature. This paper points
out the advantages of the proposed cell-level charging of CTCV and
increases the prospect of expanding it to the pack level by incorporating it
into the battery management systems
