Hysteresis Effect Induced Inductance Change and Power Loss for Boost Converter During the Voltage Conversion

From the Joules–Atherton (J-A) model, the sign of magnetization energy loss due to hysteresis at the positive-going magnetic field
$H$
is opposite to that at the negative-going magnetic field
$H$
, which is +1 if
$dH/dt > 0$
and is −1 if
$dH/dt < 0$
. This implies that an inductor has different inductances at the current ramp-up time due to
$dH/dt>0$
and ramp-down time due to
$dH/dt < 0$
. However, this phenomenon is never reported until now. In this article, the inductance of an inductor is found which is larger than the intrinsic inductance at the current ramp-up time (
$t_{\text {up}}$
) and smaller than the intrinsic inductance at the current ramp-down time (
$t_{\text {dn}}$
) for a boost converter during the continuous conduction mode (CCM) voltage converter. Moreover, hysteresis also makes the classical model of the voltage conversion ratio for boost converter design,
$V_{\text {OUT}}/V_{\text {IN}}= 1/(1-D)$
, invalid since
$D(t_{\text {up}}/T$
) is not a constant caused by the
$t_{\text {up}}$
and
$t_{\text {dn}}$
varied with the output current of boost converter, where
$t_{\text {up}} + t_{\text {dn}}= T$
. The hysteresis model aids designers in estimating the behavior of inductor current variations more accurately without having to wait for chip manufacturing and measurement to reveal the actual behavior.