In this paper, a new on-line temperature extraction
method based on the maximum recovery current di/dt for
power P-i-N diodes is proposed. Reverse recovery process of
diode is not only related to P-i-N diode chip temperature,
also related to the switching behavior of IGBT. Measuring
the negative peak voltage veE caused by recovery di/dt on
parasitic inductance between Kelvin emitter and power
emitter terminal is a new approach to monitor P-i-N diode
chip temperature. It is concluded that when the diode
temperature rising as the IGBT temperature unchanged, the
value of maximum recovery di/dt would decrease. A 3-D
database of veE_NP with varying temperature and relevant
factors is beneficial for on-line chip temperature prediction
of diodes in real-time operation.