Prediction of switching loss variations by averaged switch modeling

Abstract

Abstract-An analytical averaged equivalent circuit model is derived revealing how dominant loss mechanisms vary with converter operating point in a PWM converter. The model is based on the operational characteristics of power diodes and IGBTs. Laboratory experiments support the derived model and confirm that IGBT current tailing and diode reverse-recovery are indeed the most critical losses in a PWM converter. These losses are more significant at light load, hence reducing the energy capture of converters used in wind generation.

Practical considerations in the PWM rectifier with active filter function

“…The objective of this section is to show the effect of the active filter function over the temperature of two different IGBTs in a PWM-VSR-C. A recommended practice for IGBT safety is to maintain the average junction temperature in 125 ºC or less [12,13]. However, this method provides very optimistic results about the junction temperature reached by the semiconductors.…”

Accurate Analytical Modeling for Switching Energy of PiN Diodes Reverse Recovery

“…In (2), S is a measure of the softness of the diode's recovery (ratio of the time between the zero crossing of the current and the peak reverse current to the time between the peak of the current and the zero) and k Q is a function that defines the relationship between the stored charge in the diode and the forward current (I F ) [1], [27]. It also accounts for the diode voltage (V AK ) plus the peak inductive voltage overshoot (LdI RR /dt) resulting from the product of the switching rate and the parasitic inductance of the diode (L).…”

“…Figure 10 shows this plot using the experimental measurements at 3 different temperatures where a constant slope can be observed, as predicted by the model. The slope of this line yields the parameter k Q which relates the charge stored in the diode during the conduction of the forward current to the forward current [1]. Hence, if k Q is experimentally extracted for a specific diode, the I RR used in the model can be substituted by the I RR in (2).…”

Thermal–electrical averaging model of resonant converters based on extended describing function method

“…In [2], calculation of switching losses based on averaged switching modelling for PWM converters is discussed. Thermal-electrical simulation for resonant converters based on average models is not yet discussed in state-of-the-art publications.…”