1 Basic idea and method for parameter extraction of PIN power diode
The principle of power diode parameter identification is shown in Figure 5. In this method, the internal technical parameters of PIN power diodes as the object, using rich modeling tools Saber software for dynamic simulation of  on the physical model, and established the data transmission between Saber and Matlab by SaberLink, the simulation waveform into Matlab. Compared with the experimental waveforms, the parameters of diode physical model in Saber model are optimized by quantum genetic algorithm, and the key parameters that affect the dynamic characteristics of diodes are obtained.
1.2 Basic technical parameters of PIN power diode
The accuracy of the power electronic system simulation depends on the selected device model. Usually the semiconductor model is a selection of behavior model, without considering the physical structure of the internal power electronic devices and operation mechanism, but the semiconductor device is intended for a "black box", through the empirical formula or look-up table method to describe the behavior of electrical devices. This kind of model is more accurate in describing the steady state characteristics of power electronic devices, but the effect is not ideal when describing the transient characteristics of the power electronic devices.
In this paper, the dynamic characteristics of PIN power diode are simulated by Saber software with high model precision. PIN Saber diode model is the complete physical model of semiconductor physics structure and internal mechanism of diode based on the obtained by the analytical equation, considering the internal mechanism of charge storage effect and high power devices electric heating effect, can be more comprehensive and accurate description of the diode carrier concentration and electrical behavior. In connection with the physical model in the second part of the Saber, the main physical parameters of the PIN power diode are shown in Table 1.
1.3 Simulation of PIN power diode reverse recovery process
Because the dynamic process of power diode includes forward recovery and reverse recovery process two, the reverse recovery process embodies the change of the space charge region can also reflect the large carrier distribution during the injection, so the reverse recovery characteristics of PIN power diodes to optimize the extraction of key physical parameters. Figure 6 is the circuit used for dynamic simulation and testing
In Figure 6, VDC is a voltage source, VGG is a gate pole control pulse signal source, and IL is the initial current of the diode circuit. The steady state, IGBT in the off state, IC is zero, the diode is switched through diode IL; when VGG applied VT on the base of IGBT, IGBT conduction, IL by IGBT VDC, applying a reverse voltage on the diode VAK, enter the diode reverse recovery process, by the positive guide to become reverse blocking. The circuit is modeled and simulated in Saber, and the reverse recovery current and voltage waveform of PIN diode are obtained. The waveform is transmitted to Matlab and compared with the experimental waveform data.