Device and method for suppressing instantaneous surge of igbt switch in pwm converter system

Abstract

The present invention provides an IGBT switch instantaneous surge suppression device and method for a PWM converter system, the method steps: obtaining the total stray inductance LTotal of the PWM converter system in the stray inductance extraction time period t1-t2; based on the total stray inductance The IGBT equivalent circuit model is constructed based on the scattered inductance LTotal and the characteristics of the PWM converter system. The IGBT equivalent circuit model includes the non-inductive absorbing film capacitor CSnubber for suppressing the instantaneous surge of the IGBT switch; the PWM converter is obtained based on the IGBT equivalent circuit model The DC bus stray inductance value LDC-Link of the system; according to the DC bus stray inductance value LDC-Link, the IGBT surge voltage change preset value ΔV2 and the IGBT operating current IC to obtain the capacitance value of the non-inductive absorbing film capacitor CSnubber, The instantaneous surge of the IGBT switch is suppressed by the non-inductive absorption film capacitor CSnubber. The IGBT switch instantaneous surge suppression device and method of the PWM conversion system of the present invention can effectively suppress the IGBT switch instantaneous surge.

Description

technical field [0001] The invention relates to the technical field of PWM conversion, in particular to an IGBT switch transient surge suppression device of a PWM conversion system and a method for suppressing an IGBT switch transient surge of a PWM conversion system. Background technique [0002] In the PWM converter system, the IGBT usually operates in a high-frequency switching state. The high di / dt and the parasitic inductance of the DC bus work together to cause a serious inter-electrode voltage spike when the IGBT is turned off transiently, even exceeding the IGBT. The voltage withstand value, such as figure 1 As shown, thereby deteriorating the electrical stress, switching loss and electromagnetic interference of the IGBT. At the same time, the existence of system stray parameters may also lead to changes in the equivalent topology and parameters of the main circuit, which in turn will lead to deviations in the impedance characteristics of the system, resulting in di...

AI Technical Summary

Problems solved by technology

Such as the Hefner model and the Kraus model rely on the internal physical mechanism of the component, which can accurately characterize the dynamic and static performance of the IGBT. However, it needs to be based on a clear understanding of its internal structure, and the physical model parameters are many and complex, and involve a lot of calculus transform

As far as the functional model is concerned, it only needs to take into account the external characteristics of the IGBT, so the physical meaning is not clear, which is not conducive to parameter adjustment and extraction

However, in the traditional stray parameter extraction method, the various stages of the switching transient process are not distinguished in detail, which can easily lead to inaccurate parameter extraction, and thus cannot scientifically attenuate the surge voltage, accompanied by serious oscillation phenomenon

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