The IGBT Numerical Analysis Model And Application In The NPC Three-level Converter Loss Analysis

In recent years the Insulated Gate Bipolar Transistor (IGBT) has been widely used in modern power electronic technology. Usually the power devices models in PSpice and MATLAB ware are not able to be simulated directly for power devices. While establishing IGBT model, physical and functional models are widely used. But they have many defects, such as complex calculation, and it is very difficult to modify the parameters. Besides, they don’t consider the impact of temperature, so it isn’t so perfect on accuracy.This thesis presents a new easy approach to the IGBT model by the internal structure and principle of IGBT. The main contents of this thesis could be divided into three parts:Firstly, the basis of the theoretical part is introduced. This thesis specifically describes the background and briefly summarizes the development of the IGBT. Then the course of the evolution of IGBT structure, the principle of its work and its basic characteristics are introduced. Besides, the differences between the basic structure and equivalent circuit structure of IGBT are very detailed comparative analyzed.Secondly, combining with characteristic curve and parameters of device manufacturers and considering the impact of temperature effect, internal main parameters of IGBT are able to be derived and calculated, then the IGBT PSpice model could be set up. The established IGBT model is simulated in a single circuit and detected the static and dynamic characteristics by the impact of temperature. The model is applied to simulate the NPC three-level converter and researching loss of three-level converter. When power devices are working, there is loss in them, like the state loss and switch loss, including IGBT and diode. Most of the simulation softwares ignore the impact of outside temperature for the device parameters, then affect the loss of simulation calculation, and this paper takes account of this point in the modeling. It is very easy to modify the parameters, so the comparison of simulation and experiment is higher. Finally, a three-level converter platform is established and the experiment is done. The loss of the measured value and the simulation calculation data are compared, then the impact of the loss of the internal factors is analyzed. According to the simulation waveform, the experiment wavement and loss calculation results, verify the validity of the model built by IGBT.