Research On The Loss Calculation Method And Temperature Testing Of The IGBTs In AC-DC Converters With Chaotic SPWM Control

ABSTRACT:Chaotic sinusoidal pulse width modulation (CSPWM) has been proposed and applied into suppressing the electromagnetic interference (EMI) generated by power converters. This method has been widely researched due to its efficiency in EMI suppressing and its easy to by realized. However the power losses and the temperature feature of power switches in converters under CSPWM control have not been analyzed yet, but the power level of power electronics converter is getting higher, which result in higher power density and higher junction temperature of converter device. High junction temperature will affect the performance and service life of power devices. In recent years, practice has shown that temperature has become the main reason for power device damage. Therefore the power losses calculation and thermal analysis of the power switches under CSPWM control is very important for practical application.In this paper, the working principle and the control strategy are given, the features of Logistic map and Tent map are analyzed. Then CSPWM control is compared with traditional SPWM control based on the control strategy. Finally TMS320F28335is chose as the control chip, then CSPWM control’s programing is designed based on CCS3.3platform.Two kinds of power losses calculation methods for IGBTs in AC-DC converter under different CSPWM controls are first proposed by discrete iteration method. Then the difference of power losses of IGBT under CSPWM and traditional SPWM are calculated and analyzed.To verify the accuracy of the proposed calculation methods, ANSYS is chose to simulate the IGBT’s thermal feature. The3D-modle enhances the simulation’s accuracy. To analyze the IGBT’s temperature under different controls, the Saber-Simulink electro-thermal simulation is chose. The control part in Simulink and the thermal part in Saber show the different temperature features under different controls.Finally, the temperature experiments for the IGBTs under chaotic SPWM control and under traditional SPWM control are carried out in an AC-DC converter. The experimental results prove the accuracy of proposed calculation method and the correctness of the analysis of the difference under different controls.