Optimized Control of IGBT Asynchronous Differential Amplitude Drive to Improve Parallel Dynamic Current Sharing Characteristics

The current equalization problem in the parallel application of IGBT modules is the most central problem. Compared to the static equalization characteristics, the dynamic equalization characteristics have more variable forms, including the rate of change of current, current peak value, and other process characteristic quantities, which are the problems to be focused on. Considering the influence of the inherent parameter differences in the control loops of parallel branches, this paper proposes a method of adjusting the delay time of the drive signal and changing the amplitude of the drive signal voltage to coordinate the control of the IGBT gate pulses of different branches and achieve the uniform control of the switching process current. In this paper, the influence of the drive signal delay time and drive voltage amplitude on the IGBT switching process current is investigated, the control parameter coupling relationship is analyzed, and the parameter setting method is optimized. Based on the actual IGBT module parameters, a mathematical model of the device operating characteristics was established, the parallel IGBT switching simulation analysis was carried out, and the drive of the application of the actual working condition test method was carried out. The results proved that the selected optimization design parameters can significantly improve the dynamic equalization of parallel IGBT module current, which verifies the feasibility of the drive control optimization parameter design method.