High Insulation Voltage IGBT Drive Design For Medium And High Voltage Systems

Since the invention of high-power power electronic device IGBT,its application field has been expanding,and it has become the mainstream product in the fields of industrial application and consumer electronics.Especially in the field of high-power applications,the drive of IGBT has become a research hotspot.In high-voltage and high-power applications,IGBT drive systems are required to have a high isolation voltage level;in a variety of special operating conditions such as underwater,flammable,and explosive use,the drive system is required to achieve a considerable degree of electrical insulation;power electronic devices complex and large,it is required to provide fast and accurate driving for multiple IGBTs at the same time.This paper explores and studies high voltage isolated IGBT drivers for high power applications.First,the working principle of IGBT is analyzed,including physical model,equivalent circuit and switching process.Then the IGBT driven protection circuit and isolated power supply were analyzed and studied.In addition,we focused on multi-output high-voltage isolated power supplies.The high-voltage isolation drive power is based on the current bus and uses a high-voltage cable as the primary side of the transformer.It has the characteristics of multiple outputs and high-voltage isolation,and the arrangement of the drive space is very flexible.The system structure of the LCL-S filter network is mainly adopted.The LCL network has good filtering and constant current characteristics,so a low harmonic content and a constant bus current can be obtained.On this basis,LCL-S can achieve output voltage load independence,so it can provide stable and reliable power supply to IGBT drive.In addition,compared with single-stage LC resonance,it has better fault tolerance and greater resonance capacity;under the condition of unchanged power level,reasonable switching parameters can make the switching device withstand smaller current and voltage stress,reduce loss.The experiment was conducted by making a prototype,and the final result verified the feasibility of the scheme.In order to obtain a higher isolation voltage,this paper also proposes a two-stage isolated multi-output power supply.And two implementation forms are given: two topologies of LCL-LCCL-S and LCL-SS.Adding a transformer can significantly increase the isolation voltage,but the structure is relatively complex and requires high accuracy of the parameters.The constant current bus can be obtained in both topologies.Therefore,it is possible to achieve output voltage load independence and meet the requirement of driving stable power supply.Finally,the correctness of the theory is verified by simulation and experiment.