逆变变压器漏感对主电路和驱动电路的影响

Impact of the leakage of inverter transformer on the main circuit and the driving circuit

漏感是影响逆变电路正常工作的主要因素。通过对逆变主电路工作过程进行分析,探讨了逆变电源在开通和关断的过渡过程中,变压器的漏感对IGBT集射极电压的影响机理,在此基础上建立了MATLAB仿真模型,通过实验验证了该模型的正确性。运用仿真更直观地反映了漏感越大,则IGBT上集射极电压尖峰越大的规律。由于密勒电容的存在,在IGBT集射极电压发生变化的时刻,驱动波形Uge的负压区上出现了不希望的电压尖峰,此电压尖峰可能使处于关断状态的IGBT组误开通,使主电路中IGBT发生短路现象。漏感越大,该现象出现的可能性越大。

Leakage is one of the main factors which affect the normal work of inverter circuits.By analyzing the work process of the inverter main circuit,this article discussed how the leakage can affect the voltage between the collector and the emitter of IGBT when the power inverter is open or shutdown.On this basis,a MATLAB simulation model is established.This model is correct that is proved by trials.Through the use of simulation,it directly reflects that the voltage between the collector and the emitter of IGBT become larger when the value of leakage is bigger.Because of the Miller capacitanee,there will appear a voltage spikes at the negative voltage of driven wave which is not want,when the voltage between the collector and the emitter of IGBT is changing.These voltage spikes will make IGBT groups which are being closed mistakenly opening,and then the circuit will occur in short circuit.The leakage become larger,the probability of this phenomenon is bigger.