dV/dt对IPM中IGBT栅极电路的影响分析

The effect of dV/dt on the IGBT gate circuit in IPM is analyzed both by simulation and experiment.It is shown that a voltage slope applied across the collector-emitter terminals of the IGBT can induce a gate voltage spike through the feedback action of the parasitic capacitances of the IGBT.The dV/dt rate,gate-collector capacitance, gate-emitter capacitance and gate resistance have a direct influence on this voltage spike.The device with a higher dV/dt rate,gate-collector capacitance,gate resistance and lower gate-emitter capacitance is more prone to dV/dt induced self turn-on.By optimizing these parameters,the dV/dt induced voltage spike can be effectively controlled.     

偶氮类螯合剂的化学结构对硷金属分离性能的影响

本文对1-苯基偶氮-2-萘酚萃取碱金属进行了研究,并研究了其萃取和协萃机理。结果表明,其萃取钠、钾的机理与锂不同。对螯合剂的结构与萃取能力的关系进行了研究,发现螯合剂的酸性越大越有利于钠、钾的萃取,其在碱性水溶液中的溶解度越大也越有利于钠、钾的萃取。并提出了选择性萃取锂的最优结构。