可控直流电流源的缓冲电路设计与功耗对比研究

Design and Dissipation Study of Snubber Circuit in Controllable DC Current Source

针对可调制直流电流源IGBT关断过电压问题,进行了缓冲电路设计。分析了RCD充放电型和RCD放电阻止型缓冲电路的工作原理,介绍了参数设计方法,并对两类吸收电路的损耗进行了量化分析比较。在额定电流200 A的可控直流电流源上进行了实验,结果表明:RCD放电阻止型缓冲电路损耗显著小于RCD充放电型缓冲电路,效率更高,体积更小,更适用于开关频率较高的场合。

Aiming to reduce the turn-off over voltage of IGBT in DC current source, the snubber circuit was designed. The operating principles of both normal RCD snubber circuit and RCD clamped snubber circuit were analyzed in detail. The parameter design method was introduced. The dissipation of these two kinds of snubber circuits was compared in emphasis. Experiment was performed on a controllable DC current source of 200 A output current.Experimental result proves that the dissipation of RCD clamped snubber circuit is significantly less than the normal RCD snubber circuit, has higher effiency,needs smaller space, and more suitable for higher frequency application.