The Research On The Technology For Series Connection Of IGBTs

Because of the high voltage,high current and easy to be driven, IGBT become the optimal selection of the power convert system. As the improvement of power electronics, the voltage becomes higher and higher. Such as high inverter,HVDC and Flexible HVDC system. The voltage should be dozens of kilo-volt. Single device can't be used in these occasions. So series connection of IGBTs is necessary.In the series connection of IGBTs, as the result of the different parameters and the delay of the drive signals, the main problem is unequal sharing of voltage respectively. The devices which withstand over voltage maybe broken down and result in the fault of the whole circuit. Control technique should be adopted to avoid the voltage imbalance. Different gate side active control circuits are introduced and analyzed, inter comparison in availability,reliability and loss is given in this paper. A new control circuit is designed based on the advantage and disadvantage of the existing technology. The availability and instability are proved by simulation and experiment.The design of cooling system for high power electronic devices is introduced in this paper. Different cooling systems are analyzed. A cooling system is designed based on the experiment condition as already stated in the previous letter. Rationality of the parameters had been proved by simulation.