用于压接型IGBT器件芯片电流测量的带金属屏蔽层集成PCB Rogowski线圈的研究

Integrated Rogowski Coil Sensor for Press-pack Insulated Gate Bipolar Transistor Chips With Shielding Layers

柔性直流输电是构建能源互联网的重要途径,其中压接型IGBT器件是柔性直流输电换流阀的核心器件。由于单颗压接式IGBT芯片面积小,通流能力低,为了提高柔性直流输电的输电容量,需要将多颗压接式IGBT芯片并联。但是由于并联芯片电气参数差异,导致IGBT芯片在开关过程中出现不均流以及电流过冲现象。该文在PCB Rogowski线圈集总参数模型的基础上,分析IGBT测试过程中发射极与集电极电压的快速变化形成的电场对PCB Rogowski线圈测量误差的影响,提出用金属屏蔽层来消除电场干扰的方法,并实验验证该方法的有效性。接着仿真和实验分析PCB Rogowski线圈的自感和和分布电容(计及引入屏蔽层后屏蔽层与Rogowski线圈间的电容),首次从等效电路理论模型和实验分析由于屏蔽层引入造成对测量频带范围的不利影响。最后平衡屏蔽层引入的优缺点,设计一款集成的带金属屏蔽层的PCB Rogowski线圈来实时检测特定压接式IGBT器件内部并联芯片的电流。

HVDC flexible transmission is an important way to build global energy interconnection,in which Press-Pack IGBT is a key device of the converter valve system.Due to the small area and low current capacity of a single Press-Pack IGBT IGBT chip,multiple IGBT chips need to be connected in parallel in order to improve the transmission capacity of HVDC Flexible.However,because of the difference of electrical parameters of parallel chips,IGBT chips have uneven current and current overshoot in the switching process.Based on Lumped parameter model of Rogowski coil,this paper analyzed the influence of the electric field formed by the fast change of emitter and collector voltage of the IGBT on the measurement error of PCB Rogowski coil in the process of IGBT testing,put forward a method to eliminate the electric field interference with metal shielding layer,and verified the effectiveness of this method.Then,through simulation and test,the self-inductance and the distributed capacitance(including capacitance between the shielding layers and coils)of the Rogowski coil,and the adverse effect on the measurement frequency band caused by the introduction of shielding layer were firstly analyzed through equivalent circuit theory model and experiment.Finally,an integrated PCB Rogowski coil current sensor with metal shielding layer was designed to detect the current of parallel chips in specific crimped IGBT devices in real time.