Busbar Interference Correction for Non‐Invasive Current Distribution Sensing in Press‐Pack IGBTs

ABSTRACT

Press‐pack IGBTs are widely used in high‐voltage and high‐power applications due to advantages such as double‐sided heat dissipation and ease of series connection. However, the parallel operation of multiple chips inside the device easily leads to uneven current distribution. Therefore, it is significant to investigate non‐invasive current sensing methods for ensuring device reliability. This paper focuses on the non‐invasive sensing of internal current distribution in press‐pack IGBTs, analyses electromagnetic interference caused by busbars in converter‐valve application scenarios, and proposes a corresponding correction method. First, the structure of the converter valve and the position of the side busbars around the device are analysed. Then, the electromagnetic interference of the side busbars on current sensing is investigated, and a correction method is proposed. Simulation results show that the calculated angle is 45.22° in the absence of busbars and 44.32° after applying the proposed correction method in the presence of busbar interference. Finally, a double‐pulse experimental platform is built for validation. Under the upward‐biased condition, the proposed method corrects the offset angle from 300.15° to 350.25°, and under the leftward‐biased condition, it corrects the offset angle from 192.37° to 258.25°, thereby suppressing busbar interference and improving the accuracy of current‐offset direction identification.