Digital Active Gate Driving Automatically Minimizing Switching Loss While Keeping Surge Current Below User-Specified Target

To address the user-specified surge current targets and the trade-off problem between surge current and switching loss in gate drivers, a digital active gate driving method is proposed that automatically minimizes the switching loss while keeping the surge current below the user-specified target. A 6.5 kV IGBT is driven at 3.6 kV and 56 A load current using a digital gate driver (DGD) IC that can change the gate current in 64 levels from 0 A to 1 A in 480 ns steps. For each of the four user-specified surge current targets at turn-on, the optimum parameters of DGD are searched by repeating the double-pulse test 2500 times using the simulated annealing algorithm. As a result, the switching loss is successfully reduced by 18 % to 27 % compared with the conventional gate driving while automatically meeting the surge current targets.