Gate drive device

A gate drive device configured to drive a gate of each of two semiconductor switching elements constituting upper and lower arms of a half bridge circuit, the gate drive device comprising:

• a detection circuit configured to detect, as a detection value, a peak value of an element voltage that is a voltage of a main terminal of one of the two semiconductor switching elements, as one semiconductor switching element, or a change rate of the element voltage during a change period in which the element voltage changes;
• a determination circuit configured to determine whether an energization to the one semiconductor switching element during the change period is a forward energization in which a current flows in a forward direction or a reverse energization in which the current flows in a reverse direction;
• a calculation circuit configured to calculate a target instruction value corresponding to a switching speed of the one semiconductor switching element such that the peak value or the change rate becomes equal to or less than a permissible value of the peak value or the change rate determined according to a specification of the one semiconductor switching element based on the detection value during the change period in which the determination circuit determines that the energization to the one semiconductor switching element is the forward energization, and the permissible value;
• and
• a drive circuit configured to change a gate resistance value or a gate current value of the one semiconductor switching element based on the target instruction value, and drive the gate of the one semiconductor switching element.