Multi-series inverter arrangement

A multi-series inverter arrangement comprising:

• a DC circuit including a neutral point output terminal;
• and
• a multi-series inverter including three arms each for U, V and W phases connected in parallel with said DC circuit, each arm including:
• first, second, third and fourth switching elements connected in series, a mutual juncture point of said first and second switching elements and a mutual juncture point of said third and fourth switching elements are connected to the neutral point output terminal of said DC circuit via respective clamping diodes, and said first and third switching elements and said second and fourth switching elements are on and off controlled with each other in a conjugate relationship;
• flywheel diodes, each connected in parallel with said first, second, third and fourth switching elements;
• and
• individual gate driving circuits for said first, second, third and fourth switching elements for providing a gate current thereto,
• wherein, the gate current provided by said individual gate driving circuits for said second and third switching elements is determined to be larger than that provided by said individual gate driving circuits for said first and fourth switching elements,
• wherein the gate current includes a high gate drive forward current and a wide width gate forward current following thereto, and said individual gate driving circuits for said second and third switching elements, each includes a first gate driving circuit for providing the high gate drive forward current, a second gate driving circuit for providing the wide width gate forward current and means for detecting a tendency of an incomplete on phenomenon at the corresponding switching element, said first gate driving circuit is activated when a turn on signal for the corresponding switching element is received or when said detecting means detects the tendency of an incomplete on phenomenon at the corresponding switching element and said second gate driving circuit is activated when the turn on signal for the corresponding switching element is received.