High-speed gate drive scheme for three-phase inverter with twenty nanosecond minimum gate drive pulse

In this paper, we present a high-speed optical gate drive scheme for three-phase inverter. The gate drive signal is transmitted from control board to gate drivers with a frequency-shift keying modulation, using optical fiber. This gate drive signal transmission method is used with a commercial high-speed gate driver integrated circuit. The gate drive system is capable of producing minimum output voltage pulse of 20 nanoseconds. Using narrow voltage pulses, an active output filtering for variable speed drives can be implemented. Active output filtering is used to reduce the du/dt of a variable speed drive output voltage. This reduces the overvoltage at the end of a motor cable. An inverter prototype is constructed to study the active filtering method. The construction of the power stage utilizes MOSFETs with silicon carbide free-wheeling diodes. Measurement results for the gate drive system performance and inverter output voltage are presented.