Design Considerations for Neutral Point Clamped Converters

Despite the growing proliferation of three level converters, practical design guidelines for these systems are not readily available. This paper describes such design guidelines for the construction and control of three level converters. Loss equations that assist in thermal design and device sizing are provided along with current estimates for sizing link capacitors. The primary commutation mechanisms and the relevant parasitics effects are identified. A low inductance busplane design is presented for designs featuring dual IGBT modules and low inductance snubber capacitor connections are shown. A discussion of the control implementation using a DSP and FPGA platform is provided