MS Student Macks Johanesen with advisor A. Stillwell

When reactive power is not locally compensated, the demand over transmission lines causes active power line losses. Single phase microinverters, as seen in Figure 20, can be used for local reactive power compensation in addition to their dc to ac conversion, but typically these devices are optimized for high power factor outputs. Microinverter hardware can be optimized for full reactive power support across all power factors. The output filter inductor adds additional reactive power load, which requires a larger dc bus capacitor to buffer the double line frequency energy. A flying capacitor multilevel (FCML) inverter topology can be utilized to increase the effective switching of the inverter to limit the size of the output inductor and dc bus capacitor. The prototype of a four-level FCML has been designed, is currently being assembled, and will demonstrate the design’s full power factor range. Figure 21 shows the top layer of the printed circuit board (PCB) that was created for this project.

Figure 20 Caption: Single-phase inverter topology

Figure 21 Caption: Four-level FCML inverter PCB