Fault-Tolerant Power Electronic System for Drag Power Kites

Figure 18

Simulated voltages, currents, and states for short circuit fault S2 in motor mode: (row 1) ground converter total voltage (solid), kite converter total voltage (dashed); (row 2) current of positive (red solid) and negative (blue solid) ground converter, current of kite converter (black dashed); (row 3) voltage of positive (red) and negative (blue) tether wire at ground in solid and at kite in dashed; (row 4) current in positive (red) and negative (blue) tether wire and in shield (green) at ground in solid and at kite in dashed; (row 5) state of fuse F1# (red solid), F2# (blue solid), F3# (red dashed), F4# (blue dashed ), F5# (green solid), and F6# (green dashed) with C for conducting, OT for conducting but overcurrent triggered, and O for open or overcurrent; (row 6) kite converter voltage excess state with N for normal, O for overvoltage, UT for undervoltage triggered, and U for undervoltage; and (row 7) kite converter voltage-imbalance state with N for normal, IT for imbalance triggered, and I for imbalance. All voltages are normalized for the rated voltage, all currents are normalized for the rated current of a drivetrain group, and the time is normalized for the reference time and shifted to the fault time . All voltages are with respect to the nearest shield and the sign of all currents are counted “from left to right” in Figure 11.