Lin1 Idc Monitor + - Vdc Fault Monitor S1 Trigger S2 L IL Cin1 + Vout Coil - Zfault S2 S1 Shunt Fault (b) Load 1 Lin2 Load 2 Fault Monitor N1 T1 Shunt Fault N2 CZ Rload Step T2 Zfault RZ Rstep Movable Contact Lload Lin3 (c) Fault Monitor Load 3 I1 I2 I3 Cin3 PMSM I1 I2 I3 (a) (d) Figure 9. (a) The circuit schematic of a dc busbar with (b)-(d) electric-ship load hardware prototypes. arcing behavior may provide a benefit when considering stochastic load profiles due to the high degree of randomness in both. In this research, there are two sources of fault within the fixed impedance load. The first source is a shunt fault, which is protected by the coupled dc Z-source circuit breaker. The second type of fault, series arcing, is not protected by the dc breaker because this type of fault does not exhibit large current swings. The spark generator movable contact creates a series arcing fault condition, as shown in load 2 in Figure 9. TABLE 1. The hardware parameters. Load 1 (Coil Gun) Vdc = 375 V Lin1 = 100 μH Cin1 = 970 μF L = 2 mH Vout = 300 Vdc max Cout = 7 mF Coil = 80 μH Zfault = 15 Ω Load = 4 mH Load 2 (Fixed Impedance) Propulsion-Motor Drive Load Lin2 = 100 μH N1:N2 = 70:24 LN1 = 51 μH LN2 = 6 μH Cz = 100 μF Rz = 100 Ω Rload = 470 Ω Lload = 1 mH Rstep = 470 Ω Load 3 (Propulsion Motor) A scaled-down permanent magnet machine (PMM) controlled by a three-phase inverter was used to simulate the slow-transient behavior of an electric propulsion system. Load 3 in Figure 9 depicts the hardware setup of this motor drive load. Lin3 = 100 μH Cin3 = 1.7 mF PMSM = TI HVPMSMMTR TI HVPMSMMTR: Texas Instruments High-Voltage Permanent Magnet Synchronous Motor. IEEE Electrific ation Magazine / MARCH 2 0 2 1 31