*4.3. Comparison*

In conclusion, the existing Z-source-based inverter topologies have some of the following disadvantages: complex control techniques [25–27], high semiconductor device counts [28,29], high numbers of capacitors and inductors [30], ripples in the capacitor voltage and inductor current [31–33], unsatisfactory voltage gain [34], and leakage current [35]. Table 3 shows the characteristics of different Z-source inverters. In addition, a transformer [36,37] is used to boost input voltage and isolate input and output, which will increase the cost, weight, and volume of the inverter. So, the inverter with a common ground can deal well with these problems.

**Table 3.** Comparison between different Z-source inverters. EMI: electromagnetic interference.


In Table 3, it is easy to see that the CUK converter has low input current ripple and output current ripple, and the SEPIC converter has low input current ripple, so both CUK-based ZSI and SEPIC-based ZSI have low electromagnetic interference (EMI) [38]. Furthermore, SEPIC has the possibility of a series of resonant operations between the balancing capacitor and the parallel inductor, which can be beneficial for a soft-switching operation [39]. Therefore, SEPIC-based ZSI makes it easy to achieve a soft-switching operation.
