# Common-Ground Photovoltaic Inverters for Leakage Current Mitigation: Comparative Review
## 3 General Discussion
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Converter** & \multicolumn{2}{c}{**Features**} & \multicolumn{2}{c}{**Limitations**} \\ \hline Ref. [64] & \(\bullet\) & The input current is continuous. & \(\bullet\) & High capacitance values may be needed. \\  & & & \(\bullet\) & It does not support bidirectional power flow. \\ \hline  & & & \(\bullet\) & Its boosting gain is low. \\  & & & \(\bullet\) & Asymmetric operation during positive and \\  & & & \(\bullet\) & Negative half-cycles. This can induce DC current \\  & & & \(\bullet\) & component. \\  & & & \(\bullet\) & It needs a high number of switches; thus, more \\  & & & \(\bullet\) & complexity arises. \\ \hline  & & \(\bullet\) & It uses a low number of switches; thus, low & \(\bullet\) & It needs 2 inductors with a high inductance value; \\  & & & complexity can be acquired. & this increases the size. \\  & & \(\bullet\) & Low capacitance value is needed. & \(\bullet\) & It can offer only two voltage levels. Thus, a large \\  & & \(\bullet\) & The input current is continuous. & \(\bullet\) & filter size should be used. \\ \hline  & & \(\bullet\) & It can offer 5 voltage levels. Thus, small & \(\bullet\) & It needed high capacitance values. \\  & & & filter size is needed. & \(\bullet\) & Its boosting gain is low. \\  & & & \(\bullet\) & The switches should be over-rated to withstand \\  & & \(\bullet\) & The input current is continuous. & \(\bullet\) & the currents during capacitors \\  & & \(\bullet\) & No magnetic components are needed. & connecting/disconnecting. \\ \hline  & & & \(\bullet\) & High number of switching is required. \\  & & & \(\bullet\) & Its boosting gain is not reported. \\  & & & \(\bullet\) & Asymmetric operation during positive and \\  & & & \(\bullet\) & negative half-cycles. This can induce DC current \\  & & & & component. \\ \hline  & & & \(\bullet\) & Also, considering the internal losses of the \\  & & & & components, the voltage gain during positive \\  & & & & and negative half-cycles is significantly unequal. \\  & & & & This can result in large values of DC currents. \\  & & & \(\bullet\) & High capacitance values are needed. \\ \hline  & & & \(\bullet\) & High number of semiconductors is needed. \\  & & & & \(\bullet\) & Large input capacitance is needed for power \\  & & & & decoupling \\  & & & \(\bullet\) & It cannot support bidirectional power flow. \\  & & & \(\bullet\) & Asymmetric operation during positive and \\  & & & & negative half-cycles. This can induce DC current \\  & & & & component. \\ \hline  & & & \(\bullet\) & The input current is discontinuous. \\  & & & \(\bullet\) & The boosting gain is low. \\  & & & \(\bullet\) & High capacitance value is needed. \\ \hline  & & & \(\bullet\) & Asymmetric operation during positive and \\  & & & \(\bullet\) & negative half-cycles. This can induce DC current \\  & & & & component. \\  & & & \(\bullet\) & High input capacitance is required. \\ \hline  & & & \(\bullet\) & Asymmetric operation during positive and \\  & & & \(\bullet\) & Negative half-cycles. This can induce DC current \\  & & & \(\bullet\) & Component. \\  & & & \(\bullet\) & High number of semiconductors. \\  & & & \(\bullet\) & Large capacitance values are needed. \\  & & & \(\bullet\) & Large magnetic components are needed. \\ \hline \hline \end{tabular}
\end{table} 
Table 7: Features and limitations of voltage-source CG converters (buck/boost type). In view of these required features for PV systems, along with the associated advantages and disadvantages of the different CG converters, the following converters can represent suitable candidates for PV systems. * The buck/boost CG inverter is presented in [82] and shown in Figure 6o. This inverter needs only four switches while it can offer continuous input current along with high boosting gain. In addition, it does not need a high capacitance value for power decoupling; only one capacitor with 100 uF has been adopted for the 2 kW prototype. This inverter does not use any diodes. The reported efficiency is about 96.5% for a 2 kW prototype.