# Modern MultiPort Converter Technologies: A Systematic Review
## 2 General Classification and Operation Principles
### Partially-Isolated Multiport Converters
All of the aforementioned types of MPCs including non-isolated, isolated, and partially isolated are still evolving, and more studies continue to suggest novel approaches, circuit designs, and control algorithms which help to reduce cost and increase the efficiency of the multiport converter system. Fewer active switches are present in non-isolated multiport converters, which often also have higher efficiency than isolated multiport converters. On the other hand, isolated topologies can handle high power flow between ports with \begin{table}
\begin{tabular}{p{142.3 pt} p{142.3 pt}} \hline \hline
**Isolation Type** & **Main Results** \\ \hline \multirow{4}{*}{Partially isolated} & This research suggests a novel partially isolated multiport converter with enhanced transformer utilization and automatic current balancing capabilities. The interleaved PWM converter incorporates a flying capacitor to automatically balance inductor currents. Additionally, the proposed inclusion of a flying capacitor enhances transformer utilization by enabling 48-V/12-V battery operations with a minimal duty cycle of 0.5. \\ \hline \multirow{4}{*}{Partially isolated} & It is suggested to use a family of three-port three-level converters (TPTLCs) made of asymmetrical bidirectional halfbridge modules, which have the advantages of a simple control strategy, extended soft switching under a variety of operating conditions, and reduced voltage stress across switches. The suggested stacked TPTLC, which has several operating scenarios based on the output power of the fuel cell and the charge condition of the battery, is used as an example to explore the validity of the proposed concept. \\ \hline \multirow{4}{*}{Partially isolated} & In this study, a unique transformer-coupled dual-input converter (TCDIC) followed by a typical full-bridge inverter is offered as a two-stage stand-alone solution to several problems of PV-based stand-alone systems. Among such issues are obtaining maximum power from the PV array, the battery should be protected from overcharging and over-discharging, efficient DC to AC conversion, and suitable voltage boosting should be provided. With the suggested TCDIC, battery charge control and maximum power point tracking are both possible while still ensuring the right voltage level at the load terminal. The TCDIC’s small signal mathematical model is developed. For the proposed TCDIC, a workable control technique is developed. \\ \hline \multirow{4}{*}{Partially isolated} & The pulse width modulation in combination with the phase angle shift (PPAS) control technique, which is used in this study, uses the switch duty cycle and the phase angle of the interleaved converters as two control freedoms to accomplish decoupled voltage regulation within a specific operating range across distinct ports. A novel three-port DC/DC converter for photovoltaic (PV)-battery hybrid energy systems is created by combining an interleaved bidirectional buck-boost converter and a full-bridge converter. This converter is used as a standard example to investigate the effectiveness of the suggested PPAS control strategy. \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Application of different partially isolated MPC topologies for various systems. greater flexibility. The typical switching frequencies for isolated topologies are 100 kHz and 50 kHz, respectively.