Boost action is required for enhancing the output voltage of the sources like Photovoltaic (PV) sources, fuel cells and battery storage devices which eliminates the need of additional units. For this purpose, Switched-Capacitor (SC) based Multilevel Inverters (SC-MLI) are widely used. The proposed switched-capacitor based single-phase MLI is able to produce 13-level output ac voltage and furnishes voltage gains of 3 and 6. The same topology is also able to produce a single-phase 9-level ac output with a voltage gain of 4. The above-mentioned voltage levels and voltage gains are achieved using the proposed topology just by modifying the switching strategy used for firing the switches and does not require any modification in the proposed SC-MLI structure. The proposed configuration of single-phase MLI require less switch count to produce 9 and 13 level ac output voltage with abovementioned voltage gains. The switches connected in the proposed configuration undergo less voltage stress as compared to the MLIs suggested the in literature. The comparison of the proposed converter topology with the existing MLIs reported in the literature is included. The validation of the performance of the proposed inverter is carried out using experimental results captured on a low-power laboratory prototype.

In this work, two new topologies of single-phase hybrid multilevel inverters for symmetrical and asymmetrical configurations are presented for use in drives and control of electrical machines and the connection of renewable energy sources. The proposed topology uses 2 dc sources, 12 switches, 1 flying capacitor, and 3 diodes to generate boosted 13-levels and 17-levels for symmetric and asymmetric configuration, respectively. Self-voltage balancing of its capacitor voltage regardless of load type, load dynamics, or modulation index is a key advantage of the suggested design. The higher performance of proposed topologies in terms of the total number of switches, TSV, THD, switch stress, and dc sources are demonstrated by comparing those with recently published topologies. In addition, a widely employed nearest level control modulation approach is used to provide output voltage levels with low THD. Finally, experiments were undertaken to validate the performance of the suggested topology.

High-gain dc–dc converters are used for a number of applications including the power processing of several low-voltage renewable energy sources (solar photovoltaic and fuel cells) while they are integrated into a microgrid. This article introduces two novel designs of high power density nonisolated quadratic boost converters, which neither uphold the cascaded architecture nor involve coupled inductors in them. The proposed converters utilize the switched-inductors and switched-capacitor-based modules for voltage boosting. Despite having a higher output voltage, the proposed topology in its extended mode offloads the issue of high voltage stress at the devices. The output voltage can be extended to further higher levels without requiring additional circuits for peak inverse voltage (PIV) suppression at the output diode. The current at the input and output terminals are continuous, which facilitates the converter for various applications such as distributed generation (DG)s integration to microgrid and uninterruptible power supplies for integrated battery storage systems. The switched-inductor-switched-capacitor quadratic converter and its extended topology, extended switched-inductor-switched-capacitor quadratic converter, are analyzed thoroughly in different modes of conduction and the performance is justified by developing a hardware prototype ranging for a maximum power of 400 W. The switching frequency is maintained at 50 kHz.

Various 7-level switched-capacitor (SC) based converters are reported in the literature which furnishes a voltage gain of 1.5. However, in these topologies, the voltage rating of switches is high and the switch count is more. Further, the charging and discharging action of the switched capacitors, lead to the production of spikes having a large magnitude in source current and charging currents supplied to switched capacitors. Due to this limitation, the SC-based Multilevel Inverter (SC-MLI) cannot be used for high-power applications. To resolve these issues, an SC-MLI in an Active-Neutral-Point-Clamped (ANPC) configuration is proposed in this paper which requires switches having reduced value of voltage stresses and the switch count of the proposed converter is less. Further, to reduce the magnitude of spikes in the source and charging current supplied to switched capacitors, a soft switching circuit is included in the proposed converter. The soft charging circuit includes an inductor and a diode in the charging path of the proposed converter which ensures soft charging of the switched capacitors. The proposed converter can significantly suppress the spikes appearing in the source current by including a small value of inductance connected to the soft charging circuit. The proposed topology requires a single dc source, 2 switched capacitors, and 8 switches to generate 7-level and does not require an auxiliary diode. The absence of an auxiliary diode leads to a further reduction in losses. If the value of the modulation index is reduced to a low value, the proposed topology can maintain the self-balancing of the capacitor voltage. To highlight the various key features of the proposed 7-level topology, its comparison with the recent converter topologies suggested in the literature is carried out. To validate the efficacy of the proposed 7-level SC-MLI, experimental results are included which are captured using a laboratory prototype for different values of soft charging inductor.