A hybrid switched-capacitor multilevel inverter with self charge balancing and less number of switches

Abstract

Multilevel inverters with less number of components and power supplies play important role in most of power electronic applications. In this paper, a new switched capacitor multilevel inverter (SCMLI) is presented which can generate more output voltage levels with less number of components and one required dc power supply in contrast to some of existing topologies. This structure uses a new switched capacitor converter (SCC) which includes several capacitors that can be charged by binary asymmetrically algorithm as self-balancing. At the next, proposed SCMLI is connected to another SCMLI unit as hybrid form and then, the output voltage levels are increased with good quality using hybrid modulation technique. Several simulation results by PSCAD/EMTDC software and comparisons in different aspects such as number of required switches, capacitors, number of components that are in current path and total blocked voltage is given to confirm the effectiveness of proposed topology.

Switched-Capacitor Multilevel Inverters: A Comprehensive Review

“…15(a). Similarly, plenty of single-source SCMLIs have been presented so far [19]- [21], [31], [32], [39], [46], [48], [65], [67], [69], [160], which use the generalized version of SCCs based on basic SPSC or SC voltage tripler units in the front-end side. All the four involved switches of this unfolding FB cell need to withstand the largest MVS equal to the peak of inverter output voltage, which can severely affect the TSV index of the converter.…”

“…The triple-gain 7L inverter presented in [164], the quadruple-gain 9L inverter proposed in [51], and the generalized SC-MLIs proposed in [50], [54], and [66], respectively, are the other notable structures that have been constructed based on this HB-leg circuit design. [19]- [21], [31], [32], [39], [46], [48], [67], [71], and [160]. (b) SC-MLIs using two HB legs [25]- [27], [30], [40], [70].…”

“…A 19-level (19L) SC-based inverter using two symmetric dc sources with eight times voltage conversion gain and 12 power switches is proposed in [77], which is an example of this type of multi-input SC-MLIs. A cascaded connection of a three-level (3L) FB-based cell with the 9L derived topology of [46] can also lead to a 27-level (27L) inverter with two asymmetric dc sources [91]. However, using four switches as an FB cell in the back-end side of each unit in a cascaded version of SC-MLIs can still cause the concern of large values of MVS and TSV indexes for the converter.…”

“…15. (a) SC-MLIs with FB unfolding cell conceptualized in[19]-[21],[31],[32],[39],[46],[48],[67],[71], and[160]. (b) SC-MLIs using two HB legs[25]-[27],[30],[40],[70].…”

Switched capacitor based multi-level boost inverter for smart grid applications

“…Traditional multilevel inverters require many auxiliary circuit devices to balance the capacitors charge [6], [7]. They do not have a boost function as the the output voltage magnitude could not be greater than the scalar superimposition of the DC link voltages [8]. Current trends in multilevel inverters are alternative topologies for CHBs with less switches number and improved THD reduction.…”