Seven-Level Symmetrical Series/Parallel Multilevel Inverter with PWM Technique Using Digital Logic

Abstract

This paper attempts to come up with a proposed configuration of Multilevel inverters with a lesser number of switches that are smaller in size, lesser in cost and with a higher efficiency. Designing an inverter topology with a lesser number of switches and proper control technique is the major challenge. cascaded H-Bridge (CHB) topology are more popular among the existing configurations of multilevel inverters (MLI). Even though it can produce more levels, it needs to accommodate a huge number of switches for higher levels. The focus of this paper is to reduce the number of components for the same voltage level of cascaded H- Bridge configuration. In addition to that, generating the gating pulses for the switches is difficult when there is an asymmetry in the switches. A new symmetrical series/parallel configuration is proposed with reduced switch count and the pulse width modulation (PWM) technique is implemented with digital logic to generate the required gating pulses for the switches. The total harmonic distortion (THDI) of the output current is reduced with this PWM technique. The simulation has been carried out in MATLAB/Simulink software for both R (resistive) and R-L (resistive -inductive) loads.

Design and analysis of a new multi-level inverter topology with a reduced number of switches and controlled by PDPWM technique

“…therefore, for the same number of output levels,we can see that the new topology generates a lower rate of harmonics than the topology proposed by [18], we constat that the new proposed topology generate a rate of current harmonics lower than the topology proposed by N.Motaparthi and all. in the two cases of study (without filter THDI=6.47% , with THDI= 2.89% filter) [22]. The Table 3 below The design goals of PWM inverters are to reduce the THD in the output current and voltage.…”

Optimization of a Multilevel Inverter Design Used for Photovoltaic Systems under Variable Switching Controllers

“…The insertion of the SC cell into the H-bridge inverter helps to increase output voltage and inverter levels. Instead of using double input sources as in [24,25], the capacitor cell in this work behaves as an additional input source. Increasing the inverter level leads to a reduction in the THD, which is desirable for achieving a sinusoidal output.…”

“…Similar to the work suggested in [25], this work uses the series to parallel the configuration to achieve a 7L MLI with the least number of input sources and switches.…”

“…The work in [25] used three input sources to implement the 7L inverter; however, this work used only a single input source with an SC cell. 3.The single input source used in this work is connected to an H-bridge inverter through an SC cell operating in the series to parallel; thus, the SC cell behaves as an additional input source.…”