A NOVEL CLOSED LOOP CONTROL OF SERIES/PARALLEL MULTILEVEL TOPOLOGY FOR RESIDENTIAL APPLICATIONS

Using parallel-series converter in as DC Power supply appliance gives a good opportunity to maintain stable supply while the load is changing. A novel multilevel inverter with a small number of switching devices is proposed. It consists of an H-bridge and an inverter which outputs multilevel voltage by switching the dc voltage sources in series and in parallel. The total harmonic of the output waveform is also reduced. The proposed inverter outputs larger voltage than the input voltage by switching the capacitors in series and in parallel. The maximum output voltage is determined by the number of the capacitors. In this paper a new topology called reversing voltage is implemented to improve the multilevel performance by compensating the disadvantages just mentioned. This topology requires fewer components compared to available multilevel inverters (especially in higher levels) and requires less carrier signals and does not need separate mechanism for balancing of the capacitor voltages. This inverter consists of a one H-bridge topology and a conditioning inverter which outputs of multilevel voltage by switching the DC voltage sources in series and in parallel. Unlike traditional multilevel inverters, this topology does not require an external voltage balancing circuit; a complicated control scheme is used to maintain its voltage levels while delivering sustained real power. The simulation results based on Matlab/Simulink are discussed in detail in this paper