A novel single phase advanced multilevel inverter with adjustable amplitude of voltage levels

In this paper a novel single phase advanced multilevel inverter (MLI) with adjustable amplitude of voltage levels is proposed. High frequency single switch along with inductor is used in this proposed multilevel inverter to adjust the amplitude of voltage levels. Low frequency switches are used to generate the required number of levels. The amplitude of voltage levels is adjustable by changing the duty ratio of high frequency switch. Conventional multilevel inverters required large number of power switches, clamping diodes, capacitors and input sources. The drawbacks of conventional multilevel inverters are overcome by proposed advanced multilevel inverter. In this paper, single phase 9-Level inverter with different amplitude of voltage levels is proposed using in-phase level shifting SPWM (sinusoidal pulse width modulation) technique. Proposed 9-level single phase MLI is designed for rated power 2kW, 24V input voltage and 0.8 modulation index. Total harmonic distortion (THD) of output voltage is calculated by FFT analysis window without filter and with filter. THD of proposed 9-level single phase MLI without LC filter and with LC filter is nearly 17.38% and 3.72% respectively. The proposed advanced 9-level single phase MLI is simulated in MATLAB/SIMULINK.