Inverter is a power electronic device used to convert dc voltage into ac voltage at a fixed desired frequency. Being a power electronic device, it is more efficient and reliable due to absence of any mechanical rotating part. Now a days an inverter is not only a device but also a part of power sector but a simple inverter has only two level so the out coming wave is much distorted form fundamental sine wave which introduces the harmonics into the circuit which makes the total system less efficient along with that the age of system decreases also there is a danger of faulty operation [1]. As the harmonics by its nature have heating effect along with distortion which is not good for load as well as whole power system. So the concept of multilevel inverter arises in which the levels of the inverter is increased so that the distortion of the out- coming wave could be minimized [2, 11]. As the level rises the sinusoidality of the output wave increases and thus harmonic content decreases [6]. But in case of multilevel inverter everyone is trying to improve the level of inverter by increasing the switches but in this paper we have introduced a asymmetrical circuit for 7- level inverter with a new topology so that the level of inverter can be obtained with reduced switches with a new topology and compared the modulation results with each other so that we could obtain the various pulse width modulation (PWM) technique results in this way a deep study is being taken place on various PWM modulation techniques on asymmetrical 7 leveled multilevel inverter.

Keywords : Multi Level Inverter (MLI), Pulse Width Modulation (PWM), Phase Deposition Pulse Width Modulation (PDPWM),Phase Opposition Deposition Pulse Width Modulation (PODPWM), Alternate Phase Opposition Deposition Pulse Width Modulation (APODPWM).