A Novel Topology of Cascaded Transformer Ten Switches Multilevel Inverter

The proposed system consists of H-bridge output stage with a bi-directional switch. It can be considered as voltage synthesizer and generates five voltage levels. Single phase low frequency transformers are used in structure. The main functions of the Single phase low frequency transformers are voltage transformation and isolation. Owing to the cascaded transformers, it has a galvanic isolation between an input DC source and output loads.Additionally, since two capacitors are connected in parallel with the main dc power supply, no significant capacitor voltage swing is produced during normal operation, avoiding a problem that can limit operating range in some other multi level configuration. Here only ten switches have been used which reduces the switching losses to a great extent and since we are using diodes, conduction losses may occur but it is very negligible when compared to the switching losses. By cascading the two transformers the output voltage can be increased and also the cost is less when compared to the conventional methods because of lower switches and power driver circuits. Since the level has been increased the harmonic contents will be less and thus we can obtain a sinusoidal waveform, not a pure waveform but a waveform with less harmonic distortion. By using this method we can reduce the harmonic contents and increase the power quality to a great extent