PROJECT TITLE :

Design and Implementation of a Sensor less Multilevel Inverter with Reduced Part Count - 2017

ABSTRACT:

This letter proposes one-phase 9-level (9L) inverter topology suitable for grid-connected renewable energy systems. The proposed inverter is realized employing a T-kind neutral-point-clamped inverter connected in cascade to a floating capacitor (FC) H-bridge. Additionally, two low-frequency switches are added across the dc-link enabling the inverter to generate a 9L waveform. A sensorless voltage management based on redundant switching state is developed and embedded with PWM controller, which is accountable for regulating the FC voltage at one-quarter of the dc source voltage. The proposed PWM technique employs the generation of 9L waveform without using any voltage sensor, thereby reducing the complexity of the overall control theme. This, in turn, will create the system appealing for varied industrial applications. In comparison to traditional and recent topologies, generation of the 9L waveform employing a lower variety of elements is the notable contribution. Another important feature of the proposed inverter is that if FC H-bridge fails, it can be bypassed, and also the inverter will still operate as a 5L inverter at its nominal power rating. Furthermore, a comprehensive comparison study is included which confirms the deserves of the proposed inverter against those of alternative state-of-the-art topologies. Finally, simulation and experimental results are included for validating the feasibility of the proposed system.