Implementation of Seven-level Asymmetrical Cascaded H-bridge Inverter Using PIC16F877A Microcontroller

Abstract: Industrialisation is the transformation of agrarian society into an industrial society. Historically it is associated with growth in industries heavily dependent on fossil fuels which were often polluting; however, with the increasing focus on sustainable development most of the industries are looking for cleaner and renewable technologies. With an upward surge of power requirement, the demand for efficient inverters is pullulating as well. In this paper, asymmetrical cascaded multilevel H-bridge inverter (CHB MLI), one of the popular inverters is recced for its better output power quality, low power loss and implementation complexity, economic feasibility and relative advantages. A seven-level asymmetrical CHB MLI is used to improvise the output voltage spectrum. For the purpose, initially the system is tested in MATLAB/Simulink, then pulses are generated through pulses width modulation (PWM) technique using microcontroller and finally implemented in hardware after design and testing in Proteus ISIS. The hardware setups use MOSFETs as switching devices and low-cost PIC microcontrollers for generating the switching pulses via level shifted in-phase disposition pulse width modulation. Ultimately, the hardware outputs are verified with simulation results.

Keywords: PWM techniques, MOSFET, Inverter, Multilevel Inverter (MLI), PIC16F877A, Asymmetrical Cascaded Multilevel H-bridge inverter (CHB MLI)