An Asymmetric Seven Level Multilevel Converter for Grid Integrated Systems

The presented work deals with an asymmetric seven level cascaded configuration for solar photovoltaic (PV) grid integrated system, which contains two H-bridges with asymmetric DC link voltages i.e. unequal DC link voltage. It helps to enhance the output voltage levels that is controlled at Vdc for H-bridge1 and 2Vdc for H-bridge2 making it as 1:2 ratio for binary voltage values and attains seven level as its output voltage. Level shifted pulse width modulation (LS-PWM) technique is used to provide pulses to the respective switches of the insulated gate bipolar transistors (IGBT). Reduced switching frequency is the major attribute for the system. Power quality issues are also dealt with case in order to provide better performance for the desired system configuration within IEEE-519 and IEEE-719 standards.