Description

In this project using of flying capacitors a newly voltage balancing NNPC inverter had been developed. Multilevel inverters are very popular in medium-voltage power conversion  such as motor drives, power conditioning devices, renewable energy generation and distribution because of low voltage stress on switching devices, better harmonic reduction, low switching frequency, and less switching losses .In this topology neglecting the need of series power semiconductor devices in series, which provides four levels in output voltage. In comparison with the four-level NPC inverter, each leg consists a two flying capacitors and two diodes, the voltage across each capacitor is controlled and balanced at one-third of dc-link voltage (Vdc/3). Due to the presence of these elements the inverter can operate normally and the voltage stress is shared uniformly to all switching devices and capacitor voltage should be controlled. The effective switching states is getting from suitable logic tables. This PWM method is easy to implement and a very few reckoning. The proposed pulse width modulation is adopted for all methods. Thus results overabundance of switching states. The cogency and expediency results of the proposed topology is verified by simulation. That inverter design is help to reduce the harmonic in normal and that result was analysis in MATLAB Simulink model.