A Novel Single Phase Grid Connected Five Level Inverter for high Power Multi Level Applications

Abstract

This paper presents a single phase five level photovoltaic (PV) inverter method for grid PV system with a novel modulated Sine pulse width modulation (SPWM). The multi-level inverters are used in high power and medium voltage applications, such as common mode voltage, operation at both fundamental and high switching frequency, drawing input current with low distortion, reduced harmonic distortions. It utilizes two reference signals and a carrier signal to generate PWM switching signals. The proposed five level inverter is designed with lesser number of switches (four) which in reduces the circuit and control loop complexity efficiently. it can produce a high quality output voltage wave with a good harmonic characteristic. Finally, it reduces stresses on power switching devices, resulting in low audio and Radio Frequency (RF) noise and Electromagnetic Interference (EMI), and fewer Electromagnetic Compatibility (EMC) problems, since multilevel inverter operates with a low switching frequency and voltage switching is done for relatively lower voltage levels. The proposed system is verified through simulation and is implemented in a prototype.