Design of Pv System With Multilevel Structures for Generation of Higher Number of Voltage Levels

Abstract

A new method of generating higher number of voltage levels by stacking multilevel converters of lower space vector structures and having a single DC power supply as mentioned above with low voltage devices is presented in this paper. A photovoltaic system, also PV system or solar power system, is a power system designed to supply usable solar power by means of photovoltaics An important feature of this stacked structure is the use of low voltage devices while attaining higher number of levels. This will find extensive applications in electric vehicles since direct battery drive is possible. Stacked multi-cell converter was introduced to generate more levels. They use less number of capacitors but require more switches. Solar PV has specific advantages as an energy source: its operation generates no pollution and no greenhouse gas emissions once installed, The voltages of all the capacitors in the structure can be controlled within a switching cycle using the switching state redundancies (pole voltage redundancies). This helps in reducing the capacitor size. Also, the capacitor voltages can be balanced irrespective of modulation index and load power factor. A 9-level inverter is developed by stacking two 5-level inverters and an induction motor is run using V/f control scheme. By using the simulation results we can analyze the proposed method at both the steady state and transient state.