CLOSED LOOP CONTROL OF EMBEDDED Z-SOURCE INVERTER WITH FUZZY CONTROLLER FOR SOLAR PV APPLICATIONS

This paper proposes the use of Embedded Z –source inverter system   with fuzzy controller for Solar Photo Voltaic (PV) applications with adjustable speed drives.  Closed loop operation FUZZY control strategies of EZSI system are proposed. EZSI produces the same voltage gain as Z-source inverter (ZSI) but due to the DC sources embedded within the X- shaped impedance network, it has the added advantage of inherent source filtering capability and also reduced capacitor sizing. This can be achieved without any extra passive filters. By controlling the shoot-through duty ratio and modulation index, EZSI system can produce any desired AC output voltage even greater than DC rail voltage and it also provides ride-through capability under voltage sag.  These advantages are more significant for ASD to regulate the speed. The operational analysis and simulation results declared that EZSI is suitable for renewable energy applications to reduce the system complexity and thereby improving the efficiency of the inverter.