Power Quality Improvement for Grid Connected Renewable Energy Conversion System Using FLC

Power quality management for a hybrid power system (solar and wind power) is done by fuzzy logic using a seven level cascaded multilevel inverter is proposed here. The implementation of the seven level cascaded inverter is to maintain the THD level of the power system with in IEEE standard (5%). The hybrid scheme comprises one set of rectifier unit which is connected to the wind system. PV voltage and rectifier voltage is given as input to the seven level inverter. The proposed inverter reduces the switching loss complexity, size and cost. The PWM signals are originated by using FL controller. MPPT algorithm is implemented to improve the voltage of PV panel. The inverted three phase voltage is obtained by functioning the FL membership functions which helps in maintaining the harmonics level below 5%. The fuzzy logic technique has been encouraged in the field of research of converter, motor drives and other intelligent controllers. This process has quick access and it is simpler to integrate. Mamdani model of FL has enhanced in this paper to give linear output when compared to Tsukeno model. Fuzzy logic controller was developed and verified for three phase systems using the simulink MATLAB 2009a in which the components are arranged according to the circuit required. In MATLAB based defuzzification centroid method of fuzzification is done to defuzzify.