GENETIC ALGORITHM BASED ELIMINATION OF HARMONICS IN THREE PHASE INVERTER

In recent years multilevel inverter has taken a vast place in industrial application and is also used in various other applications such as static power converter for high power applications, FACTS devices, HVDC and also as electric drives for all ac motors when DC supply is used. Another major advantage is that their switching frequency is lower than a traditional inverter, for this it has less switching losses and higher voltage capability. To drive this inverter Pulse Width Modulation (PWM) is used. Space Vector Modulation (SVM) is the popular PWM method and possibly the best among all the PWM techniques as it generates higher voltages with low total harmonic distortion and works very well with field oriented (vector control) schemes for motor control. High quality output spectra can be obtained by eliminating several lower order harmonics by adopting a suitable harmonic elimination technique. Genetic Algorithm (GA) optimization technique is used to achieve proper switching angles to reduce the THD and elimination of a selective lower order harmonics with fundamental components at the desired values.