Comparison of Different Topologies of Fuzzy Logic Controller to Control D-STATCOM

This paper demonstrates the controlling of D-STATCOM using fuzzy logic control technique, and different topologies of fuzzy logic controller with proportional plus integral control. The value of energy loss (e(dc)) at VSC is found out from a rule-base specified on error (e) and change of error (Delta e) of the operated variable. All topologies are tested for different loads (non-linear& unbalanced linear load). Performance comparison between the PI-like FLC, PI gain scheduled FLC and Hybrid FLC-PI controller are realized in terms of various performance criteria such as peak overshoot, settling time(t(s)) and rise time(t(r)) of the DC link voltage. Under all the three topologies, THD of the grid side current is well within the IEEE standards and UPF at grid side is maintained.