Performance Analysis of UPFC Embedded with Five Level Cascaded H Bridge Inverter with SPM and SVM Techniques and ANN Controller

Abstract

Power System Networks when subjected to faults behave in an abnormal pattern which could be called Non Linear behaviour. Conventional or traditional Controlling methods offer limited support to the controlling units like the FATCS devices in making the Power System network less effected by the faulty conditions and also in regaining normalcy. Artificial Neural Networks are Non Linear information processing devices, which are built from interconnected elementary processing devices called neurons. A Fuzzy Logic system is based on a mathematical formulation that takes in analog input values in terms of logical values and processes them. In general Fuzz Logic Controllers work on the If - Then Rule of Computations. The Performance improvement of UPFC with reference to the Transient stability and Dynamic stability enhancement incorpoating ANFIS, ANN, Fuzzy Logic and a PI controller is analysed. The UPFC is embedded with a 3 level cascaded H Bridge inverter. The Response time taken by UPFC with ANN, Fuzzy controller and PI Controller are computed. Cascaded H Bridge Inverters offer high level of Voltage Support, Low Switching Stress and Good Modularity. The system response to the Reference commands or the correction commands is very faster in ANN than in Fuzzy Logic based and  PI controller based UPFC. This aspect is shown by calculating the times like settling time in all the four cases of faults like LG, LL, LLG, LLL and also even when the loads are changed from normal to highly Inductive and highly capacity. The UPFC is connected to the IEEE 5 bus system between the buses 3 and 4 for checking its capabilities. The improvement in the performance of UPFC with ANN Controller over the Fuzzy Logic based and the conventional PI controller based UPFC is depicted in the end result. Simulations results prove that  the ANFIS controller based UPFC overperforms ANN Controller , the  FUZZY LOGIC Controller  Based and PI Controller based UPFC.The Simulations are carried using MATLAB Software