Voltage regulation of STATCOM using fuzzy self tuning PI controller

Electric power quality is the most essential part in relation with utilities and consumers. Almost all our day today electronic equipments are extremely sensitive to even a slight variation in electric supply. The probability of power quality is very dominant in this point of consideration. The sensitivity factor of various sensor equipments can improve safety to the surroundings but of the same it demands a frequent shutdown of the process even for a minor disturbance. Thus the sensitivity is regarded as a major power quality problem. Analysis of power quality and its related problems demands to an important area in the electrical design. Harmonic contents, poor power factor, supply voltage variations are some of the leading power quality issues under current considerations. The properly designed filters are the most suitable solution for these problems. Filter classification can be made as active passive and hybrid categories. The proposed Intelligent Power Quality Conditioner (IPQC) has ultimate capability to improve the power quality at the point of installation on power disturbances. Artificial intelligence based gain scheduling is an alternative technique commonly used in designing controllers for nonlinear systems. Fuzzy system transforms a human knowledge into mathematical rule base. The Static Synchronous Compensator (STATCOM) is a shunt compensating Flexible Alternating Current Transmission System (FACTS) device. This work deals with a linear approximation based control scheme for designing the STATCOM. This is done by pole placement technique to make the mathematical model linear and achieving stability. This controller tuned the PI controller gains according with the system parameters under this faulty operating period and these results are compared with fuzzy and self tuning PI controllers. The power flow analysis is performed on an IEEE-14 bus system with the above controllers and performance is evaluated. The voltage regulation and the reactive power compensation are obtained for critical point of voltage stability in the system under faulty conditions. The active filter has an additional capability to regulate the distribution line voltage by means of adjusting reactive power. The main objective is to produce a regulated output across the dc link capacitor, by controlling the reactive power. The linear controllers were modeled and designed to achieve the objective. Flexible AC Transmission System (FACTS) devices are found to be very effective in a transmission network for better responses. The effect of STATCOM for improving the stability of the test system at faulty condition is investigated. In this paper a Fuzzy logic controller is designed, and finally these responses are compared with a fuzzy self tuning PI controller and Simulation results show that STATCOM is effective in midpoint voltage regulation on transmission line.