A Three Phase D-STATCOM to Compensate AC and DC loads by using Fuzzy Logic DC Link Voltage Controller

A Fuzzy Logic control the transient response of the distribution static compensator (D-STATCOM) is very important while compensating rapidly varying unbalanced and nonlinear loads. Any change in the load affects the dc-link voltage directly. The sudden removal of load would result in an increase in the dc-link voltage above the reference value; where as a sudden increase in load would reduce the dc-link voltage below its reference value. The proper operation of D-STATCOM requires variation of the dc-link voltage within the prescribed limits. Conventionally, a proportional integral (PI) controller is used to maintain the dc-link voltage to the reference value. A Fuzzy Logic controls the transient response of the distribution static compensator (D-STATCOM) is very important while compensating rapidly varying unbalanced and nonlinear loads. It uses deviation of the capacitor voltage from its reference value as its input. However, the transient response of the conventional PI dc-link voltage controller is slow. In this paper, a fast-acting dc-link voltage controller based on the energy of a dc-link capacitor is proposed. Mathematical equations are given to compute the gains of the conventional controller based on fast-acting dc-link voltage controllers to achieve similar fast transient response. The detailed simulation and experimental studies are carried out to validate the proposed controller.