Centralized voltage control method using plural D-STATCOM with controllable dead band in distribution system with renewable energy

The authors propose voltage control method using centralized control of D-STATCOM with controllable dead band to control all the node voltages dynamically. To maximize the acceptable amount of RES, centralized control system meters each node voltage installed D-STATCOM, and control all the node voltages based on each node voltage. The target voltage of D-STATCOM near a substation is modified by another node voltage to regulate all the node voltages within proper range. The amount of correction for the target voltage is determined by the amount of deviation from a threshold which is set between upper limits of the dead band and proper range. Conventional method has potential to command inappropriate reactive power due to delay time based on communication time and calculation for commands of reactive power. Proposed method compensates for the lack of reactive power based on the delay time using the predictive control.