Reactive Power Compensation of Coal Conveyor Belt Drives by Using D-STATCOMs

This paper discusses feasibility of conventional and fully static reactive power compensation techniques used in the solution of power quality problems of coal conveyor belt drives and also describes the features and field performance of the distribution type static synchronous compensator (D-STATCOM) prototypes in such applications. They are composed of 2-level, 3-leg voltage/current source converters (VSC/CSC), low-pass input filters and Delta/Y connected coupling transformers to allow their connection to medium voltage load bus. Reactive power is controlled in both capacitive and inductive regions by phase-shift-angle control. Dominant voltage/current harmonics of VSC/CSC are eliminated by selective harmonic elimination method (SHEM). Developed D-STATCOMs are shown to comply with IEEE Std 519-1992 even for the weakest supply. Viability of D-STATCOM in reactive power compensation of conveyor belts has been proven in the field.