Extending multi-function capabilities of individual-phase decoupled P-Q control of VSCs to include active filtering under symmetrical and asymmetrical operating conditions

This paper contributes to establish Individual-Phase Decoupled P-Q Control as a methodology for operating VSCs for both symmetrical and asymmetrical conditions. This paper extends the scope of the Individual-Phase Control of a D-STATCOM (voltage source converters) by showing that it can implement active filtering under asymmetrical operating conditions. This is accomplished by a combination of: (i) a Fliege notch filter; (ii) dead-beat control of the VSC; (iii) an innovative predictive estimation method which exploits periodicity of the distorted waveforms. Active filtering capability is on top of previously demonstrated capabilities to provide support against voltage droop while simultaneously balancing unequal distribution loads. Claims are validated by experimental test results from a laboratory scale D-STATCOM model.