Effect of DC capacitance of a STATCON on the dynamic performance at a weak HVDC terminal

This paper investigates the effect of the DC capacitance of an advanced static VAr compensator or STATCON on the dynamic performance at a high voltage direct current (HVDC) inverter terminal where the AC system has a very low short circuit ratio (SCR). The simulation results show that the STATCON behaves almost equally well under severe AC disturbance while the DC capacitance of the inverter is varied over a wide range. The studies also examine the operating characteristics of the STATCON corresponding to the low-order harmonic resonances as a function of the DC capacitor size. It can be concluded that the second harmonic of the AC system has little effect on the stable operation of the STATCON. In determining the DC capacitance size of the inverter, the low-order harmonic resonances are not a matter of concern.