An Interactive Control Strategy of STATCOM and VDCOL for Suppressing Weak Receiving Commutation Failure of HVDC

Abstract

In order to reduce the probability of commutation failure in HVDC weak receiving system, and improve the recovery characteristics of the DC system after a fault, an interactive control strategy of STATCOM and VDCOL (Voltage Dependent Current Order Limiter) was proposed. AC voltage compensation was derived based on the Current -time Area, and added to the STATCOM constant AC voltage control of outer loop to adjust the reactive power of the STATCOM output. Meanwhile, an additional DC current control functions was applied to LCC-HVDC system VDCOL. Simulation in PSCAD/EMTDC showed that the proposed interactive control strategy can restrain commutation failure effectively when the short-circuit fault occurs in the AC bus of the weak receiving system, and the improved VDCOL can strengthen the ability of the DC system to resume stable operation as soon as possible.