Back-to-back HVDC system performance with different smoothing reactors

The function of the DC smoothing reactor in a back-to-back DC system is addressed and the impact of the DC system performance is evaluated with respect to sensitivity to variation of the size of the DC reactor. Results obtained with a DC simulator are used to illustrate the effects on several performance indices, among them the inverter-valve recovery-voltage distortion, bypass pair formation and communication failure, and AC and DC harmonics. Information is presented which may lead to the reduction in size of reactors currently supplied and expedite the ultimate elimination of the reactor. Results indicate that only a relatively small DC reactor is required to reduce significantly the voltage distortion, surge current, and AC and DC harmonics.<>