High Voltage Dc Transmission Practice Questions

Both region are connected by HVDC link as well as AC line. So AC link is possible when both regions have frequency. By changing fringe angle ( $\alpha$ ) of converter, we can change the power sharing, between the AC line and HVDC link.

The rectifier consumes reactive power and inverter supplies reactive power from/to the respective connected AC systems because no reactive power can be transmitted over a dc link.

HVDC system are economical for long distance bulk power transmission by overhead lines, due to reduced power and cable costs. The DC line is an asynchronous link and it can interconnect two rigid systems operating at different frequencies. Converters and converter transformers requires reactive power in the operation. The AC/DC converters are sources of harmonics on AC as well as DC side.

D.C. line inductor, reduce the harmonic current in the DC line and possible transient over currents. Converters and converter transformers consume reactive power. The reactive power may be supplied from (i) AC filter (ii) Shunt Capacitor (iii) AC Network (iv) Static compensators (v) Synchronous condensers.