The advantages and disadvantages of using HVDC to interconnect AC networks

The traditional design of the power system involves generators which are sited far from the demand. The increasing use of renewable energy resources is continuing this system and is introducing new challenges in power transmission in terms of reliably and efficiently. Interconnection with these power systems is making the grid becoming more complex. The appearance of HVDC system gives engineers alternative for power transmission. The use of HVDC transmission technology is well known and has benefits in the following areas; bulk electricity delivery, long-distance transmission, asynchronous interconnections, transmission costs and environment. This paper will give a brief introduction of HVDC system and discuss the advantages and disadvantages of HVDC systems. Two new HVDC applications in China and Indian are introduced together with an insight into the offshore DC grid in the North Sea.