Introduction:
In a previous post, we learned what HVDC transmission systems are and their applications. And we had also discussed the types of HVDC links. But in this post, we will discuss all types of HVDC links separately.
Types of HVDC links
- Monopolar HVDC link
- Bipolar HVDC link
- Homopolar HVDC link
Monopolar HVDC link
In this link, we use only one polarity to transmit the power. And for the returning conductor, we use earthed electrodes. to complete the circuit. Sometimes we have to also use earthed electrodes along the line, like every 15 km. Two converters are used at both ends of this system. We use earthed electrodes for the return path in this system, which is why we do not currently use it.
Bipolar HVDC link
In this link system, both polarities (positive and negative) would be transmitted. Converters are also used at both ends. Earthed electrodes are connected from
the midpoint of the converters. as shown in the figure. The potential of the earthed electrodes is half the transmitted polarity. If a fault occurs in either polarity, then we can continue to supply power through the second polarity with the help of earthed electrodes.
This link system is mostly used these days. This type of HVDC link is more reliable than other links.
Homopolar HVDC link
In this system, power is transmitted by two wires with the same polarity. Two earthed electrodes are used at the midpoint of the converters. These two operate in parallel. Operation in parallel reduces the insulation required in this system.
1 thought on “What are the types of HVDC links and which is best?”