Power distribution is a very lengthy and tedious project. It involves a certain number of steps to make sure that the end user is able to get its required voltage ranges, in order to operate the required appliances. High voltage distribution from power generation grid to user end is done using High Voltage Power Cable also called as HV cable.
A High Voltage (HV) Cable comprises of conductor and insulating material to protect it from the installation environment. It is different from overhead lines as they do not need any insulating material. Due to the construction, its applications are also different and AC and DC power transmission is of unique concern. Sometimes, in high voltage transmission, there is a leakage of current caused by skin effect so necessary prevention techniques are taken into consideration to control high voltage stress and to equalize the dielectric stress on its insulation.
High Voltage(HV) AC Power Cable
High voltage power cables help to transmit voltages over 1000 volts. HV cables usually have multiple cores and the conductors have the ability to transmit 2000 amperes. The strands are usually reshaped to provide a smoother overall circumference. Different layers are present to prevent air-filled cavities between the conductor and the insulation. The outer layers help to eliminate any leakage current.
High Voltage (HV) DC Power Cable
The HV DC Power Cable has a similar construction as the AC Cable. But its testing and the physics behind the transmission of an analog signal and the digital signal is different. The smoothness of the semiconducting layers if of prime importance. Most of the application of DC Cables is the places where AC Power cannot be transmitted or used. The largest cable that is made is between Norway and Holland can transmit around 700 Megawatts.
The HVDC Power Cables are tightly insulated because it has to bear the high pressure of water and still transmit DC power whose capacity is equal to a large power station.