Optimal Operation Voltage for Maximal Power Transfer Capability on Very Long HVAC Cables

Abstract

An analytical approach towards the operation of very long HVAC cables has been developed. The main physical phenomena have been expressed with simplified analytical equations. A comparison with numerical simulations has shown acceptable accuracy. A set of long distance cable parameters has been introduced. The main conclusion is that beyond a certain specific cable length, the operation voltage should be optimised rather than set to the rated voltage value. Operation at the power factor fx1 has been found to be optimal with regards and power transmission capability. The developed equations can help to gain a better understanding of the subject matter, and the introduced long distance parameters enable to easily compare the long distance capabilities of different cables. It is concluded, that for very long HVAC cable projects, it makes sense to consider cables with very high voltage rating, even though they might not be operated at rated voltage. Such cables can be beneficial due to their thicker insulation layer resulting in lower capacitance. The results also highlight the importance of HVAC cables with low capacitance for very long distance applications, which might lead to a new niche market of specialised cables.