Full Scale Test on a 100km, 150kV AC Cable

This paper presents some of the results obtained from the electrical measurements on a 99.7 km, 150 kV three-phase AC cable, connecting 215 MW offshore wind farm Horns Rev 2, located in Denmark west coast, to Denmark's 400 kV transmission network.
The measurements were performed at nominal voltage. The cable was energised from the grid side with the receiving end open. An 80 Mvar shunt reactor was installed in the middle of the cable and it was energised together with the cable.
The use of nominal voltage allows to present and to verify some of the phenomena that are common in long HVAC cables, but unusual in overhead lines.
In this paper is made a characterization of the cable and the power transmission system in which the cable is installed, followed by a description of the measurement equipment and of the test setup/procedures.
A theoretical explanation and presentation of different analysed phenomena is conducted. The cases analysed in this paper are: Zero-missing phenomenon, Ferranti effect, energisation transient, effect of the cable's connection in the busbar voltage and cable disconnection.
For all the phenomena described in the paper measurement data are presented and it is verified if the obtained results are in accordance with the theory and also with simulations performed in PSCAD/EMTDC.
With the exception of the cable disconnection, for all the remaining cases introduced in this paper the measurements confirmed the theoretical expectations. Depending on the cable disconnection sequence, an overvoltage may appear in one of the phases, this overvoltage depends on the mutual inductance between the shunt reactor phases and it is not shown in the simulations.
The measurement's data files and extra information about the cable and power transmission system can be received by contacting the first author of this paper.