Transients in Power Systems with a Large Share of HV Cables

Disturbances resulting from switching operations, failures, lightning strikes or loads variations can cause abnormal currents and voltages dangerous for the equipment and the analysis and evaluation of the latter is essential for the reliability of the system [1], [2]. The conventional HV networks are built mainly as overhead, but the progressive increase in the share of cable lines leads to significant topological and parametric changes in the network, and hence its behaviour during transients. Ensuring the reliable and safe operation of the equipment requires the study of the current and the phenomena encountered during transients in networks with a large share of cables. This paper presents a study and analysis of some phenomena caused by switching operations in a real HV electrical network, part of the electric power system. For the purposes of comparison, the paper also represents some transient phenomena typical for overhead lines (OHL) although they are widely studied. The studies were performed in ATP-EMTP.