CALCULATION OF CORONA DISCHARGE PARAMETERS FOR MULTI-WIRE LIGHTNING PROTECTION

Abstract

The article presents the results of theoretical calculating the parameters of a corona discharge when protecting the territory of substations from direct lightning strikes using multi-drop lightning protection. The parameters of the corona discharge are important when calculating the energy losses in the wires of overhead power lines in bad weather. (Research purpose) The research purpose is in developing a computational model and analyze the processes of lightning protection of a substation by placing parallel grounded cables suspended on supports that are placed outside the substation territory. (Materials and methods) The solution is based on a well-known relation for a typical dipole model of a charged thundercloud cell. (Results and discussion) The article present the calculated theoretical dependences, mathematical formulation and algorithm for numerical calculation of the two-dimensional problem that form the basis for calculating multi-wire lightning protection, as well as the calculation results of cable lightning protection of a transformer substation based on two-dimensional numerical modeling and comparison of the results of calculations using analytical expressions with the results of two-dimensional numerical modeling. Despite the noticeable difference between the limit currents calculated by different methods, the difference between the average current between them is small compared to the currents themselves, so one can use its arithmetic mean to determine the actual current. (Conclusions) The obtained results allow to take into account changes in the parameters of the corona formed in the electric field of a thundercloud along its cable length due to its sag, since such changes in the input parameters have a noticeable effect on the corona process, in some cases it is more significant than the effect associated with the actual sag of the cables.