HV Transmission line and tower inspection safe-fly zone modelling and metrology

[摘要] ENGLISH ABSTRACT: The deployment of Unmanned Aerial Vehicles (UAV) for power line inspectionrequires the definition of safe-fly zones. Transient Over-Voltages (TOVs) on theOverhead Transmission Lines (OHTLs) put the UAV at risk if it encroaches on thesezones.In order to determine the safe-fly zones of a UAV in the vicinity of OHTLs, realisticfull-scale experimental tests are done. Non-linearity in breakdown effects renderssmall-scale testing and computational work inaccurate. Experimental work is usedto describe the close-up approach distances for worst-case scenarios. Testingcannot provide a full solution due to the limitation of the equipment available.Further tests must therefore be done at a specialised facility.Experiments are run in two phases, namely non-linear and linear tests in the HighVoltage (HV) laboratory. The non-linear tests are done to derive Minimum ApproachDistances (MAD). The linear experiments are used to calibrate FEKO, thesimulation tool, to the measurement environment. Once correlation between thelinear test data and the simulated data is found, confidence is derived in both thesimulation model and the test setup. The simulations can then be used todetermine a geometric factor as an input into F. Rizk's prediction equations.The Rizk equations are used to describe the safe-fly zones alongside OHTLs as anaddition to the non-linear experimental work. Along with the standard'ssuggestions, the Rizk predictions are formulated in such a way that line-specificsolutions can be determined. The suggested clearance values are provided in termsof per unit values, which can be selected in accordance with historical line data.Power line sparking is investigated to better understand the line radiationphenomenon. This understanding could assist in the line inspection process, aswell as in the layout of power lines near radio quiet areas. Knowledge of OHTLradiation patterns can aid in the location of corona and sparking sources in theinspection process.Aerial sparking measurements are taken using a UAV carrying a spectrumanalyser. Measured sparking levels are used to verify a ComputationalElectromagnetic (CEM) model. The CEM model can then be used to furtherinvestigate OHTL radiation characteristics.

[发布机构] Stellenbosch University