Modelling and management of microshocks under high voltage transmission lines

People can be exposed to "microshocks" which are caused by the high electric fields present under, or near, high voltage equipment or transmission towers. This is due to the capacitive coupling between the HV equipment and the human body. For example if a person underneath an HV line touches or comes close to touching an earthed object, discharges can occur to the individual. This is known as microshocks. Detailed knowledge of the physics of the discharges between the metallic object and the human body is necessary to model the process successfully. Laboratory measurements of the transient currents and voltages are given in this paper to show the characteristics of microshocks. Simulations in CDEGS and PSCAD/EMTDC are presented and compared to laboratory measurements. Early modelling work is encouraging and future activities are described.