The article discusses the selection of cables for power lines connecting wind turbine generators at the wind power plant. The screen cross-section of these cables should be selected considering the value of the screen current at double line-to-earth fault. To calculate this current, the dimensions of the cable should be known. However, these parameters are hidden and cannot be used during designing. Therefore, a highly simplified method is currently used in practice. It is shown that the errors from the highly simplified method are up to 33%. Authors propose a simplified method based on open data of cable manufacturers. The proposed method is compared with simulation results of a common model of cable power line and takes into account self and mutual inductances of the cores and screens. It is shown that the error of the proposed method is smaller than 4.0% for real cable power lines at wind power plants. However, for a long section of cable power line (2.5 km) the error of calculation might increase up to 6.3%. This allows us to use the proposed method for designing. In addition, the authors show how the results of the highly simplified method can be corrected to improve accuracy.

A method for identifying single-phase-to-ground faults through pin isolation in networks with isolated neutral is proposed. It involves installation of devices on each tower of overhead power line. Those devices will be powered by the current of the single phase-to-ground faults. When the short-circuit current flows through the grounding step-down of the tower, the device sends a signal trough a GSM network to the control center. It is shown that such devices can be powered even by the minimum values of the fault current, that is why there is no need in further short-circuiting to find the localization of the fault. Estimated the minimum required capacity of the energy accumulator for reliable transmission of the signal through the GSM network. Refere nces 5, figures 5.

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