Transmission Capacity of Long-Distance Power Lines Equipped with Shunt Compensation Devices

The article discusses a methodology for substantiating the transmission capacity of a long-distance power line equipped with shunt compensation devices. It has been determined that the transmission capacity of a long-distance power line is only limited by a condition of maintaining the standardized static stability margin, whereas the distribution of voltages along the line turns out to be permissible in all modes. The article considers power line versions with a double-circuit line and with a single-circuit line equipped with a shunt compensation device, both having the same transmission capacity. The transmission capacity substantiation is illustrated on the example of a 500 kV long-distance power line with a length of 1000 km. The version with the required capacity equal to 1470 MW involves the need to install two shunt compensation devices in the line middle part. A technical and economic comparison is carried for the versions of a double-circuit line, a single-circuit line equipped with two series capacitive compensation devices, and a single-circuit line equipped with two shunt compensation devices, each having the same transmission capacity. The comparative analysis results have shown that the version with shunt compensation devices is more economically efficient than the version involving the use of series capacitive compensation, the investments and reduced costs for which are almost a factor of 1.5 higher than those for the former.