Application of the 20 kV Voltage Class in the Electric Power Supply Systems of Modern Megalopolises
Megacities are characterized by a high level of energy consumption, a significant density of electrical loads and increased requirements for the reliability of power supply to consumers. Traditionally in the USSR and further in Russia, voltage classes of 6 and 10 kV are used for urban distribution electric networks. The increasing density of electric load and electricity consumption does not allow in extremely cramped conditions of developing cities to provide electricity through existing cable lines with a voltage of 6-10 kV due to their limited bandwidth and lack of reliability. The technical condition of the equipment and cable lines in the 6-10 kV supply networks has significant physical and moral deterioration. Existing networks have insufficient redundancy and have practically exhausted their ability to connect new consumers. These circumstances required a decision to switch to a voltage class of 20 kV, which is a strategic direction for the development of medium voltage electrical networks in Moscow. According to this decision, since the 2000s, electric networks with a voltage of 20 kV have been actively developing in Russia and in Moscow. This article analyzes the implemented approaches to the use of an electric network of 20 kV in megacities of different countries.