Application of a Phase Shifting Device for Increasing the Grid Transmission Capacity

Abstract

At present, the problem of improving the performance of advanced electric power systems is solved by actively introducing and developing the technologies of active-adaptive electric networks like Smart Grid or Flexible AC Transmission Systems (FACTS). By using the FACTS technologies, it becomes possible to control power flows in large distribution networks, due to which inter-area ties are used more efficiently, the power equipment loading is optimized, and the distribution of electricity becomes on the whole more economically efficient. Phase shifting transformers (PSTs) and phase shifting devices (PSDs), which allow electric power flows to be controlled by making an additional phase shift between the device busbars at its connection point, are among the FACTS elements. PSTs, the phase shift in which is adjusted mechanically using the on-load tap changer (OLTC), are the most widely used phase shifting apparatuses. The PSD equipped with a thyristor switching system developed at the Krzhizhanovsky Energy Research Institute is considered.

Materials of scientific research and development works and methods of the mathematical modeling carried out in the RastrWin3 software environment were used.

The possibility of using the PSD equipped with a thyristor switching system for increasing the permissible power flows in the controlled Donskaya - Staryi Oskol section has been demonstrated. It has been shown that the permissible power flows for the considered section can be increased by 4–7% in different repair configurations.

For determining the optimal PSD connection point and its settings, it is recommended to use a number of criteria, such as relieving the current overload of system elements, increasing the permissible power flows through sections, decreasing the losses, increasing the steady- state and transient stability, and others.