Sources of Low-Frequency Oscillations in Power Systems, Their Localization and Damping

This article deals with the issues of identifying and studying high-amplitude, low-frequency oscillations in the electrical regime parameters (LFO ERP) of an electric power system. These problems are currently important for ensuring operating stability of the generation equipment and maintaining dynamic stability of the power system. Solving the problems of identifying LFO ERP, determining the source of the oscillations, monitoring the oscillatory stability of the power system, and effective damping of the LFO, is a necessary condition for the operational reliability of a power system. In modern power systems a wide variety of possible sources of LFO are observed, such as: periodically varying load, e.g., stops and starts of pumps in the oil and gas industry or motors for machines operating over a wide range of speeds with frequent starts and stops; disconnection of the load (of individual electrical transmission lines), that cause disruption of permissible power flows at any point of the power system, which leads to dynamic oscillatory instability; incorrect adjustment of the automatic voltage regulator (AVR) and/or channels for stabilization of the automatic excitation regulator (AER) of the generator under consideration or associated with it; periodic variation in the torque on a generator shaft. The use of devices for synchronized vector measurements (DSVM) makes it possible to determine with high accuracy the sources of the LFO in a power system, regardless of their nature and, depending on the number of installed measurement devices in the power system, these can be specified for the final primary equipment.