Instantaneous power of a doubly fed induction generator with the unbalanced stator windings

Doubly fed induction generators have become widespread in generation systems in which maintaining the rotor speed cannot be fully performed by adjusting the drive mechanism. Purpose. Establishing instantaneous power of a doubly fed induction generator in an autonomous system with a nonlinear load under the condition of changing the machine stator windings’ electrical parameters. Methodology. As a result, of the known studies analysis, the presence of technical solutions that provide control of the generator rotor current even under conditions of nonlinear or asymmetric load was established. Using the known provisions of the electrical engineering theory and the electric machines theory using the instantaneous power balance principles, the balance equations for a three-phase double feed induction generator were determined. Findings. A model was synthesized for studying the processes of power components distribution of the equivalent circuit elements of a doubly fed induction generator in a visual programming package. The specified model allows simulating the modes of the machine with linear and nonlinear generator loading and asymmetry of the stator windings’ electrical parameters. Under the conditions of conducting experiments, a significant change was noted in the electromagnetic power spectrum of a phase rotor windings under conditions of asymmetry, which is characterized by the presence of power harmonics with a 50 Hz frequency, which corresponds to the interaction of the rotor phases’ direct current with the alternating voltage components of the rotor circuit’s corresponding element. Originality. During the study under the condition of asymmetry of the stator windings’ electrical parameters, it was established that the electromagnetic power harmonics of the stator windings’ phases have values that exceed the nominal power of the machine by a magnitude order and, being formed into the total power of the three phases, mutually compensate each other. Moreover, the level of these harmonics is sensitive to the nature of the asymmetry at a frequency of 100 Hz. In the power of three phases of elements of a doubly fed induction generator under the experiment conditions, constant components dominate, the level of which for the stator circuit is sensitive to the nature of the electrical parameters’ asymmetry of the stator windings and leads to changes by more than 2.3 % for the stator windings electromagnetic power and 2.2 % for the mechanical power. Practical value. The obtained results can be used in the future to improve the systems for the mode parameters control of a doubly fed induction generator to energy performance increase of the complex.