Tłumienie oscylacji strumienia magnetycznego i mocy maszyny dwustronnie zasilanej

The doubly fed machine (DFM) is useful as a generator in wind power plants and hydro-electric power stations, as well as a shaft generator on ships. However, small oscillations occur in almost each system with DFM independently of supply way if intermediate variables have been changed rapidly. The stator flux vector components form an oscillating system. Oscillations are very weak damped and may be transformed into transients of power. These ones can affect a work of other power sources and loads connected together with DFM to the same grid. The mentioned problem appeared in the literature sources several times. The effective damping methods consist in application of inverse feedbacks to correct properties of control systems with DFM. The former structure proposed by author includes the damping feedback with signals obtained from relationships of induction machine's mathematical model. This solution cannot be applied in practice due to big distortion of signals existing in damping feedback. Asymmetries of machine and inverter as well as non-linear characteristic of machine magnetic circuit are the most probable reasons of this distortion. The oscillations may be damped in the DFM control system if the feedback contains signals obtained by filtration of DFM's active and reactive power with the aid of band-pass filter applied for each component of the power. The structure of such system and investigation results are presented in the paper.