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The paper is devoted to investigations of dynamic processes in a local power system consisting of wind turbines with a magnetic continuously variable transmission. Due to low inertia of wind turbine generator rotors, there is a problem of ensuring dynamic stability at sharp load changes or at short circuits in an autonomous power system. To increase dynamic stability of the system, two algorithms for controlling a magnetic continuously variable transmission are presented. The first algorithm stabilizes a rotation speed of the high-speed rotor of a magnetic continuously variable transmission from the generator side in a local power system consisting of wind turbines with uniform synchronous generators with permanent magnets having equal moments of inertia. Undoubtedly, local power systems having only the wind turbines with equal mechanical inertia time constants are not widely used due to stochastic nature of wind energy. Therefore, wind power systems are combined with a diesel generator or a gas-turbine unit. Investigations show that the use of the only speed stabilization algorithm is not enough for such power systems, because there is a possibility for occurrence of asynchronous operation under specific power changes due to the difference in moments of inertia of generator rotors. Thus, the second algorithm uses the phase shift compensation in accordance with a primary generator in an autonomous power system consisting of non-uniform generators having different mechanical inertia time constants. As a primary generator, a diesel generator or a gas-turbine unit having a primary speed controller may be used. It should be noted that algorithms of stabilization for speed and phase angle are extended by an inertial circuit of aerodynamic compensation for torque of rotation from the wind turbine side to reduce loading on an energy storage unit of the magnetic continuously variable transmission at disturbances from the generator side and the turbine side.

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This article presents theoretical calculations of using a plasma actuator in a wind turbine for increasing its regulating ability. Calculations were done taking into account the pressure difference caused by an ozone layer. A series of calculations were carried out based on the QuickField software with the use of calculations of elastic deformations for determination of the influence on the resultant lift force. Distribution of the dielectric strength was calculated that is required for estimation of the ionization area. Vector diagrams were presented which show the influence of the plasma actuator at different sides of a wind turbine blade on the resultant lift force. The equation describing the influence of the plasma actuator was derived. Investigations carried out in this article have shown that the maximum regulating effect is about 25%. It should be noted that the position of the plasma actuator on the blade also influences the value of the lift force. Therefore, regulating properties of wind turbines are improved. Theoretical calculations were validated experimentally at the National Renewable Energy Laboratory in Denver. Note that the main advantages of the plasma actuator as the part of a wind turbine are simplicity and the possibility of increasing regulating properties of a wind turbine.

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