| Popis: |
The main converter of mechanical wind energy into electricity in wind turbines is an electric generator. Typically, such systems use synchronous generators with permanent magnets on the rotor. The main disadvantage of this design is the complexity or the impossibility of adjusting the output parameters of the generator: voltage, power, etc. Known methods and tools aimed at solving this problem relate to cases where the wind speed is constant, ie constant. In real conditions, the nature of the wind is changeable. The average annual wind speed for Ukraine varies between ≈ 5-6 m / s. The current value of wind speed depends on weather conditions, time of day and season. Accordingly, the nature of the output power of the generator will be variable. In this paper, the authors evaluate the effectiveness of the correction of the output power of the generator of the multiplier wind turbine at discrete and random values of wind speed. The main power unit of this study is a magnetoelectric synchronous generator with two-sided arrangement of magnets on the rotor and with axial magnetic flux. To solve this goal, a numerical simulation mathematical model of the system was developed, consisting of a multiplier-free wind turbine and a magnetoelectric synchronous generator with two-way arrangement of magnets on the rotor and with axial magnetic flux in the MATLAB-Simulink software package. The developed simulation model takes into account the change of the output parameters of the generator when the wind speed changes and vice versa, the system in which the change of the initial state of the generator leads to a change in the parameters of the rotor of the wind turbine. The variability and discreteness of wind speed is realized in the MATLAB-Simulink system by generating signals, the values of which at certain points in time are a random variable distributed according to the normal (Gaussian) law with predetermined parameters. Using the developed mathematical model, numerous simulation experiments were performed, which investigated the efficiency of correction of the output power of the studied system when connecting static capacitors to the armature winding of the generator and when applying current to the additional winding of the magnetoelectric generator. When connecting an additional magnetizing capacitance ≈30 μF to the generator terminals, there is an increase in output power by ≈5-10%. When the voltage is applied to the excitation winding Uf = 8 V, there is an increase in the output power of the generator ≈30-40% than without regulation. Therefore, it is a more efficient way to correct the output power of the magnetoelectric generator. The developed mathematical model can be used in further research to synthesize the control law of the additional winding of the magnetoelectric generator for the most efficient conversion of mechanical wind energy into electrical energy. |
