| 摘要 |
A pulse inverter with variable pulse frequency for producing a sinusoidal alternating current is provided, wherein the pulse frequency variation is dependent on the configuration of the alternating current to be produced, the pulse frequency at the passage-through-zero of the alternating current to be produced is a multiple greater than in the region of the maximum amplitude of the alternating, current and the lowest pulse frequency in the region of the maximum amplitude of the alternating current is at least 100 Hz. In a preferred embodiment, the pulse frequency in the region of the passage-through-zero of the alternating current to be produced is in the range of about 14-18 kHz, and in the region of the maximum amplitudes of the current it is about 500 Hz to 2 kHz. A wind power installation may be provided with a pulse inverter as described above, or alternatively, a plurality of wind power installations provided with pulse inverters as described above are connected in parallel relationship. The switching frequency of the pulse inverter is variable, dependent on the alternating current to be produced. In that respect, in the region of the passage-through-zero of the alternating current produced, the switching frequency is at a maximum and the pulse duty cycle is at a minimum. In the region of the maximum amplitudes of the alternating current, the switching frequency is at a minimum, and the pulse duty cycle is at a maximum.
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