Variable-speed constant-frequency wind power generation device having energy storing device

Abstract

The invention provides a variable-speed constant-frequency wind power generation device having an energy storing device. An output shaft of a wind turbine with a fixed propeller pitch is connected to an input shaft of a permanent magnet generator; the permanent magnet generator is coaxially connected to a regulating motor; an armature winding of the permanent magnet generator is connected to a power grid through a primary synchronization switch; the armature winding of the regulating motor is connected to an alternating current end of an engine aside converter; a direct current end of the engine aside converter is connected to the direct current end of a net aside converter; the energy storing device is connected to the direct current end of the engine aside converter through a charge-discharge device; an alternating end of the net aside converter is connected to a low-voltage end of a transformer; and a high-voltage end of the transformer is connected to the power grid through a secondary synchronization switch. The invention applies the energy storing device in the permanent magnet wind power generation device, therefore realizing the stable variable-speed constant-frequency running as well as flexibly changing the active power and the reactive power output by a power generation device based on the self-regulation capability when the maximum wind power is transformed so as to ensure the power balance of the power grid.

Description

technical field [0001] The invention relates to a wind power generating device in the field of electrical engineering. In particular, it relates to a wind power generating device which adopts a permanent magnet generator and has an energy storage device, and can realize variable speed and constant frequency power generation operation. Background technique [0002] In the existing wind power generation technology, in addition to double-fed generators and traditional asynchronous generators, permanent magnet generators are widely used due to their advantages such as high power density, reliable operation, and simple maintenance. In order to ensure that the output frequency of the permanent magnet wind turbine is constant when the wind speed changes, that is, to achieve variable speed and constant frequency, the following two methods are currently adopted: [0003] The first method is to pass the electric energy output by the generator armature winding through a power electron...

AI Technical Summary

Problems solved by technology

[0006] When using the first method, the power of the converter must be greater than the rated power of the generator, and the use of a large-capacity power electronic converter will inevitably increase the cost of the entire power generation device; secondly, when the load remains unchanged, When the wind speed increases, the output power of the generator will also increase accordingly. After the excess active power is injected into the grid, it will inevitably have an adverse effect on the stable operation of the grid.

[0007] When the second method is used, since this method stabilizes the rotor speed of the generator by adjusting the amount of converted wind energy, the maximum wind energy conversion cannot be achieved while ensuring the active power balance of the power grid.

In addition, the additional pitch adjustment mechanism will not only increase the cost, but also make the structure of the device complex and reduce the reliability. It is also necessary to adjust the angle of attack of the blades through mechanical transmission to stabilize the generator speed. Therefore, when the wind speed changes, the adjustment process of the generator output frequency is relatively slow

[0008] In short, besides the high cost and complicated structure of the permanent magnet generator wind power generation device that uses the above two methods to realize variable speed and constant frequency operation, the biggest problem is that it cannot simultaneously realize the maximum wind energy conversion and output power during operation. flexible adjustment

Images