From Baidu Encyclopedia:
Direct-drive permanent magnet wind turbines have the following advantages:
1. High power generation efficiency: Direct drive wind turbines do not have a gearbox. , reducing transmission losses and improving power generation efficiency, especially in low wind speed environments, the effect is more significant.
2. High reliability: The gearbox is a component with a high frequency of failures in the operation of wind turbines. Direct drive technology eliminates the need for gearboxes and accessories, simplifies the transmission structure and improves reliability. of the sex of the unit. At the same time, the unit operates at low speeds, has fewer rotating parts and has greater reliability.
3. Low operating and maintenance costs: the use of ent technologyGearless direct drive can reduce the number of wind turbine parts and components, avoid regular gearbox oil replacement, and reduce operation and maintenance costs.
4. Excellent grid access performance: Switching to low voltage of the direct drive permanent magnet wind turbine makes the voltage at the grid connection point drop and the wind turbine can operate continuously on the grid. within a certain voltage drop range, thereby maintaining the stable operation of the power grid.
The direct drive wind turbine has no gearbox, and the low-speed wind wheel is directly connected to the generator. All harmful impact loads are also borne by the generator system, which requires high generator requirements. the generator
Demand is very high. At the same time, in order to improve the efficiency of electricity generationtee, the number of poles of the generator is very large, generally around 100 poles. The generator structure becomes very complex and bulky, and the entire machine needs to be lifted and transported. maintained. And the use of permanent magnet and rare earth materials adds some uncertainty factors.
The concept of semi-direct drive arose from problems encountered in the development of direct-drive, dual-fed wind turbinesas part of a process of large-scale development. .characteristics of both.
The difference between a semi-direct drive wind turbine and a direct drive wind turbine:
1. The principles of the two are different,
1. A direct drive wind turbine is a generator directly driven by the wind, also known as a gearless wind turbine. This generator is driven by a multipolar motor directly connected to the turbine,thereby eliminating the need for a traditional component such as a multi-pole motor. a gearbox.
2. The semi-direct drive wind turbine adopts single-stage or double-stage speed-increasing gearbox, multi-pole synchronous generator and full-capacity converter. In addition, in order to reduce the weight of the machine room, semi-direct drive wind turbines are mostly compact designs, that is, the low-speed shaft is eliminated or the length of The low shaft speed is reduced and the power output is reduced. The shaft of the speed increase box is directly connected to the main shaft of the generator.
2. The advantages of both are different
1. The direct drive wind turbine has no gearbox, which reduces transmission losses and improves power generation efficiency, especially in low conditions. wind speed environments, the effand is more significant.
2. The semi-direct drive generator rotates at high speed. This feature determines that the semi-direct drive can on the one hand improve the reliability and service life of the gearbox, at the same time as the direct drive generators, it can take into account the corresponding design of the generator and improve design and manufacturing conditions. of high power direct drive generators.
3. The structures of the two are different.
1. The direct drive wind turbine uses a multi-pole motor and a directly connectable turbine for drive, eliminating the need for a traditional component such as a gearbox. Since the gearbox is a component that is easily overloaded and has a high rate of premature damage in megawatt-level wind turbines, there is no direct drive wind turbine without a gearboxesses.
2. The concept of semi-direct drive arose from the problems encountered in the development of large-scale direct-drive and dual-fed wind turbines, taking into account the characteristics of both. Structurally speaking, semi-direct drive is similar to double drive and has the characteristics of various configuration forms. At the same time, the pinless structure currently under investigation also has a similar appearance to the direct drive.
The above content refers to Baidu Encyclopedia - Semi-direct drive wind turbine
The above content refers to Baidu Encyclopedia - Direct drive wind turbine