Answer: Peak velocity ratio λ = RΩ/?, where Ω is the angular velocity, ? is the wind speed and R is the fan radius. When the wind turbine operates at a constant blade tip speed ratio, i.e. λ is always constant. When the wind speed of the wind turbine changes, the speed of the wind turbine must change accordingly to ensure that the ratio between the two is the same. constant This is generally applicable when the wind speed is lower than the rated wind speed.
When the wind turbine operates at a constant speed, no matter how the wind speed changes, the speed of the wind turbine must remain constant until it reaches the rated power. When the wind speed is higher than the rated wind speed, the wind rotor is limited to absorb wind energy from the wind through active stall or pitch adjustment, so that the generator maintains output powerie constant.
At what wind speed does wind power generation equipment have the highest efficiency and minimum damage to the equipment?
Wind turbines do not generate more electricity the faster they spin. Note that the power output of a generator can be roughly thought of as proportional to the product of speed and torque. The torque here is the electromagnetic torque obtained by the excitation of the generator. The torque is so great that the wind cannot move the turbine. At this time, the rotation speed is 0, the torque is very large, and the power output is 0. When the torque is zero, the speed accelerates to a very high level. It's actually a flying car, which is extremely dangerous. Since the electromagnetic torque is 0, the power output is 0. The power is 0 at both extremes, so there is an optimal speed thati maximizes power output.
The ideal value of this optimal speed can be calculated from Baez's theory, which is the ratio between the linear speed of the blade tip and the wind speed in front of the wheel. At a certain wind speed, there is a non-linear relationship between fan power and blade tip speed ratio. Through the theoretical derivation, the optimal peak speed ratio for each wind speed can be calculated. A wind turbine is a device that converts wind energy into mechanical energy, then allows machines to operate and finally generates alternating current. In fact, wind energy can also be considered solar energy because it is also used to generate electricity and is not harmful to our environment.
It is capable of producing a large amount of energy due to its internal structure, rather than dependingof the external rotation speed of the blade. It's better to spin your own windmill faster. gear inside that turns silently. The windmill rotates at a speed of 20 to 30 times per minute, and the wind is not enough. That doesn't mean it can't spin faster. This is due to the weight and length of the blades. you see it from a distance, don't think it's big, in fact it is. The blade is more than 20 meters long, and the weight can be imagined. If you turn too fast it will put a lot of pressure on the. base. If a generator collapses or its blades break, it could cause an accident and injure nearby residents. If it spins slowly, there will be no such thing. This will ensure that the windmill blades will not be injured, prone to accidents, and will not affect their power generation efficiency. After all, there's a little engine hidden inside! he,even if the strong wind outside turns very slowly. There are reduction gears and gears inside, and its speed will also increase by about fifty times, basically maintaining a speed of about fifteen hundred revolutions per minute.
Can wind turbines achieve higher efficiency even if their speed is very slow?
Efficiency has nothing to do with wind speed, and high efficiency can be achieved at low wind speed.(The efficiency of mechanical parts is not considered)
According to conservation of energy, the power of the wind turbine is related to the wind speed
According to aerodynamics and the Bates limit theory, the rate of wind energy utilization of wind turbine The limit is 59%
Each wind turbine has a fixed maximum wind energy utilization rate. This efficiency is linked to the tip speed ratio of the wind turbine (the ratio between the tip speed of the bladee and the current wind speed).
For example, an optimal peak speed ratio (i.e. the peak speed ratio when the energy utilization rate highest wind turbine is achieved) is 9. The wind turbine has a rotor diameter of 100 m and a wind turbine speed of 12 revolutions. It then has the highest yield at 3.14*100*12/60/9=7 m/. s
The wind turbine turns slowly does not mean inefficient. In fact, it's more interesting. In normal operation, the efficiency is highest when the speed is lower than the rated speed, but the net power of the Internet is relatively small. (Wind turbine is a kind of power generation equipment. Each type of wind turbine has its own rated power/wind speed/operating speed, etc. There is an overall optimal value of wind capture efficiency wind energy in the design of its turbine, which corresponds to a specific set of (variable The comcombination of propeller angle) and (blade tip speed ratio), generally speaking, the pitch angle is close to 0 degrees and the blade tip speed ratio is about 7 to 8. The basic principle of wind turbine design is to be able to capture. When the power provided by the aerodynamic energy is less than its nominal power, the wind energy must be captured as efficiently as possible, but it cannot exceed certain constraints, such as its nominal speed. The aerodynamic energy that can be captured is greater than its rated power, wind energy capture must be actively reduced. Friends who know more can know the power curve as the wind speed gradually increases from the cutoff. in wind speed, the steady-state power curve can be essentially divided into three segments: the part below the rated speed. In the sectionon load, the pitch angle is optimal at that time and the blade tip speed ratio is optimized by adjusting the. load torque of the motor, thus maintaining the optimal capture efficiency of the wheel. The efficiency of this section of the advanced low-speed fan can reach 50.%+, which is very good, but the output power is only less than half of the rated value. In this range, the wind speed increases and the speed increases linearly. At a certain wind speed, it reaches the rated speed of the wheel, and then the following paragraph: located in the partial load section of the rated speed. The pitch angle is always close to 0 degrees and the wheel always runs at the rated speed (fluctuations are allowed, but the set value is the rated speed. The speed is maintained by adjusting the motor load torque and speed blade tip is the nominal speed). The report is no longers optimal. As the wind speed increases, the motor load increases linearly, reaching full power at a certain wind speed (i.e. the wind speed exceeds the rated wind speed). next section: the full power section. The motor load torque cannot continue to increase to reduce the turbine speed. At this time, the tilt angle should be increased to reduce wind energy capture. The tilt angle gradually increases (nonlinearly) and finally reaches the cutoff wind speed. When cutting, the rated speed of the new low-speed fan is only 10 rpm, and the minimum operating speed can be about half. the first section of the power curve, so it seems very slow. The wheel is indeed very slow but the speed is less than this. It is relatively constant, no more than two or threerevolutions per minute, which is usually when the car is warmed up and ready to start. If the rotation is barely noticeable and cannot be done in a few minutes, it is usually in parking condition. Even under feathering conditions, the wind load cannot be completely zero. There is a very small couple that can simply be overcome. in the drive chain pushes the turbine a little.